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<title><![CDATA[Editorial department of the Journal of National University of Defense Technology -->Early Online Releases]]></title>
<item>
<title><![CDATA[Analysis of the framework and key technologies of solid rocket motor digital twin system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401110000003]]></link>
<description><![CDATA[solid rocket motors have the advantages of simple structure, high reliability, and large thrust. They have become an important power device for air transportation and missile,  are a key research object for aviation and aerospace superpower. In order to break through the traditional design and management model of solid engines that has long been based on experience and semi-experience, reduce the difficulty of design, development, and maintenance, A management model should be established around the entire lifecycle of solid rocket motors to meet the development needs of rapid iteration, digitization, and intelligence of solid rocket motors. Based on the concept of digital twins, this article divides the development process of digital twins into four stages: physical simulation, computer simulation, virtual reality mapping, virtual reality combination, establishes a digital twin system framework for each stage of solid rocket motors, and the key technologies at each stage were summarized. These can be used as technical routes to promote the development of related disciplines and technology accumulation, and provide theoretical reference for the research and application of solid engine digital twin systems.]]></description>
<pubDate>2026/5/15 16:56:50</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[gaojingwei,罗振炼,王东辉]]></author>
</item>
<item>
<title><![CDATA[Signal reconstruction contrastive learning method utilizing window features]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202505150000006]]></link>
<description><![CDATA[With the rapid growth of signal data in industrial internet, the issue of missing labels has become increasingly prominent, making self-supervised learning a critical solution. To address the problems of coarse feature granularity, unstable representation, and weak transferability in existing contrastive learning methods for signal recognition tasks, a window-based signal reconstruction contrastive learning approach was proposed. The method divided feature maps into multiple fixed windows and introduces local similarity constraints to construct a fine-grained contrastive structure. It also incorporated a signal reconstruction module to enhance the stability and semantic consistency of feature representations. Furthermore, a loss function integrating reconstruction error was designed to improve the feature fitting capability to the original signals. Experiments on three signal recognition datasets—RML, ADS-B, and CSI—show that the proposed method achieves up to 28.32% higher performance compared to other contrastive approaches. Cross-dataset transfer accuracies reach 65.36%, 66.17%, and 66.96%, respectively, significantly outperforming existing methods and demonstrating strong transfer and generalization capabilities.]]></description>
<pubDate>2026/5/15 15:39:27</pubDate>
<category><![CDATA[专题：电磁空间资源智能认知与利用]]></category>
<author><![CDATA[WANG Yangyang]]></author>
</item>
<item>
<title><![CDATA[Optimized risk budget allocation for loitering munition interception evasion]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202512240000003]]></link>
<description><![CDATA[When Loitering Munitions (LMs) perform adversarial tasks, they face challenges such as unknown interception strategies of Non-Cooperative Targets (NCTs), measurement noise, strong system coupling, and non-convexity. To address these challenges, this paper proposes an interception evasion algorithm for LMs based on optimized risk budget allocation. The algorithm adopts the Alternating Direction Method of Multipliers (ADMM) to decompose the original coupled non-convex problem into a convex control optimization subproblem and a risk budget allocation subproblem with an analytical solution, and solves the two subproblems alternately via iteration. In particular, the risk budget equation establishes dynamic associations among estimation uncertainty, interception situation, and risk budget, and enables the algorithm to effectively deal with NCTs with heterogeneous maneuvering capabilities. Simulation results demonstrate that the proposed algorithm ensures that the LM cluster achieves reliable and safe evasion performance under three typical NCT interception strategies.]]></description>
<pubDate>2026/5/6 13:25:00</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[ZHAO Meijiao,]]></author>
</item>
<item>
<title><![CDATA[Optimized risk budget allocation for loitering munition interception evasion]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202512240000003]]></link>
<description><![CDATA[When Loitering Munitions (LMs) perform adversarial tasks, they face challenges such as unknown interception strategies of Non-Cooperative Targets (NCTs), measurement noise, strong system coupling, and non-convexity. To address these challenges, this paper proposes an interception evasion algorithm for LMs based on optimized risk budget allocation. The algorithm adopts the Alternating Direction Method of Multipliers (ADMM) to decompose the original coupled non-convex problem into a convex control optimization subproblem and a risk budget allocation subproblem with an analytical solution, and solves the two subproblems alternately via iteration. In particular, the risk budget equation establishes dynamic associations among estimation uncertainty, interception situation, and risk budget, and enables the algorithm to effectively deal with NCTs with heterogeneous maneuvering capabilities. Simulation results demonstrate that the proposed algorithm ensures that the LM cluster achieves reliable and safe evasion performance under three typical NCT interception strategies.]]></description>
<pubDate>2026/5/6 13:20:45</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[ZHAO Meijiao,]]></author>
</item>
<item>
<title><![CDATA[A review of the development of radar signal deinterleaving]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202502210000002]]></link>
<description><![CDATA[Radar signal deinterleaving is to deinterleave the radar pulse description words obtained by electronic reconnaissance, which is the basis for radar recognition. At present, the effect of radar signal deinterleaving is mainly affected by factors such as parameter variation, measurement errors, high pulse density and high pulse loss. Radar signal deinterleaving methods can be divided into conventional methods and intelligent methods. Among the conventional deinterleaving methods, the research on pre-deinterleaving mainly focuses on the clustering algorithm itself, and the commonly used algorithms include K-Means, fuzzy C-means, data field, DBSCAN, graph theory and self-organizing neural network. The representative methods of main deinterleaving include histogram methods, spectral transform methods, correlation matching methods, plane transform methods, Kalman filter methods and multi-station time difference methods. The representative methods for the condition of known parameters is sample graph methods. The tools used in the intelligent deinterleaving method include supervised neural network, support vector machine, automata and Markov chain, etc. The relevant researches mainly focus on methods with supervised neural networks, and the representative methods include the deinterleaving methods using multiple neural network to deinterleaving by iteration, the deinterleaving methods based on image data semantic segmentation and the deinterleaving methods based on sequence data semantic segmentation. In the future, the conventional deinterleaving methods still has room for development in the direction of improving the clustering adaptability and the new main deinterleaving theory. The intelligent deinterleaving methods can be developed in the direction of the efficient deinterleaving neural network, few-shot deinterleaving model training and the deinterleaving under the condition of anti-intelligence. The recognition effect-oriented deinterleaving method is also worth exploring.]]></description>
<pubDate>2026/4/22 9:39:46</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[WANG Chao]]></author>
</item>
<item>
<title><![CDATA[Study on the law of remaining bearing capacity of cylindrical shells with cutouts under axial compression load]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202508060000001]]></link>
<description><![CDATA[To reveal the law of remaining bearing capacity of cylindrical shells with multiple cutouts under axial compression load, the interactive influence mechanism of hole radius r, hole spacing d, and arrangement angle θ is studied through a combination of quasi-static tests, numerical simulations, and machine learning, and SHAP analysis is used to quantify the parameter contribution. The results show that r is the main cause of the decrease in bearing capacity (with the highest contribution), and the bearing capacity decreases significantly with the increase of r; the influence of hole spacing d is jointly regulated by θ and r. When θ≠0, increasing d can improve the bearing capacity, and the larger r is, the more significant the improvement; θ is generally positively correlated with the remaining bearing capacity, but when θ=30° and d≤4mm, shear failure is induced, leading to a non-monotonic decrease in bearing capacity. SHAP analysis shows that under axial compression load, r has the greatest influence on the remaining bearing capacity of the shell, followed by θ, while d has the smallest influence and is only obvious when θ is large, and there are significant interactions among the three.]]></description>
<pubDate>2026/4/20 14:59:56</pubDate>
<category><![CDATA[力学]]></category>
<author><![CDATA[LUO Junhao,,]]></author>
</item>
<item>
<title><![CDATA[Predictive-Correction and Consensus Based Autonomous Spatio-Temporal Cooperative Guidance for Gliding Vehicles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202511180000005]]></link>
<description><![CDATA[This paper addresses the cooperative guidance problem for multiple hypersonic glide vehicles under complex terminal constraints and proposes a cooperative guidance method that integrates individual prediction-correction and group distributed consensus. The core innovation lies in constructing a two-layer cooperative guidance architecture. At the individual guidance layer, by combining optimal guidance with a prediction-correction strategy, high-precision integrated control over terminal position, flight path angle, azimuth angle, and impact time is achieved. At the group cooperation layer, a distributed cooperative framework with time-to-go as the coordination variable is designed. Considering the vehicles" trajectory characteristics and capability constraints, a coordination variable autonomous update algorithm based on consensus protocol and the mean method is proposed, thereby enabling autonomous time synchronization and trajectory coordination for multiple vehicles under leaderless conditions. Simulation results demonstrate that the proposed method can ensure the vehicle cluster simultaneously satisfies multiple terminal constraints and achieves high-precision time and space coordination under stringent spatiotemporal constraints.]]></description>
<pubDate>2026/4/17 10:20:37</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[Jianwen Zhu]]></author>
</item>
<item>
<title><![CDATA[Predictive-Correction and Consensus Based Autonomous Spatio-Temporal Cooperative Guidance for Gliding Vehicles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202511180000005]]></link>
<description><![CDATA[This paper addresses the cooperative guidance problem for multiple hypersonic glide vehicles under complex terminal constraints and proposes a cooperative guidance method that integrates individual prediction-correction and group distributed consensus. The core innovation lies in constructing a two-layer cooperative guidance architecture. At the individual guidance layer, by combining optimal guidance with a prediction-correction strategy, high-precision integrated control over terminal position, flight path angle, azimuth angle, and impact time is achieved. At the group cooperation layer, a distributed cooperative framework with time-to-go as the coordination variable is designed. Considering the vehicles" trajectory characteristics and capability constraints, a coordination variable autonomous update algorithm based on consensus protocol and the mean method is proposed, thereby enabling autonomous time synchronization and trajectory coordination for multiple vehicles under leaderless conditions. Simulation results demonstrate that the proposed method can ensure the vehicle cluster simultaneously satisfies multiple terminal constraints and achieves high-precision time and space coordination under stringent spatiotemporal constraints.]]></description>
<pubDate>2026/4/17 10:18:13</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[Jianwen Zhu]]></author>
</item>
<item>
<title><![CDATA[Progress of Two-Dimensional Semiconductor Transistors and Integrated Circuits]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202601220000011]]></link>
<description><![CDATA[Two-dimensional semiconductors are identified by the International Roadmap for Devices and Systems as key candidate materials for future sub-1nm nodes, owing to their atomic-scale thickness, smooth surface without dangling bonds and capability to suppress short-channel effects. Focusing on the current status of the full-chain development of two-dimensional semiconductors from basic materials science to system-level integration, the intrinsic physical advantages over traditional silicon-based materials and the progress in preparation processes were systematically analyzed. The latest progress and technical bottlenecks of core process modules including contact resistance engineering, gate dielectric integration and device architecture evolution of two-dimensional semiconductor transistors were reviewed in detail. Meanwhile, the development trajectory from early single-transistor verification to large-scale integrated circuits was traced comprehensively, and the collaborative challenges among materials, processes and design during the integration process were analyzed. The unique potential of two-dimensional semiconductors in emerging paradigms such as in-sensor computing, neuromorphic computing and van der Waals heterogeneous integration is further discussed.]]></description>
<pubDate>2026/4/17 10:08:14</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[DING Rongxiang,,,]]></author>
</item>
<item>
<title><![CDATA[Review on the development status of satellite clusters and trajectory planning methods]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202602020000002]]></link>
<description><![CDATA[Satellite clusters, as a distributed collaborative spacecraft system, possess significant application value in areas such as Earth observation, on-orbit assembly, and deep space exploration. Given the constraints of the dynamic space environment and limited on-orbit computing resources, the primary challenge is to devise an effective technique for cluster trajectory planning to ensure the successful execution of cluster tasks. Based on typical satellite cluster systems both domestically and internationally, related application scenarios and developmental tendencies were summarized. The development status of satellite cluster trajectory planning methods was comprehensively elaborated. From the perspectives of Euclidean space and manifold space, the advantages and disadvantages of existing methods were discussed. Starting from recent popular machine learning techniques, the development status of satellite cluster trajectory planning methods that combine deep learning and reinforcement learning with traditional approaches was introduced. Finally, the challenges were encapsulated, and future research avenues were anticipated.]]></description>
<pubDate>2026/4/13 9:27:59</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[Zhou Heng]]></author>
</item>
<item>
<title><![CDATA[Efficient OpenCL Programming System for Multi-Core DSPs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202601220000005]]></link>
<description><![CDATA[With the widespread application of multi-core digital signal processors in high-performance computing and artificial intelligence, achieving efficient and portable parallel programming on these heterogeneous architectures has become a significant challenge. An efficient OpenCL-based heterogeneous parallel programming system, MOCL4, is designed and implemented for the domestically developed heterogeneous multi-core DSP platform (FT-M7032). MOCL4 collaborates runtime and compiler optimizations to efficiently map OpenCL"s SPMD execution model onto the DSP"s SIMD vector units, while supporting efficient DMA-based data transfers across memory hierarchies. Experimental results show that MOCL4, while ensuring correctness of OpenCL semantics, significantly improves kernel execution performance. The average speedup on the PolyBench benchmark suite is 10.12x, and its performance on typical compute-intensive tasks (e.g., GEMM) is close to that of manually optimized code. MOCL4 provides a parallel programming solution for multi-core DSPs that balances high performance with programmability.]]></description>
<pubDate>2026/4/10 9:13:21</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[GAO Wanrong,,,,,,]]></author>
</item>
<item>
<title><![CDATA[Studying the water-oxygen corrosion behavior of BN interphase layers possessing different degrees of crystallinity in SiC/SiC composites]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202508200000001]]></link>
<description><![CDATA[BN of two levels of crystallinity degrees were deposited by BCl3 and NH3 on the surface of continuous SiC tows. Water-oxygen corrosion of the BN coatings was carried out at 550~1000℃, with a gas content of H2O 14%/O2 8%/N2 78% and flow rate of 6cm/min. For corrosion at 950℃ or higher, highly crystallized BN is almost run out after 0.5h corrosion; 10%, 37%, and 94% of BN is run out after corroded at 700, 800, and 900℃ for 0.5h separately. Poorly crystallized BN could be corroded comparably at temperatures ~150℃ lower than highly crystallized BN. Melt infiltrated SiC/SiC with BN interphase layer of dual crystallinities was designed and fabricated. Static fatigue test was carried out in the water-oxygen corrosion environment at 1300℃ for more than 100h until fracture. BN at the fracture surface without any pull-out effect was totally oxidized and vaporized regardless of the degrees of crystallinity. Two millimeters away from the fracture point, the inner highly crystallized BN was slightly oxidized while the outer poorly crystallized BN was partially oxidized and re-crystallized. Due to the protection of the SiC matrix, the water-oxygen corrosion rate of BN interphase layer in the composites was significantly slower than that of naked BN coatings on the surface of fibers. BN of different crystallinity degrees exhibits different oxidation behaviors, and highly crystallized BN could be protected by poorly crystallized BN.]]></description>
<pubDate>2026/4/7 9:43:19</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[Qi Zhe,]]></author>
</item>
<item>
<title><![CDATA[From Geometric Analysis to Semantic Reasoning: The Evolution of Robotic Grasping Perception Paradigms]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202602020000003]]></link>
<description><![CDATA[Robotic grasping perception is a fundamental prerequisite for autonomous manipulation and embodied intelligence. The technical paradigm is undergoing a profound shift from analytical methods based on explicit geometric modeling to intelligent perception frameworks driven by data-driven learning and enhanced semantic reasoning. Research on robotic grasping perception was systematically reviewed along the lines of paradigm evolution. The evolutionary process was described through three progressive stages: analytical geometry-driven methods, visual data-driven methods, and semantic understanding and reasoning enhancement. Representative algorithms and key technical pathways for each stage were examined and analyzed. Through a comparative analysis of input modalities, data requirements, generalization ability, and task adaptability across different paradigms, the advantages and limitations of various methods in unstructured environments were summarized. Furthermore, the evolution of grasping datasets from planar benchmarks to large-scale comprehensive data was systematically traced, and the quantitative evaluation system composed of task reliability and proposal accuracy was analyzed. Prevailing challenges—including sim-to-real transfer, inference efficiency, cross-modal information fusion, and the extension to complex tasks—are identified. Future development trends that integrate embodied foundation models with dexterous manipulation are discussed to provide references for building general-purpose robotic grasping systems with high generalization performance and robust task comprehension.]]></description>
<pubDate>2026/4/7 9:33:21</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[黄雨行,徐凯,易任娇,朱晨阳,邹世龙]]></author>
</item>
<item>
<title><![CDATA[Investigation on the effects of magnetic field configurations on thermochemical nonequilibrium turbulent flow control]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202601130000001]]></link>
<description><![CDATA[To investigate the flow control effects of applied magnetic fields on hypersonic vehicles, four magnetic field configurations—stagnation-point dipole, globally uniform, dual-window locally uniform, and parameterized fields—were comparatively studied for the OREX reentry condition (Ma=9.06, H=48.4km). A 10-fold scale-up model was employed to achieve a turbulent Reynolds number of Re=2.23×106. The thermochemical nonequilibrium Navier-Stokes equations were solved using a two-temperature model, an 11-species chemical reaction mechanism, and the k-ω SST turbulence model. Results show that the parameterized magnetic field achieved optimal flow control performance, with the total wall heat flux reduced by 8%~14%. In the shoulder region, ionization reactions were significantly enhanced by the parameterized field, resulting in an approximately 67% increase in electron number density. A unique vibrational temperature overshoot phenomenon (Tv > T) was observed along the stagnation line under the dipole field configuration. Wall heat flux decomposition analysis indicated that vibrational heat flux accounted for over 99% of the total, demonstrating the necessity of the two-temperature model. These findings provide a theoretical foundation for magnetic field optimization design in magnetohydrodynamic thermal protection technology.]]></description>
<pubDate>2026/4/7 9:17:25</pubDate>
<category><![CDATA[航空宇航科学与技术·机械工程]]></category>
<author><![CDATA[Du Yang,,,]]></author>
</item>
<item>
<title><![CDATA[Studying the water-oxygen corrosion behavior of BN interphase layers possessing different degrees of crystallinity in SiC/SiC composites]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202508200000001]]></link>
<description><![CDATA[BN of two levels of crystallinity degrees were deposited by BCl3 and NH3 on the surface of continuous SiC tows. Water-oxygen corrosion of the BN coatings was carried out at 550~1000℃, with a gas content of H2O 14%/O2 8%/N2 78% and flow rate of 6cm/min. For corrosion at 950℃ or higher, highly crystallized BN is almost run out after 0.5h corrosion; 10%, 37%, and 94% of BN is run out after corroded at 700, 800, and 900℃ for 0.5h separately. Poorly crystallized BN could be corroded comparably at temperatures ~150℃ lower than highly crystallized BN. Melt infiltrated SiC/SiC with BN interphase layer of dual crystallinities was designed and fabricated. Static fatigue test was carried out in the water-oxygen corrosion environment at 1300℃ for more than 100h until fracture. BN at the fracture surface without any pull-out effect was totally oxidized and vaporized regardless of the degrees of crystallinity. Two millimeters away from the fracture point, the inner highly crystallized BN was slightly oxidized while the outer poorly crystallized BN was partially oxidized and re-crystallized. Due to the protection of the SiC matrix, the water-oxygen corrosion rate of BN interphase layer in the composites was significantly slower than that of naked BN coatings on the surface of fibers. BN of different crystallinity degrees exhibits different oxidation behaviors, and highly crystallized BN could be protected by poorly crystallized BN.]]></description>
<pubDate>2026/4/2 9:37:23</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[Qi Zhe,]]></author>
</item>
<item>
<title><![CDATA[Precise processing technology of 3D measured points for aviation blades: method breakthrough and applications]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202510220000001]]></link>
<description><![CDATA[To address critical bottlenecks in the 3D inspection of complex aero-engine multi-assembly and aim-film holes blades, s an integrated high-precision data processing methodology and equipment system was presented.An automatic segmentation method for measurement points of multi-assembly blade based on improved density-based clustering and adaptive K-means++ algorithm is proposed to rapidly identify complex cross-sectional features. A Variance Minimization Matching(VMM) optimization model of minor out-of-tolerance was constructed to achieve high-precision adaptive alignment of blade surfaces. The proprietary software iPoint3D and the HScan/RobotHScan hardware series were developed.  Using the above method as the core, software and hardware tools such as the data processing and key feature parameter evaluation software iPoint3D, as well as the series of 3D measurement hardware equipment HScan/RobotHScan, have been developed. These have been validated through typical engineering cases involving aerospace casting blades and high/low pressure turbine blades.. The results indicate that the proposed method achieves precise processing of three-dimensional measurement points for aerospace blades. This effectively resolves challenges in the batch inspection of complex blades, providing critical technical support and engineering solutions for the intelligent manufacturing of core aero-engine components.]]></description>
<pubDate>2026/3/23 15:48:37</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[XU Wei]]></author>
</item>
<item>
<title><![CDATA[Incremental recognition method for modulated signals driven by features and semantics]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202505150000002]]></link>
<description><![CDATA[To address the issue of insufficient recognition accuracy caused by the continuous emergence of novel modulated signals in dynamic scenarios, an incremental recognition method for modulated signals driven by feature and semantics is proposed. First, a multi-dimensional feature representation of modulated signals is constructed. A class-incremental knowledge distillation learning mechanism is introduced into a parallel temporal convolutional network to mitigate feature drift under multi-task iteration in dynamic environments. Meanwhile, a modulated semantic map is built based on multi-dimensional features, and a nearest neighbor strategy is adopted to classify both new and existing modulated signals. Furthermore, a joint loss function is designed by integrating distance loss, Laplacian eigenvalue optimization loss, and knowledge distillation loss, which enhances intra-class compactness and inter-class separability of different modulated signals in the semantic space, thereby improving recognition accuracy. Experimental results demonstrate that the proposed method achieves an average recognition accuracy of 84.46% across multiple incremental tasks, outperforming conventional incremental recognition methods by 10%. It effectively enhances the capability of incremental recognition of signal modulation types in dynamic scenarios.]]></description>
<pubDate>2026/3/19 10:54:20</pubDate>
<category><![CDATA[专题：电磁空间资源智能认知与利用]]></category>
<author><![CDATA[李雯池,,杨凯,,,远航,张泽辉]]></author>
</item>
<item>
<title><![CDATA[Decoupled prediction-differential neural networks for solving high-order differential equations]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503180000002]]></link>
<description><![CDATA[Physics-informed operator learning methods (e.g., PI-DeepONet), while advantageous for accelerating the solution of partial differential equations (PDEs), face challenges of high training costs in high-order problems due to limitations of automatic differentiation. To address this, a novel prediction-differential decoupled neural network architecture, UNet-RBF, is proposed. It employs U-Net as the prediction network to extract spatial features of PDE parameters and utilizes a lightweight Radial Basis Function (RBF) network as the differential network to impose physical constraints. By freezing the RBF network parameters during training, the prediction task is decoupled from differential computation, significantly reducing the computational overhead of automatic differentiation. Numerical experiments demonstrate that UNet-RBF substantially improves the training efficiency and stability for solving high-order PDEs while maintaining high prediction accuracy (relative error less than 1%). Compared to the traditional PI-DeepONet, the training efficiency for fourth-order problems is increased by over 1500%, and the model exhibits stronger robustness, offering an effective pathway for the rapid and accurate solution of complex physical problems.]]></description>
<pubDate>2026/2/4 16:53:42</pubDate>
<category><![CDATA[力学]]></category>
<author><![CDATA[Peng Bo,]]></author>
</item>
<item>
<title><![CDATA[Decoupled prediction-differential neural networks for solving high-order differential equations]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503180000002]]></link>
<description><![CDATA[Physics-informed operator learning methods (e.g., PI-DeepONet), while advantageous for accelerating the solution of partial differential equations (PDEs), face challenges of high training costs in high-order problems due to limitations of automatic differentiation. To address this, a novel prediction-differential decoupled neural network architecture, UNet-RBF, is proposed. It employs U-Net as the prediction network to extract spatial features of PDE parameters and utilizes a lightweight Radial Basis Function (RBF) network as the differential network to impose physical constraints. By freezing the RBF network parameters during training, the prediction task is decoupled from differential computation, significantly reducing the computational overhead of automatic differentiation. Numerical experiments demonstrate that UNet-RBF substantially improves the training efficiency and stability for solving high-order PDEs while maintaining high prediction accuracy (relative error less than 1%). Compared to the traditional PI-DeepONet, the training efficiency for fourth-order problems is increased by over 1500%, and the model exhibits stronger robustness, offering an effective pathway for the rapid and accurate solution of complex physical problems.]]></description>
<pubDate>2026/2/3 10:41:22</pubDate>
<category><![CDATA[力学]]></category>
<author><![CDATA[Peng Bo,]]></author>
</item>
<item>
<title><![CDATA[Data-Driven Generalizable Aerodynamic Analysis Model for Fast Shape Design Optimization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503140000002]]></link>
<description><![CDATA[Data-driven generalizable aerodynamic analysis models demonstrate strong capability in performing real-time reliable aerodynamic analysis for any geometry under arbitrary aerodynamic conditions. It represents a key technology for achieving high-speed intelligent optimization design of aircraft. However, the construction of high generalizable analysis models for complex aerodynamic geometry remains severely constrained by the curse of dimensionality, which necessitates large number of training data, thereby impeding practical implementation and broader application. This paper presents two studies in data-driven airfoil and wing optimization design. By establishing a rational parametric characterization of the aerodynamic shape design space, the adverse effects of the curse of dimensionality were effectively circumvented. A data-driven aerodynamic analysis model with demonstrable generalizability was constructed utilizing approximately 100,000-scale CFD training datasets, enabling high-efficiency optimization design of relevant aerodynamic shapes. As a summary of the author"s preliminary work, this paper aims to inspire the academic community to conduct further research in the field of data-driven aerodynamic optimization design and to promote the advancement of intelligence in the field of aircraft design.]]></description>
<pubDate>2026/1/28 15:05:06</pubDate>
<category><![CDATA[专题：临近空间智能飞行技术]]></category>
<author><![CDATA[李记超]]></author>
</item>
<item>
<title><![CDATA[Key Technologies and Evolutionary Development of Space-Based Constellations for Electromagnetic Environment Sensing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202507150000002]]></link>
<description><![CDATA[The electromagnetic environment serves as the fundamental medium for radio wave propagation and profoundly influences the operational efficiency of global information infrastructure systems, including communications, navigation, and security.The research focused on electromagnetic environment sensing constellations developed within the commercial spaceflight sector and summarized the evolutionary development of electromagnetic environment sensing constellations through three major phases: the military electromagnetic reconnaissance–dominated era, the stage of global collaborative competition, and the phase of commercial and national co-leadership. Representative constellations and their functional characteristics were outlined for each phase.Current in-orbit constellations were categorized into four primary types—propagation environment sensing, broadband RF signal sensing, typical operational signal sensing, and multimodal integrated sensing—and their functional characteristics, core capabilities, key technologies, and application scenarios are analyzed.Ongoing development trends are identified in commercial space-based electromagnetic environment sensing toward space–ground system integration, multi-satellite network collaboration, multimodal fusion, and real-time artificial intelligence integration.]]></description>
<pubDate>2026/1/16 9:15:11</pubDate>
<category><![CDATA[专题：电磁空间资源智能认知与利用]]></category>
<author><![CDATA[张明高]]></author>
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<title><![CDATA[Construction and comparative study of equivalent model of 38mm compound non-lethal kinetic energy projectile]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503050000001]]></link>
<description><![CDATA[To solve the problem of the lack of standardized verification projectiles for non-lethal blunt ballistic impacts in China, three equivalent strategies of equal density scaling, equal mass scaling and equal volume scaling were proposed based on NATO SIR-X projectile, and a finite element model of 38mm composite projectile was constructed. Through the impact simulation experiment of rigid wall and human chest target, the multi-dimensional equivalence of the model was verified by the criteria of momentum, kinetic energy, specific kinetic energy, bluntness and viscosity (VCmax). The results show that the equal-mass scaled projectile B is the closest to SIR-X projectile in terms of impact characteristics (mean absolute difference between displacement-time curve ≤1.19 mm) and damage effect (VCmax deviation ≤2.53%), which verifies its feasibility as a domestic standardized test projectile, provides a theoretical basis for the design of composite non-lethal kinetic energy projectiles adapted to the caliber of riot guns in China. The proposed comprehensive evaluation method based on multi-dimensional damage criteria can provide support for the intrinsically safe design of new non-lethal kinetic energy projectiles.]]></description>
<pubDate>2026/1/15 15:29:29</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[ZHANG Zhaohui]]></author>
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<title><![CDATA[Genetic-Dynamic Time Warping Strategy Preference Fitting in Multi-party Crisis Games]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202404030000001]]></link>
<description><![CDATA[To analyze and predict decision-making in complex multi-party crisis game scenarios, a novel strategy preference fitting method that integrates agent-based modeling with the “Genetic-DTW (genetic-dynamic time warping)” algorithm is proposed. By fitting historical time-series data from intelligent agents in multi-party crisis game, this study simulates the decision-making processes of international actors during crises and predicts system state transitions. Combining expert knowledge with machine learning, our model achieves promising results in capturing strategy preferences of actors in multi-party games, obtaining an average DTW distance of 9.35 in historical case state sequence prediction tasks. This approach provides an innovative research path for understanding multi-party crisis decision-making. The proposed modeling and calibration methods can be widely applied to other complex multi-party game scenarios, including multilateral multi-round negotiations, multilateral economic sanctions, and regional conflicts.]]></description>
<pubDate>2025/12/30 17:19:59</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[陈俞舟,傅曼青,李知,刘万里,刘鑫,唐世平]]></author>
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<title><![CDATA[Multi-field coupled viscoelastic constitutive model for pressure cure of solid propellant grain]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412310000001]]></link>
<description><![CDATA[The pressure cure process of solid propellant grains involves complex thermo-chemo-mechanical coupled effects, leading to empirical design and monotonous pressure control in engineering practice, which restricts technological advancement. To address this issue, a three-dimensional viscoelastic constitutive model and its incremental equations were established considering the coupled effects of curing reaction heat, cure volume shrinkage, and viscoelastic evolution derived from thermo-rheologically complex material behavior. The influences of multi-field coupled effects, thermo-rheologically complex material behavior, cure reaction exothermy, cure volume shrinkage coefficient, and pressure on the pressure cure process were analyzed. Results indicate that multi-field coupled effects significantly impact cure residual stress, and neglecting thermo-rheologically complex material behavior results in underestimation of cure residual stress. Partial pressure unloading during the cure stage effectively reduces cure residual stress. The findings provide theoretical support for optimizing the pressure cure process of solid propellant grains.]]></description>
<pubDate>2025/12/29 17:37:43</pubDate>
<category><![CDATA[力学]]></category>
<author><![CDATA[吴栋,]]></author>
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<title><![CDATA[Multi-Mode Optimal Control Allocation and Fault-Tolerant Control of Compound Tilt-Rotor Aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501110000002]]></link>
<description><![CDATA[The compound tilt-rotor unmanned aerial vehicle (UAV) combines the advantages of both fixed-wing and rotorcraft, and is currently widely used. However, its over-actuated characteristics pose challenges for the design of control allocation systems and stable operation under actuator failure conditions. This paper proposes a multimodal optimization control allocation and fault-tolerant control strategy. First, based on the dynamic characteristics of tilt-rotor aircraft, kinematic and dynamic models are established. By utilizing angular acceleration feedback to compensate for unmodeled dynamic parts, a compound incremental nonlinear dynamic inversion control law is designed. Secondly, the distribution method of virtual control quantities and actual control inputs is studied. A multi-objective comprehensive optimization function is designed based on requirements such as stability and energy consumption and solved using a small-dimensional strictly convex quadratic programming method. Then, based on the control al]]></description>
<pubDate>2025/12/29 17:35:04</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[liangzhuang,,]]></author>
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<title><![CDATA[Offline Design and Online Scheduling for Imaging Satellite Mission Planning Algorithms Driven by Large Model Intelligent Agents]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202507270000001]]></link>
<description><![CDATA[To enhance the scheduling efficiency of imaging satellites for regular emergency scenarios (e.g., disaster warning, intelligence acquisition) and address the performance limitations of fixed scheduling algorithms in complex, dynamic situations and the lag associated with manual algorithm design, this study proposes a large language model (LLM)-driven AI agent collaboration framework. The framework decomposes the complex scheduling problem into two subproblems: task allocation and single-satellite planning. The algorithm design process is further divided into two phases: initial algorithm generation and evolutionary algorithm optimization. The resulting executable meta-tasks are autonomously completed by multiple agents through collaborative communication to design the optimal algorithm. The entire framework operates fully automatically and intelligently, supporting offline training and seamless online deployment to ensure real-time response capabilities for emergency tasks. Experimental results demonstrate that algorithms automatically generated by this framework significantly outperform those designed by human experts in both solution quality and computational efficiency.]]></description>
<pubDate>2025/12/23 15:16:26</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[陈佳威,陈盈果,林翔,王俊琦,徐世龙,周庆瑞]]></author>
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<title><![CDATA[Research on wind field prediction model in aerospace transition zone based on height-aware neural operator]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202508220000001]]></link>
<description><![CDATA[To address the issues of low computational efficiency and insufficient modeling of multi-altitude physical characteristics in traditional numerical prediction methods for the aerospace transition zone, a HAFNO (height-aware Fourier neural operator) model was proposed. A height-aware weighting mechanism was introduced to adaptively distinguish physical features across different altitude layers while maintaining O(n log n) computational complexity. Additionally, a multi-altitude coupled preprocessing framework and an adaptive loss function incorporating spatial gradient constraints were constructed. Experimental results based on MERRA-2 data demonstrate that HAFNO outperforms benchmark models such as ConvLSTM and DeepONet in the 50~70 km altitude range. The average RMSE (root mean square error) is reduced by 12.8% compared to the standard FNO, with a maximum correlation coefficient of 0.994, providing an efficient deep learning technical approach for environmental forecasting in the aerospace transition zone.]]></description>
<pubDate>2025/12/23 15:12:57</pubDate>
<category><![CDATA[专题：空天过渡区大气科学前沿]]></category>
<author><![CDATA[WuYang]]></author>
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<title><![CDATA[Hybrid Strategy-Optimized Harris Hawk Optimization for AOA/TDOA Joint Positioning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202504240000001]]></link>
<description><![CDATA[To address the issues of insufficient local search capability, susceptibility to local optima, and slow convergence in existing Angle of Arrival (AOA) and Time Difference of Arrival (TDOA) joint positioning methods under complex environments, a Hybrid Strategy-Optimized Harris Hawk Optimization (HSHHO) algorithm is proposed. The proposed algorithm constructs a dual-mode cooperative framework consisting of the original and quasi-reflective populations, and employs a bidirectional elite migration strategy to facilitate information exchange and complementary advantages between the two populations. Additionally, during the algorithm"s exploration and exploitation phases, the Golden Sine Optimization and Cauchy Mutation Strategy are respectively integrated to refine the population update mechanism, thereby enhancing the algorithm’s global exploration and local exploitation capabilities. Simulation results demonstrate that, compared with existing algorithms, the HSHHO algorithm exhibits superior performance in terms of convergence speed, global search capability, local refinement, and positioning accuracy.[1]]]></description>
<pubDate>2025/12/22 17:11:53</pubDate>
<category><![CDATA[系统科学]]></category>
<author><![CDATA[qinhucheng,]]></author>
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<title><![CDATA[System-of-Systems Engineering for General Design: State of the Art, Research Framework, and Future Directions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202509040000001]]></link>
<description><![CDATA[The SoS (system-of-systems) nature of modern warfare necessitated in-depth research into SoSE (system-of-systems engineering), at the meso-level, mission-oriented operational SoS design gradually emerged as a critical yet challenging focus within SoSE. Drawing on foundational studies in system general design and SoSE, this paper explored through three dimensions: current state of the art, research frameworks, and future directions. First, based on the systems engineering design process model, this paper reviewed and synthesized domestic and international advances in SoSE technologies across five stages: requirements analysis, solution design, simulation experiments, alternative evaluation, and solution optimization. Building upon this review, a research framework for top-level SoSE design was constructed from the dual perspectives of knowledge domains and business workflow. Finally, the study examined the development trends through a synthesis of successful frontier fruits in related areas. The study systematically consolidates the research framework and technical approaches for SoSE oriented toward general design, contributing to the formation of a research community in SoS general design and fostering coordinated, collaborative advancement of related technologies.]]></description>
<pubDate>2025/12/17 14:43:36</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[陈子夷,黄智捷,李静晶,李小波,梁浩哲,明梦君,王泊涵,王涛,王维平,闫玉铎,朱智]]></author>
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<title><![CDATA[Liquid Film/Regenerative Composite Cooling Characteristics of Liquid Oxygen/Kerosene Rocket Engine]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202505230000001]]></link>
<description><![CDATA[A heat and mass transfer model was established for the coupled heat transfer process involving regenerative cooling and film cooling in a specific liquid oxygen/kerosene rocket engine, and numerical simulation calculation was made. To comprehensively consider the heat and mass process such as convection heat transfer, radiation heat transfer, thermal conductivity, deposition thermal resistance, evaporation and entrainment, the thrust chamber was divided into three areas, the heating section, the evaporation section, and the gas film section to be calculated. The influences of the liquid film mass flow rate, the injection position of the liquid film and the mass flow rate at each liquid film inlet on the regenerative and film cooling characteristics were analyzed. The results show that: (1) When the liquid film mass flow rate is small, an increase in the liquid film mass flow rate does not significantly change the composite cooling characteristics, but the length of the liquid film zone becomes longer. (2) In the regenerative and liquid film cooling, the different injection positions of the liquid have a significant impact on the wall temperature. As the injection position of the liquid film moves towards the throat, the heat flux density and wall temperature at the throat decrease. (3) Film and regenerative cooling can effectively reduce the wall temperature. The cooling liquid film can significantly reduce the wall temperature and heat flux density. Meanwhile, the gas film formed by the evaporation of the liquid film and the deposited carbon can effectively provide cooling protection for the wall.]]></description>
<pubDate>2025/12/10 15:36:56</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[YU Fuming,]]></author>
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<title><![CDATA[Research on the optimal matching method of configuration and trajectory for morphing aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202505190000001]]></link>
<description><![CDATA[The coupling effect between geometric configuration adjustment and flight trajectory generation in morphing aircraft is found to lead to issues such as a sharp increase in trajectory design variables. A gliding morphing aircraft was taken as the research object to analyze the configuration-trajectory coupling characteristics. A configuration-trajectory matching design model was established. A multi-fidelity aerodynamic approximation modeling method for morphing aircraft was proposed, and the dynamic equations considering the configuration-trajectory coupling effect were constructed. Based on a surrogate model and sequential quadratic programming, a configuration-trajectory integrated planning method was developed to conduct the matching design study, resulting in the optimal morphing design scheme under the best trajectory. The maximum range achieved by the variable-sweep-wing-span scheme is 2.16 times that of the fixed-configuration scheme and 1.26 times that of the variable-sweep scheme, thus verifying the effectiveness of the optimal configuration-trajectory matching design method. Methodological support is provided for the overall design of future intelligent morphing aircraft.]]></description>
<pubDate>2025/12/10 14:52:27</pubDate>
<category><![CDATA[专题：变形飞行器多学科耦合建模仿真与优化技术]]></category>
<author><![CDATA[Wu Zeping,]]></author>
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<title><![CDATA[Real-time Rolling Optimization of Dynamic Weapon Target Assignment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503310000003]]></link>
<description><![CDATA[To effectively address dynamic target variations and emergencies in battlefield environments, a DWTA (dynamic weapon target assignment) method based on a real-time rolling mechanism was proposed. An allocation model based on the cumulative probability of destruction and a weapons scheduling model aiming at the shortest operational completion time were established. To adapt to the time-varying availability of weapons, a VLC-DPSO (variable length coding discrete particle swarm optimization) algorithm was introduced, utilizing discrete optimization through copying optimal solution segments. Moreover, a hierarchical closed-loop optimization of assignment and scheduling was achieved by integrating the genetic algorithm for weapon scheduling sequence optimization. Simulation experiments show that, compared with the traditional genetic algorithm and particle swarm optimization algorithm, the proposed VLC-DPSO algorithm achieves better strike effects in both small-scale and large-scale scenarios, especially showing significant advantages in large-scale scenarios. Furthermore, experimental scenarios with randomly introduced new targets verify the proposed method"s robust adaptability to battlefield emergencies.]]></description>
<pubDate>2025/12/8 15:51:11</pubDate>
<category><![CDATA[系统科学]]></category>
<author><![CDATA[LU Gang]]></author>
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<title><![CDATA[Extra-atmospheric ascent debris avoidance guidance method for launch vehicles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202507050000001]]></link>
<description><![CDATA[A debris avoidance guidance method wasis proposed to utilize the detection information from the space debris situational awareness system to actively avoid space debris and achieve high-precision orbital insertion. An optimal guidance problem for launch vehicle ascent debris avoidance was formulated. The motion of space debris was modeled using Kepler dynamics with state uncertainties, and a debris threat radius was defined based on state   uncertainties. A state uncertainty propagation predictor based on polynomial chaos expansion was designed. Taking the measurement errors of the current position and velocity vectors of debris as initial values, the time-varying threat radius of the debris was obtained by predicting the uncertainty propagation of the debris state errors. Through derivation of the optimal guidance form for debris avoidance, a two-stage linear tangent guidance law for single debris avoidance and a guidance strategy for multiple debris avoidance were proposed. Simulation results show that the proposed debris avoidance guidance method can achieve the active avoidance for multiple debris and satisfy the orbital insertion accuracy.]]></description>
<pubDate>2025/12/1 10:12:44</pubDate>
<category><![CDATA[专题：变形飞行器多学科耦合建模仿真与优化技术]]></category>
<author><![CDATA[GUO Kang,]]></author>
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<title><![CDATA[Spatial-Temporal Normalizing Flow for Robust Multivariate Time Series Anomaly Detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202504120000001]]></link>
<description><![CDATA[Recent advancements in Artificial Intelligence of Things (AIoT) technologies have brought about an increasing popularity in leveraging deep learning algorithms to detect potential failures in cyber-physical systems (CPS). Typically, an anomaly detection model is deployed to monitor the multivariate time series (MTS) generated by sensors to identify abnormal operation states. However, the contemporary unsupervised deep learning models for MTS anomaly detection are susceptible to contamination in the training dataset and are incapable of capturing the spatial-temporal correlations in MTS, result in suboptimal practical detection performance. In this paper, we propose a novel framework called Spatial-Temporal Normalizing Flow (STNF) to tackle the above problems. Our framework extends the conditional normalizing flow for MTS density estimation, aiming to achieve robust anomaly detection against training dataset pollution. Additionally, we introduce a patched Long Short-Term Memory (LSTM) module to effectively learn robust representations of long-term dependencies within MTS. Moreover, a dynamic graph construction module is devised to model the complex and evolving correlations among different dimensions of MTS. We evaluate our approach on three real-world CPS datasets and report improvements over the state-of-the-art approaches in terms of both performance and robustness.]]></description>
<pubDate>2025/12/1 10:12:05</pubDate>
<category><![CDATA[专题：数智驱动的运筹与决策]]></category>
<author><![CDATA[戴超凡,马武彬,唐琪登,吴亚辉,袁文博,周浩浩]]></author>
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<title><![CDATA[Residual network intelligent prediction method for hypersonic inlet internal contraction basic flowfield]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501140000006]]></link>
<description><![CDATA[Hypersonic internal compression inlets are typically designed using streamline tracing technology based on the basic flowfield, and the quality of the basic flowfield design directly determines the performance metrics of the inlet. In this study, the quasi-uniform B-spline method is applied to achieve the parametric design of the internal compression basic flowfield. A fast prediction model for the internal compression basic flowfield is established based on the residual neural network architecture of deep learning, realizing the goal of "parametric design-flowfield prediction." The predicted flowfield cloud images are quantitatively evaluated using image quality assessment methods, and key flowfield characteristic parameter distributions are extracted to enable rapid acquisition of flowfield cloud images and characteristic parameter distributions based on design parameters. The results show that the developed basic flowfield fast prediction model achieves high prediction accuracy for flowfields corresponding to given geometric parameters. The average peak signal-to-noise ratio (PSNR) of the predicted total flowfield is 42.51 dB, and the average structural similarity index (SSIM) is 0.9973. Additionally, the model can effectively extract key flowfield characteristic parameter distributions from the predicted results, providing robust support for the rapid design and optimization of internal compression basic flowfield.]]></description>
<pubDate>2025/11/21 17:36:16</pubDate>
<category><![CDATA[专题：临近空间智能飞行技术]]></category>
<author><![CDATA[范晓樯,,,熊冰,]]></author>
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<title><![CDATA[Enhanced heat transfer by combining dual synthetic jets actuator with different metal-water micron particle multiphase flow]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202409120000001]]></link>
<description><![CDATA[In order to improve the heat dissipation capacity of the electronic equipment system of the near space vehicle and solve the problem of high heat flux of integrated and miniaturized electronic devices，the paper had a study on the heat transfer performance of dual synthetic jets actuators, by making use of two-phase flow composed of micron-particle and water and their combination. The mechanism of enhancing heat transfer capacity with dual synthetic jets actuator is was studied and analyzed. The flow process of the dual synthetic jets actuator and Cu-water micron particle fluid in the tube is was modeled, and the influence of five particle concentrations on the enhanced heat transfer capacity of the fluid is was simulated by the single Euler model. CUO-water and Al2O3-water micron particle fluids are were simulated. The results show that the heat transfer capacity of fluid can be enhanced by the dual synthetic jets. The heat transfer capacity in-creases with the increase of micron particle concentration. The two-phase flow heat transfer capacity of different metal particles varies with the thermal conductivity of metal particles. In the example, a microparticle fluid of Cu particles with a dual synthetic jets actuator on and a particle concentration of 8% is synthesized, and the chip temperature is reduced from 328.225K to 303.816K.]]></description>
<pubDate>2025/11/21 17:11:33</pubDate>
<category><![CDATA[专题：临近空间智能飞行技术]]></category>
<author><![CDATA[罗振兵,,于新莹]]></author>
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<title><![CDATA[Cooperative Co-evolutionary Optimization Method for Multi-Constraint Satellite Pursuit-Evasion Game]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412230000001]]></link>
<description><![CDATA[Traditional methods often exhibit low efficiency in addressing multi-objective and multi-constraint optimization problems, failing to meet the requirements of dynamic and complex environments. In this case, a hybrid cooperative co-evolution algorithm was proposed based on cooperative co-evolution mechanisms, zebra optimization algorithms, and differential game theory. A phased optimization strategy was adopted to dynamically and adaptively optimize trajectories and strategies, while a multi-population co-evolution mechanism was introduced to enhance global exploration capability and local convergence performance. Differential game theory was integrated to improve the stability and reliability of game strategies. Simulation results demonstrate that this method significantly improves mission completion efficiency under multi-constraint conditions. It effectively balances dynamic strategy adjustments for both pursuers and evaders, providing an effective solution for satellite pursuit-evasion games in space-based target reconnaissance and surveillance missions.]]></description>
<pubDate>2025/11/21 17:11:10</pubDate>
<category><![CDATA[专题：临近空间智能飞行技术]]></category>
<author><![CDATA[韩昊东,刘田青,马宸宇浩,王俊琦,许旭升,袁秋帆,张勃,周大明]]></author>
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<title><![CDATA[Aerothermoelastic Analysis of the TPS Panel Using Kriging-Based Aerodynamic and Aerothermal Surrogate Models]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501140000003]]></link>
<description><![CDATA[High-speed vehicles are characterized by a wide speed range and lightweight structures, and they face complex aerodynamic and thermal environments as well as structural stability challenges. Under the coupled effects of fluid-structure-thermal interactions, aerothermoelastic problems have become a major focus of attention. However, in the calculation of high-speed aerodynamic and thermal loads, engineering algorithms offer high computational efficiency but lack accuracy, while numerical simulation methods provide high precision at a significantly higher computational cost. Therefore, a typical thermal protection system (TPS) panel of a High-speed vehicle was focused, and aerodynamic and aerothermal surrogate models based on the Kriging method were developed, which achieved a four-orders-of-magnitude improvement in computational efficiency. Based on these surrogate models, a computational framework for the aerothermoelastic analysis of the TPS panel was established using the finite element method and a self-developed heat conduction program. The aerothermoelastic behavior of the TPS panel was then analyzed within this framework. This research will provide an important theoretical foundation for the rapid and accurate prediction of aerodynamic and thermal loads, the design of thermal protection systems, and the flight safety assessment of High-speed vehicles.]]></description>
<pubDate>2025/11/21 17:10:43</pubDate>
<category><![CDATA[专题：临近空间智能飞行技术]]></category>
<author><![CDATA[冀春秀,唐硕,谢丹,易子钧]]></author>
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<title><![CDATA[Low Overload Ratio Multi-Missile Self-Organizing Cooperative Fencing and Attack Method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501140000007]]></link>
<description><![CDATA[As regional security issues have become increasingly severe, the strike capability of individual missiles is gradually failing to meet operational demands, necessitating improved strike efficiency through multi-missile coordination. This paper investigated the control problem of coordinated multi-missile fencing and attack against unknown maneuvering targets and explored the design of the overload ratio, which represents the relationship between missile maneuverability and target maneuverability. Inspired by the self-organizing behavior of biological swarms, this study designed a multi-missile cooperative fencing algorithm using sliding mode control. The algorithm included an attraction term to the the target, a repulsion term between adjacent missiles, and a relative velocity convergence term between missiles and the target. The analysis showed that, under this algorithm, the upper bound of the overload ratio could be calculated based on the initial conditions and control parameters, providing technical support for missile formations with a low overload ratio. Numerical simulation results showed that the proposed algorithm effectively achieved multi-missile fencing and attack against unknown maneuvering targets with a low overload ratio. It maintained a safe distance during the fencing phase and rapidly reduced inter-missile spacing during the attack phase by removing the repulsion term to enable coordinated engagement.]]></description>
<pubDate>2025/11/21 17:10:14</pubDate>
<category><![CDATA[专题：临近空间智能飞行技术]]></category>
<author><![CDATA[何金刚,孟中杰,张凡,周赢]]></author>
</item>
<item>
<title><![CDATA[Analysis of nonconstant aerodynamic characteristics on the flight performance of morphing vehicles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501130000001]]></link>
<description><![CDATA[The unsteady aerodynamic effects on the flight performance of morphing aircraft remain unclear. The unsteady aerodynamic characteristics during morphing were investigated, and their impact on flight performance was quantitatively analyzed. A dynamic model incorporating unsteady aerodynamic effects was established, with morphing rate and flight velocity as key parameters. A qualitative comparison was conducted between the flight performance under unsteady and quasi-steady aerodynamic models. Two typical flight scenarios were designed, and the pseudo-spectral method was employed to quantify the influence of unsteady aerodynamic effects on mission performance in maximum range operations and no-fly zone avoidance. The results indicate that the unsteady aerodynamic model introduces deviations in flight state accuracy compared to the quasi-steady model, which correlate with morphing rate and flight velocity. These deviations predominantly occur in low-altitude, low-speed (below Mach 3) flight regimes. During no-fly zone avoidance, where morphing is more pronounced, a trajectory deviation of approximately 1800m accumulates within 250s. In contrast, maximum range operations exhibit a smaller deviation of around 350m over 1000s of flight.]]></description>
<pubDate>2025/11/21 17:06:26</pubDate>
<category><![CDATA[专题：临近空间智能飞行技术]]></category>
<author><![CDATA[杨召]]></author>
</item>
<item>
<title><![CDATA[Intelligent reconstruction method of isolator flow field based on combined detail feature enhancement]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412040000006]]></link>
<description><![CDATA[Aiming at issues such as the loss of complex wave system structural features in intelligent reconstruction methods for supersonic flow fields, along with the inability to effectively capture the temporal evolution characteristics of unsteady flow fields, which together lead to the inaccurate identification of the shock train leading edge,. A neural network model based on combined detail feature enhancement to address these issues was proposed. High-precision predictions of the density gradient field was achieved based on sparse pressure data. The main wave system structure features of the flow field was established by connecting multiple layers of convolutional networks in series. A residual network with skip connections was used to integrate features from receptive fields of different scales, enhancing the model's ability to express detail features in reconstructed flow fields. Validation was conducted using a dataset constructed from numerical simulations of ramjet engines. Compared to multilayer convolutional neural networks, this method improves the average Peak Signal-to-Noise Ratio across the entire test set by 9.5%. Moreover, the reconstructed flow field's STLE position closely matches the numerical computation results, further demonstrating the effectiveness of the proposed method.]]></description>
<pubDate>2025/11/21 17:01:48</pubDate>
<category><![CDATA[专题：临近空间智能飞行技术]]></category>
<author><![CDATA[邓  雪,田  野,吴京润,胥梦绮,张  华]]></author>
</item>
<item>
<title><![CDATA[Ballistic missile maneuverability limited anti-interception game trajectory optimization method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503130000001]]></link>
<description><![CDATA[Aiming at the problem of maneuverability limitation in the process of penetration and interception, a game trajectory optimization strategy solution based on adaptive dynamic programming is proposed. By establishing an affine nonlinear differential game model and considering the limited maneuverability, the performance index function of the control energy term with integral form was designed. The saddle point control strategy of the game was derived based on the differential game theory, and an evaluation network was designed based on the adaptive dynamic programming algorithm to approximate the solution of the differential game strategy. The weight adaptive updating law of the evaluation neural network was given and its stability was proved. Simulation results show that the proposed strategy solving method can achieve anti-interception effect and accurately strike enemy targets under the circumstance of limited maneuverability.]]></description>
<pubDate>2025/11/21 16:58:50</pubDate>
<category><![CDATA[专题：临近空间智能飞行技术]]></category>
<author><![CDATA[YouYongan]]></author>
</item>
<item>
<title><![CDATA[A review of online reinforcement learning control for systems with unknown models: theory, methods, and challenges]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202506300000002]]></link>
<description><![CDATA[In the fields of intelligent manufacturing, aerospace, and robotics, control systems often operate under unknown dynamics. This significantly limits the effectiveness of traditional model-based control methods. Reinforcement learning (RL), as a data-driven intelligent control approach, enables policy learning and optimization through interaction with the environment, showing great potential for solving optimal control problems in such model-unknown scenarios. This survey focuses on the issue of unknown dynamic models in continuous-time systems and first reviews the development of general reinforcement learning algorithms and their application in model-known scenarios through industrial examples and theoretical analysis methods. It also summarizes representative methods for model-unknown scenarios, such as model-based RL, off-policy integral RL, and Q-learning approaches. The survey also introduces Lyapunov-based theoretical analysis tools and important assumptions. It discusses cutting-edge topics such as RL under partial observability using large language models, safe RL, and stability and robustness enhanced RL, while highlighting the challenges faced by existing methods.]]></description>
<pubDate>2025/11/11 8:47:47</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[Haoran Zhang,]]></author>
</item>
<item>
<title><![CDATA[Pressure Development Model of Explosives Combustion Under Limited Pressure Relief Conditions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202406110000001]]></link>
<description><![CDATA[Aiming at the problem that the unexploded ordnance irradiated by high energy laser is easy to explode, which will cause great harm to the surrounding environment, the theory of stable combustion of shell charge under the condition of pre-opening hole iwas systematically sorted out. Based on the explosive exponential combustion law and the choking flow theory model of gas products, the pressure development model of shell charge during combustion, under the condition of limited pressure relief was established. A simplified calculation method for the combustion area of cylindrical charge was proposed. A calculation program was written based on Computational software to study the development law of the combustion pressure of unexploded ordnance charge under different pressure relief hole diameter. The variation law of the diameter of the safety relief hole and the diameter of the projectile body had been obtained. The consistency between the relevant results and the experimental results proves the correctness and applicability of the theory, which can provide theoretical support for laser combustion destruction of unexploded ordnance]]></description>
<pubDate>2025/11/4 9:14:42</pubDate>
<category><![CDATA[力学]]></category>
<author><![CDATA[wangchongxu]]></author>
</item>
<item>
<title><![CDATA[Time-coordinated re-entry trajectory planning for hypersonic glide vehicle cluster]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202404170000001]]></link>
<description><![CDATA[Starting from the cooperative mission requirements of hypersonic gliding vehicles, a cooperative trajectory planning method for cluster re-entry was proposed to address the trajectory planning problem in complex re-entry environments. The re-entry dynamics of a cluster of vehicles was modeled, and a longitudinal trajectory control scheme was designed based on the control volume and re-entry corridor constraints. This approach aims to mitigate the oscillation problem during trajectory calculation and improve the feasibility of trajectory solution. On this basis, the trajectory planning scheme under two forms of cooperation was proposed, which completed the decision of cooperative time according to the mission requirements and the gliding capability analysis results of the aircraft cluster, and utilized the hp adaptive pseudo-spectral algorithm to plan the cooperative trajectory that satisfies the no-fly zone and time constraints. Simulation results show that the proposed method can plan 3D trajectories that satisfy the specified constraints and coordinated time under different mission scenarios. This has significant reference value for the cooperative planning research of hypersonic glider vehicles.]]></description>
<pubDate>2025/10/16 16:08:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[chenshunyi,,,,]]></author>
</item>
<item>
<title><![CDATA[Enhancing Adversarial Robustness in Object Detection: A Gradient Alignment Approach]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503210000001]]></link>
<description><![CDATA[To better address the problem of insufficient adversarial robustness of object detection models under adversarial attacks, an adversarial robustness enhancement method for object detection models based on gradient alignment is proposed. During the adversarial training phase, we construct a composite loss function based on adversarial loss and alignment loss, and by introducing a gradient alignment strategy, the gradient differences between adversarial examples and clean examples can be constrained. Furthermore, combining the supervisory signals of knowledge distillation and the representational capability of self-supervised learning, our approach maximizes the feature similarity between adversarial and clean examples. Experimental results on the PASCAL VOC and MS COCO datasets demonstrate that the proposed method effectively improves the model"s adversarial robustness accuracy against adversarial examples.]]></description>
<pubDate>2025/10/16 11:06:30</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[XUE Wei]]></author>
</item>
<item>
<title><![CDATA[Prescribed performance fault-tolerant tracking control for morphing aircraft under actuator faults]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202506280000001]]></link>
<description><![CDATA[To address the problems of actuator faults, composite disturbances, and time-constrained convergence encountered during wing deformation of morphing aircraft, a prescribed performance sliding mode fault-tolerant tracking control method was proposed. A longitudinal nonlinear model and fault model of the morphing aircraft were established, which were decoupled into attitude and velocity subsystems to simplify controller design. Improved nonlinear disturbance observers were introduced to accurately estimate and compensate for actuator faults and composite disturbances in real time. Prescribed performance sliding mode fault-tolerant controllers were designed to ensure that tracking errors converge to a prescribed precision range within prescribed time, completely independent of initial states, thereby guaranteeing both transient and steady-state performance while maintaining flight safety. The uniformly ultimately bounded stability of the system and prescribed time convergence of tracking errors were rigorously proved via Lyapunov function. Simulation results validate the effectiveness, robustness, and fault-tolerant performance of the proposed method.]]></description>
<pubDate>2025/10/14 16:04:22</pubDate>
<category><![CDATA[专题：无人系统智能自主控制与集群协同]]></category>
<author><![CDATA[YE Ziqi]]></author>
</item>
<item>
<title><![CDATA[Covert Maneuvering Trajectory Planning Method of Spacecraft Swarm under complex constraints]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202505280000001]]></link>
<description><![CDATA[To address the mission requirements of spacecraft swarm covertly approaching and observing space targets, this study proposes a swarm covert maneuver trajectory planning method based on improved sequential convex programming (SCP). Given the numerous, nonlinear, and strongly coupled constraints in multi-satellite cooperative covert maneuvers, strategies such as polyhedral cones and rotating hyperplanes are employed to convexify constraints related to covert zones and collision avoidance, thereby reducing problem complexity and improving computational efficiency. Additionally, to prevent premature termination of the SCP solver due to improper initial guesses, a penalized iterative recovery mechanism is introduced. Simulation results demonstrate that the proposed convex approximation techniques effectively reduce problem-solving difficulty, and the improved SCP method successfully generates feasible swarm covert trajectories that satisfy complex constraints.]]></description>
<pubDate>2025/10/10 11:21:40</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[蔡伟伟,李国盛,田镜文,杨乐平,张润德]]></author>
</item>
<item>
<title><![CDATA[A Positioning and Speed Measuring System of Linear Motor Applied in Electromagnetic Sled]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202311020000001]]></link>
<description><![CDATA[In view of the contradiction between the need of the electromagnetic sled for real-time accurate position and speed information and the limitation or high cost of traditional position and speed measurement methods, a new measurement system based on vernier caliper structure was proposed and designed. The principle of high precision positioning and the corresponding position analysis method was expounded, and the position prediction algorithm and Kalman filter algorithm were designed to improve the accuracy and real-time performance. The hardware circuit and software program were designed to realize the function, and a synchronous belt guide rail experimental platform was built to verify the designed system. The test results show that the system can achieve millimeter-level positioning accuracy, and performs well in terms of real-time capability, accuracy and engineering application. The positioning and speed measurement system was applied to the electromagnetic levitation propulsion platform.]]></description>
<pubDate>2025/9/29 10:00:19</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[Jin Yuxin,,,]]></author>
</item>
<item>
<title><![CDATA[Effect of mode Ⅱ interlaminar fracture toughness on the tensile properties of Carbon/Glass hybrid composites]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202309120000001]]></link>
<description><![CDATA[Fiber hybridization is one of the effective means to improve the toughness and ductility of fiber-reinforced polymer matrix composites, hence avoiding their catastrophic brittle failure. The interlaminar fracture toughness is an important factor affecting the mechanical behavior of fiber hybrid composites. In this paper, two kinds of epoxy resins with different toughness, 7901 and 9A16, were used as the matrix. Interlayer carbon/glass hybrid composites with different numbers of carbon fiber layers were designed and manufactured. The effects of mode Ⅱ interlaminar fracture toughness (GⅡC) on the failure mode and mechanical properties of carbon/glass hybrid composites were investigated through both theoretical and experimental investigation. The results showed that, the higher mode Ⅱ interlaminar fracture toughness was, the more the carbon layer tended to fail in fragmentation, which was beneficial for achieving pseudo-ductility. In addition, the GⅡC on the modulus and strength of hybrid composites was marginal]]></description>
<pubDate>2025/9/29 9:59:25</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[陈丁丁,蒋俊,宋龙杰,唐俊,邢素丽,尹昌平,张发豪]]></author>
</item>
<item>
<title><![CDATA[Optimized design of stiffened panels considering the twist angle error of stringers]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202311280000004]]></link>
<description><![CDATA[To meet the requirements of lightweight and low error sensitivity in the optimization design of stiffened panels, the optimization design of stiffened panels is carried out considering the twist angle error of stringers. The finite element model of post-buckling instability of stiffened panels under axial compression was established, and the sensitivity of the load-carrying capacity to the twist angle error on stringers and the distribution characterisation of the torsional stringer was analyzed. At the same time, a sequential approximate optimization method based on surrogate model was proposed by using parallel sequential sampling strategy, and the lightweight design of stiffened panel was carried out under the influence of twist angle error of stringers. The optimal results show that, compared with the optimization design scheme without error influence, the optimization scheme considering the twist angle error of stringers has lower sensitivity to the twist angle error when the weight is reduced by more than 32%, which can effectively improve the reliability and engineering application value of the optimized structure.]]></description>
<pubDate>2025/9/29 9:48:52</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[雷勇军,LIU GUANRI,,于宝石,张大鹏]]></author>
</item>
<item>
<title><![CDATA[A sequence approximation optimization design method for remote guided rocket based on improved augmented radial basis functions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202407170000001]]></link>
<description><![CDATA[Long-range guided rockets have a long range and high power, and have been widely integrated into modern weapon and equipment systems, becoming one of the weapon systems that countries are competing to develop. Long-range guided rockets are complex systems composed of multiple subsystems, and multidisciplinary, nonlinear, and time-consuming characterize their design process. To improve the design performance of long-range guided rockets, a multidisciplinary parametric model of long-range guided rockets is first established to achieve high-precision performance simulation of guided rockets. Secondly, a sequence approximation optimization method based on an improved augmented radial basis function is proposed, which enhances the generalization ability of the augmented radial basis function model through anisotropic techniques. Recursive evolution experimental design and fast cross-validation are used to improve the efficiency of approximation modeling, and an imprecise search strategy is applied for sequence sampling. The effectiveness of the proposed optimization method is verified through numerical examples. Finally, a sequence approximate optimization design of the long-range guided rocket is carried out, and the maximum range increased by 16.7% compared to before optimization while satisfying design constraints.]]></description>
<pubDate>2025/9/29 9:48:22</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[蔡伟伟,,田镜文,,,]]></author>
</item>
<item>
<title><![CDATA[Optimization Methods for Key Elements in Intelligent Diagnosis of Open-Circuit Faults in Power Electronic Inverters]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202506270000001]]></link>
<description><![CDATA[To address the challenges of intelligent diagnosis for open-circuit faults in power electronic inverters, such as the lack of actual fault samples and the issue of varying characteristic adaptability, a set of optimization methods was proposed from two key intelligent elements: data and algorithm, to support the practical applications of intelligent diagnosis for open-circuit faults in power electronic inverters. For the data element, a fault sample amplification method based on inverters′ characteristics was proposed, which finds out the minimum number of practical samples required for model training. For the algorithm element, an attention-enhanced method and a frequency points adaptive training method for the diagnosis model were proposed, which significantly improve model training effectiveness and diagnosis accuracy under wide-frequency inverter operation. The effectiveness of the proposed optimization methods for the intelligent elements was validated by experiments.]]></description>
<pubDate>2025/9/29 9:44:33</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[黄永乐,李鑫,刘宾礼,罗毅飞,申皓澜,唐  欣]]></author>
</item>
<item>
<title><![CDATA[Fault detection technology for permanent magnet synchronous motor based on detection coil]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202409290000003]]></link>
<description><![CDATA[Permanent magnet synchronous motors are widely used in the field of propulsion motors due to their high efficiency, high torque density, and other advantages. This article focuses on the research of fault diagnosis methods for common stator turn short circuits and rotor eccentricity in surface mounted permanent magnet synchronous motors. Most existing methods are based on stator port voltage and current to extract fault features, but the aggregated parameter information obtained from the motor ports is easily affected by winding structure, pole slot coordination, and other factors, resulting in effective fault signals being overwhelmed and small information dimensions, leading to low signal-to-noise ratio and poor dynamic performance in detection.
In order to obtain internal magnetic field information that can directly characterize the state of the motor, and considering the compact structure of high-power density motors, this paper uses a flexible printed circuit board (FPCB) with small space occupation and a large number of turns to make a detection coil, and arranges it in the stator slot to capture magnetic field information. A fast fault diagnosis method based on fault feature extraction is proposed for inter turn short circuit and eccentricity faults. For mixed faults, decoupling of fault diagnosis cannot be achieved through simple coefficient correction. A fault discrimination scheme based on convolutional neural networks is proposed, and the performance of different types of learning methods is compared. The experimental results show that under mixed fault conditions, an accuracy evaluation of about 98% for inter turn short circuits is achieved, and the eccentricity detection error of AlexNet is only about 5% when the training data proportion is 60%.]]></description>
<pubDate>2025/9/29 9:39:21</pubDate>
<category><![CDATA[]]></category>
<author><![CDATA[huang wen,]]></author>
</item>
<item>
<title><![CDATA[Non-invasive Inductance Identification Method for Permanent Magnet Synchronous Motors Based on Virtual Voltage Vector Orientation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202410070000001]]></link>
<description><![CDATA[To achieve accurate and stable online identification of inductance parameters for permanent magnet synchronous motors (PMSMs), an online inductance observation method based on virtual voltage vector excitation and current differential response is proposed. Firstly, by introducing the concept of a virtual voltage vector–oriented coordinate system, it is analytically derived and proven that the d- and q-axis inductances of a PMSM can be observed independently of the angular position in the conventional d-q synchronous reference frame. The implementation procedure for extracting virtual voltage vectors and current differential information is discussed in detail, enabling non-intrusive inductance identification without any signal injection. The effectiveness and accuracy of the proposed method are validated by comparison with offline test procedures in IEEE standards.]]></description>
<pubDate>2025/9/29 9:38:04</pubDate>
<category><![CDATA[]]></category>
<author><![CDATA[周杨威,]]></author>
</item>
<item>
<title><![CDATA[Order-preserving triggering mechanism and data buffering method for collective communication hardware offloading]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503040000002]]></link>
<description><![CDATA[To further optimize the hardware offloading of collective communication based on the NIC(network interface card ) in the "Tianhe" network, and to support more types of collective communication algorithms and larger message sizes, this study investigated the order-preserving triggering mechanism and data buffering methods for collective communication hardware offloading was investigated. An order-preserving triggering mechanism for concurrent multitasking was proposed, which meets the desired semantics of collective communication and ensures the reproducibility of floating-point computation results. A dynamic network data buffering method based on hash tables and pulsed credit flow control was proposed to alleviate the contradiction between limited hardware buffering resources and the high demand for buffering a large amount of network data from concurrent multitasking. Experimental results show that compared with software-based collective communication operations, this workmethod can support the hardware offloading of various algorithms for several typical collective communication operations, with significant performance improvement. Meanwhile, the hardware implementation cost is low, especially with high utilization of buffering resources.]]></description>
<pubDate>2025/9/29 9:36:28</pubDate>
<category><![CDATA[专题：计算机系统与技术]]></category>
<author><![CDATA[徐金波,,]]></author>
</item>
<item>
<title><![CDATA[Online calibration algorithm of Vehicle-mounted SINS/1D-LDV Lever-Arm error]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501190000001]]></link>
<description><![CDATA[Aiming at the problem that the lever-arm velocity error between the measured speeds of one-dimensional Laser Doppler Velocimeter (1D-LDV) and Strapdown Inertial Navigation System (SINS) caused by their different installation positions in the vehicle-mounted integrated navigation systems composed of 1D-LDV and SINS, an online calibration algorithm based on Kalman filter is proposed to calibrate and compensate the mounting lever-arm. By introducing a reference point that maintains alignment between the velocity direction and the carrier's direction of motion during movement, the traditional lever-arm velocity error model was improved, so that it can accurately characterize the actual relationship between the measured velocities from the 1D-LDV and SINS. The vehicle experiment results show that the calibration algorithm can effectively calibrate the arm error between 1D-LDV and SINS. By using the 1D-LDV measured velocity (after lever-arm error compensation) and the gyroscopic data from the SINS to perform dead reckoning, the horizontal positioning errors in two experimental trials are reduced from 8.80 m and 6.60 m to 7.07 m and 5.48 m respectively, demonstrating a moderate improvement in navigation and positioning accuracy.]]></description>
<pubDate>2025/9/23 10:35:57</pubDate>
<category><![CDATA[光学前沿]]></category>
<author><![CDATA[Zhang Tao]]></author>
</item>
<item>
<title><![CDATA[Multi-scale learning algorithm for infrared UAV target detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202409280000001]]></link>
<description><![CDATA[Infrared cameras are suitable for complex environments, and the use of infrared images to detect black-flying UAV targets has important application value. Aiming at the problems such as small size of UAV target, few pixels in the image, weak texture detail information, and the difficulty of the algorithm to effectively extract the infrared UAV target features resulting in low detection accuracy, this paper proposes a target detection algorithm with multi-scale learning. By constructing a multi-scale feature fusion structure in the neck network of the model, introducing a multi-scale feature learning module, cascading the features of the deep network and the shallow network, acquiring the features of the target at multiple scales, enriching the semantic and feature information of the feature map, the algorithm significantly improves the accuracy of the detection of the target of small UAVs. The SIoU is used instead of the CIoU loss function in the training process, which minimizes the loss of the network model in the training process and improves the regression accuracy. The experimental results show that compared with other infrared small targets and mainstream detection algorithms, the method proposed in this paper can effectively improve the detection accuracy of UAV targets, and can meet the detection accuracy requirements for detecting UAV targets in practical applications.]]></description>
<pubDate>2025/9/15 18:51:50</pubDate>
<category><![CDATA[仪器科学与工程]]></category>
<author><![CDATA[ZuoZhen]]></author>
</item>
<item>
<title><![CDATA[Multi-scale learning algorithm for infrared UAV target detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202409280000001]]></link>
<description><![CDATA[Infrared cameras are suitable for complex environments, and the use of infrared images to detect black-flying UAV targets has important application value. Aiming at the problems such as small size of UAV target, few pixels in the image, weak texture detail information, and the difficulty of the algorithm to effectively extract the infrared UAV target features resulting in low detection accuracy, this paper proposes a target detection algorithm with multi-scale learning. By constructing a multi-scale feature fusion structure in the neck network of the model, introducing a multi-scale feature learning module, cascading the features of the deep network and the shallow network, acquiring the features of the target at multiple scales, enriching the semantic and feature information of the feature map, the algorithm significantly improves the accuracy of the detection of the target of small UAVs. The SIoU is used instead of the CIoU loss function in the training process, which minimizes the loss of the network model in the training process and improves the regression accuracy. The experimental results show that compared with other infrared small targets and mainstream detection algorithms, the method proposed in this paper can effectively improve the detection accuracy of UAV targets, and can meet the detection accuracy requirements for detecting UAV targets in practical applications.]]></description>
<pubDate>2025/9/11 16:44:36</pubDate>
<category><![CDATA[仪器科学与工程]]></category>
<author><![CDATA[ZuoZhen]]></author>
</item>
<item>
<title><![CDATA[Adaptive Active Disturbance Rejection Control Method for Linear Motor Parameters Based on Deep Reinforcement Learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501260000001]]></link>
<description><![CDATA[This study presents an adaptive active disturbance rejection control strategy integrating deep reinforcement learning (DRL) with enhanced particle swarm optimization (PSO), aiming to improve the speed and thrust control performance of permanent magnet synchronous linear motors (PMSLMs). A mathematical model of the motor was established to analyze its dynamic characteristics, followed by the design of a DRL-PSO (DRLPSO) control framework. This framework leverages reward mechanisms in reinforcement learning to interact with the environment, dynamically optimizing ADRC parameters to accommodate varying operating conditions and external disturbances. The modified PSO algorithm incorporates partitioned inertia weights and cyclically utilizes historical global optimal data to iteratively update control policies, refining neural network weights and thereby enhancing search efficiency and optimization accuracy. Experimental results show that the proposed DRLPSO-ADRC method achieves significantly higher tracking precision in position and velocity, along with improved system stability and resistance to thrust disturbances, compared to conventional PSO-ADRC algorithms. These findings validate the effectiveness of the innovative control strategy.]]></description>
<pubDate>2025/8/5 23:35:03</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[宋琳,,]]></author>
</item>
<item>
<title><![CDATA[Imaging Prior-Driven Super-Resolution for Object Detection under Oblique Views]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202506060000001]]></link>
<description><![CDATA[Object detection is a key technology for intelligent interpretation of remote sensing (RS) images. Existing object detection methods were primarily designed for nadir-imaging satellite RS images. Additionally, their insufficient utilization of imaging prior information makes them struggle to effectively address the significant object scale variations caused by UAV oblique imaging. To address the demand for high-accuracy object detection under oblique imaging perspectives, an imaging prior-driven super-resolution (IPSR) approach was proposed. An imaging distance model was established based on multiple parameters including camera focal length, flight altitude, and pitch angle, enabling the estimation of imaging distances at arbitrary positions in the image. Then, full-image adaptive SR reconstruction was performed based on distance estimation, effectively mitigating intra-image scale disparities under oblique imaging perspectives. Experiments on the UAV multi-view imaging dataset VSAI and satellite imagery dataset DOTA-v1.5 demonstrate that IPSR can be integrated with any mainstream object detection model. It significantly enhances the detection accuracy of these models under oblique imaging conditions (achieving gains of 6-7 mAP on VSAI and 3-4 mAP on DOTA-v1.5). Besides, it exhibits the versatility of the proposed method across multiple scenarios.]]></description>
<pubDate>2025/7/31 18:46:22</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李  璋,刘敏豪,裴云祥,滕锡超,王  堃,王  梓,于起峰]]></author>
</item>
<item>
<title><![CDATA[Interference avoidance beam planning method between NGSO constellation and GSO satellite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202409130000001]]></link>
<description><![CDATA[With the rapid expansion of non-geostationary satellite orbit (NGSO) constellation systems, spectrum resources have become increasingly congested. To address the issue of spectrum sharing between NGSO and geostationary satellite orbit (GSO) systems, this paper proposes an interference-avoidance beam planning method for spaceborne phased array antennas, based on spatial isolation zones. By analyzing interference scenarios between NGSO and GSO systems, the Earth’s surface is discretized into a grid based on latitude and longitude for uniform spatial enumeration. A time-sliced aggregate interference analysis model is then established to assess the interference from NGSO systems to segments of the GSO arc. Based on the interference-to-noise ratio (I/N) threshold criterion, an optimization objective for phased array antenna beam planning is formulated to facilitate spectrum sharing between NGSO and GSO systems. Furthermore, the mapping mechanism between spatial isolation zones and beamforming strategies is elucidated, leading to the proposed method for interference-avoiding beam planning. Simulation results validate the effectiveness of the approach, offering a valuable reference for the design and implementation of low Earth orbit (LEO) satellite constellations.]]></description>
<pubDate>2025/7/22 11:31:57</pubDate>
<category><![CDATA[专题：电磁空间资源智能认知与利用]]></category>
<author><![CDATA[高翔,,,,,]]></author>
</item>
<item>
<title><![CDATA[Application of robust Kalman filter to time-frequency system integrity monitoring]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202504210000001]]></link>
<description><![CDATA[In order to improve the sensitivity of time-frequency system integrity monitoring, a time-frequency system integrity monitoring method based on robust Kalman filter was proposed. In this method, a robust Kalman filter model is constructed using the historical measurement data of time difference, the time difference prediction bias and the frequency bias are estimated in real time, and the consistency detection is carried out separately, so that the integrity monitoring is realized. The model and method were verified through measured data and simulation analysis, and the results show that: this method can effectively detect and identify single faults of phase jump and frequency jump, and alarm the user; in a single fault scenario, compared with the traditional integrity monitoring method, the detection sensitivity is increased by about 25.0%; in a multi-fault scenario, the method can effectively detect faults, but there is a problem of insufficient fault identification, and the detection sensitivity is reduced by about 26.2% compared to a single fault, but it is still better than the traditional method.]]></description>
<pubDate>2025/7/22 11:27:40</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[GuoYu,,,]]></author>
</item>
<item>
<title><![CDATA[Autonomous online fault detection and diagnosis method for dual-axis RINSs in redundant configuration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202411040000002]]></link>
<description><![CDATA[To address the fault diagnosis challenges faced by inertial navigation systems on long-endurance naval vessels in underwater or other global navigation satellite system-denied environments, an autonomous online FDD(fault detection and diagnosis) algorithm for DRINSs(dual-axis rotational inertial navigation systems) in redundant configuration was proposed. The joint state equation was constructed based on the error states of two sets of DRINSs as the system state, and the residual-normalized strong tracking filter could be established based on geometric constraint observation between the two. Furthermore, the asynchronous rotation strategy for two sets of inertial navigation systems was designed. The gyro drifts and accelerometer biases of both systems were proved to be observable and they could be estimated separately. The modified Bayes FDD algorithm was constructed based on the estimation results of the error states. The fault confirmation stage was designed to improve the robustness of the algorithm. The experimental results demonstrate that the proposed algorithm can achieve the autonomous online diagnosis of inertial sensor faults, and the correct diagnosis rate is greater than 99%, which can effectively guarantee the reliability of navigation information for inertial navigation systems on long-endurance naval vessels.]]></description>
<pubDate>2025/7/9 11:28:11</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[梁钟泓,廖志坤,罗晖,牟鹏程,王林,王元涵]]></author>
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<title><![CDATA[Space Mission Design Industrial Software ATK 3.0: Development Progress and Technical Breakthroughs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202504020000003]]></link>
<description><![CDATA[Space mission design software spans the entire lifecycle of space missions and is regarded as the cornerstone of the aerospace industrial software system. Leveraging nearly three decades of technical expertise in the field of manned spaceflight, the research team from the National University of Defense Technology initiated the development of the indigenous software ATK (Aerospace Tool Kit) in 2020. By the end of 2024, the ATK 3.0 version was officially released, encompassing five major categories and 21 functional modules, including standard platform, visibility and coverage analysis, mission analysis, orbital design, and secondary development. The development of ATK has been deeply and continuously supported by China’s Manned Spaceflight Program, pioneering a collaborative research and development model characterized by "engineering-driven demand + centralized academic development." This software has had a significant impact in aerospace engineering, space security, and academic education, marking a solid first step toward replacing STK (Systems Tool Kit). This paper reviews the development history of ATK, elaborates on its functional features, and focuses on analyzing its breakthroughs in core technologies such as large-scale software architecture design, computational kernel development, and orbital maneuver planning. While ATK faces challenges in enhancing its functionality and building its application ecosystem, the paper outlines its future development roadmap and strategic objectives .]]></description>
<pubDate>2025/7/8 9:05:08</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[罗亚中,王  华,杨  震,周建平]]></author>
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<item>
<title><![CDATA[Research progress and prospect of atomic interference gyroscope]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202502050000002]]></link>
<description><![CDATA[As a representative of the next generation of gyroscopes , atomic gyroscopes have become a focal point of research in the field of high-precision inertial navigation and has garnered significant attention due to its theoretically ultra-high precision, exceptional long-term stability, and immense potential for miniaturization and integration. Among them, the atom interferometric gyroscope, as a type of atomic gyroscope, had attracted widespread interest in the field of inertial navigation.. The development of atomic interferometric gyroscopes was systematically reviewed. Beginning with fundamental principles, it elaborates on critical technical components including atomic source preparation, interferometric loop construction, and phase resolution. Through rigorous analysis, the paper establishes intrinsic correlations between core performance parameters such as sensitivity and ultimate accuracy while elucidating their mutual constraint mechanisms. Furthermore, it reveals the physical origins of engineering bottlenecks including limited data update rates and narrow dynamic ranges.?Finally, the article outlines future development directions and trends for atomic interference gyroscopes, emphasizing the need for in-depth research in several areas: solving external interference issues to improve accuracy,  improving chip processing technology for miniaturization and integration, enhancing combined inertial sensors, increasing data update rates, and exploring ways to expand dynamic range.]]></description>
<pubDate>2025/7/8 9:04:21</pubDate>
<category><![CDATA[光学前沿]]></category>
<author><![CDATA[王雨潇,]]></author>
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<title><![CDATA[Two-dimensional α-In2Se3 based Photodetectors for Tunable and Broadband Polarization Response via Thickness Regulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501060000004]]></link>
<description><![CDATA[A modified physical vapor deposition method for the controllable growth of α-In2Se3 was proposed, and the broad-spectrum response performance of three thicknesses of α-In2Se3 nanosheets in the visible to near-infrared wavelength range was systematically studied. The results indicate that the thickness of α-In2Se3 nanosheets can significantly regulate the photoelectric performance, and the photoresponsivity and specific detection rate increase with increasing thickness. In addition, it was found that the α-In2Se3 with a thickness of 32.8 nm exhibited a photocurrent anisotropy ratio (dichroic ratio) of 4 at 635 nm, indicating good polarization-sensitive detection functionality. In summary, the two-dimensional α-In2Se3 prepared by the physical vapor deposition method demonstrates a wide visible-infrared spectral response and good polarization detection ability, making it an ideal candidate material for two-dimensional multifunctional optoelectronic devices.]]></description>
<pubDate>2025/7/8 9:04:05</pubDate>
<category><![CDATA[光学前沿]]></category>
<author><![CDATA[高伟,李京波,舒胜,杨孟孟]]></author>
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<title><![CDATA[Vertical damping of the superconducting electrodynamic suspension system and its improving method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202308290000002]]></link>
<description><![CDATA[Due to the low damping characteristic of the superconducting electrodynamic suspension (EDS) system which may cause suspension instability problem, a six degree-of-freedom dynamic model for the high speed maglev sled system is established, and it is found that its suspension damping would become negative when the traveling speed exceeds 23.6 m/s, resulting in suspension instability to the maglev sled. The vertical damping ratio of the EDS system is calculated using the least square fitting method, and the relationship between the vertical damping and the speed is then obtained. To stablilize the suspension system, a distributed dynamic vibration absorbers (DVA) scheme is proposed, and the effects of the DVA parameters on the suspension stability are investigated; to minimize the influence of the DVA scheme on the acceleration performance of the maglev sled, the feasibility of applying low mass (≤ 1kg) DVAs to the maglev sled is disccussed; further, the vibration suppression effect of this scheme is investigated considering the vertical misalignments of guideway girders, which shows that the proposed scheme can significantly increase the damping and stability of the suspension system, and it also well suppresses the vibration of the sled-body caused by misalignments of the ground suspension coils. This scheme provides a useful reference for the design of the suspension system of the maglev sled system, the vaccum tube high speed maglev train, etc.]]></description>
<pubDate>2025/7/8 9:03:24</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈 强,李 杰,谭亦秋,王连春,周丹峰,朱鹏翔]]></author>
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<item>
<title><![CDATA[Detecting domain-specific social events via temporal evolution feature mining]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202307250000001]]></link>
<description><![CDATA[In view of the insufficient mining of implicit associative relationships and the problem of neglecting the temporal evolution factor, we propose a domain-specific social events detection method via temporal evolution feature mining. Our model divides data into slices by time, and takes duplicate event records from different sources into account which reflects the importance of events, and constructs entity interaction graph, which reduces the impact of database error. Multi-relational graph convolutional network is improved to update graph structure information of historical evolution sequence by interaction relationships. Attention mechanism is used to learn core features to obtain global embedding of sequence units. Implicit association is mined sufficiently. Based on recurrent neural network, temporal evolution features are extracted to obtain the global embedding and the temporal evolution factor is mined effectively. Experiment results show that our method can be applied to detection task, which is better than existing methods.]]></description>
<pubDate>2025/7/8 9:02:28</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[段嘉顺,潘岩,张鑫,赵东旭]]></author>
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<item>
<title><![CDATA[Reinforcement learning method via meta-learning the exploring latent variable]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202305210000001]]></link>
<description><![CDATA[The efficient online exploration of intelligent agents is important in reinforcement learning tasks, but still faces the problem of low utilization of interactive data with environment, or the need for additional tasks’ data. To solve this problem, an online exploration latent variable that obtained the characteristics of current task to assist the agents to behave was introduced. There was no need for additional multi-task data or additional environmental interaction steps in the current task. The exploring latent variable was updated in the learnable environment model, and the environment model underwent supervised updates based on the intelligent agent and real environment interaction data. The exploration in advance in the simulated environment model was assisted by the exploring latent variable, and thus the performance of agents in the real environment was improved. The performance in typical continuous control tasks was raised by about 30% in the experiments, which was of guiding significance for the single-task exploration and meta reinforcement learning research.]]></description>
<pubDate>2025/7/8 9:00:41</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李艺颖,周伟]]></author>
</item>
<item>
<title><![CDATA[Large language model-based legal defense document generation for power grid enterprises with data augmentation and rule guidance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412130000004]]></link>
<description><![CDATA[To enhance the ability of large language models to generate legal documents for the power grid sector under few-shot conditions, a few-shot legal document generation method based on large language models (LLM) was proposed, integrating data augmentation and rule guidance techniques. The proposed method addressed key challenges in power grid legal document generation, such as data scarcity, high domain specificity, and the complexity of legal practice. Experimental results show that the method achieves excellent performance in generating power grid legal defense documents, significantly improving the quality and professionalism of the generated texts.]]></description>
<pubDate>2025/7/8 8:58:24</pubDate>
<category><![CDATA[专题：人工智能]]></category>
<author><![CDATA[查小云,丁群晏,胡伟,黄成燕]]></author>
</item>
<item>
<title><![CDATA[Study on the Impact of Work Parameter Errors on the Correction Mechanism of Trajectory Correction Projectile Equipped with Lateral Impulses]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202409040000001]]></link>
<description><![CDATA[The lateral impulses, functioning as a correction mechanism, is subject to work parameter errors resulting from variations in product batches and storage conditions, which directly impact its striking accuracy. This study systematically measures the engine""s impulse, thrust, and operating time through static and dynamic tests, while also examining the effects of assembly errors, particularly radial eccentricity.Static test results indicate that radial eccentricity causes the thrust direction to deviate from the ideal ballistics, significantly reducing the accuracy of the work parameters. Dynamic tests confirm the continuous ignition characteristics under rotating projectile conditions, illustrating the substantial influence of pulse force on rotational speed.Ballistic simulation analysis further reveals that both radial eccentricity and thrust errors markedly diminish correction accuracy, adversely affecting the distribution characteristics of ballistic impact points. By integrating experimental and simulation findings, this research investigates the sensitivity of various work parameter errors to final impact point precision, providing essential data to optimize the design of pulse correction mechanisms. This work establishes a foundation for enhancing smart munitions control capabilities and advancing research in related fields.]]></description>
<pubDate>2025/7/1 17:35:04</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[XING BINGNAN]]></author>
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<item>
<title><![CDATA[A link noise correction method of two-way satellite time and frequency transfer through combination of hydrogen maser and cesium clock]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202410210000002]]></link>
<description><![CDATA[Due to the lack of strict periodicity in link noise of two-way satellite time and frequency transfer, when calculating the frequency drift of hydrogen atomic clocks through least squares fitting, some link noise will be included, resulting in bias in the calculation of link noise. Regarding this issue, the accurate frequency drift of the hydrogen atomic clock could be worked out by comparing the clock bias between the hydrogen and cesium clocks within the local timekeeping station. Furthermore, frequency drift of hydrogen clocks across different sites could be obtained. This method could reduce the impact of frequency drift on least squares fitting and obtain more accurate total noise data.The results indicate that this hydrogen-cesium joint two-way satellite time and frequency transfer noise correction method reduces the noise calculation deviation from 10ns to 0.3ns compared to the calculation method only relying on hydrogen atomic clocks, effectively improving the accuracy of link noise calculation.]]></description>
<pubDate>2025/7/1 15:00:06</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[lixiaoyi,]]></author>
</item>
<item>
<title><![CDATA[Effect of mechanical properties and temperature on impact ignition of PTFE/Al reactive material]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501100000001]]></link>
<description><![CDATA[To investigate the mechanical properties of Polytetrafluoroethylene/Aluminum (PTFE/Al) reactive materials and temperature effects on their impact ignition behavior, eight PTFE/Al reactive material specimens were fabricated through controlled sintering conditions. Stress-strain curves at varying temperatures were obtained using a universal testing machine, while impact ignition thresholds under corresponding temperatures were determined through drop-weight experiments. Experimental results demonstrated that sintering duration significantly influenced the elastic modulus of PTFE/Al composites, with elevated temperatures inducing material softening. At high-temperature conditions, specimens sintered for 40 min exhibited enhanced yield strength and demonstrated higher reactivity under drop-weight loading. Further analysis revealed a linear negative correlation between material strength and impact ignition thresholds under isothermal conditions, with the slope of this linear relationship exhibiting exponential decay as temperature increased. The findings of this study provide a significant theoretical foundation for the performance optimization and engineering applications of PTFE/Al reactive materials.]]></description>
<pubDate>2025/6/5 8:58:39</pubDate>
<category><![CDATA[力学]]></category>
<author><![CDATA[汤文辉,周敬辕]]></author>
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<title><![CDATA[Lightweight Photovoltaic Module Defect Detection with YOLOv8-DM]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412130000003]]></link>
<description><![CDATA[Given the challenges posed by photovoltaic component damage detection and the high demands placed on human and computational resources by existing detection technologies, an improved lightweight model named YOLOv8-DM was proposed based on YOLOv8n.  The integration of  Electroluminescence imaging with object detection methods was implemented to achieve PV defect detection. Innovative components were introduced, including a Dynamic Scale Feature Pyramid Network  and an Inverted Residual Multiscale Attention Mechanism, along with a Ghost module enhanced by dynamic convolution. These modifications were specifically designed to address the deficiencies observed in the YOLOv8n model regarding feature representation and multiscale object recognition, which enhanced fine-grained detection capabilities and reduced computational complexity. When evaluated on the augmented PVEL-AD dataset, the model demonstrated an improvement of 3% in recall rate and 3.3% in mAP50 compared to the baseline model, with a 34% reduction in parameter count and a 20% decrease in computational demand. The optimized architecture was validated to effectively meet the practical requirements for high-accuracy PV defect detection with lower computational costs.]]></description>
<pubDate>2025/6/5 8:57:42</pubDate>
<category><![CDATA[专题：人工智能]]></category>
<author><![CDATA[Yang Wei,]]></author>
</item>
<item>
<title><![CDATA[Multi-robot Dynamic Visualization Research Platform Based on Three-wheeled Omnidirectional Mobile Robot]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503100000001]]></link>
<description><![CDATA[To better investigate the complex collective behaviors in distributed collaborative robots, a multi-robot dynamic visualization research platform based on three-wheeled omnidirectional mobile robot is designed. The purpose of the platform is to provide an intuitive and flexible experimental environment for promoting the testing and development of multi-robot algorithms. The platform was composed of self-developed, low-cost, small, omnidirectional wheeled mobile robots and visual multi-touch screens that supported gesture recognition and shape detection of objects placed on them, enabling the configuration of various dynamic rendering scenarios. With this platform, researchers are able to focus on the design and optimization of algorithms in multi-robot systems without being limited to specific scenarios or task settings. The robot's motion performance was tested, and multi-robot algorithms were successfully tested in multiple task scenarios, initially validating the platform's effectiveness and flexibility.]]></description>
<pubDate>2025/6/5 8:50:25</pubDate>
<category><![CDATA[专题：人工智能]]></category>
<author><![CDATA[朱鹏铭]]></author>
</item>
<item>
<title><![CDATA[Asymmetric Actor-Critic Reinforcement Learning Method for Long-Sequence Autonomous Manipulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412160000001]]></link>
<description><![CDATA[Long-sequence autonomous manipulation capability becomes one of the bottlenecks hindering the practical application of intelligent robots. To address the diverse long-sequence operation skill requirements faced by robots in complex scenarios, an efficient and robust asymmetric Actor-Critic reinforcement learning method was proposed. This approach aims to solve the challenges of high learning difficulty and complex reward function design in long-sequence tasks. By integrating multiple Critic networks to collaboratively train a single Actor network, and introducing GAIL (generative adversarial imitation learning) to generate intrinsic rewards for the Critic network, the learning difficulty of long-sequence tasks was reduced. On this basis, a two-stage learning method was designed, utilizing imitation learning to provide high-quality pre-trained behavior policies for reinforcement learning, which not only improves learning efficiency but also enhances the generalization performance of the policy. Simulation results for long-sequence autonomous task execution in a chemical laboratory demonstrate that the proposed method significantly improves the learning efficiency of robot long-sequence skills and the robustness of behavior policies.]]></description>
<pubDate>2025/6/5 8:48:32</pubDate>
<category><![CDATA[专题：人工智能]]></category>
<author><![CDATA[瞿宇珂,卢惠民,罗嘉威,倪子淇,RenJunkai,]]></author>
</item>
<item>
<title><![CDATA[A review of diffusion models for inverse problems in image processing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412140000001]]></link>
<description><![CDATA[Diffusion models represent a novel type of generative artificial intelligence models. Compared to traditional networks such as Generative Adversative Networks, Variational Autoencoders, and Flow models, diffusion models are characterized by their robust training, high fidelity and diversity in generation, and strong mathematical interpretability, and so they have been widely applied in fields of computer vision, signal processing, multi-modal learning and so on. Diffusion models are capable of sufficiently learning and exploring the deep generative priors from the training images, providing a novel paradigm for solving inverse problems in image processing. To systematically review the current developments of diffusion models, particularly the latest advancements in solving inverse problems in image processing, this paper provides a comprehensive survey on diffusion models for inverse problems in image processing. We firstly present its fundamental principles and recent developments, and then emphasize the introduction on the primary technical approaches as well as our specific application achievements for solving inverse problems in image processing. Finally, we outline the future research directions.]]></description>
<pubDate>2025/6/5 8:47:20</pubDate>
<category><![CDATA[专题：人工智能]]></category>
<author><![CDATA[WANG Zelong,,]]></author>
</item>
<item>
<title><![CDATA[Partial-CLEAN Integration Algorithm for Aeroacoustics Source Region]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412110000003]]></link>
<description><![CDATA[Source region integration algorithm is a kind of data processing method to extract noise characteristics of each component in wind tunnel test model. To solve the interference problem of integration results caused by sound source sidelobe outside the target integration, a Partial-CLEAN integration algorithm is proposed. This algorithm divides the model region into target and non-target regions, and uses the CLEAN algorithm to find the strongest sound source positions at each frequency point in the non-target region. It iteratively removes interference from non-target region sound sources on the target region, thereby achieving more accurate integration results. Through simulation and wind tunnel test data analysis, the Partial-CLEAN integration algorithm can effectively separate mutually interfering noise sources, especially sound sources of 3kHz and below, extract more accurate target sound sources, and provide a new tool for aerodynamic noise analysis.]]></description>
<pubDate>2025/6/4 16:38:47</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[范正磊,,赵佳钐]]></author>
</item>
<item>
<title><![CDATA[Convolutional Neural Network Mixed-Precision Quantization Considering Layer Sensitivity]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501100000003]]></link>
<description><![CDATA[To address the problem of how to faithfully map neural networks to resource-constrained embedded devices, a mixed-precision quantization method for convolutional neural networks based on layer sensitivity analysis is proposed. The sensitivity of convolutional layer parameters is measured by calculating the average trace of the Hessian matrix, providing a basis for bit-width allocation. A layer-wise ascending-descending approach is employed for bit-width allocation, ultimately achieving mixed-precision quantization of the network model.Experimental results demonstrate that compared to the fixed-precision quantization methods DoReFa and LSQ+, the proposed mixed-precision quantization method improves recognition accuracy by 10.2% and 1.7%, respectively, at an average bit-width of 3 bits. When compared to other mixed-precision quantization methods, the proposed approach achieves over 1% higher recognition accuracy. Additionally, noise-injected training effectively enhances the robustness of the mixed-precision quantization method, improving recognition accuracy by 16% under a noise standard deviation of 0.5.]]></description>
<pubDate>2025/6/4 16:33:23</pubDate>
<category><![CDATA[专题：人工智能]]></category>
<author><![CDATA[刘海军,,]]></author>
</item>
<item>
<title><![CDATA[HEO Satellite Synchronous Belt Surveillance Mission Architecture and Orbital Maneuver Co-Design: An ATK-Powered Integrated Framework]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412310000002]]></link>
<description><![CDATA[non-coplanar flyby is an effective method for monitoring important satellites in geosynchronous orbits. Taking the scenario of patrollong the geosynchronous belt with an elliptical orbit as an example,the paper proposed a method for solving the minimal orbital intersection distance(MOID) between any two elliptic orbits,proving that the optimal flyby point for the patrollong satellite is the Asending Node.The paper used ATK to model the mission scenario,investigating the variations in the optimal flyby point position in J2 gravitational model.The paper studied the variations in terminal constraints such as relative distance and sun phase angle at flyby point in the situation of different local times and different flyby directions.The paper proposed a transfer strategy that satisfies the maximum transfer time and terminal constraints,using the Astrogator in ATK,the mission parameters for the mission under different gravitational model assumptions are solved.The paper analyzed mission parameter corresponding to different true anomaly angles in two-body model,validating the effectiveness of the strategy and providing a basis for planning multiple patrol sequences.]]></description>
<pubDate>2025/6/4 16:32:40</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[lilinhong,梁彦刚]]></author>
</item>
<item>
<title><![CDATA[Optimization Design of Emergency Observation Constellation: Application of ATK Secondary Development Technology]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202501170000001]]></link>
<description><![CDATA[Due to the limitations of the number of satellites, scale and manoeuvrability, it is difficult for the existing earth observation constellations to respond quickly to emergency needs of a high degree of randomness. In order to meet the demand for rapid design of emergency earth observation constellations, an emergency earth observation constellation design method was proposed. Based on the secondary development and coverage analysis function of the Aerospace Tool Kit, the method adopted a one-dimensional data hierarchical clustering method to group ground targets, and then applied the differential evolution algorithm to optimize the restricted walker subconstellation configuration for the target groups, and finally generated the restricted hybrid walker earth observation constellation. Simulation results demonstrate that the method can rapidly generate emergency constellations compared with conventional walker constellations and violent optimisation results, and minimize satellite deployment quantity while ensuring the effective completion of the earth observation mission.]]></description>
<pubDate>2025/6/4 16:32:06</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[郭帅,,,,]]></author>
</item>
<item>
<title><![CDATA[A Fault Sidebands Cluster Penalized Regression Extraction Method for Health Monitoring of Gear Transmission Systems]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202410170000003]]></link>
<description><![CDATA[Gear faults manifest in the frequency spectrum as multi-order modulation sideband clusters centered on the meshing frequency and its higher-order harmonics, spaced by the gear rotation frequency. In order to automatically focus the fault side frequency components, a method of fault side frequency cluster extraction with penalty regression was proposed. The Adaptive sparse group lasso (ASGL) regression self-data-driven strategy was used to determine the penalty coefficient and update the spectrum weight online to find the fault sideband clusters. Based on the sideband weight coefficients obtained from Sparse Group Lasso (SGL) regression, a new index called the Sparse Group Lasso Sidebands Indicator (SSI) was proposed for the health monitoring of gear transmission systems, enabling the early fault warning and location of gear transmission systems. The results show that the proposed method can provide more accurate early fault detection and fault location results.]]></description>
<pubDate>2025/6/3 16:18:17</pubDate>
<category><![CDATA[专题：人工智能]]></category>
<author><![CDATA[黄宇昊,Kong Detong,,李鑫宇,刘超,张乐平]]></author>
</item>
<item>
<title><![CDATA[Combinatorial enumeration and time-interval contrastive learning for sequential recommendation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202410280000004]]></link>
<description><![CDATA[To address the problem of inadequate self-supervised signal quality in contrastive learning models for sequential recommendation, a combinatorial enumeration and time-interval contrastive learning model was proposed. The model generated enhanced sequences which preserved temporal information through time-interval perturbation-based data augmentation. A combinatorial enumeration strategy was introduced to integrate user behavior and time-interval information, constructing multi-view augmented sequence pairs. The model employed a multi-head attention mechanism to encode user behavior sequences and optimized self-supervised signals through multi-task joint training, which improved overall performance. The proposed model is well-suited for scenarios with high data sparsity and uneven interaction behaviors, effectively addressing challenges in self-supervised signal modeling. Experimental results on three real-world datasets demonstrate that the model outperforms state-of-the-art contrastive learning models in terms of Hit Ratio (HR) and Normalized Discounted Cumulative Gain (NDCG). Specifically, HR@5 and NDCG@5 improve by 5.61% and 8.53%, respectively.]]></description>
<pubDate>2025/6/3 16:17:49</pubDate>
<category><![CDATA[专题：人工智能]]></category>
<author><![CDATA[zhangwenxuan,]]></author>
</item>
<item>
<title><![CDATA[A research review of graph reinforcement learning algorithms and their applications in the industrial field]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412150000001]]></link>
<description><![CDATA[Successful application of reinforcement learning in decision support, combinatorial optimization, and intelligent control has driven its exploration in complex industrial scenarios. However, existing reinforcement learning methods face challenges in adapting to graph-structured data in non-Euclidean spaces. Graph neural networks have demonstrated exceptional performance in learning graph-structured data. By integrating graphs with reinforcement learning, graph-structured data was introduced into reinforcement learning tasks, enriching knowledge representation in reinforcement learning and offering a novel paradigm for addressing complex industrial process problems. the research progress of graph reinforcement learning algorithms in industrial domains was systematically reviewed, summarized graph reinforcement learning algorithms from the perspective of algorithm architecture and extracted three mainstream paradigms, explored their applications in production scheduling, industrial knowledge graph reasoning, industrial internet, power system and other fields, and analyzed current challenges alongside future development trends in this field.]]></description>
<pubDate>2025/6/3 16:17:17</pubDate>
<category><![CDATA[专题：人工智能]]></category>
<author><![CDATA[李大字,,]]></author>
</item>
<item>
<title><![CDATA[Intention recognition for forced motion of the space non-cooperative target based on BiGRU network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202411050000001]]></link>
<description><![CDATA[In order to solve the problem that it is difficult to identify the forced motion intention of non-cooperative targets, An intention recognition method based on BiGRU network was proposed in this paper. The non-cooperative target was categorizes into five forced motion intentions: "Forced Round Fly-Around", "Forced Drip-drop Fly-Around", "Fixed-point Oscillating", "Line Approach" and "Hop Approach", and the forced motion intention maneuver information dataset of the non-cooperative target was established. Based on the maneuver time series information of the non-cooperative target after entering the observation range of our spacecraft, the BiGRU network was utilized to train on the potential correlation between the time series data and the forced motion intention, so as to realize the intention recognition of the non-cooperative target. The simulation results demonstrated that the detection accuracy of the BiGRU network-based forced motion intention recognition method for non-cooperative targets achieved 98.35%. This method can improve the ability to identify the intentions of non-cooperative targets and provide a technical reference for the safety of our spacecraft in orbit.]]></description>
<pubDate>2025/6/3 16:16:45</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[黄贺祥,]]></author>
</item>
<item>
<title><![CDATA[Mission planning and independent software design of spacecraft rendezvous and proximity operations]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202410280000002]]></link>
<description><![CDATA[Aiming at the lack of universal software for spacecraft RPO (rendezvous and proximity operations) mission planning, the RPO planning model and software were studied. The concept of RPO element was proposed, and an element system was constructed, which consists of four categories: rendezvous, proximity, companion flight, and departure. RPO missions could be formed by combining multiple elements. A mission planning model for RPO elements was established. Calculation formulas for the mission control segments, stop conditions, control parameters, and constraints were provided. Based on the ATK (aerospace tool kit), a RPO mission planning tool was designed and implemented. Simulations were conducted using examples of GEO rendezvous and sun synchronous fly around, and the results show that the established RPO elements and software can effectively design RPO missions.]]></description>
<pubDate>2025/6/3 8:29:09</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[王华,于大腾]]></author>
</item>
<item>
<title><![CDATA[Dual-path neural network learning method for free-return orbit integrating dynamic characteristics]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202503280000003]]></link>
<description><![CDATA[The free-return orbit serves as the preferred orbital scheme for crewed spacecraft in Earth-Moon transfers, yet its design involves stringent constraints and significant initial-value dependency in existing algorithms. This study addresses the Earth-Moon transfer trajectory planning for manned lunar exploration by proposing a dual-path neural network learning method to optimize free-return orbit initialization. First, a free-return orbit design framework is established, and the near-earth solution space characteristics are analyzed. Second, integrating the spatial partitioning characteristics of ascending and descending orbital phase in solution spaces, a dual-path neural network architecture designed via parameter-correlated transformation is proposed to ensure the completeness of orbital solutions. Finally, utilizing astromaster of Aerospace Tool Kit, the Earth-Moon free-return orbit planning under the dual-path network learning-based initialization method is implemented and validated through simulation. The results provide an effective reference for mitigating initial-value dependency in manned lunar mission orbit design.]]></description>
<pubDate>2025/5/27 15:54:11</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[李海阳,,,,Zhu Binyu]]></author>
</item>
<item>
<title><![CDATA[Mix variational mode decomposition long short-term memory for predicting of reservoir surface displacement and deformation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202304100000001]]></link>
<description><![CDATA[In order to improve the prediction accuracy of the displacement and deformation of YANFGHE reservoir, the displacement and deformation of non-linear and non-stationary reservoir was predicted by changing the decomposition method of VMD(variational mode decomposition) and integrating VMD and LSTM (long short-term memory). A MVMDLSTM (mixed variational mode decomposition long short-term memory) model prediction method was proposed.   The reliability of the new method was analyzed by comparing different single prediction models with the combined model and different data sets. The experimental results show that the MVMDLSTM model can effectively attenuate the bias of the single prediction model and the empirical mode decomposition combination model estimation, and the prediction accuracy of the MVMDLSTM model is better, which provides an effective data decision-making for the stabilization and monitoring of the prediction and warning of the reservoir"s slow sliding and creeping and other small deformations.]]></description>
<pubDate>2025/5/26 8:17:39</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈红康,贺小星,鲁铁定,孙喜文,王海城]]></author>
</item>
<item>
<title><![CDATA[Anti-off-target control of target tracking for small video satellite based on field of view zoning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202310120000002]]></link>
<description><![CDATA[An anti-off-target control method for small video satellite target tracking based on visual field zoning was proposed to address the problem of high initial relative angular velocity between small video satellite and observation targets, which can easily deviate from the camera field of view and cause off target. This method divided the rectangular imaging field of the satellite camera into inner and outer parts according to the inscribed circle. The inner and outer parts of the inscribed circle were designed with tracking controllers based on potential function and Euler rotation method respectively. By using the Barbarat‘s lemma, the asymptotic stability of control laws in two parts was proved, and it was also proved that the potential function controller can ensure that target would not leave the inscribed circle of visual field after entering it. Through controller comparison and simulation, the results show that the Euler rotation method has a stronger ability to suppress target deviation from the field of view compared with PD control. Compared with the full Euler rotation method, the field of view partition control combining the Euler rotation method and potential function method can effectively achieve anti-off-target control for faster maneuvering targets, thereby achieving continuous tracking and observation.]]></description>
<pubDate>2025/5/26 8:13:16</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[Fan Caizhi,,,]]></author>
</item>
<item>
<title><![CDATA[theoretical analyses and simulations of the pulsed LDV]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212130000003]]></link>
<description><![CDATA[Continuous-wave laser Doppler velocimeters (LDV) are limited in low-altitude velocity measurement due to factors such as the low power of continuous-wave lasers and optical system diffraction. By introducing the concept of "virtual distance" to expand the feuillet? model, the time-domain echo signal model for pulsed LDV has been established. Simulation results indicate that pulsed LDV can perform velocity measurement through the accumulation of hard target echo signals. Pulsed LDV can also utilize longer laser pulse widths for detection without restricted by spatial resolution. this paper verifies the feasibility of high-precision velocity measurement using long pulses with pulsed LDV, laying a theoretical foundation for future experimental validation of the pulsed LDV. Pulsed LDV is capable of detecting echo signals scattered from targets at 5 km and beyond, significantly extending the working distance range of LDV. This makes LDV applicable in integrated navigation of low-altitude aircrafts and planetary surface landing navigation for spacecrafts.]]></description>
<pubDate>2025/5/26 8:12:53</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[陈兰剑,金世龙,周健]]></author>
</item>
<item>
<title><![CDATA[Spatial-temporal encoder-decoder model for traffic flow prediction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302130000003]]></link>
<description><![CDATA[Traffic flow prediction plays a crucial role in alleviating traffic congestion. Many research methods did not fully explore dynamic hidden correlations in traffic data. To address this challenge, an encoder-decoder-based traffic prediction model was proposed by studying the dynamic spatio-temporal variation characteristics. In the model, both encoder and decoder mainly consisted of multi-head spatio-temporal attention mechanism modules, and a connection attention mechanism was added in between to analyze the spatio-temporal correlations of the road network. The model also used a dynamic embedding module consisting of a combination of both spatio-temporal embedding coding and adaptive graph convolution to analyze the dynamic and static information of nodes. Experiments on two real datasets demonstrated that the spatio-temporal model outperformed the baseline model for long- and short-term traffic prediction. Thus, the spatio-temporal encoder-decoder model can effectively handle complex spatio-temporal sequences and improve the traffic flow prediction accuracy.]]></description>
<pubDate>2025/5/26 8:12:34</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[张锦]]></author>
</item>
<item>
<title><![CDATA[Online Map Generation Method from Remote Sensing Images via Semi-supervised Adversarial Learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202405110000001]]></link>
<description><![CDATA[In the existing remote sensing image generation online map methods, the most common method is based on the fully supervised learning model or unsupervised learning model. To address the resource consumption issue of obtaining precise paired samples in existing fully supervised learning, while also considering the quality of network map generation, a novel semi-supervised online map generation model based on generative adversarial networks was proposed, which aimed to realize the direct generation of intelligent remote sensing images into network maps by using only a few precisely matched data and a large amount of unpaired data. In addition, a semi-supervised learning strategy based on transformation consistency regularization and sample enhanced consistency was designed, which overcomed the inconsistency problem caused by imprecise paired data and derives better generalization performance of the model. Adequate comparison experiments were conducted on different map datasets. The generated online maps outperform the competing methods on the quantitative metrics and visual quality, which validate the effectiveness and speed of semi supervised network map generation methods.]]></description>
<pubDate>2025/5/26 8:12:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[Wu Jiangjiang]]></author>
</item>
<item>
<title><![CDATA[Analysis on the thrust characteristics of flexible deformable self-pressurized water rocket]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202301200000001]]></link>
<description><![CDATA[Since the thrust characteristics directly affect the launch speed, altitude and flight range of the water rocket, in order to improve the thrust performance of the water rocket, a flexible and deformable self-pressurized elastic air pressure cabin scheme was designed based on the existing fixed volume pressure chamber, and its performance was evaluated. With Bernoulli"s theorem and deformation coordination relation, a coupled model of internal pressure, nozzle velocity and thrust of water rocket was established. Moreover, the influence of different initial states (water volume ratio and inflation air pressure) on water rocket thrust was also studied with the numerical calculation method, and the thrust difference was compared and analyzed further between the fixed air pressure cabin and the elastic air pressure cabin under the same initial conditions. The research results show that the improved flexible and deformable self-pressurized elastic air pressure cabin could effectively increase the water jet velocity during the launch, and the thrust generated by the water rocket in the same initial state increases significantly by 46.95%. Important reference for improving the flight performance of water rockets and the optimal design of new flexible deformation water rocket scheme is provided.]]></description>
<pubDate>2025/5/26 8:12:04</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[丁少哲,刘龙斌,张士峰]]></author>
</item>
<item>
<title><![CDATA[Stability analysis and simulation of transverse mode-coupled self-excited vibration of rocket]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202308150000003]]></link>
<description><![CDATA[In order to study the self-excited vibration of rocket in the flight test, a two-degree-of-freedom linear system based on the coupling of elastic force and aerodynamic force was established, and the displacement feedback between pitch and yaw degree-of-freedom maked the system obtain energy from the outside and cause the self-excited vibration. By analyzing the stability of the motion equation of the system, the criterion of losing asymptotic stability of equilibrium point and generating self-excited vibration was obtained. The time history curves of pitch and yaw angular displacement were obtained by solving ordinary differential equations with Runge-Kutta method. The comparison between the simulation results and the measured data shows that the vibration divergence phenomenon during the flight of rocket is the mode-coupling self-excited vibration caused by displacement feedback. In addition, the analysis results show that the beat or constant frequency vibration usually occurs before and after the self-excited vibration.]]></description>
<pubDate>2025/5/26 8:11:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[高峰,商霖,宋志国,孙向春,张海瑞]]></author>
</item>
<item>
<title><![CDATA[Anomaly detection based on graph neural network for multivariate time series with missing data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202312030000002]]></link>
<description><![CDATA[Addressing the issue of anomaly detection on missing multivariate time series data in real IoT（Internet of things） environments, a novel method on multivariate time series anomaly detection algorithm intergrated with graph embedding of missing information was proposed. Using a joint learning framework of pre-interpolation and anomaly detection task fusion, a GNN（graph neural network） pre-interpolation module based on time series Gaussian kernel function was designed to realize the joint optimization of pre-interpolation and anomaly detection task. A graph structure learning method for embedding missing information in time series data was proposed, using graph attention mechanism to fuse missing information masking matrix and spatiotemporal feature vectors, effectively modeling the potential connections of missing data distribution in multivariate time series. The performance of the algorithm was verified on real IoT sensor datasets. Experimental results prove that the proposed method significantly outperform the mainstream two-stage methods on the task of missing multivariate time series anomaly detection. The comparative experiment of the pre-interpolation module fully prove the effectiveness of the GNN pre-interpolation layer based on the Gaussian kernel function.]]></description>
<pubDate>2025/5/26 8:11:26</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[Gao Yang,,,,]]></author>
</item>
<item>
<title><![CDATA[Intelligent attitude control method of launch vehicle during the ascending phase considering load reduction in high wind zone]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412130000001]]></link>
<description><![CDATA[To address the aerodynamic load reduction requirement when the launch vehicle flying in high wind zone during the ascending phase, an intelligent attitude control method with adaptive learning rate is proposed. Taking a certain type of launch vehicle as the research object, the dynamic model in the pitch plane is established. A deep reinforcement learning framework suitable for flight control of the launch vehicle during the ascending phase is developed based on soft Actor-Critic (SAC), and a reward function that comprehensively considers control accuracy, control system stability, and load reduction effectiveness is designed. On this basis, an adaptive iteration of learning rate is implemented based on a step-size learning rate scheduler to quickly improve the convergence of the controller, and an early stopping mechanism which can automatically end the training process is designed to enhance training efficiency. Simulations show that the proposed method can effectively improve load reduction performance of the launch vehicle while ensuring attitude tracking accuracy and control system stability. Additionally, it has strong adaptability and generalization ability to external uncertain disturbances.]]></description>
<pubDate>2025/4/10 11:11:45</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[Zhou Shou]]></author>
</item>
<item>
<title><![CDATA[Research on the influences of motion characteristics of JPC under water]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303080000003]]></link>
<description><![CDATA[This paper uses LS-DYNA finite element analysis software and is based on JPC water penetration tests to investigate the effect of liner parameters (wall thickness, material), charge aspect ratio on the movement characteristics of JPC in water. It has been shown that the head diameter of the JPC becomes larger and produces mass erosion after entering the water, and there are two phases in the effective length of the JPC in the water, including the growth phase and the decrease phase, and the velocity of the JPC decays exponentially. Increasing the thickness of the liner and the charge aspect ratio will improve the erosion resistance and the velocity storage capacity of the JPC. The optimum range of values for the thickness of liner is in the ranges of 0.036D<sub>k</sub> to 0.055 D<sub>k</sub>. After a charge aspect ratio higher than 1.25, the charge structure has less effect on the movement characteristics of the JPC in water. The density of the material has an important influence on the velocity decay pattern of the JPC during water penetration, The ability of a JPC with a high density to store velocity in water, with the velocity decay pattern converging if the densities are similar. The higher density of the JPC has the greater the ability to store velocity in water, and if the densities are similar the velocity decay pattern tends to be the uniform. The copper, tantalum and tungsten liners are suitable for use in the underwater shaped charge warhead.]]></description>
<pubDate>2025/4/10 11:10:51</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈兴,卢永刚,张存旺]]></author>
</item>
<item>
<title><![CDATA[Free vibration characteristics analysis of FG-CNTRC Kirchhoff plates on viscoelastic substrates in a thermal environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302220000003]]></link>
<description><![CDATA[FG-CNTRC demonstrate significant engineering value in advanced equipment manufacturing due to their exceptional mechanical properties and designable characteristics. The critical problem of nano-reinforcement scale effects on mechanical response mechanisms was addressed through integration of nonlocal theory with the Eshelby-Mori-Tanaka method, resulting in the development of a nano-to-macro multiscale constitutive model. Based on mathematical characterization of spatially gradient-distributed CNTs, thermo-mechanical coupling effects from environmental temperature and visco-Pasternak foundations were incorporated. Vibration governing equations for nanocomposite structures were established through Kirchhoff plate theory and energy variational principles, with characteristic frequencies of simply-supported plates subsequently solved. The influence mechanisms of CNTs" characteristic parameters and thermo-mechanical coupling effects on the natural frequency of structural systems was analyzed. The results demonstrate that the constitutive model effectively characterizes the stiffness-weakening effect induced by CNTs" scale effects. This effect simultaneously suppresses the stiffness enhancement from matrix elastic parameters while significantly increasing sensitivity to temperature variations. Moreover, the critical volume fraction for structural reciprocating vibration shows positive correlation with matrix damping parameters.]]></description>
<pubDate>2025/4/10 11:09:02</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[雷勇军,吴栋,于宝石,张大鹏]]></author>
</item>
<item>
<title><![CDATA[Few-shot Space Target Recognition Method Based on Adaptive Cross Fusion of Local Features]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202304280000002]]></link>
<description><![CDATA[In the few-shot recognition scenario of space targets observed at low frequency, the drastic changes in the image representation of space targets in different poses pose challenges to the extraction of discriminative features and the correlation of features between images. To address these issues, the few-shot space target recognition method based on adaptive cross fusion of local features was proposed. Based on the existing few-shot learning framework, the feature cross fusion module based on self-attention and cross-attention is used to adaptively learn the correlation between local features, improve the discriminant and robustness of feature in different poses, effectively explore the similarity between the support set and the query set, and improve the accuracy of feature association with representation differences. Meanwhile, the sample label weight based on neighborhood density is employed into the loss function to solve the learning bias problem of the network model caused by unbalanced space target datasets. Through the verification on different datasets, the proposed method is proved to achieve higher recognition accuracy．]]></description>
<pubDate>2025/4/10 11:07:37</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[王壮,谢文茜]]></author>
</item>
<item>
<title><![CDATA[Anti-off-target control of target tracking for small video satellite based on field of view zoning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202310120000002]]></link>
<description><![CDATA[An anti-off-target control method for small video satellite target tracking based on visual field zoning was proposed to address the problem of high initial relative angular velocity between small video satellite and observation targets, which can easily deviate from the camera field of view and cause off target. This method divided the rectangular imaging field of the satellite camera into inner and outer parts according to the inscribed circle. The inner and outer parts of the inscribed circle were designed with tracking controllers based on potential function and Euler rotation method respectively. By using the Barbarat‘s lemma, the asymptotic stability of control laws in two parts was proved, and it was also proved that the potential function controller can ensure that target would not leave the inscribed circle of visual field after entering it. Through controller comparison and simulation, the results show that the Euler rotation method has a stronger ability to suppress target deviation from the field of view compared with PD control. Compared with the full Euler rotation method, the field of view partition control combining the Euler rotation method and potential function method can effectively achieve anti-off-target control for faster maneuvering targets, thereby achieving continuous tracking and observation.]]></description>
<pubDate>2025/4/10 11:06:42</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[Fan Caizhi,,,]]></author>
</item>
<item>
<title><![CDATA[Intelligent attitude control method of launch vehicle during the ascending phase considering load reduction in high wind zone]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202412130000001]]></link>
<description><![CDATA[To address the aerodynamic load reduction requirement when the launch vehicle flying in high wind zone during the ascending phase, an intelligent attitude control method with adaptive learning rate is proposed. Taking a certain type of launch vehicle as the research object, the dynamic model in the pitch plane is established. A deep reinforcement learning framework suitable for flight control of the launch vehicle during the ascending phase is developed based on soft Actor-Critic (SAC), and a reward function that comprehensively considers control accuracy, control system stability, and load reduction effectiveness is designed. On this basis, an adaptive iteration of learning rate is implemented based on a step-size learning rate scheduler to quickly improve the convergence of the controller, and an early stopping mechanism which can automatically end the training process is designed to enhance training efficiency. Simulations show that the proposed method can effectively improve load reduction performance of the launch vehicle while ensuring attitude tracking accuracy and control system stability. Additionally, it has strong adaptability and generalization ability to external uncertain disturbances.]]></description>
<pubDate>2025/4/10 11:04:56</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[Zhou Shou]]></author>
</item>
<item>
<title><![CDATA[Multi-round Social Advertising Sequence Influence Maximization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202410300000002]]></link>
<description><![CDATA[Existing research on sequential ad recommendations mainly focuses on user preferences for ads, insufficiently considering positive relationships between ads. Starting from the associations between ads, incorporates both ad networks and user networks into consideration, a multi-round social advertising influence maximization model based on triggering model was constructed. An ad edge based greedy strategy based on multi-round reverse influence sampling was proposed to enhance platform revenue, with theoretical proofs of its strict lower bound guarantee. Experiments showed that compared to existing optimal methods, this method increased the average ad propagation influence revenue by 35%, significantly enhancing ad recommendation effectiveness, providing a new solution for ad sequence recommendations.]]></description>
<pubDate>2025/4/10 11:01:36</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[Fu Bingyang,,,,,]]></author>
</item>
<item>
<title><![CDATA[Mix variational mode decomposition long short-term memory for predicting of reservoir surface displacement and deformation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202304100000001]]></link>
<description><![CDATA[In order to improve the prediction accuracy of the displacement and deformation of YANFGHE reservoir, the displacement and deformation of non-linear and non-stationary reservoir was predicted by changing the decomposition method of VMD(variational mode decomposition) and integrating VMD and LSTM (long short-term memory). A MVMDLSTM (mixed variational mode decomposition long short-term memory) model prediction method was proposed.   The reliability of the new method was analyzed by comparing different single prediction models with the combined model and different data sets. The experimental results show that the MVMDLSTM model can effectively attenuate the bias of the single prediction model and the empirical mode decomposition combination model estimation, and the prediction accuracy of the MVMDLSTM model is better, which provides an effective data decision-making for the stabilization and monitoring of the prediction and warning of the reservoir"s slow sliding and creeping and other small deformations.]]></description>
<pubDate>2025/4/3 9:53:45</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈红康,贺小星,鲁铁定,孙喜文,王海城]]></author>
</item>
<item>
<title><![CDATA[Markov chain reliability optimization method for augmented space subset simulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303270000001]]></link>
<description><![CDATA[Aiming at the reliability-based design optimization problem of complex structural systems, an efficient optimization method based on subset simulation and Markov chain simulation in augmented space was proposed. Considering the reliability-based design optimization problem in which the design parameters were distributed parameters of basic random variables, the target failure probability was transformed into a posterior density function of the design parameters in the augmented space, obtained a set of initial failure samples in the whole design domain through subset simulation, and then adopted the efficient Markov chain simulation to generate more failure samples in the gradually smaller design domain under the sequential approximate optimization framework. The target posterior density function was estimated and updated, and the decoupling approach was used to solve the transformed optimization problem to finally obtain the optimum. Compared with the existing methods, the proposed method requires only one reliability analysis and can avoid local optimal solution, resulting in the global optimal solution. Examples were given to illustrate the applicability of the proposed method in engineering and its superiority in the accuracy and efficiency of analysis and calculation.]]></description>
<pubDate>2025/4/3 9:46:59</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈敬强,董一巍,谭智勇,袁修开,张景豫]]></author>
</item>
<item>
<title><![CDATA[Bayesian estimation of missile hit accuracy for Dirichlet distribution]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302130000004]]></link>
<description><![CDATA[Based on the differential impact of the spatial distribution of impact points on target damage effectiveness, the probability distribution model of missile hitting different important areas of target was constructed to realize expansion of the traditional hit accuracy concept. Aimed at the reality of actual missile hitting targets with complex process, high cost and low frequency, Bayesian method was used to fuse multi-source information, and missile hit accuracy was estimated based on the idea of region division, distribution determination, prior fusion and posterior solution. The Dirichlet distribution was selected as the prior distribution of hit accuracy parameters, the Dempster-Shafer (D-S) evidence theory was used to fuse the prior information and the posterior distribution of accuracy parameters was solved by Markov chain Monte Carlo (MCMC) method. Example results show that this method can describe the probability of missile hitting different important areas of the target in detail, and scientifically integrate multiple types of prior information about hit accuracy, which provides theoretical references for missile hit accuracy estimation methods and test schemes optimization.]]></description>
<pubDate>2025/4/3 9:46:21</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[陈童,胡涛,李明贵,梁俊鹏,刘昊邦]]></author>
</item>
<item>
<title><![CDATA[Modeling and Simulation of Effectiveness Evaluation of the Anti-missile Equipment System Driven by Data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202409020000004]]></link>
<description><![CDATA[Aiming at the problems that traditional effectiveness evaluation methods can not reflect the evolution, emergence and adaptability of the anti-missile equipment system, a data-driven effectiveness evaluation method of anti-missile equipment system was proposed. Based on the analysis of the characteristics of anti-missile equipment system and the shortage of traditional effectiveness evaluation method. the Bayes optimization algorithm was used to optimize the convolutional neural network hyperparameters, and the efficiency evaluation model of Bayes convolutional neural network was constructed. The flow and steps of Bayes-CNN (Bayesian convolutional neural network) system effectiveness evaluation algorithm were studied, and a set of completed efficiency evaluation algorithm was formed. Designed and validated the simulation experiment, input a lot of test data to Bayes-CNN model for training and learning, so as to obtain the simulation prediction of the effectiveness of anti-missile equipment system. The experimental results show that the error between the actual and expected output is very small, and the non-linear fitting effect is great so that it had a high degree of feasibility and reliability.]]></description>
<pubDate>2025/4/3 9:45:40</pubDate>
<category><![CDATA[航空宇航科学与技术]]></category>
<author><![CDATA[zhao hai yan,]]></author>
</item>
<item>
<title><![CDATA[Multi-view heterogeneous graph embedding method with hierarchical projection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202312030000001]]></link>
<description><![CDATA[A self-supervised graph embedding approach based on hierarchical projection network called Multi-view heterogeneous graph projection network(MeghenNet) was introduced to learn low-dimensional representations from multiple views, and the concept of multiple-view heterogeneous graphs was formalized for modeling heterogeneous graphs from various sources simultaneously. A hierarchical attention projection that involves a cross-relation projection to extract semantics information within each view was employed, followed by a cross-view projection to aggregate contextual information from other views. The mutual information between the view-specific embeddings and the corresponding high-level summary was computed to ensure the information consistency across views. Experimental results on several real-world datasets demonstrate that the proposed method outperforms state-of-the-art approaches when handling multi-view heterogeneous graphs.]]></description>
<pubDate>2025/4/3 9:44:55</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈纯,郝韵致,,,,,]]></author>
</item>
<item>
<title><![CDATA[S-Cypher: A Temporal Query Language on the Temporal Property Graph Model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202411070000001]]></link>
<description><![CDATA[Traditional graph data models lack explicit temporal dimension representation, which may lead to complex temporal queries and potential loss of temporal information integrity. To address this limitation, a temporal property graph data model and a corresponding temporal graph query language called S-Cypher were proposed. The temporal graph data model represents utilized object nodes to represent entities, and introduced property nodes and value nodes to represent entity properties. Valid time was recorded on nodes and edges between object nodes to express temporal information, and the recorded valid time adhered a set of temporal constraints. S-Cypher served as a temporal extension to Cypher, ensured compatibility while providing a concise and comprehensive temporal graph query syntax, including temporal data types, temporal graph pattern matching, time window constraints, and temporal paths. An implementation scheme for executing S-Cypher temporal graph queries on Neo4j was also provided. The experimental results demonstrate that the query time of S-Cypher is on average 1.29 times that of Cypher, indicating that S-Cypher can effectively manage temporal graph data in Neo4j with satisfactory performance.]]></description>
<pubDate>2025/4/3 9:42:21</pubDate>
<category><![CDATA[软件工程]]></category>
<author><![CDATA[蒋甜甜,,]]></author>
</item>
<item>
<title><![CDATA[Station keeping control method based on deep reinforcement learning for aerostat using ambient wind]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212030000001]]></link>
<description><![CDATA[Aiming at the station keeping control problem of Stratospheric aerostat in dynamic wind field, a station keeping controller designed based on deep reinforcement learning D3QN algorithm for different control channels of aerostat operated with ambient wind, studied the impact of different reward functions on the performance of regional resident controllers. Station keeping control simulation was carried out under the task constraint of a station keeping duration of three days and a station keeping radius of 50 km. Results show that: compared with the station keeping controller designed by DDQN method, the performance of the controller designed by D3QN method is significantly improved. When the control trajectory of aerosat is only adjusted by altitude, the average station keeping radius can reach 25.26 km, and the station keeping ratio is 96%. With the aid of horizontal propulsion, the average station keeping radius can be significantly reduced and the station keeping time ratio can be significantly increased. At the same time, the strong robustness of the station keeping controller based on deep reinforcement learning was verified, and the controller can be designed with different reward functions to meet the requirements of different station keeping tasks.]]></description>
<pubDate>2025/3/13 15:20:42</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[柏方超,邓小龙,侯中喜,龙远,杨希祥]]></author>
</item>
<item>
<title><![CDATA[Curriculum reinforcement learning algorithm for flexible job shop scheduling problems]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401040000004]]></link>
<description><![CDATA[To address the issue of the lack of generalization capability of deep reinforcement learning in flexible job shop scheduling problems, a method combining curriculum learning and deep reinforcement learning was proposed. The training instance difficulty was dynamically adjusted, with an emphasis on enhancing the training of the most difficult instances, to adapt to different data distributions and avoid the forgetting problem during the learning process. Simulation test results demonstrated that the algorithm maintained decent performance on large-scale untrained problems and benchmark datasets. It achieved better performance on four large-scale untrained problems with two artificial distributions. Compared to exact methods and metaheuristic methods, for problem instances with larger computational complexity, it could rapidly obtain solutions of decent quality. Moreover, the algorithm could adapt to flexible job shop scheduling problems with different data distributions, exhibiting a relatively fast convergence speed and good generalization capability.]]></description>
<pubDate>2025/3/13 10:47:19</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[Lu Chao,,]]></author>
</item>
<item>
<title><![CDATA[Image anomaly detection algorithm using multi-level feature fusion network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212080000001]]></link>
<description><![CDATA[Image anomaly detection aims to identify and locate the abnormal region in an image. To address the issue on the insufficient utilization of different-level feature information in the existing methods, an image anomaly detection method based on multi-level feature fusion network was put forward. By using the pseudo anomaly data generation algorithm incorporated with the anomaly prior knowledge, the anomaly data of the training set were augmented, and then the anomaly detection task was transformed into a supervised learning task. A multi-level feature fusion network was constructed to enriches the low-level texture information and high-level semantic information of features by fusing the different levels of features in the neural network, which could make the features used for anomaly detection more discriminative. In the training phase, the score constraint loss and the consistency constraint loss were designed and combined with the feature constraint loss to train the whole network model. Experimental results on the MVTec dataset showed that the proposed model could achieve 98.7% AUROC (Area Under the Receiver Operating Characteristic) in the detection task, 97.9% AUROC in the pixel-wise localization task and 94.2% Per-Region-Overlap in the localization task, which outperformed several existing anomaly detection approaches.]]></description>
<pubDate>2025/3/12 8:28:51</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[唐俊,王科,王年,张艳,左金梅]]></author>
</item>
<item>
<title><![CDATA[Coating Damage Detection of Vessels Using Corrosion Electric Field]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211080000001]]></link>
<description><![CDATA[The corrosion electric field is an obvious physical field feature of vessels due to its special characteristics of low frequency, obvious line spectrum features and cannot be eliminated. There are apparent distribution characteristics corresponding to different coating damage regions of a vessel, which are adequate for determining the possible damaged coating region. Therefore, a novel method combining Refined Composite Hierarchical Fluctuation Revise Dispersion Entropy (RCHFRDE) and improved Harris Hawk Optimization-kernel based extreme learning machine (IHHO-KELM) was proposed. We proposed RCHFRDE to extract the feature of electric field signatures. The feature vectors were input into the IHHO-KELM classifier to detect the damage region. The numerical and physical scale experiments were conducted to validate the feasibility and reliability of the proposed method. This damaged region was efficiently predicted, achieving satisfactory accuracy of 94.67% and 89.00% in numerical and measurement data respectively, which provided a complement for non-contact detection methods, especially with less prior environment information.]]></description>
<pubDate>2025/2/20 8:40:01</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[胡育诚,刘武强,柳懿,汪石川,王向军]]></author>
</item>
<item>
<title><![CDATA[Sparse Direction Finding for GNSS Spoofing Source in Underdetermined Scenarios]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211200000001]]></link>
<description><![CDATA[Aiming at the problem that the traditional subspace-like direction finding algorithm fails in underdetermined scenarios and requires the number of signal sources as a priori information, a GNSS spoofing source direction finding method based on coprime array is proposed to improve the application security of satellite navigation receivers in spoofing environment. Specifically, we first construct the cyclic correlation matrix to reduce the impact of noise on the performance of the coprime array signal processing, and the virtual domain equivalent array signal is obtained by vectoring the cyclic correlation matrix. On this basis, an optimization problem based on sparse signal reconstruction in virtual domain is designed to achieve high-precision, multi-degree of freedom direction finding for sources by minimizing the fitting error. Finally, the simulation results show that compared with traditional subspace algorithm, the proposed algorithm has higher estimation accuracy, and the direction finding results are still reliable under the case of underdetermined.]]></description>
<pubDate>2025/2/20 8:38:44</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[沈  锋,,]]></author>
</item>
<item>
<title><![CDATA[MBSE Modeling and Reliability Evaluation Method for Complex System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211250000001]]></link>
<description><![CDATA[To solve the problem of lack of early reliability evaluation in complex system design process, a model-based system engineering (MBSE) method is proposed to support the design and reliability evaluation of complex systems. With the characteristics of complex system development, a MBSE modeling method based on "Mission, Operation, Function, Logic, Physic and Reliability" (MOFLP-R) was proposed to support design and reliability assessment of complex system. KARMA, a system modeling language based on "Graph, Object, Property, Point, Relationship and Role" (GOPPRR), was used to express the MOFLP-R process. Then, in order to evaluate the reliability of the complex system, the code generation was used to map the diagram to the numerical model. Finally, the method was applied to a hydraulic system case and the results showed that the proposed method is effective for complex system design and evaluation.]]></description>
<pubDate>2025/2/20 8:37:13</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[鲁金直,马君达,王国新,]]></author>
</item>
<item>
<title><![CDATA[Specific accelerator architecture conforming to particle transport simulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212260000001]]></link>
<description><![CDATA[Particle transport simulation is one of the main applications of high performance computers. But facing to its fast growing compute requirements, the general-purpose microprocessors cannot adapt to the particle transport program features, owing to the complexity architecture of its single core, and then it is difficult to obtain high ratio of performance and power. Therefore, the program features of the particle transport non-deterministic numerical simulation were extracted and analyzed. Based on the characteristics of the algorithm, the architecture of accelerator core was designed, including pipeline structure, branch prediction unit, multi-level Cache hierarchy and main memory design. A specific accelerator architecture was designed in accordance to the particle transport program features. The simulation results of running the particle transport program on the general architecture simulator show that, as compared with ARM Cortex-A15, the proposed specific accelerator can achieve 4.6 times performance improvement under the same power consumption, and 3.2 times under the same area.]]></description>
<pubDate>2025/2/20 8:36:30</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[黎铁军,刘津津,许炜康,张建民]]></author>
</item>
<item>
<title><![CDATA[Design and Verification of the Improved Guidance System for a Boost-Glide Missile]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202301030000001]]></link>
<description><![CDATA[The boost-glide missile is a kind of precision guided weapons, which flies in complex and changeable flight conditions with high requirements for the guidance law. The flight state variation model of the missile is established, the improved optimal guidance law with the impact angle constraint is derived by the optimal control method, and the longitudinal guidance coefficients and lateral guidance coefficients are introduced into the guidance law. The influence of single guidance coefficient on guidance precision is analyzed and the selection method of guidance coefficients is determined. The influence of fixed impact angle constraint and dynamic impact angle constraint on guidance precision are analyzed according to the requirements of different flight missions. The numerical simulation and the hardware-in-the-loop simulation are finished with a small solid propellant boost-glide test vehicle. The simulated results show that the improved optimal guidance law is reasonable with high guidance precision.]]></description>
<pubDate>2025/2/20 8:35:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[白锡斌,樊晓帅,江振宇,张士峰]]></author>
</item>
<item>
<title><![CDATA[Local shape optimization design of super-pressure balloon under bidirectional tension]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212260000002]]></link>
<description><![CDATA[Tandem balloon system provides a solution to the problem of long-duration station-keeping of near-space aerostat, and its contained super-pressure balloon needs to be adapted to specific load and boundary conditions. Based on the natural-shape equations, a numerical method of local shape optimization of the two poles of spherical super-pressure balloons is proposed. Through the smooth connection of the numerical solution generatrix segment and the arc generatrix segment, the complete generatrix of super-pressure balloon with a certain angle at two poles is obtained, which is symmetrical up and down. The stress distributions of the super-pressure balloons before and after the local shape optimization are analyzed by the finite element method, and the effectiveness of the local balloon shape optimization method is verified. On this basis, the key factors affecting the effectiveness of local balloon shape optimization are analyzed, including the arc length of the numerical solution generatrix segment, circumferential stress input condition, local shape, and the radius of the arc generatrix segment, providing an important reference for the selection of key parameters in the local shape optimization of spherical super-pressure balloon.]]></description>
<pubDate>2025/2/20 8:32:59</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[骞航,张冬辉,张泰华]]></author>
</item>
<item>
<title><![CDATA[Fault detection and isolation method for launch vehicle based on multiple models]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211280000002]]></link>
<description><![CDATA[Aiming at the problem of fault diagnosis of sensors and actuators of launch vehicles, a multiple model fault detection and isolation algorithm is proposed. The small deviation attitude dynamics model of the launch vehicle is established, and the Kalman filter of the system is designed; Combined with the idea of special observer, multiple Kalman filter banks with different structures are used to generate corresponding residuals, so that a single residual is only sensitive to a fault of the sensor or actuator. The fault isolation strategy is deduced theoretically to achieve the detection and isolation of different fault types of the launch vehicle. Simulation analysis shows that when no fault occurs, the residual results do not exceed the set threshold, and the algorithm does not alarm; When the sensor or actuator fails, the proposed isolation strategy can accurately locate the fault, which verifies the effectiveness of the algorithm.]]></description>
<pubDate>2025/2/20 8:29:17</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[程玉强,宋立军,谢昌霖,杨述明]]></author>
</item>
<item>
<title><![CDATA[Robotic Parallel Disassembly Sequence Planning Method Based on Reinforcement Learning and Genetic Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401310000001]]></link>
<description><![CDATA[To improve the disassembly efficiency and reduce disassembly energy consumption, the robotic parallel disassembly mode was introduced in the disassembly sequence planning problem, a robotic parallel disassembly sequence planning model was constructed, and a genetic algorithm based on reinforcement learning was designed. To verify the correctness of the model, a mixed integer linear programming model was constructed. In the algorithm, a goal-oriented encoding and decoding strategy was constructed to improve the quality of the initial solution. Q learning was used to select the best crossover and mutation strategies in the iteration process to enhance the algorithm's adaptability. Finally, in an engine disassembly case with 34 tasks, the superiority of the proposed algorithm was verified by comparing with four classic multi-objective algorithms. The analysis of the disassembly schemes shows that the robotic parallel disassembly mode can effectively shorten the completion time and reduce disassembly energy consumption.]]></description>
<pubDate>2025/2/20 8:27:14</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[李新宇,卢超,马晓艺,汪开普,殷旅江]]></author>
</item>
<item>
<title><![CDATA[Keypoints detection and uncertainty synchronous prediction for satellite monocular pose estimation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401100000001]]></link>
<description><![CDATA[Satellite monocular pose estimation usually extracts the 2D keypoints of the satellite in the images, and then solves the PnP (Perspective-n-Points) problem with the given corresponding 3D coordinates of the keypoints to obtain the relative position and attitude between the camera and the satellite, in which the accuracy of satellite keypoints detection is the key to determine the accuracy of monocular pose estimation. To solve this problem, a high-precision satellite keypoints detection method was proposed, which predicted the image coordinates of the keypoints and gave the uncertainty of keypoints coordinate prediction synchronously. Then, a weighted PnP constraint equation was constructed to solve the relative position and attitude on this basis, which significantly improved the accuracy of satellite monocular pose estimation. Relevant experiments were carried out on the public satellite monocular pose estimation dataset named SPEED, and the experimental results show that the proposed keypoints detection method for synchronously predicting keypoints coordinates and their uncertainty can significantly improve the accuracy of satellite keypoints detection,and by solving the weighted monocular pose estimation problem, the accuracy of satellite monocular pose estimation has been significantly improved.]]></description>
<pubDate>2025/2/15 10:21:24</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李璋,苏昂,王靖皓,王梓]]></author>
</item>
<item>
<title><![CDATA[Tension-compression asymmetric viscoelastic plastic constitutive model of HTPB propellant]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206150000004]]></link>
<description><![CDATA[Tensile and compressive creep behavior of propellants in solid motors due to the influence of the gravity and long-term storage might affect the interior ballistics and structural integrity. In order to investigate the change trends of tensile and compressive creep for HTPB propellant, the 1 000s tensile, 1 000s compression and 28-day tensile creep tests were designed and carried out in this work. Meanwhile, the Saint-Venant body and the compressive-tensile asymmetry factor were introduced to establish a propellant viscoelastic plastic constitutive model that takes into account compressive-tensile asymmetry. The range of application of this equation was obtained by fitting and analyzing the parameters in the constitutive equation. The results indicate that the compressive creep process of propellant was mainly dependent on stress level. At the same stress level, viscoelastic deformation of tensile creep is about 1.62 times that of compressive creep, while compressive yield stress is 3.82 times that of tensile yield stress. The tension-compression asymmetric viscoelastic plasticity constitutive model can well characterize the tensile-compression creep response of propellants at the lower stress levels. The conclusions and research method in this work can provide reference for structural integrity analysis and storage life evaluation of solid motor.]]></description>
<pubDate>2025/1/16 20:55:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[邓旷威,李海阳,申志彬]]></author>
</item>
<item>
<title><![CDATA[Uncertainty analysis of thrust during variable operating conditions of solid divert and attitude control motor]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202309280000002]]></link>
<description><![CDATA[To investigate the dynamic uncertainty of thrust of the pintle SDACM (solid divert and attitude control motor), the study focuses on the uncertainty of the thrust performance during variable operating conditions of the SDACM was carried out with the consideration of the uncertainties of the geometric parameters of the pintle gas valve. Computation model of the thrust during variable operating condition process of the SDACM was established by combining the working principle of the SDACM, the regular mathematical model of thrust and the zero-dimensional internal ballistic equation. On this basis, the uncertainty propagation was performed by Monte Carlo simulation method according to the uncertainty models of the geometry parameters of the SDACM, and the variation law of the thrust uncertainty over time after the transient motion of the pintle was obtained, thereby the uncertainty analysis of the thrust in the process of variable operating conditions was realized, and the uncertainty variables were weighted in order of importance. Quantification and evaluation of thrust uncertainty in the real-time regulation process of the SDACM can provide more reasonable design requirements for the control system, and save the development cost of the SDACM while meeting the design requirements.]]></description>
<pubDate>2025/1/16 20:55:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[gaojingwei,,,,,]]></author>
</item>
<item>
<title><![CDATA[Radar echo characteristic analysis and parameter estimation method for rotor UAV]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211160000001]]></link>
<description><![CDATA[The proliferation of “low, slow and small” UAVs (unmanned aerial vehicles) poses a serious threat to flight safety in airspace. Accurate analysis of the characteristics of UAV echo signals is of great significance for the detection of non-cooperative UAVs. Based on the time-domain integral echo model of rotor UAV target and the principle of cepstrum algorithm, the frequency-domain expression and cepstrum expression of echo signal were derived, the corresponding relationship between echo signal parameters and frequency-domain and cepstrum characteristics was analyzed, and a parameter estimation method for UAV echo signal was proposed, and the effectiveness of this method was verified by simulation and measured data. The results show that, it can estimate the bandwidth and rotation frequency of UAV echo signal more accurately and provide an important reference for target detection and recognition of UAV.]]></description>
<pubDate>2025/1/16 17:50:39</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[刘鲁涛,莫禹涵,谢良正]]></author>
</item>
<item>
<title><![CDATA[Load-balanced deadlock resolution algorithm in multi-chiplet network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212120000002]]></link>
<description><![CDATA[To solve the inter-chiplet deadlock and network connectivity problems caused by link failures in multi-chiplet network, an optimized packet retransmission mechanism for multi-chiplet network was proposed. By using the "message merging" function in the retransmission mechanism, the number of control packets and the network load was reduced; By using the "message forwarding" function and adopting the forwarding to neighbor strategy, the fault-tolerant cost of the inter-chiplet network link failure was reduced. And more balanced load of the intra-chiplet network was realized. The simulation results show that the proposed method can increase the saturation bandwidth by 12.5% - 25% with similar latency compared with the turn restriction strategy. Furthermore, it can increase the saturation bandwidth by up to 50% in case of link failures. "Message merging" can effectively reduce the number of control packets, thus reduce the overall load of the network. "Packet forwarding" has lower fault-tolerance cost and can ach]]></description>
<pubDate>2025/1/16 17:49:46</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈志强,,,周宏伟]]></author>
</item>
<item>
<title><![CDATA[Coupling analysis of thermodynamic environment for air-to-air missile]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212090000001]]></link>
<description><![CDATA[With regard to accurately predicting thermodynamic environment for air-to-air missile, fluid-thermal-solid coupling analysis should be adopted, and coupling effects on flow field and structure-temperature field should be investigated. A fluid-thermal-solid multi-field coupling simulation model for air-to-air missile is established via using partition algorithm, and the coupling relationships among structural deformation, temperature and pressure are analyzed and the coupling effects on temperature and pressure simulation results are examined as well. Results show that, missile bending deformation is caused by aerodynamic and aerothermal, and the structure deformation could lead to the variation of missile temperature field and pressure field. The main reason for the variation is induced by the structure deformation from aerodynamic effect. The predicting accuracy of missile thermodynamic environment can be affected by the coupling effects. If the missile slenderness ratio, or the angle of attack or the flight speed is small, the coupling effects have a little influence on thermodynamic environment for supersonic missile. If the missile slenderness ratio, the angle of attack and the flight speed are large, high predicting accuracy can be obtained by considering coupling effects.]]></description>
<pubDate>2025/1/16 17:49:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[徐立友,徐世南]]></author>
</item>
<item>
<title><![CDATA[Image anomaly detection algorithm using multi-level feature fusion network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212080000001]]></link>
<description><![CDATA[Image anomaly detection aims to identify and locate the abnormal region in an image. To address the issue on the insufficient utilization of different-level feature information in the existing methods, an image anomaly detection method based on multi-level feature fusion network was put forward. By using the pseudo anomaly data generation algorithm incorporated with the anomaly prior knowledge, the anomaly data of the training set were augmented, and then the anomaly detection task was transformed into a supervised learning task. A multi-level feature fusion network was constructed to enriches the low-level texture information and high-level semantic information of features by fusing the different levels of features in the neural network, which could make the features used for anomaly detection more discriminative. In the training phase, the score constraint loss and the consistency constraint loss were designed and combined with the feature constraint loss to train the whole network model. Experimental results on the MVTec dataset showed that the proposed model could achieve 98.7% AUROC (Area Under the Receiver Operating Characteristic) in the detection task, 97.9% AUROC in the pixel-wise localization task and 94.2% Per-Region-Overlap in the localization task, which outperformed several existing anomaly detection approaches.]]></description>
<pubDate>2025/1/16 17:48:48</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[唐俊,王科,王年,张艳,左金梅]]></author>
</item>
<item>
<title><![CDATA[Curriculum reinforcement learning algorithm for flexible job shop scheduling problems]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401040000004]]></link>
<description><![CDATA[To address the issue of the lack of generalization capability of deep reinforcement learning in flexible job shop scheduling problems, a method combining curriculum learning and deep reinforcement learning was proposed. The training instance difficulty was dynamically adjusted, with an emphasis on enhancing the training of the most difficult instances, to adapt to different data distributions and avoid the forgetting problem during the learning process. Simulation test results demonstrated that the algorithm maintained decent performance on large-scale untrained problems and benchmark datasets. It achieved better performance on four large-scale untrained problems with two artificial distributions. Compared to exact methods and metaheuristic methods, for problem instances with larger computational complexity, it could rapidly obtain solutions of decent quality. Moreover, the algorithm could adapt to flexible job shop scheduling problems with different data distributions, exhibiting a relatively fast convergence speed and good generalization capability.]]></description>
<pubDate>2025/1/16 17:47:00</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[Lu Chao,,]]></author>
</item>
<item>
<title><![CDATA[Improved Fast Sparse Bayesian Learning Algorithm for Underwater Acoustic Channel Estimation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212150000001]]></link>
<description><![CDATA[In order to guarantee the long-term stable communication of underwater devices, the improved sparse Bayesian learning algorithm based on Fast Marginal Likelihood Maximization (IFM-SBL) was proposed to estimate underwater acoustic channels with low complexity and high performance. Especially in the case of low signal-to-noise ratio (SNR), the performance of proposed algorithm can be further improved by threshold denoising and DFT transform denoising. Simulation and sea trial results show the output bite error rate (oBER) after channel estimation of FM-SBL is similar to that of EM-SBL, and it has good robustness in both low SNR and fast or slow time-varying channels. The running speed of FM-SBL and IFM-SBLalgorithm is 90% better than that of EM-SBL algorithm, which greatly reduces the estimation time.]]></description>
<pubDate>2025/1/14 16:53:25</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[笪良龙,贾书阳,刘宝衡,张小川,邹司宸]]></author>
</item>
<item>
<title><![CDATA[Design and verification of three-dimensional spatial deployment method for unmanned aerial vehicle base station]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211040000003]]></link>
<description><![CDATA[In order to overcome the problems of high computational complexity and long simulation cycle caused by the character-istics of strong dynamics, high timeliness, multiple constraints, and strong coupling during the three-dimensional spatial deployment of Unmanned Aerial Vehicle Base Station (UAV-BS), An efficient global optimization (EGO) was proposed to determine the three-dimensional spatial deployment location of UAV-BS. Considering that the EGO algorithm mainly obtains new sampling points by optimizing the expectation improvement(EI) function, the improved differential evolu-tion(DE) algorithm  was proposed to optimize the EI function. The improved DE algorithm improved the optimization ability and convergence speed by adopting the successful parent selecting framework(SPS Framework) and the offspring generation strategy self-adaptive selection framework(SA Framework). Three typical engineering problems were select-ed to test the performance of the improved EGO algorithm. The results show that the optimization ability, optimization speed, and stability of the improved EGO algorithm are significantly improved. On this basis, an application example of using the improved EGO algorithm to deploy a UAV base station in three-dimensional space was given.]]></description>
<pubDate>2025/1/14 16:53:03</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[曹江,,]]></author>
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<title><![CDATA[Filling and repairing holes in geometric model for scientific engineering computing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211100000001]]></link>
<description><![CDATA[In the process of geometric model processing by mesh generation software, a filling method based on B-spline surface was proposed to solve the hole problem caused by missing geometric surface information. The hole boundaries were extracted from the given set of B-spline curves based on their the topological relationship, and curve approximation fitting and combination techniques were employed to process the curves within individual holes to obtain compatible curves. Hole repair was achieved by first constructing unidirectional interpolating ruled surfaces and tensor product surfaces from the curves, these surfaces are then combined through interpolation and Boolean sum operations to generate bilinear difference B-spline surfaces for filling the holes. In addition, the ruled surface was applied as an alternate method in complex special holes to ensure the overall robustness of the method. Experimental results show that the method was highly general and can be applied to the dirty geometry repair of various types of morphological holes in real-world industrial geometric models, providing clean and closed geometric models for subsequent mesh generation.]]></description>
<pubDate>2025/1/14 16:52:45</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[高翔,龚春叶,刘增晟,徐传福,张翔]]></author>
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<item>
<title><![CDATA[Design and analysis of in-cabin assembly system based on hybrid robot]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210170000001]]></link>
<description><![CDATA[The internal space of the space capsule is narrow, and the deep space is large. There are many kinds of equipment to be installed, large batches, heavy loads, and high assembly risks. In order to meet the requirements of automatic assembly of equipment in the spacecraft cabin and obtain an assembly robot with small structure size, large workspace, high load capacity and high flexibility, a lightweight, high load 8-DOF hybrid attitude adjustment robot cabin assembly system based on PRR/PR (PRR) R mechanism was proposed. The position mapping relationship, velocity mapping relationship, Jacobian matrix, acceleration mapping relationship of the hybrid assembly robot are analyzed. The dynamic model of the hybrid assembly robot is established, and the mapping relationship between the driving force, driving torque and joint speed is obtained. The stiffness model of the hybrid robot is established to solve the deformation degree of the mechanism after the six dimensional force is applied to the end of the mechanism. The kinematics and dynamics theoretical calculation results of the parallel mechanism are verified by the ADAMS simulation model. The theoretical stiffness model is verified by ANSYS finite element simulation. It provides a feasible scheme and theoretical basis for the realization of large equipment assembly automation in a narrow and long space.]]></description>
<pubDate>2025/1/14 16:52:14</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭禹彤,刘毅,姚建涛,易旺民,赵永生]]></author>
</item>
<item>
<title><![CDATA[Station keeping control method based on deep reinforcement learning for aerostat using ambient wind]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212030000001]]></link>
<description><![CDATA[Aiming at the station keeping control problem of Stratospheric aerostat in dynamic wind field, a station keeping controller designed based on deep reinforcement learning D3QN algorithm for different control channels of aerostat operated with ambient wind, studied the impact of different reward functions on the performance of regional resident controllers. Station keeping control simulation was carried out under the task constraint of a station keeping duration of three days and a station keeping radius of 50 km. Results show that: compared with the station keeping controller designed by DDQN method, the performance of the controller designed by D3QN method is significantly improved. When the control trajectory of aerosat is only adjusted by altitude, the average station keeping radius can reach 25.26 km, and the station keeping ratio is 96%. With the aid of horizontal propulsion, the average station keeping radius can be significantly reduced and the station keeping time ratio can be significantly increased. At the same time, the strong robustness of the station keeping controller based on deep reinforcement learning was verified, and the controller can be designed with different reward functions to meet the requirements of different station keeping tasks.]]></description>
<pubDate>2025/1/14 16:51:25</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[柏方超,邓小龙,侯中喜,龙远,杨希祥]]></author>
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<title><![CDATA[Effect of normal overload on convective heat transfer process of working fluid in thermoelectric conversion system on aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211060000001]]></link>
<description><![CDATA[To grasp the effect of normal overload on the airborne thermoelectric conversion system, the convective heat transfer process of working fluid in heat exchange ducts was simulated. Results show that the growth of normal overload makes the flow field changed, which finally leads to the decreasing wall temperature. Along the duct, the formation of one wall temperature peak is closely related to the change of turbulent heat flux near the heated wall. When the normal overload increases from 0g to 2g, the flow structure with 8 vortexes converts to the two main vortexes structure, which makes turbulent heat flux of fluid near the heated wall increases gradually due to the thinner temperature boundary layer. Hence, local heat transfer coefficient can be increased by 80%. With the enhancement of heat transfer in duct, the wall temperature decreases and the maximum of wall temperature drop can be up to 290K.]]></description>
<pubDate>2025/1/14 16:50:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[钮耀斌,王中伟,杨烜]]></author>
</item>
<item>
<title><![CDATA[Improved Co-Evolutionary Algorithm for Solving Many-Objective Cloud Workflow Scheduling Problem]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401050000005]]></link>
<description><![CDATA[Cloud workflow is one of the most significant patterns, widely applied in tackling with the large-scale complicated computing tasks. In recent years, with the ever-growing scale and complexity of computing tasks, the demand for computing resources has getting higher in a corresponding explosive ascending trend. Cloud computing converges massive computing resources, providing users with on-demand computing services in the form of virtual machines. It undoubtedly serves as a potential ideal runtime environment for workflows. Moreover, Cloud workflow scheduling is devoted to allocating reasonable resources for different workflow tasks to meet the expected scheduling effects and targets. In general, the cloud workflow scheduling objectives involve time, cost, reliability, resource utilization, load balancing and other aspects. However, the current mainstream optimizations, up to now, typically attempt to formulate the cloud workflow scheduling problem as a single objective or multi-objective optimization problem at most three objectives. Whereas, these strategies might be less feasible to address many-objective cloud workflow scheduling problem with more than four objectives. Thus, we directly model cloud workflow scheduling into a many-objective problem, and then introduce a Dual-Stage Improved Co-Evolutionary Algorithm which aims to effectively balance the convergence and diversity, using a dual-stage strategy and various indicator characteristics to provide more affluent decision information for workflow scheduling. Experiments reveal that the proposed algorithm apparently outperforms the existing algorithms, which can find a better scheduling solution in most cases.]]></description>
<pubDate>2025/1/14 16:50:18</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[高亮,姬小晖,卢超,周佳军]]></author>
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<item>
<title><![CDATA[BeiDou-3 satellite autonomous time synchronization algorithm for clock jumps]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208040000001]]></link>
<description><![CDATA[Aiming at the problem that the time on the satellite deviates from the time of the entire network constellation caused by the abnormal jump of the satellite clock, an autonomous time synchronization algorithm for Beidou-3 satellites for the jump of the satellite clock is designed. By introducing robust least-squares estimation, the time synchronization algorithm of distributed satellite constellations is improved, so that it can quickly detect abnormal clock jumps and have the ability of autonomous time synchronization. Using the same simulation environment as the Beidou-3 satellite and introducing actual on-orbit test data, the algorithm is accurately evaluated. The results show that within 60 days, the time synchronization error of each satellite in the constellation does not exceed 3.68ns, and when a satellite jumps abnormally, the algorithm can restore time synchronization within 1 hour, which improves the reliability of the algorithm under clock jumps.]]></description>
<pubDate>2024/12/3 11:26:19</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[贺红雨,,,,孙建锋,田艳,]]></author>
</item>
<item>
<title><![CDATA[Efficient node screen method for UAV swarm cooperative location based on location variance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303300000001]]></link>
<description><![CDATA[In order to solve the problem of node screen with high precision and high real-time in the hybrid cooperative positioning of UAV swarm, an efficient node screen algorithm was proposed. The algorithm used the variance of positioning as the basis for evaluating positioning accuracy and used the recursive relationship between the variance of positioning caused by the removal of one node to select the specified number of nodes for positioning calculation. At the same time, the algorithm added an operation volume adjustment factor to solve the problem of large computation volume and poor real-time performance of traditional node selection algorithms in the case of a large number of nodes. Through simulation experiment, the variance and operation time consumption obtained by the algorithm are compared with the corresponding results of other optimization methods. The experimental results show that the algorithm greatly reduces the amount of calculation while ensuring the positioning accuracy, and has good real-time performance and feasibility.]]></description>
<pubDate>2024/12/3 11:23:57</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[郭冬,何永明,李群,伦伟成,张灿]]></author>
</item>
<item>
<title><![CDATA[Reliability modeling method in presence of nonconjugate distributions of random parameters]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208160000001]]></link>
<description><![CDATA[To obtain accurate product lifetime prediction results, random parameters which obey non-conjugate distributions were introduced to describe the unit-to-unit variation of products in the reliability model. For long-life products with monotonic degradation, the reliability model was proposed based on the Gamma process with non-conjugate random parameters. Extending the traditional conjugate distribution of random parameters to non-conjugate distribution, unified expression of life distribution function under different parameter distributions was derived, and the lifetime prediction values were calculated by using the MC(Monte Carlo) method. MCMC(Markov chain Monte Carlo) method was adopted for parameter estimation. The calculation algorithm for the likelihood function under different distributions and the selection criterion for the parameter distribution were presented, and the effect of the distribution of random parameters on the product reliability was analyzed. The simulation test and the application example show that this modeling method can select an appropriate distribution. Simultaneously, the accuracy of parameter estimation and lifetime prediction of the method is validated.]]></description>
<pubDate>2024/12/3 11:23:17</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[鲁相]]></author>
</item>
<item>
<title><![CDATA[Key Techniques and On-Orbit Verification for Space-based IoT System in TT-5 Satellite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208300000001]]></link>
<description><![CDATA[The Space-based Internet of Things (SIoT) is an effective supplement and extension of the ground-based IoT, and it is a basic technical means to build the interconnection of all things and ubiquitous perception. This paper takes the SIoT integrated in Tiantuo-5 as an example, aims at the application requirements of multi-domain and multi-scenario covering land, sea and air, focuses on solving the high-reliability detection of the signals of Automatic Identification System (AIS), Automatic Dependent Surveillance-Broadcast (ADS-B) system and the multiple access of Data Collection System (DCS), achieves real-time supervision of navigation and aviation goals and the global layout of extremely massive narrowband IoT sensor terminals, and provide reference scheme for the demonstration, construction, development and scale application of our country’s SIoT.]]></description>
<pubDate>2024/12/3 11:23:03</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈利虎,崔俊伟,李松亭,杨磊,余孙全,赵勇]]></author>
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<item>
<title><![CDATA[Design of CTLE with SS-LMS adaptive equalization algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208040000004]]></link>
<description><![CDATA[With the continuous advancement of advanced processes and technologies, in order to ensure the accuracy of data during high-speed transmission, equalizers need to provide higher compensation and lower power consumption to achieve efficient communication. A high-gain and low-power adaptive CTLE(continuous time linear equalizer) was designed based on the 12 nm CMOS(complementary metal-oxide-semiconductor) process, which adopted a two-stage cascade structure to compensate for channel attenuation and improve the quality of the received signal. In addition, the adaptive module used the Sign-sign Least Mean Square algorithm to accelerate the convergence speed of the tap coefficients. Simulation results showed that when the transmission rate was 16 Gbps, the equalizer could compensate for a half-bit rate channel attenuation of -15.53 dB, and the equalizer coefficients converged within 16×10^4 UI data. Moreover, after convergence, the received error rate was lower than 10^-12.]]></description>
<pubDate>2024/12/3 11:22:41</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈建军,李刚,唐明华,尤浩龙,赵珍阳]]></author>
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<item>
<title><![CDATA[In-network collaborative computing method for low-latency demand of military IoT tasks]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210110000001]]></link>
<description><![CDATA[To solve the problem of high-communication latency consumption when sensor data during the round trip to the server application layer in the military IoT, an in-network collaborative computing method for multiple devices with low-latency tasks demands is proposed. This method relies on a network architecture with P4 switches as the core and employs a data-plane programming strategy based on the P4 program to complete the packet processing within the switch. A task mapping strategy is designed to map the task set to a switch network topology, thus realizing a collaborative operation mode in which tasks are computed while being transferred on the network topology path. After that, a latency optimization model is built to find the best mapping result, and the task is further optimally scheduled through the heterogeneous earliest finish time (HEFT) algorithm. The experimental results show that when the data size of a single packet is 1000Byte, the output latency of this method is reduced by about 54.2% and 72.1% compared with the local service and cloud service, respectively. Therefore, the proposed method effectively reduces latency, offering a practical solution to meet the low-latency demands of tasks.]]></description>
<pubDate>2024/12/3 11:21:55</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李瑞彪,马步云,任继军,任智源]]></author>
</item>
<item>
<title><![CDATA[Cooling characteristics for supersonic film on flat/convex surfaces in hypersonic mainstream]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202309280000001]]></link>
<description><![CDATA[Supersonic film cooling technology is widely used in active thermal protection of hypersonic aircraft. A numerical simulation method was used to investigate the effects of the Mach number at the cooling gas"s inlet , blowing ratio and the nozzle"s height on the supersonic film cooling characteristics for both flat and curved surfaces, and the effectiveness of film cooling was experimentally verified. Results show that regardless of whether the cooled wall is flat or curved, the supersonic gas film has good wall adhesion characteristics and can effectively cool the wall. In comparison, the cooling effect of supersonic gas film on curved surfaces is better than that on flat surfaces. Increasing the Mach number at the inlet of the cooling gas and blowing ratio can improve cooling efficiency. As the height of the spray seam increases, the film cooling efficiency increases and gradually reaches a constant value. When the height of the spray seam is large enough, the advantage of further increasing the height of the spray seam is not significant.]]></description>
<pubDate>2024/12/3 11:21:15</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[CHEN Bohong,]]></author>
</item>
<item>
<title><![CDATA[Review and prospect of emitter manufacturing technology for ionic liquid electrospray thruster]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208160000002]]></link>
<description><![CDATA[ILET(ionic liquid electrospray thruster), one of the electrostatic micro-thrusters, has recently become a hot topic for researchers. The emitter is the core component that significantly affects the thruster performance, so its manufacturing is considered as one of the key technologies for the ILET development. Combined with the operating principle and the development history of ILET, the characteristics of propellant transport and manufacturing requirements for all three types of emitters, namely capillary, externally-fed and porous emitters, were analyzed. Based on this, the typical manufacturing materials and related manufacturing technologies were reviewed, while the advantages and disadvantages of different manufacturing technologies such as ion etching were summarized and remarked. For the proven manufacturing method of ultrafast laser ablation based on porous material, the development suggestions including emitter design, novel material fabrication, and study on laser-matter interaction mechanism were given.]]></description>
<pubDate>2024/12/3 11:20:54</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[车碧轩,郭大伟,李小康,吴建军,杨云天]]></author>
</item>
<item>
<title><![CDATA[Uncertainty analysis of thrust during variable operating conditions of solid divert and attitude control motor]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202309280000002]]></link>
<description><![CDATA[To investigate the dynamic uncertainty of thrust of the pintle SDACM (solid divert and attitude control motor), the study focuses on the uncertainty of the thrust performance during variable operating conditions of the SDACM was carried out with the consideration of the uncertainties of the geometric parameters of the pintle gas valve. Computation model of the thrust during variable operating condition process of the SDACM was established by combining the working principle of the SDACM, the regular mathematical model of thrust and the zero-dimensional internal ballistic equation. On this basis, the uncertainty propagation was performed by Monte Carlo simulation method according to the uncertainty models of the geometry parameters of the SDACM, and the variation law of the thrust uncertainty over time after the transient motion of the pintle was obtained, thereby the uncertainty analysis of the thrust in the process of variable operating conditions was realized, and the uncertainty variables were weighted in order of importance. Quantification and evaluation of thrust uncertainty in the real-time regulation process of the SDACM can provide more reasonable design requirements for the control system, and save the development cost of the SDACM while meeting the design requirements.]]></description>
<pubDate>2024/12/3 11:19:22</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[gaojingwei,,,,,]]></author>
</item>
<item>
<title><![CDATA[Application of Fiber Bragg grating sensor in real-time monitoring of internal strain of solid rocket motor grain structure]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205240000002]]></link>
<description><![CDATA[Internal strain response monitoring of solid motor grain structure is an important supporting means for structural integrity evaluation and life prediction of solid rocket motor grain. An embedded strain measurement method based on fiber bragg grating sensor was proposed to solve difficult problems in measuring the internal strain response of solid rocket motor grain. The solid rocket motor tester of embedded fiber bragg grating strain sensor was designed, and the cold pressurization test was carried out on the tester. The axial and circumferential strains in the grain structure were obtained under cold pressurization test. The research shows that the test method proposed can obtain the circumferential strain and axial strain in internal grain. The research results can lay a foundation for the further application of fiber bragg grating sensor in the measurement of solid motor grain structure, and provide a reference for the development and application of solid motor monitoring and detection technology.]]></description>
<pubDate>2024/12/3 11:18:52</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[张焘]]></author>
</item>
<item>
<title><![CDATA[Study of the characteristics of Ti/Al/Mg impedance-graded shields under hypervelocity impact]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210090000001]]></link>
<description><![CDATA[In order to explore the hypervelocity impact characteristics of the Ti/Al/Mg impedance-graded shields, the protection characteristics of the impedance-graded shields are simulated, using the AUTODYN finite element software, and compared with the aluminium alloy shields with equal surface density. On this basis, the effects of Ti/Mg, t/D and impact angle θ on the hypervelocity impact characteristics of impedance-graded shields are researched. The results show that the impedance-graded shields has better protective properties than the aluminium alloy shields. The ratio of Ti/Mg has an effect on the clouds expansion characteristics of the external bubble debris within 5%, increasing the ratio of Ti/Mg can reduce the mass of the large debris in the centre of the projectile, and the ratio of Ti/Mg is between 0.625 and 1 for the best performance of shields energy absorption. As the ratio t/D increases, the rate of expansion of the external bubble debris cloud and the mass of the centre projectile becomes smaller, while the energy absorption per unit surface density of the shields decreases. The impact of the impedance-graded shields is advantageous to the dissipation of the kinetic energy of the projectile, but a smaller largest central fragment of the debris cloud. The influence of the " slipping effect" on the impact characteristics of the impedance-graded shields is more significant when θ is greater than 40 or 50°; Finally, the empirical formula of the dimensionless perforation area of the impedance-gradient shields is obtained based on the dimensional analysis.]]></description>
<pubDate>2024/12/3 11:18:15</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[卫国宁,]]></author>
</item>
<item>
<title><![CDATA[Low-frequency fatigue characteristics of NEPE solid propellant]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202404250000002]]></link>
<description><![CDATA[To investigate the damage evolution process of low-frequency fatigue-loaded NEPE (nitrate ester plasticized polyether) solid propellant and get the influence law of fatigue loading history on tensile mechanical properties of NEPE solid propellant, the NEPE solid propellant low-frequency fatigue tests and uniaxial tensile tests with constant strain rate were conducted by the electronic universal testing machine. Based on the microscopic morphology and testing curves of test piece after fatigue loading, the influential mechanism of microscopic and mesoscopic damage on the NEPE solid propellant macroscopic mechanical behavior was further analyzed. Results indicate that the NEPE solid propellant matrix microcracks and voids at the matrix/particle interface are induced by low-frequency fatigue loads, leading to nonnegligible stress-softening behavior and residual strain. During and after fatigue loading, the attenuations of macroscopic mechanical properties of NEPE solid propellant are all exponentially related to the maximum loading strain. Part of microscopic damage by low-frequency fatigue load can recover, while the remaining fatigue damage may enhance the molecular chain orientation ability, and thus lead to the fatigue-strengthening phenomenon in materials.]]></description>
<pubDate>2024/12/3 11:16:19</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[雷勇军,,,,zhangwenqin]]></author>
</item>
<item>
<title><![CDATA[Analysis of the influence mechanism of preload variation on axial connection stiffness of clamp band joint]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209150000001]]></link>
<description><![CDATA[Through the mechanics behavior analysis of each component in the clamp band joint, a method for calculating the axial connection stiffness of the clamp band joint considering the change of preload was proposed. A fine three-dimensional finite element model was established considering the nonlinearity of the structure, and the accuracy of the finite element model was verified by axial tensile stiffness experiment. Combined with the simulation model, the theoretical calculation of the device connection stiffness was modified. Based on the established finite element and computational theoretical model, the influence mechanism of the distribution and variation of the belt tension and the initial belt preload on the device strength and connection stiffness was revealed. The results show that the proposed theoretical model considers the circumferential distribution difference caused by the structure layout and the amplitude variation caused by the axial tensile load of the belt tension, which can accurately calculate the axial connection stiffness of the device and predict the connection failure load, and has important engineering application value.]]></description>
<pubDate>2024/12/3 11:15:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[江  涛,雷勇军,李昊,于宝石,张大鹏]]></author>
</item>
<item>
<title><![CDATA[Automatic computing framework and implementation for supersonic flow]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209230000001]]></link>
<description><![CDATA[The process of grid generation and flow field simulation can be automated to enhance the efficiency of CFD simulation, which has a great potential for applications. This paper proposes an auto-CFD technology framework based on the tie-dye algorithm, which can generate grids automatically and initiate inviscid flow field calculation quickly without geometry clean-up after inputting solid models. A 2D numerical example verifies that the calculation accuracy of this technology is comparable to that of the unstructured finite volume method, but with a significant improvement in calculation efficiency. Moreover, a 2D Auto-CFD software is developed that can start the calculation automatically with hand-drawn models in real time. The Auto-CFD technology is also extended from 2D to 3D space, and the irregular point cloud obtained by laser scanning the car is used as the solid model to demonstrate the adaptability of this technology to complex shape problems. This paper employs the tie-dye algorithm, which is compatible with all finite difference methods and has a strong universality. It is expected to overcome the technical difficulties in the existing Auto-CFD software.]]></description>
<pubDate>2024/12/3 11:14:41</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈洁,刘君,卢俊宇,汪骥,徐春光]]></author>
</item>
<item>
<title><![CDATA[Tension-compression asymmetric viscoelastic plastic constitutive model of HTPB propellant]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206150000004]]></link>
<description><![CDATA[Tensile and compressive creep behavior of propellants in solid motors due to the influence of the gravity and long-term storage might affect the interior ballistics and structural integrity. In order to investigate the change trends of tensile and compressive creep for HTPB propellant, the 1 000s tensile, 1 000s compression and 28-day tensile creep tests were designed and carried out in this work. Meanwhile, the Saint-Venant body and the compressive-tensile asymmetry factor were introduced to establish a propellant viscoelastic plastic constitutive model that takes into account compressive-tensile asymmetry. The range of application of this equation was obtained by fitting and analyzing the parameters in the constitutive equation. The results indicate that the compressive creep process of propellant was mainly dependent on stress level. At the same stress level, viscoelastic deformation of tensile creep is about 1.62 times that of compressive creep, while compressive yield stress is 3.82 times that of tensile yield stress. The tension-compression asymmetric viscoelastic plasticity constitutive model can well characterize the tensile-compression creep response of propellants at the lower stress levels. The conclusions and research method in this work can provide reference for structural integrity analysis and storage life evaluation of solid motor.]]></description>
<pubDate>2024/12/3 11:14:06</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[邓旷威,李海阳,申志彬]]></author>
</item>
<item>
<title><![CDATA[Experimental study of mechanical properties of HTPB propellant under extreme temperature]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202405210000003]]></link>
<description><![CDATA[In order to study the mechanical properties and failure mechanism of solid propellant under extreme low temperature environment, the uniaxial tensile test of a three-component butyl hydroxyl propellant was carried out under different temperatures, wide range of superimposed pressure values and high strain rate conditions by adopting the self-developed wide-temperature-superimposed pressure loading test system and the electron microscope scanning observation of fracture morphology, which analyses the effects of temperature, tensile rate and superimposed pressure values on the mechanical properties of propellant and discusses the damage and destruction mechanism of propellant under different working conditions. The effect of temperature, tensile rate and peripheral pressure value on the mechanical properties of propellant was analysed, and the damage mechanism of propellant under different working conditions was discussed. The results show that when the tensile rate increases, the superimposed pressure increases and the temperature decreases, the elongation of the "dewetting" point of the propellant decreases, the "dewetting" point moves forward, and "dewetting" occurs inside the propellant. There are superimposed pressure and strain rate thresholds, above which the propellant is more prone to "dewetting" behaviour. At low temperature, the maximum elongation of the propellant is more sensitive to changes in high tensile rate, but it has good mechanical properties, its maximum tensile strength and maximum elongation with the increase in superimposed pressure and the trend of increasing; the propellant damage damage form with the decrease in temperature and the increase in tensile rate, the performance of the "dewetting" damage, matrix fracture and particle cracking three damage modes combined.]]></description>
<pubDate>2024/12/3 11:12:26</pubDate>
<category><![CDATA[力学]]></category>
<author><![CDATA[SUN Haitao,,]]></author>
</item>
<item>
<title><![CDATA[Novel leader-following fixed-time cooperative guidance law with impact angle constraints]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206300000001]]></link>
<description><![CDATA[To deal with the problem that multiple missiles cooperatively attack maneuvering targets with impact angle constraints, a novel leader-following fixed-time cooperative guidance law is proposed. Firstly, the leader-following cooperative guidance model is established according to the relative motion between the target and missiles; Secondly, based on the fixed-time sliding mode control theory, the guidance law in the directions normal to the line-of-sight (LOS) is designed, so that the leader and followers can accurately attack the maneuvering target from the desired angles; Then, based on the consistency error function and the fixed-time sliding mode reaching law, a guidance law in the LOS direction of the followers is designed, which fully utilize the information exchange between missiles, and the time-to-go of the followers can quickly achieve consensus with that of the leader missile in fixed time. Finally, simulations and comparison verification indicate that the designed guidance law in this paper has higher control accuracy for time and angle constraints, no singularity and chattering phenomenon, faster convergence speed and the convergence time bound is dependent on the initial states, which fully verifies the effectiveness and superiority of the proposed leader-following cooperative guidance law in this paper.]]></description>
<pubDate>2024/11/26 11:29:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[常新龙,马峰,尤浩,赵久奋]]></author>
</item>
<item>
<title><![CDATA[OVMD-MF algorithm for fiber optic leakage current sensing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207110000001]]></link>
<description><![CDATA[Aiming at Low response and weak measurement ability of the all-fiber optic leakage current sensor in the ship power network, a denoising method based on the combination of variational modal decomposition (VMD) and morphological filtering (MF) was proposed to improve the ability of weak current measurement. The hunter-prey optimization algorithm was used to search for the optimal combination of model number and quadratic penalty term based on the minimum entropy of the Hilbert spectrum, and the intrinsic mode functions component were obtained by completing the variational mode decomposition. The practical modal function component was determined by setting the correlation coefficient threshold to complete the signal reconstruction. The structure factor and scale coefficient of MF were determined by hunter-prey optimization algorithm with the signal-to-noise ratio as the fitness function. The reconstructed signal was subjected to time-domain denoising processing to further denoise in the leakage current signal. This method significantly improve the signal-to-noise ratio and reduce the minimum mean square error to the existing filtering methods by simulation analysis and experimental verification. The leakage current resolution is achieved to 3mA with this denoising algorithm.]]></description>
<pubDate>2024/11/26 11:28:40</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[陈亮,吴健华,张晓锋]]></author>
</item>
<item>
<title><![CDATA[Redundant force suppression method of servo actuation system performance test platform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209010000002]]></link>
<description><![CDATA[In order to solve the problem of the real-time parameter adjustment when suppressing redundant force by the structural invariance compensation method, a mathematical model and a simulation model of a servo actuation system performance test platform were established, respectively. A decoupling control method for speed feedforward compensator was proposed, and a fuzzy controller was designed to suppress the redundant force. And the inhibition effects of the three control methods including the traditional PI control, traditional PI feedforward compensation control and fuzzy PI feedforward compensation control on the redundant force of the test platform were compared. The simulation results show that the loading accuracy of the test platform can be improved by the fuzzy PI feedforward compensation control method with the most significant suppression effect on the redundant force. The effectiveness of this control method was verified by the comparison between the experiments and simulations. This study provides a theoretical reference for the servo actuation system test platform to loading with heavy thrust and high precision.]]></description>
<pubDate>2024/11/26 11:25:31</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[袁斌林,张士峰]]></author>
</item>
<item>
<title><![CDATA[Sample Size Design of Launch Vehicle Combined with SPOT and Bayesian Recursive Estimation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209160000001]]></link>
<description><![CDATA[Aiming at the small sample data of launch vehicle, this paper combine the sequential posterior odd test（SPOT）and Bayesian recursive estimation method, and it can improve the traditional sample size design from hypothesis testing and parameter estimation, respectively. When evaluating the performance indexes of launch vehicle following the normal distribution, the composite equivalent coefficient is introduced to fuse multi-source data, which can make up for the shortage of experimental data or test data. Then, it considers the two types of risks and confidence requirements comprehensively, to design a reasonable and effective evaluation test. Through the analysis of examples, the results verified that the proposed method are authentic and credible, which can reduce the sample size demand effectively, and can be used for the sample size test design of launch vehicle.]]></description>
<pubDate>2024/11/26 11:24:21</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[段晓君,黄彭奇子,张银辉]]></author>
</item>
<item>
<title><![CDATA[Time and Frequency Transfer via LEO Spacecraft in Near Circular Orbit]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210070000001]]></link>
<description><![CDATA[Aiming at solving the problem of using the two-way "Λ" configuration to achieve high-stability time-frequency comparison between the ground station and the LEO spacecraft in near circular orbits, a new method for longer-term stability calculation was proposed. The method used the statistical characteristics of the short-term data to generate pseudo-measurements and fill the data gaps. The validity of the algorithm was verified using data simulated. The Hill equation, the relative motion model in the time-transfer model and the relativistic frequency shift model were combined to analyze and calculate the requirements on the orbit determination. For ps-level stability specifications for one day integration time, the radial and tangential errors are around 10m, and the normal error is about 1200m. For sub-ps level stability specifications for one day integration time, the radial and tangential errors are around 1m, and the normal error is about 120m. The results shows that the error of the orbit determination is not the factor that limits the performance of satellite-ground time-frequency comparison to achieve 0.01ps-level short-term stability and 0.1ps-level long-term stability.]]></description>
<pubDate>2024/11/26 11:23:45</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘通]]></author>
</item>
<item>
<title><![CDATA[Fluctuation error quantization aided improved Cascade protocol]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202308220000001]]></link>
<description><![CDATA[Aiming at the problems of low reconciliation efficiency and key leakage of the classical Cascade protocol, an improved Cascade protocol aided by fluctuation error quantization was proposed. Before reconciliation, the statistical characteristics of the fluctuation difference of channel magnitude feature of legitimate nodes were studied and a fluctuation error quantization method was proposed by using it. Then based on the proposed quantization method, an improved Cascade protocol was designed by grouping and partitioning reconciliation. Numerical results demonstrate that the proposed improved Cascade protocol effectively improve the reconciliation efficiency, reduces the computational complexity required for information reconciliation and the possibility of key information leakage at the cost of partial reconciliation success rate. In addition, compared with the existing key generation schemes, the scheme based on the proposed protocol has a lower key inconsistency rate and a higher key generation rate.]]></description>
<pubDate>2024/11/26 11:22:49</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈宇豪,骆俊杉,王世练,谢顺钦,周壮]]></author>
</item>
<item>
<title><![CDATA[Influence of Tensile Rate on Parallel Rheological Framework Model of HTPB Propellant]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206160000001]]></link>
<description><![CDATA[In order to analyze the effect of different combinations of stretching rates of hydroxyl-terminated polybutadiene binder (HTPB) propellants on the accuracy of the parallel rheological framework model, a nonlinear viscoelastic constitutive model of the propellants was developed based on the parallel rheological framework method. Combined calibration of the constitutive model for different tensile rates, the corresponding constitutive model parameters were obtained and compared with experimental results using finite element models and numerical calculations. The constitutive model errors of the calibration for different rate groups were compared and analyzed. The results showed that the model can be calibrated more accurately when a combination of high rate and low rate groups was used, without the need for extensive experiments at intermediate rates. And the high rate propellant tensile test rate could be up to 3000 mm/min, no need to increase the rate. This analysis gave justified suggestions for simplifying propellant material tests and improving the efficiency of the experiments. Provided a method for rapidly predicting the mechanical properties of propellant materials.]]></description>
<pubDate>2024/11/26 11:22:07</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李道奎,申志彬,徐一航,周仕明]]></author>
</item>
<item>
<title><![CDATA[Progress and development trend of composite solid propellant constitutive model research]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202405170000002]]></link>
<description><![CDATA[As an important energy source of solid rocket motors, the mechanical properties of composite solid propellants have always been the focus of attention in the engineering field. This paper focuses on the macroscopic constitutive model and the fine-scale mechanical model in the characterisation of propellant mechanical properties. The development of the two types of models is systematically sorted out. The differences between the models are clarified. The applicable conditions of various models are pointed out. The difficulties and challenges of macro and fine mechanical models in the characterisation of propellant mechanical properties at the present stage are analysed. The proposal of mechanical models represented by cross-scale mechanical models will help to solve the problem of propellant mechanical property characterisation. The key in the future modelling of propellant mechanical characterization is the experimental research under complex conditions, focusing on the development of high precision and high performance multiscale numerical computation methods, as well as the integration of data-driven technology represented by artificial intelligence technology into model innovation.]]></description>
<pubDate>2024/11/26 11:20:11</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[徐一航,]]></author>
</item>
<item>
<title><![CDATA[Application of improved brain storm optimization in multi-AUVs cooperative search moving targets]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208290000001]]></link>
<description><![CDATA[A cooperative search method of multiple AUV (autonomous underwater vehicle) based on improved BSO (brain storm optimization) algorithm was proposed to search underwater moving targets. The target motion was predicted based on Markov process, both the detection information and prediction information were used to update the target existence  probability. AUVs shared the coordination of pheromones, the target existence probability, and environmental uncertainty , then planed the search path by rolling optimization strategy. The effectiveness and robustness of the proposed method are verified by simulation. The simulation results show that the method can search moving targets under different motion patterns, the search effect is better than the random algorithm, traversal algorithm and BSO algorithm, it is not sensitive to different initial departure positions of AUVs, improving the flexibility of tactical use.]]></description>
<pubDate>2024/11/20 10:16:13</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[高永琪,马威强,王鹏]]></author>
</item>
<item>
<title><![CDATA[Center-constrained contrastive learning with self-ensemble decision for satellite anomaly detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206280000001]]></link>
<description><![CDATA[Telemetry data is the important basis for ground operators to judge the status of the on-orbit satellites. Anomaly detection can effectively ensure the reliable operation of satellites in orbit. To deal with the problem of the existing telemetry anomaly detection algorithms, such as the poor discrimination capability of the feature, and loss of decision-making information, a self-ensemble anomaly detection method based on center-constrained contrastive learning was proposed. The method mapped the normal samples to a compact feature distribution by combining contrastive loss and center loss, and then a multi-view and multi-level ensembled feature decision method was used to obtain the anomaly score of the sample. The method improves the adaptability of the model to the complex working conditions of the satellite. The proposed method is robust to noise, and achieves 21.7% improvement of F1 score than that of the state of the art method. The results of the experiment demonstrate the feasibility of the method, which can provide effective support for satellite operation.]]></description>
<pubDate>2024/11/13 15:21:51</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭国航,胡钛,李虎,刘玉荣]]></author>
</item>
<item>
<title><![CDATA[Simulation of High-power Microwave Effect for UAV’s SAR]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208040000003]]></link>
<description><![CDATA[In terms of the problem that synthetic aperture radar (SAR) in unmanned aerial vehicle (UAV) is easy to be attacked by high-power microwave (HPM) weapons in the complex electromagnetic environment of the battlefield, the field-circuit joint simulation of high-power microwave front-gate coupling of UAV’s SAR was carried out. The model of the SAR’s antenna is established in the CST software. The model of antenna is irradiated with a pulse-modulated sinusoidal signal to simulate the HPM signal, and the antenna port coupling voltage waveform is collected. On the basis of electromagnetic energy front-gate coupling, antenna port coupled voltage signal is injected into the RF front-end circuit modelof SAR, which fully simulated the coupling process of high-power microwave signal from field to circuit. The power input and output curves of RF front-end devices are simulated, and the curves for evaluating the high power microwave front-gate coupling effect of UAV’s SAR are given in combination with the damage or burnout threshold of the devices. The simulation results show that the low noise amplifier in the RF front-end circuit of SAR receiver is the main target of HPM signal damage. At the same time, HPM signal will trigger a spike leak in the PIN limiter, which threatens the low noise amplifier of the  subsequent circuit.]]></description>
<pubDate>2024/10/21 9:43:54</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[陈亚洲,沈衍,王玉明]]></author>
</item>
<item>
<title><![CDATA[Fast software implementation of the block cipher uBlock]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204060000001]]></link>
<description><![CDATA[To optimize the software implementation of block cipher uBlock algorithm, the AVX2（Advanced Vector Extension 2) instruction set supporting 256-bit data width was implemented, the automatic optimization level of the compiler was increased, optimizing the calling process of functions, and the methods of data storage structure optimization, high-level parallelism and low latency instruction logic optimization were used in order to implement parallel computing under the single-thread condition. Using this efficient combination method, the speed values of the software implementation of uBlock-128/128 algorithm, uBlock-128/256 algorithm and uBlock-256/256 algorithm are 269%, 182% and 49% higher than the original code. Based on these optimization methods,the implementation of single-key scenario and multi-key scenario are given for three algorithm versions of uBlock-128 /128, uBlock-128/256 and uBlock-256/256.]]></description>
<pubDate>2024/10/9 18:16:00</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[高莹,胡洋,田蕾,汪龙昕,伍前红,严宇,张宇鹏]]></author>
</item>
<item>
<title><![CDATA[Experimental design of the effect of ablation on the opening process of the Soft Insulator of Pulse Solid Rocket Motor]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206290000002]]></link>
<description><![CDATA[Aiming at the problem that the soft insulator of pulse motor can not accurately describe its state and regular in the actual working process, a soft insulator opening test system was designed, which approximately simulated the working process the soft insulator in the pulse motor. The opening characteristics of the ablative and non ablative the soft insulator was compared, and the deformation law of the ablative and non ablative interlayer from the mechanism was explained by the means of scanning electron microscope. The test results show that the ablation rate calculated by the ablation simulation test is approximately equivalent to the insulator of a test pulse motor, and the relative error can be controlled within 5%; the deformation of the non ablated insulator is “Valley pile” and the deformation of the ablated insulator is “Bulb”. The established soft insulator layer opening test system, which provides a feasible technical approach and means for the design and test verification of the soft insulator of pulse motor.]]></description>
<pubDate>2024/10/9 18:09:23</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[卞云龙,李海阳,申志彬,王志强,朱洪兵]]></author>
</item>
<item>
<title><![CDATA[Novel leader-following fixed-time cooperative guidance law with impact angle constraints]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206300000001]]></link>
<description><![CDATA[To deal with the problem that multiple missiles cooperatively attack maneuvering targets with impact angle constraints, a novel leader-following fixed-time cooperative guidance law is proposed. Firstly, the leader-following cooperative guidance model is established according to the relative motion between the target and missiles; Secondly, based on the fixed-time sliding mode control theory, the guidance law in the directions normal to the line-of-sight (LOS) is designed, so that the leader and followers can accurately attack the maneuvering target from the desired angles; Then, based on the consistency error function and the fixed-time sliding mode reaching law, a guidance law in the LOS direction of the followers is designed, which fully utilize the information exchange between missiles, and the time-to-go of the followers can quickly achieve consensus with that of the leader missile in fixed time. Finally, simulations and comparison verification indicate that the designed guidance law in this paper has higher control accuracy for time and angle constraints, no singularity and chattering phenomenon, faster convergence speed and the convergence time bound is dependent on the initial states, which fully verifies the effectiveness and superiority of the proposed leader-following cooperative guidance law in this paper.]]></description>
<pubDate>2024/10/9 18:06:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[常新龙,马峰,尤浩,赵久奋]]></author>
</item>
<item>
<title><![CDATA[Noise-aware MEMD-XGBoost method for GNSS vertical time series modeling and prediction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206300000002]]></link>
<description><![CDATA[The study of GNSS(Global Navigation Satellite System) vertical time series is helpful for monitoring and analyzing the movement of crustal plates, and the prediction of GNSS vertical time series can provide an important basis for judging the movement trend. A MEMD-XGBoost model was constructed based on empirical mode decomposition and eXtreme gradient boosting algorithm for GNSS vertical time series prediction and analysis. In order to verify the prediction performance of the model, the vertical time series data of 8 GNSS stations were selected for prediction experiments. The feature construction results show that multiple empirical mode decomposition can accurately extract the original time series information and provide effective features. The modeling results show that the MEMD-XGBoost model can effectively improve the data quality. The prediction results show that the prediction results of the MEMD-XGBoost model have high precision and accuracy, and the degree of error dispersion is small, the model has strong stability and robustness, and can better predict the movement trend and seasonal changes in the U direction of the GNSS station. Therefore, the model can be applied to GNSS vertical time series modeling and prediction research.]]></description>
<pubDate>2024/10/9 18:00:34</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[贺小星,李祯,鲁铁定]]></author>
</item>
<item>
<title><![CDATA[The performance evaluation of PPP-B2b compared with CNES RTS product]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207140000005]]></link>
<description><![CDATA[The PPP-B2b service based on Beidou GEO satellites broadens the real-time PPP application scenarios. For analyzing PPP-B2b actual service performance, PPP-B2b data and IGS data for a period of 30 days as well as offshore shipborne dynamic data were used for evaluating orbit and clock offset accuracy and testing real-time PPP positioning performance, at the same time, CNES archived products were used for control experiment. The radial accuracy of BDS-3 and GPS track of PPP-B2B service is 0.07 m and 0.089 m respectively, worse than that of CNES product and BDS-3 clock offset accuracy is 0.029 m, better than 0.057m of CNES product. accuracy. In static PPP based on PPP-B2B, BDS and BDS-3+GPS average convergence time is less than 20 minutes, better than that of GPS, and the convergence accuracy is higher. than GPS. In kinematic PPP, BDS and BDS+GPS average RMS values in the NEU directons are better than 11 cm, better than 26 cm of GPS. In offshore measure testing, BDS+GPS average RMS values of PPP-B2b in the NEU directons are 0.028 m, 0.074 m, 0.081 m, and the convergence time is 12.4 min.]]></description>
<pubDate>2024/10/9 17:54:54</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[贺凯飞,姬生月,王振杰,郑千里]]></author>
</item>
<item>
<title><![CDATA[Research on high-rate pulse charging characteristics of lithium-ion batteries under different state of charge]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207200000002]]></link>
<description><![CDATA[With the development of lithium battery technology, it has been more and more widely used in military and civilian fields. In order to further expand the application range of lithium batteries, the high-rate pulse charging characteristics of lithium-ion batteries in different state of charge were studied based on the high-power energy recovery in electromagnetic launch scenarios. Based on the pseudo-two-dimensions electrochemical model, a high-rate pulse charging model of high-power lithium batteries was established by optimizing the diffusion coefficient. This model was used to analyze the variation of lithium deposition potential of lithium batteries charged by high-rate pulse with different state of charge. Through the cycling experiment and post-mortem analysis of lithium batteries, the aging behavior and aging mechanism of lithium batteries in different state of charge high-rate pulse charging are studied, and the aging mechanism is consistent with the simulation analysis results. The above research results can not only provide a reference for the application of lithium batteries in high-power energy recovery scenarios, but also provide a reference for the optimization of fast-charging lithium batteries.]]></description>
<pubDate>2024/10/9 17:53:59</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[龙鑫林,武杨洋]]></author>
</item>
<item>
<title><![CDATA[Collaborative coverage path planning algorithm for Multi-Area by Truck-supported multi-UAV]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207260000002]]></link>
<description><![CDATA[To study the application of Unmanned Aerial Vehicles (UAVs) in area reconnaissance, a cooperation mode of truck-supported multi-UAV coverage reconnaissance and a collaborative path planning algorithm is proposed. With the goal of minimizing the task completion time, a mixed integer programming model was established considering the road constraints on the vehicle path and the energy constraints of the UAVs. A heuristic algorithm based on the idea of iterative relaxation was designed to solve this problem. In the test scene of 60 square kilometers, 16 target areas are randomly set. The proposed algorithm realizes the coverage path planning of the truck and the UAVs, and the total task time is 1.593 h, which verifies the feasibility of the model and the effectiveness of the algorithm.]]></description>
<pubDate>2024/10/9 17:07:43</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[陈洪辉,田双喜,,]]></author>
</item>
<item>
<title><![CDATA[User-oriented UAV-aided MEC network performance optimization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205310000001]]></link>
<description><![CDATA[The UAV-assisted mobile edge computing network is used for efficient data communication with wireless terminals, which breaks the situation of fixed deployment of traditional edge servers. The UAV has high line-of-sight (LOS) and high mobility, which makes air-ground communication possible, and improves communication efficiency and user experience. On the premise of ensuring users" QoE, the objective function is established to minimize system energy consumption. In order to solve the problem of non convex objective optimization, a multi-objective joint optimization algorithm for optimizing system energy consumption is proposed based on the block coordinate descent method (BCD), by jointly considering the trajectory of the UAV, the size of the user unloading task and the power of the UAV. Simulation results show that the proposed algorithm can converge quickly. Compared with other existing benchmark schemes, the designed scheme reduces the computing energy consumption of end users by 12.8% while ensuring user QoE, and the system performance is significantly improved.]]></description>
<pubDate>2024/10/9 17:05:34</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[武清清,薛建彬,张海军]]></author>
</item>
<item>
<title><![CDATA[Particle swarm optimization based data imputation method for mixed features]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207150000001]]></link>
<description><![CDATA[Aiming at the deficiency of traditional data imputation methods in effectively using the label information and random characteristics of missing data, a particle swarm optimization based imputation method for mixed features was proposed. The value of continuous feature was modeled as Gaussian distribution, and the mean and standard deviation were used as optimization parameters. The value probability of categorical features was optimized as a parameter. The classification accuracy rate was used as the optimization target to make full use of random information of label information and missing data. Four statistical methods and two evolutionary algorithm based imputation methods were used to compare the results on six typical classification datasets. The results show that the proposed method significantly outperforms other comparison algorithms in terms of classification accuracy indicator, and has better time overhead at the same time, which can effectively solve the data missing problems of mixed features.]]></description>
<pubDate>2024/10/9 17:04:05</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李庚松,刘坤,刘艺,秦伟,任小广,王强,郑奇斌]]></author>
</item>
<item>
<title><![CDATA[A 3D path planning method for underwater vehicle based on real terrain]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202301040000003]]></link>
<description><![CDATA[Aiming at the problem of poor applicability of current path planning results for underwater vehicles, a three-dimensional path planning algorithm for underwater vehicles based on improved particle swarm optimization was proposed. The algorithm builds a Voronoi map based on the real terrain data of sea area, and uses Dijsktra algorithm to generate the initial path set that meets the requirements of navigation safety as the initial particles of particle swarm optimization algorithm, so the generation efficiency of initial particles is improved. Meanwhile, the particles' positions update method is improved based on the location of adjacent nodes on the path, which makes the planned path more smooth and more suitable for underwater vehicle navigation. The simulation results show that the proposed algorithm is more robust and has better applicability than the traditional particle swarm optimization algorithm in path planning.]]></description>
<pubDate>2024/10/9 16:53:53</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[包长春,程兴华,]]></author>
</item>
<item>
<title><![CDATA[Stepwise star map recognition method using rotation-invariant features]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206140000001]]></link>
<description><![CDATA[A new star map identification method was proposed to solve the problem of "space lost" of star sensor. The distance mapping vector was used to calculate the dispersion between the reference star and the navigation star, shorters the list of the navigation star database, and obtains the candidate navigation star. The Angle feature vector and the distance feature vector were used to match the unique corresponding navigation star of the reference star through the similarity calculation. The feasibility of this method was evaluated by the performance test of simulated star map and real star map. The results show that the proposed method is robust to noise and can guarantee the recognition rate of more than 93.8% under the influence of location noise, false stars and missing magnitude.]]></description>
<pubDate>2024/10/9 16:52:32</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[段  辉,李新宇,闫兴旭,张志利,赵军阳,周召发]]></author>
</item>
<item>
<title><![CDATA[Evaluation method of gas-solid two-phase mixed combustion process in solid rocket ramjet]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202308010000001]]></link>
<description><![CDATA[In order to reasonably evaluate the primary gas/air mixing combustion process in the secondary combustion chamber of solid rocket ramjet, a particle mixing degree and particle combustion efficiency based on particle mass concentration were proposed. The numerical simulation method of engine is established and verified by ground test. Aiming at the mixing combustion process in the afterburner under different working conditions, the changing trend of mixing degree and combustion efficiency in different definitions was compared by numerical simulation. The results showed that the proposed particle mixing degree and particle combustion efficiency showed the greatest correlation, and the average maximum information coefficient reached 0.9163 under different working conditions. Moreover, the primary gas/air mixing and combustion process show the following correlation laws: the particle combustion efficiency increases with the increase of particle mixing degree, and when the particle mixing degree exceeds a certain threshold, the particle combustion efficiency remains relatively stable.And the law is verified by experiments.]]></description>
<pubDate>2024/10/9 16:48:57</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[黄利亚,孟梁,薛鸿涵,杨和,张家瑞]]></author>
</item>
<item>
<title><![CDATA[Improved design of piezoelectric injector actuator drive control circuit]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203230000001]]></link>
<description><![CDATA[For the self-developed piezoelectric injector and actuator, a compensation control strategy based on voltage feedback and an accurate and reliable six-stage circuit driving mode were designed, and the closed-loop compensation control of the driving voltage at both ends of the actuator inside the piezoelectric injector was realized. It improves the utilization rate of circuit energy and reduces the peak current. At the same time, the drive circuit was tested. The test shows that the charging time is shortened by 0.06ms, the discharge time is slightly shortened by 0.01ms, the minimum pulse width for the actuator to reach the maximum displacement is shortened to 0.3ms, and the peak current is reduced by 3A , the drive circuit has improved in both sensitivity and reliability.]]></description>
<pubDate>2024/10/8 8:28:31</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[刘楠,刘振明,童大鹏]]></author>
</item>
<item>
<title><![CDATA[Attitude control of propeller-fin cooperative propulsion for the underwater robot]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206080000003]]></link>
<description><![CDATA[In order to improve the maneuverability and stability of underwater robots, a novel underwater robot driven by quadrotor and undulating fin is developed and its attitude control algorithm is proposed. The kinematics and dynamics model of cooperative propulsion by the propellers and the fin is established. The resistance coefficient is obtained by fluid numerical simulation. And the six-degree-of-freedom dynamic model of the robot is constructed. The attitude control strategy using hybrid drive of propellers and fin is proposed. A four degrees of freedom cascade  proportional-integral-derivative controller and a control allocation algorithm are designed. The simulation model is established in Matlab/Simulink software, in which pose curves in fixed depth cruise motion, heave motion and pivot steering motion are simulated and analysed. In addition, the influence of random interference on attitude control is simulated. The experimental results show that the robot has good attitude control performance. At the maximum undulating frequency, the attitude angle error of the prototype is less than ±4°; and the depth error is less than ±5cm. The simulation and experimental results verify the feasibility of the novel underwater robot and the attitude control algorithm of propeller-fin cooperative propulsion.]]></description>
<pubDate>2024/10/8 8:27:51</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[罗自荣,尚建忠,夏明海,徐毓泽,殷谦,曾潇丰]]></author>
</item>
<item>
<title><![CDATA[Multi-Station fusion sorting algorithm for radar signals based on PCN trend]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206090000003]]></link>
<description><![CDATA[With the continuous development of electronic countermeasure technology, the electromagnetic environment is becoming more and more complex. Aiming at the situation that the existing sorting algorithms are more or less dependent on prior information or difficult to adapt to multi-function radar, a multi station fusion sorting algorithm based on set pair potential of partial coefficients was presented. The partial connection number (PCN) parameter was introduced from the set pair analysis in the mathematical field to establish a clustering model . On this basis, the decision level fusion of clustering results was carried out by using the arrival time difference parameter in the multi station cooperation mode. The actual measurement data and simulation results show that the algorithm can adapt to multi-functional radar systems such as search, acquisition and tracking,and realize the accurate clustering and fusion of radar pulse signals without any prior information. The sorting success rate is more than 97% in case of the jamming pulse ratio is lower than 60%.]]></description>
<pubDate>2024/10/8 8:27:09</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李金凯,李品,刘鲁涛]]></author>
</item>
<item>
<title><![CDATA[Traffic sign detection and recognition algorithm based on improved YOLOv5s algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207050000001]]></link>
<description><![CDATA[Aiming at the problem of low detection and recognition accuracy of traffic signs in complex traffic scenes, a target detection and recognition method based on improved YOLOv5s model is proposed. Firstly, ISODATA algorithm is used for clustering analysis of TT100K data set to select the prior frame which is more suitable for the size of traffic signs. The new prior frame can cover the size of traffic signs more comprehensively and improve the detection accuracy of the model. Secondly, the difference of the width ratio and height ratio between the real frame and the prior frame is used to replace the difference of the width ratio and height ratio between the real frame and the prior frame to improve the positioning loss function, which solves the problem of penalty disappearing when the width ratio is the same but the actual size is different. Finally, the feature graph is further up-sampled to obtain a larger scale feature graph and then fused with the backbone network feature graph to obtain a new feature graph with richer feature information for small target detection and recognition, which improves the accuracy of small target detection and recognition. Experimental results show that compared with the YOLOv5s algorithm, the improved algorithm can improve the average accuracy by 9.5%.]]></description>
<pubDate>2024/10/8 8:26:23</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[郭君斌,于传强,于琳]]></author>
</item>
<item>
<title><![CDATA[Location Selection Method of Missile Launching Position  Based on GIS and Improved TOPSIS]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205290000001]]></link>
<description><![CDATA[In order to accurately and effectively determine the location selection of missile launch position, overcome the disadvantages of strong subjective factors and the difficulty to judge the pros and cons of the location selection scheme in the current position location process, a two-stage position location selection method based on Geographic Information System (GIS) and improved Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) is proposed. In the primary selection stage, the index system affecting the location selection of launch position is constructed, and the comprehensive weight of each index is obtained by using the improved analytic hierarchy process. Aiming at the quantitative index, the multi-loop buffer zone is established by GIS technology for spatial analysis, and the selection scheme of launch position location selection is obtained. In the precise selection stage, combined with the scores of each index of the alternative scheme, and aiming at the qualitative index, the grey correlation improved TOPSIS is used for comprehensive evaluation to obtain the optimal location scheme of missile launching position. The example verification shows that this method has good operability and applicability, and the influence of subjective factors is small, which can provide decision-making basis for the location selection of missile launching positions.]]></description>
<pubDate>2024/10/8 8:24:08</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李亚雄,王顺宏,杨新智,张鑫伟,赵久奋]]></author>
</item>
<item>
<title><![CDATA[Quasi-sequence decoupling method for life reliability optimization of turbine blades]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207060000001]]></link>
<description><![CDATA[It was difficult to balance the efficiency and accuracy of multi-mode life reliability-based design optimization (RBDO) of turbine blades with film holes in the presence of random uncertainty, a quasi-sequence decoupling method of RBDO based on adaptive Kriging surrogate model was proposed. The construction process of the limit state surface surrogate model in reliability constraint was updated in real time with the search iteration of the design parameters, and the surrogate model strictly ensured the accuracy of surrogate model and feasible region judgment in each iteration step. The proposed method avoided updating the limit state surface in non-access domain of design parameters, so that obtaining a high convergence speed and strong robustness. The embedded real-time update strategy built a cooperative surrogate model in the extended space and shares training sample points, and adaptively trained the Kriging model of the objective function until convergence, so that it was able to ensure the surrogate accuracy and significantly improve the optimization efficiency. In addition, an integrated and automatic simulation system for life reliability optimization was developed, which verifies the high efficiency and engineering feasibility of the proposed method and software in the turbine blade life RBDO problem.]]></description>
<pubDate>2024/10/8 8:23:29</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[贾贝熙,刘波,宋坤苓,谭健美,邢晨光]]></author>
</item>
<item>
<title><![CDATA[Experimental Investigation on Frost Growth on the Cold Surface under High Air Temperature Conditions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206170000002]]></link>
<description><![CDATA[The precooler is one of the core components of the Hypersonic Precooled Combined Cycle Engine (HPCCE). Frost formation on the air side of the microchannels of the precooler reduces the performance of the precooler much. An experiment was conducted to investigate the frost/condense droplet growth characteristics on three different irregular surfaces of different surface roughness (Ra=0.97μm,Ra=1.78μm,Ra=1.92μm) under the high air temperature conditions(Ta=50℃). The effect of the air temperature(Ta=50℃ and 18℃), surface temperature (Tw=-10.9℃,-23.0℃,-28.0℃) and the irregular surface structure on frost crystal/condense droplet growth are studied. What is more, the densification mechanism of the frost layer is summarized and analyzed. The results show that the frost crystals grow faster as the air temperature increases or when the surface temperature decreases. It is also found that the droplets prefer to form on the edges of the samples. The condensed droplets near the edges of the samples grow much faster than those far away from the edges. Besides, the influence of the surface structure not only exists in the early stage of frost growth but also in the whole experiment process. The influence mechanism of the irregular surface structure is analyzed. It should be noticed that further research on the frosting mechanism of the irregular surface is still needed.]]></description>
<pubDate>2024/10/8 8:21:25</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[岳晓菲,]]></author>
</item>
<item>
<title><![CDATA[Optimal Control Design Method for Missile Three-Loop Autopilot]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303210000001]]></link>
<description><![CDATA[To optimize the design process of an autopilot and find the optimal design parameters, a new design method based on optimal control for a three-loop autopilot was proposed. It generates a three-loop autopilot topology by designing the cost function of the optimal control problem, and obtains multiple parameters of the three-loop autopilot by solving the optimal control problem. The impact of penalty weights in the cost function on the performance indicators of the autopilot was further studied and analyzed. Experimental results show that the three-loop autopilot designed by optimal control method has better performance compared with traditional design methods. And it also has good robustness against model-parameter uncertainties and unmodeled high-frequency dynamics of the system.]]></description>
<pubDate>2024/9/29 8:21:30</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[白圣建,徐婉莹,张巍,郑永斌]]></author>
</item>
<item>
<title><![CDATA[Multi-scale feature extraction and feature selection network for radiation source identification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211290000001]]></link>
<description><![CDATA[Convolutional neural networks currently applied to radiation source identification process the time-series IQ( in-phase and quadrature-phase) signals in two ways: one way transforms them into images, and the other way extracts shallow features of the IQ time-series data. The former way leads to a large computational effort of the algorithm, while the latter way leads to a low accuracy of the recognition rate. To address the above problems, a multi-scale feature extraction and feature selection network was proposed. To address the above problems, a multi-scale feature extraction and feature selection network was proposed. After inputting the IQ signal, the shallow and multi-scale features of the IQ signal were extracted by the multi-scale feature extraction network. Then the data dimension of multi-scale features was reduced by the feature selection network. Feature enhancement was achieved by the adaptive linear rectification unit, and a single fully connected layer was used to classify the radiation source.Comparison experiments with ORACLE(Optimized Radio clAssification through Convolutional neuraL nEtworks), CNN-DLRF(Deep Learning for RF Device Fingerprinting in Cognitive Communication Networks) and IQCNet (8,32,3)( (convolutional neural network structure based on IQ correlation features) on the FIT/CorteXlab RF fingerprint recognition dataset show that the proposed network improves the recognition accuracy and reduces the computational effort to some extent.]]></description>
<pubDate>2024/9/27 8:56:27</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[丁宦城,王文钦,张顺生]]></author>
</item>
<item>
<title><![CDATA[Constellation configuration and coverage analyses of Starlink phase III]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205230000001]]></link>
<description><![CDATA[Based on the synchronous orbit precession, the constellation evolution of Starlink Phase I and Phase II is analyzed, the problems of multiple Walker-δ sub-constellation configuration are revealed, the mechanism of the recursive orbit and common track constellation configuration of Starlink Phase III is studied, and the coverage characteristics is simulated and analyzed. The results show that: the recursive orbit and common track satellite chains with different inclination can achieve synchronous precession with small differences in orbital altitude, and have continuous and compact ground coverage bands, which has the obvious advantages of more stable configuration, better coverage performance, more convenient control and application, and lower comprehensive cost compared to the multiple Walker-δ sub-constellation configuration, especially suitable for giant LEO Internet satellite systems. This study can provide a reference for accelerating the construction of similar satellite systems in China.]]></description>
<pubDate>2024/8/27 15:37:25</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[骆  盛,王  迪,王  磊,王  勇]]></author>
</item>
<item>
<title><![CDATA[Simulation analysis on the thermal characteristics of a 5A emission current hollow cathode]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205160000001]]></link>
<description><![CDATA[The thermal electron emission hollow cathode is the key component of the ionization of gas and neutralization of ion thruster beam current. Its temperature distribution directly affects the in-orbit performance and service life of the thruster. In this paper, a thermal simulation model of 5A emission current hollow cathode is established by using finite element method (FEM), and the model verification and temperature analysis under typical working condition are investigated. The results show that the model can better reflect the energy transmission process inside the hollow cathode. The comparison error between the simulation results and the test results of the balance temperature of hollow cathode is less than 5%. The temperature difference of hollow cathode is mainly caused by heating current. The ambient temperature mainly affect the external components of hollow cathode, and the high ambient temperature under the influence of solar irradiation, which is more conducive to the start-up of the thruster. When the hollow cathode is heated and in self-sustaining discharge state, the temperature of the emitter reaches 2122℃ and 2126℃ under the ambient temperature is 0℃ and 94℃, respectively, which is close to the temperature resistance limit of the emitter. Therefore, the hollow cathode must avoid the extreme condition.]]></description>
<pubDate>2024/7/20 18:02:42</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[代鹏,耿海,谷增杰,孙明明,王东升]]></author>
</item>
<item>
<title><![CDATA[Reconstructed Filter Design for Broadband Communication Interference Cancellation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210280000002]]></link>
<description><![CDATA[A new subband division and reconstruction framework around the requirements of broadband communication interference cancellation was proposed, and the subband division filter banks and the reconstruction filter were designed which simplified the conditions for complete reconstruction and made the reconstruction filter had the characteristics of complementary transition in band amplitude. The simulation and experiment results show that the reconstruction filter can effectively reduce the bit error rate of reconstructed communication signals and solve the spectrum fluctuation phenomenon in the process of subband signal splicing. Therefore, the subband division and reconstruction framework and the design of the reconstruction filter proposed can effectively reconstruct the frequency-hopping communication signal, which provide new technical route and theoretical method for subband division and reconstruction engineering practice of broadband interference cancellation.]]></description>
<pubDate>2024/7/20 18:02:42</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[何方敏,李亚星,刘宏波,孟进,王  泽,张雲硕]]></author>
</item>
<item>
<title><![CDATA[A Precise Analysis and Measurement Method for TSN Delay Composition]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205120000001]]></link>
<description><![CDATA[Time-Sensitive Networking (TSN) is a promising deterministic networking technology that guarantees the deterministic transmission for time-critical traffic by planning and reserving time resources on switching paths. The delay constraint adopted by the TSN planning takes the time period named Δt as a crucial parameter. As there is difference between the delay parameters provided by TSN standard and the Δt, calculating Δt based on the standard delay parameters inevitably adds additional waiting delay, which we call bubble delay. We analyze the negative impact of the bubble delay on the decreasing planning success rate and increasing the end-to-end transmission delay, and propose a bubble-free delay constraint by analyzing the delay composition of Δt in a fine-grained manner. Finally, we build a real environment based on two customized TSN devices and test the delay constraints. The results show that in the experiments with bubble delay constraints, the bubble delay accounts for at least 26.4% of the end-to-end transmission delay. In the experiments testing bubble-free delay constraints, the bubble delay was eliminated and the planning success rate was improved by 8.9% to 39.1%.]]></description>
<pubDate>2024/7/20 18:02:42</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[付文文,姜旭艳,全  巍,孙寅涵,孙志刚]]></author>
</item>
<item>
<title><![CDATA[A parallel rendering algorithm for large-scale particles by wrapping surface reconstruction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205120000003]]></link>
<description><![CDATA[A parallel rendering algorithm based on wrapping surface reconstruction was proposed for large-scale particles in distributed environments so as to visualize the particles in high quality. In the algorithm, particle clusters were represented and then rendered in the form of a series of continuous surfaces, where the distribution of the physical variable was also shown. The algorithm was parallelized in distributed environments, thus more than a hundred million particles can be visualized using a lot of processing cores. In terms of algorithm implementation, the issue of inter-block cracks during parallel computation was be solved, and the method for rapidly finding adjacent particles was presented. Meanwhile, based on visibility culling, the particle data were filtered and thus the rendering efficiency was improved. As a result, smooth surfaces with lighting can be used to expressively exhibit inner structures and physical variable distributions of particle clusters for large-scale particles. The experiment results demonstrate that using the proposed algorithm, the rendering of more than 100 million particles is realized in five seconds on 512 processing cores with about 60% parallel efficiency. The proposed algorithm has been successfully applied to practical simulation applications such as massively parallel non-equilibrium molecular dynamics simulations.]]></description>
<pubDate>2024/7/20 18:02:42</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[艾志玮,曹  轶,王华维]]></author>
</item>
<item>
<title><![CDATA[Simulation analysis of detecting capability of IR system for fight plane]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205130000001]]></link>
<description><![CDATA[After establishing the infrared radiation ellipsoid modal of plume, the way for calculating 3～5μm IR of the fight plane was improved and the IR space distribution curve of the fight plane was developed. The curve showed that there are four directions which has the same maximum IR at the plane nose and the plane rear. Considering the IR absorption of O3 in 3-5μm band, the IR transmitting obstruction by the ground and the detecting object in outer atmosphere, the IR atmosphere transmitted model was further improved with the concept of the IR transmission distance in the atmosphere. The operation range curves of two kinds IR system which use different IR detector were obtained by the IR system detection model. The curves showed that the detection directions which have the maximum operation range are different from the radiation directions which have the maximum IR intensity of the fight plane. The curves also showed that the atmosphere absorbing reduction is more important than the IR intensity of the fight plane if the operation range of IR system is very far.]]></description>
<pubDate>2024/7/20 18:02:42</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[童忠诚,王亮,吴俊]]></author>
</item>
<item>
<title><![CDATA[Sub-global Parallel Optimization Design of Servo Performance of Electric Cylinder Lifting Mechanism]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205060000002]]></link>
<description><![CDATA[Abstract: Aiming at the influence of the nonlinear part of the electric cylinder lifting mechanism on the servo performance of the weapon station, the optimization method of servo performance was studied based on the application background. Firstly, the means of gain fluctuation, gap, unbalanced moment, and friction in the designable nonlinear part were analyzed; Secondly, the mathematical models, design constraints, and objective optimization functions of kinematics, dynamics, and control strategies were established based on the mechanism layout and controller parameters; Finally, a sub-global parallel optimization method was proposed. The multi-objective optimization based on the interior point method was carried out for the designable nonlinear part, and the local optimization problem of local serial optimization is solved. The composite control strategy based on PI controller + DOB observer was designed separately, and the mismatch problem between the mechanical inertia parameters, controller parameters, and observer nominal model was solved. It is verified that the optimization results of the sub-global parallel optimization method are better on the whole and more in line with the engineering practice.]]></description>
<pubDate>2024/7/20 18:02:42</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[范大鹏,任广安,万子平,谢馨,郑杰基]]></author>
</item>
<item>
<title><![CDATA[Dynamic modeling and analysis of carrier-based aircraft and arresting hook]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205060000003]]></link>
<description><![CDATA[Arresting hook of carrier-based aircraft plays an important role in arresting process, its main function is connecting aircraft and arresting cable and thus to transmit force and motion between aircraft and arresting gear. To study the influence of characteristics of arresting hook on arresting results, the rigid body dynamics model of the plane motion carrier-based aircraft was established, the effect of longitudinal cushioning of the arresting hook was considered and the rigid body dynamics model of the spatial motion arresting hook was established. Lagrange’s equation of first kind was employed to establish the revolute pair model of the aircraft and the arresting hook. The dynamics models of the system consists of the carrier-based aircraft and its arresting hook were finally established and the models were united with dynamics model of arresting gear to simulate the arresting process. The experiment of the arresting process of certain type aircraft was carried out. The experiment results and simulation results of the arresting process were compared and analyzed. The effectiveness and accuracy of the dynamics model established in this paper were demonstrated. The significant influence of characteristics of the arresting hook on arresting overload was revealed.]]></description>
<pubDate>2024/7/20 18:02:42</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[丁智深,刘勇,欧阳斌]]></author>
</item>
<item>
<title><![CDATA[Angular resolution analysis of four-channel mainlobe jamming cancellation for monopulse at subarray level]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209020000001]]></link>
<description><![CDATA[In this paper, the four-channel mainlobe interference cancellation technique for monopulse radar at subarray level is studied. Firstly, the signal model of four-channel interference cancellation at two-dimensional subarray level is established. Based on the signal-to-noise ratio analysis, a method to quantitatively characterize the angular resolution of mainlobe interference cancellation technique is proposed. Subsequently, the analytical expression of the angular resolution of interference cancellation is derived, and the theoretical boundary of blind zone is defined. Finally, correctness of this analytical expression is verified by simulation and experiment. Conclusions of this paper can provide reference for theoretical boundary analysis and engineering implementation of four-channel mainlobe interference cancellation technique.]]></description>
<pubDate>2024/7/20 18:01:10</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[郭宇,刘让,孟进,吴灏]]></author>
</item>
<item>
<title><![CDATA[High Efficient Training Method of MiniGo on Large-scale Heterogeneous Computing Platform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206270000001]]></link>
<description><![CDATA[An efficient multi-level parallel training method suitable for training MiniGo agents on large-scale heterogeneous computing platforms was proposed, including task level parallelism between nodes, CPU-DSP heterogeneous parallelism and DSP core parallelism. Efficient I / O deployment and eliminated the bottleneck of network communication was realized. A heterogeneous computing memory management oriented to CPU-DSP shared memory structure was proposed to reduce the data handling between heterogeneous devices. Shared memory programming optimization was realized, and the dense convolution calculation operator acceleration optimization was realized by DSP. Results show that compared with 16 core CPU calculation, the maximum acceleration ratio of single core DSP operator acceleration is 16.44, In this method, the scale of computing nodes is expanded from 1067 to 4139, the time required to reach the given termination condition is reduced from 43.02 hours to 16.1 hours, and the expansion efficiency is 69.1%. Evaluation shows that this method can realize the efficient parallel training of MiniGo on large-scale heterogeneous computing platforms.]]></description>
<pubDate>2024/7/20 17:15:39</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[窦勇,贺周雨#,姜晶菲,李东升,李荣春#,乔鹏]]></author>
</item>
<item>
<title><![CDATA[Numerical simulation of transverse combustion instability in a rectangle model rocket combustor]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205100000002]]></link>
<description><![CDATA[To study the transverse combustion instability characteristics of the rocket combustor, numerical simulations of transverse combustion instability in a model rocket combustor were conducted based on the detailed chemical reaction mechanism (GRI Mech 3.0) and the FGM (flamelet-generated manifolds) method. Accuracy of the numerical model was verified by comparing it with the experimental data. Pressure field was analyzed by the DMD (dynamic mode decomposition) method, and the dynamic characteristics of the flow fields were investigated. Driving characteristics of combustion instability were quantitatively estimated by Rayleigh Index. It is found that the transverse combustion instability that occurred in the experiment can be effectively captured by the numerical model. Dominant frequency identifi by the numerical study differed from the experimental value by less than 1%. Transverse pressure oscillations in the combustion chamber are coupled with that the longitudinal mode in the oxidizer post, leading to the pulsated propellant mass flow rate. Driving regions of combustion instability are mainly located on both sides of the combustion chamber, and the most marginal injectors played a critical role in keeping combustion instability. Heat release pulsations which periodically provide the energy source for the pressure oscillations are highly enhanced by the interactions between the propellant and the sidewall of the combustion chamber. Combustion instability limit-cycle is formed.]]></description>
<pubDate>2024/7/20 17:14:40</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭康康,聂万胜,任永杰,仝毅恒,徐伯起]]></author>
</item>
<item>
<title><![CDATA[Constellation configuration and coverage analyses of Starlink phase III]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205230000001]]></link>
<description><![CDATA[Based on the synchronous orbit precession, the constellation evolution of Starlink Phase I and Phase II is analyzed, the problems of multiple Walker-δ sub-constellation configuration are revealed, the mechanism of the recursive orbit and common track constellation configuration of Starlink Phase III is studied, and the coverage characteristics is simulated and analyzed. The results show that: the recursive orbit and common track satellite chains with different inclination can achieve synchronous precession with small differences in orbital altitude, and have continuous and compact ground coverage bands, which has the obvious advantages of more stable configuration, better coverage performance, more convenient control and application, and lower comprehensive cost compared to the multiple Walker-δ sub-constellation configuration, especially suitable for giant LEO Internet satellite systems. This study can provide a reference for accelerating the construction of similar satellite systems in China.]]></description>
<pubDate>2024/7/20 17:13:55</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[骆  盛,王  迪,王  磊,王  勇]]></author>
</item>
<item>
<title><![CDATA[Blind detection method of the weak target echo in the GNSS-R passive radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205050000001]]></link>
<description><![CDATA[The two signals received by the reference channel and the echo channel are processed respectively to detect the target in the traditional Global Navigation Satellite System-Reflected(GNSS-R) passive radar system. The signal processing process of the dual channel configuration is complex and the amount of computation is relatively large. A receiver equipped with an antenna is required for each channel of the dual channel configuration, the hardware cost is relatively high and the channel structure is complex in engineering implementation. To solve this problem, a blind detection method of the weak target echo of single channel GNSS-R passive radar based on higher-order cyclic cumulant is presented. Firstly, the strong direct wave signal is extract by the principal component analysis（PCA）method. Then the weak echo signal is extract from the single channel mixed signal by applying the characteristics of the higher-order cyclic frequency of the weak echo signal different from other signals. Finally the blind detection of the weak target echo is realized by Matched Filtering. The blind echo extraction performance and target detection performance of the proposed method are verified by the simulation result.]]></description>
<pubDate>2024/7/20 17:13:07</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[白琳,尚社,宋大伟,王俊,温媛媛]]></author>
</item>
<item>
<title><![CDATA[Adaptive energy detection with joint wavelet-frequency domain transform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204270000001]]></link>
<description><![CDATA[The traditional energy detection method is susceptible to the interference of low signal-to-noise ratio (SNR) environment in the field of spectrum sensing, and neglecting the localization of available frequency bands can also affect the discriminative results of spectrum states. In order to improve the noise sensitivity and discrimination accuracy of energy detection, we propose an adaptive energy detection method by combining wavelet-frequency domain transform. Firstly, the signal is decomposed by discrete wavelet packet transform to obtain the sub-band signal and calculate the sub-band energy; secondly, the computational complexity of the adaptive threshold is reduced by combining the norm of energy so as to facilitate comparison with the sub-band energy; finally, the frequency domain information of the available spectrum is located by fast Fourier transform. And the adaptive energy detection method is simulated to explore the variable relationship between the adaptive threshold and different performance parameters. The simulation results show that the method has good environmental adaptability and system stability compared with the traditional fixed threshold method, and the detection error is smaller in different SNR environments. In addition, the frequency domain analysis of the sub-band signal to achieve the reordering of the normalized frequency range, which further improves the accuracy of spectrum sensing.]]></description>
<pubDate>2024/7/20 17:12:31</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[何继爱,李志鑫,王婵飞,张晓霖]]></author>
</item>
<item>
<title><![CDATA[Dynamic Integral Sliding Mode Control for Nonminimum Phase Hypersonic Vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212070000002]]></link>
<description><![CDATA[Aiming at the zero dynamic instability caused by nonminimum phase property of hypersonic vehicles, a model transformation method based on the B-I (Byrnes Isidori, B-I) standard form is proposed to achieve decoupling of internal and external dynamics of the system. A dynamic integral sliding-mode control method was proposed, forming an augmented closed-loop system with external dynamics, internal dynamics and dynamic parameters. A sliding mode parameter tuning method was proposed to make the augmented system remain dynamic stable under different operating conditions and perturbation conditions, and the trimmed point of external output was always zero. The proposed method could accurately track the output trajectory command with zero dynamic stability, and realize the longitudinal trajectory stability tracking control of nonminimum phase hypersonic vehicle. Lyapunov stability analysis was used to prove the stability of the proposed control method, and constant dynamic pressure trajectory tracking and Monte Carlo simulations were carried out. Simulation results show that the DISMC(Dynamic Integral Sliding Mode Control) method maintains good tracking accuracy and robustness under perturbation conditions, and stabilizes the zero dynamics of the system effectively.]]></description>
<pubDate>2024/7/20 17:11:26</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[丰航,孙明玮,王雨潇,赵昱宇]]></author>
</item>
<item>
<title><![CDATA[3D target track before detect algorithm in complex environment with interference and clutter]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211090000001]]></link>
<description><![CDATA[Aiming at the problem of 3D target detection in complex environment with random false target interference and strong clutter, a multi-level track before detect algorithm based on the parallel-line-coordinate transformation was proposed. Radar measurement points were placed in the normalized radial range-time plane, azimuth-time plane and pitch angle-time plane successively, the non-coherent accumulation and points filtering were carried out in each level, and each level was processed only on the results of the previous level. Based on the prior information, track constraint and track fusion were carried out to obtain the final detection result. The performance of the algorithm was verified and analyzed through simulation. The results show that the proposed algorithm can effectively filter out false measurement points and achieve the detection of real tracks under different signal-to-interference clutter ratios, measurement errors, and clutter density.]]></description>
<pubDate>2024/7/20 17:10:42</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[张嘉毫,]]></author>
</item>
<item>
<title><![CDATA[Performance analysis and power optimization for jamming- interception system with imperfect interference cancellation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210220000002]]></link>
<description><![CDATA[In order to describe the effects of interference cancellation performance on the simultaneous jamming and intercepting system quantitatively, the concept of jamming-intercepting outage probability with imperfect interference cancellation was proposed, the closed-form expression for jamming-intercepting outage probability was derived and the asymptotical expression was further obtained for ideal interference cancellation. Based on the closed-form expression, the optimal jamming power that minimizes the jamming-intercepting outage probability was identified. Finally, the accuracy of the analytical results and the correctness of optimal jamming power were justified through Monte-Carlo simulations. The results demonstrated that the jamming-intercepting outage probability decreases as the interference cancellation rate increases, decreases first and then increases as the jamming power and the transmit power increases, and the optimal jamming power increases as the transmit power increases, while the optimal jamming-intercepting outage probability converge to constant as the transmit power increases.]]></description>
<pubDate>2024/7/20 17:08:43</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[葛松虎,郭宇,李毅,孟进,邢金岭,张雲硕]]></author>
</item>
<item>
<title><![CDATA[Workflows scheduling powered by execution time prediction model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205210000001]]></link>
<description><![CDATA[For the problem of workflow job scheduling, the critical path method is proposed to predict the execution time of the workflow and allocate resources. The Parallel Application Directed Acyclic Graph (PAD) is introduced to describe the relationships among the sub-jobs of a workflow. Suitable resources are allocated to the sub-jobs according to their execution sequence. Based on the information about the sub-jobs and the system resources assigned to them, the execution time of each sub-job is predicted by a Gradient Boosting Decision Tree-based algorithm, and the critical path of the workflow is calculated. The prediction execution time of the workflow is the sum of the prediction time of each sub-job on the critical path. If the workflow prediction execution time satisfies the user's requirement, the workflow is executed according to the scheduling. Comparative experiments show that the prediction errors of the execution time of two workflows are 5.72% and 1.57%, respectively. Compared with the default scheduling algorithm of Spark, the proposed workflow scheduling algorithm shortens the completion time of the two workflows by 15.71% and 15.44%, respectively.]]></description>
<pubDate>2024/7/18 10:15:48</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[胡亚红,毛家发,邱圆圆]]></author>
</item>
<item>
<title><![CDATA[Network slice programmable data plane model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205260000002]]></link>
<description><![CDATA[In order to enable the programmable data plane to support more different network protocols, the deparser based on RMT was extended. The extended deparser and two Reconfigurable Match Table (RMT) pipelines constitute a protocol independent network slice programmable data plane model. Since reduced instruction set is used in RMT architecture and complex instruction set is used in the extended deparser, the extended architecture is called Hybrid-instruction RMT(HiRMT). HiRMT could support Segment Routing IPv6, multiple semantics for Segment ID (SID), micro SID (uSID), Multi-protocol Label Switching (MPLS) and Virtual Extensible Local Area Network (VXLAN). This architecture has broad application prospects. The performance test of the deparser module on the Corundum prototype platform shows that the extended deparser can process the packet size up to 512 bytes with a throughput of 100Gbps with fewer resources.]]></description>
<pubDate>2024/7/17 9:36:41</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[刘忠沛,吕高锋,王继昌,杨翔瑞]]></author>
</item>
<item>
<title><![CDATA[On-orbit fault diagnosis and location method for the propulsion system of TianTuo-5 satellite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202310250000001]]></link>
<description><![CDATA[A failure mode and effects analysis method (FMEA) is used to ensure that the Tiantuo-5 satellite can carry out on-orbit scientific test missions successfully. This method aims to systematically and comprehensively evaluate the possible risks of various components of the satellite propulsion system from the perspectives of incidence and severity. According to the working characteristics of the satellite propulsion system, a set of fault detection and location methods are proposed according to its on-orbit working state and standby state respectively. The effectiveness of the method has been verified in on-orbit practice, successfully guaranteeing the healthy operation of Tiantuo-5. Thus, this work has accumulated valuable experience for the upcoming satellite propulsion systems along with their fault diagnosis.]]></description>
<pubDate>2024/7/17 8:16:39</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[zhao yong,]]></author>
</item>
<item>
<title><![CDATA[Cascading failure model for multi-level interdependent networks based on delay distribution under load objective]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205160000002]]></link>
<description><![CDATA[In the multi-level interdependent network where the target node was under load, in order to prevent the occurrence of large-scale cascading failures, enhance the robustness of the network and improve the efficiency of load completion, a cascading failure model with adjustable parameters was proposed. New initial loads and node capacities were set in this model, a load delay distribution mechanism was constructed and load redistribution rules were formulated based on the heterogeneity and uniformity of load distribution. The cascading failure conditions of this model were analyzed and parsed, and simulation experiments were carried out through the WS-BA interdependent network. The results showed that under a certain network capacity, the robustness and efficiency of the network could be improved by reasonably adjusting the heterogeneity and uniformity parameters.]]></description>
<pubDate>2024/7/16 15:43:40</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[高家隆,黄健,]]></author>
</item>
<item>
<title><![CDATA[Experimental and Simulation Analysis on Fatigue Fracture Behavior of 2195-T8 Al-Li Alloys with Defects]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205170000001]]></link>
<description><![CDATA[The study of the fatigue fracture behavior of Al-Li alloys is of great significance for the evaluation of structural life and safety as an alloy material widely in aerospace. This study aimed to explore the fatigue crack propagation behavior of 2195-T8 Al-Li alloy with prefabricated defects using the constant-amplitude tensile-tension fatigue test and the equivalent crack model method. The results showed that the fatigue cracks were initiated from holes at the bottom of the defect. With the propagation of the cracks, the propagation speed in the length direction of the crack surface was the highest, while the speed in the depth direction was the least. The fatigue fracture of the 2195-T8 alloy displayed a typical delamination fracture phenomenon. The delamination of the alloy greatly hindered the crack tip propagation in the depth direction, which in turn led to crack bifurcation. After crack bifurcation, the propagation rate increased sharply along with the volume of the plastic region at the tip, which led to the rapid fracture of the sample. The above results comprehensively show that 2195-T8 Al-Li alloys with defects would be reduced under effects of crack propagation inclination and delamination.]]></description>
<pubDate>2024/7/16 8:32:46</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[金国锋,李玉龙,刘德俊,田  干,张  炜]]></author>
</item>
<item>
<title><![CDATA[High-precision constant pressure control of the gas in the variable leakage chamber]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205130000002]]></link>
<description><![CDATA[In precise testing and control occasions, stable air pressure supply is often required. However, the use of pressure regulating valves has low accuracy and slow response, which cannot meet the requirements of high-precision air supply and is difficult to deal with leakage situations. In this paper, a high-precision constant pressure control system based on Fuzzy PI was designed for small volume chambers by using a proportional directional valve with high frequency response. In order to verify the effectiveness of the system under leakage conditions, an additional proportional valve was connected to the chamber to carry out experimental studies under three conditions of confinement, constant leakage, and variable leakage. The results showed that the designed constant pressure control system can adapt to a variety of harsh conditions. Under the condition of greatly varying leakage, the maximum steady-state errors of 10 L, 20 L and 30 L chambers for the target pressure of 0~0.4 MPa were around 610 Pa, 550 Pa and 490 Pa , respectively. The pressure control precision achieved was close to the precision of the pressure sensor itself, much higher than the precision regulated by the traditional precision pressure reducing valve, and much faster in response. In addition, the test results also showed that the designed controller has good adaptability to the chambers with volume ranges of 10 L to 30 L.]]></description>
<pubDate>2024/7/15 17:25:06</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[刘磊,罗辉,浦晨玮,钱鹏飞,吴洁]]></author>
</item>
<item>
<title><![CDATA[Modeling and analysis of spatial resolution in noncooperative interference cancellation technique]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210110000002]]></link>
<description><![CDATA[In this paper, based on noncooperative interference cancellation, the characterization parameters of spatial resolution are proposed through establishing the receiving signal model of different array manifolds. It is used to measure the resolution and cancellation ability of different array manifolds for similar arrival angles when the arrival angles of interference signal and communication signal are close. Meanwhile, the factors affecting the spatial resolution are analyzed. The new evaluation criterion for array design of noncooperative interference cancellation is provided. The paper derived the array transfer factor and output signal to interference plus noise ratio (SINR) as the evaluation criterions of array spatial resolution. From three aspects of array configuration, number of array element and array radius, the spatial resolution of different array manifolds were analyzed by simulation. And the results were verified by experiments. The experimental results were in good agreement with theoretical analysis and simulation, and the importance of spatial resolution on interference cancellation was proved. It provides the basis for subsequent array manifold optimization and auxiliary antenna design.]]></description>
<pubDate>2024/7/15 16:18:34</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[何方敏,李亚星,李哲宇,罗康,孟进,张嘉毫]]></author>
</item>
<item>
<title><![CDATA[Analysis of Modeling and Interference Suppression Requirement of Multi-source Wideband Interference Cancellation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210280000001]]></link>
<description><![CDATA[In this paper, the theoretical model of multi-source wideband interference cancellation is established, and the influence of the number of sampling antennas and time-domain filters on the interference suppression performance is obtained. The effect of correlation between interference sources on interference suppression performance is analyzed, and the difference of interference cancellation ratio (ICR) between multiple interference sources and single interference source is studied, and the compression coefficient is proposed as an index to measure the interference cancellation ratio of multiple interference sources. Based on this, the interference suppression requirement of multi-source wideband interference cancellation is obtained. The experiment results show that increasing the number of sampling antennas and time domain filters can significantly improve the interference cancellation ratio of the double interference sources. Besides, in the same scene, the ICR of double interference sources is more than 10 dB lower than that of single interference source. As the power difference between two interference sources becomes larger, the compression coefficient decreases, and the interference cancellation ratio gradually decreases. When the power difference between the two sources exceeds 25 dB, the compression coefficient is close to 1, and the double interference sources are equivalent to single interference source.ce between the two sources exceeds 25 dB, the double interference sources are equivalent to single interference source.]]></description>
<pubDate>2024/7/15 16:05:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[葛松虎,何方敏,孟进,秦焕丁,王衡峰,邢金岭]]></author>
</item>
<item>
<title><![CDATA[Design and magnetic field analysis of linear phase-shifting transformer with hairpin filling structure]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204120000006]]></link>
<description><![CDATA[Based on the original linear phase-shifting transformer, a linear phase shifting transformer with a hairpin filling structure is designed with reference to the theory of linear motor, which effectively solves the problems of complicated winding method, large size and modular series-parallel connection. The working principle of the linear phase-shifting transformer system is briefly introduced; the design method of linear phase-shifting transformer with half-filled slot structure is proposed with reference to the design method of linear motor and rotary motor; the hairpin structure is adopted to eliminate a series of problems caused by the half-filled slot structure at the connection; finally, the finite element simulation is used to verify the comparison. The results show that the designed linear phase shifting transformer with a hairpin structure has a good output waveform and a small distortion of the air gap magnetic field.]]></description>
<pubDate>2024/6/11 9:21:29</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[薛婕,严思念,赵镜红]]></author>
</item>
<item>
<title><![CDATA[Satellite Domain Corpus Construction and Named Entity Recognition Recognition]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204150000003]]></link>
<description><![CDATA[Aiming at the lack of named entity corpus in the satellite domain and the low recognition performance of existing algorithms, this paper proposes a satellite domain entity labeling method considering fuzzy boundaries, constructs a corpus containing 8 common satellite domain entities where the granularity is finer and the coverage is wider in comparison with the existing corpora in this field. Based on this, a transfer learning and multi-network fusion satellite domain entity recognition algorithm is proposed. The algorithm uses pretrained Bidirectional Encoder Representations for Transformers (BERT) to smoothly transfer the semantics of the corpus for subword-level features, a Bidirectional Long-Short Term Memory (BiLSTM) network for capturing contextual information to determine boundaries, and label prediction is achieved using a conditional random field (CRF) as a decoder. The experimental results show that, compared with traditional models such as BiLSTM, the proposed algorithm has better recognition performance where the F1 score in 8 entities is all above 92% and the micro-average F1 score reaches 96.10%.]]></description>
<pubDate>2024/6/11 9:20:44</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈志敏,石会鹏,王静,徐聪,杨甲森,张鑫宇]]></author>
</item>
<item>
<title><![CDATA[Analysis and Evaluation Method for Invulnerability of Weapons]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204200000002]]></link>
<description><![CDATA[In view of the problem that the current evaluation of the survivability of weapons and equipment is mainly statistical and lacks physical support, in order to establish the transmission relationship between the structural parameters and the protective performance of each component, the concept of invulnerability is proposed, and the invulnerability analysis method based on the limit damage and the invulnerability characterization method based on the generalized protection time were proposed. And through the index to the quantitative mechanism of combat missions, task-oriented invulnerability evaluation method is proposed. The tires system performance invulnerability was studied as an example.The results show that: The invulnerability analysis method based on limit damage can realize the construction of physical transfer relation from physical space to performance space; the invulnerability characterization method based on generalized protection time can reflect the comprehensive influence of amplitude distance and difficulty degree on invulnerability; the task-oriented invulnerability assessment method can introduce operational mission requirements into invulnerability evaluation and reduce the influence of subjective weight assignment on evaluation results. case analysis verify the feasibility and effectiveness of the proposed method.]]></description>
<pubDate>2024/6/11 9:20:10</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[高蕾,高钦和,黄通,刘志浩,马栋,王冬]]></author>
</item>
<item>
<title><![CDATA[Analysis of cavitation-induced vibration sensitivity in regulating valve using multiple measuring points]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205110000003]]></link>
<description><![CDATA[Abstract: Aiming at the difference in the cavitation sensitivity of the control valve at different measuring points of the regulating valve body, study on the difference of cavitation induced vibration and the cavitation sensitivity of different measuring points was carried out. A test platform for cavitation-induced vibration acceleration signal acquisition of regulating valve was built, and the acceleration signals of cavitation vibration of regulating valve at multiple measuring points were simultaneously collected. Two characterization parameters, the acceleration level ratio and the gravity frequency, were proposed. Frequency spectrum of the cavitation vibration signal of regulating valve was divided by the 1/3 octave frequency spectrum, and finally the frequency band most sensitive and location of measuring points to cavitation development was obtained. Results show that the vibration signals of measuring point on the same surface of the regulating valve body are similar, and the signals on different surface are significantly different. Vibration signals of the regulating valve are anisotropic. Development of cavitation extent mainly causes the vibration intensity of the frequency band above the center frequency of 10000 Hz to increase. It is suitable for monitoring cavitation state of control valve.]]></description>
<pubDate>2024/6/11 9:19:32</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[韦建秋]]></author>
</item>
<item>
<title><![CDATA[Research on resonant frequency control method of acoustic mechanical antenna]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204030000001]]></link>
<description><![CDATA[Acoustic mechanical antenna is one of the important types of mechanical antenna, the resonant frequency of acoustic mechanical antenna is highly coupled with its natural frequency. However, the current acoustic mechanical antenna is limited by material size and has high resonant frequency, which can not to meet the needs of very low frequency or lower frequency band. In order to control the resonant frequency of acoustic mechanical antenna, the vibration modeling of acoustic mechanical antenna was carried out. Three methods were proposed: adding unilateral fixed constraint, increasing free end mass and removing some materials of antenna. Proposed method was verified by finite element simulation. Results show that the three methods can effectively control the resonant frequency of acoustic mechanical antenna, and are in good agreement with the analytical model. Influence of three methods of regulating resonant frequency on the electric field or magnetic field intensity radiated by the antenna through the stress distribution was studied, which has important reference significance for the design of acoustic mechanical antenna.]]></description>
<pubDate>2024/6/11 9:18:51</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[崔勇,黄玉平,李良亚,陶云飞,王琛,袁志鸿]]></author>
</item>
<item>
<title><![CDATA[Time efficient attitude maneuver path planning on SO(3) and time scaling method under complex constraints]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203160000001]]></link>
<description><![CDATA[For the large-angle attitude maneuver of spacecraft under complex constraints, a efficient maneuver path planning for attitude and time scaling method on 3-dimensional special orthogonal group was proposed. Aiming at handling the attitude constraints during maneuvering, a gradient-based obstacle avoidance methodology was designed and the attitude routes and desired angular velocity trajectory was obtained on the virtual time domain. Considering the maximum output torque of the actuator, an iterative nonlinear time scaling method was proposed to adjust the angular velocity/control torque . Simulation results show that the proposed method not only satisfies the attitude constraints and the control torque constraints during the spacecraft maneuver process, but also significantly shortens the maneuver time comparing with existing methods. Novel results provide a new insight for efficient constrained attitude planning and controller design.]]></description>
<pubDate>2024/6/11 9:18:07</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈雪芹,霍涛,鲁明,吴凡,岳程斐]]></author>
</item>
<item>
<title><![CDATA[Multi-sensor cooperative planning of space objects detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203020000001]]></link>
<description><![CDATA[To solve the low detection efficiency problem of using the whole arc segment as the decision variable in the traditional scheduling problem, a mathematical model with the space objects of multi-sensor cooperative detection as the background was established, and an adaptive immune genetic algorithm was proposed. Considering various factors such as the space objects attribute, type, launch time, RCS grade, and purpose, a multi-level fuzzy comprehensive evaluation model was constructed, and the 1-9 scale method was adopted to obtain the priority of the spatial target. Target priority maximization, consider various constraints such as detection time, sensor capacity, and so on, get solutions by adaptive immune genetic algorithm, and evaluate the planning results from two aspects of detection resource consumption and task completion rate. By comparative analysis with the improved heuristic algorithm and traditional evolution algorithm, this algorithm improves the task completion rate while also reducing resource consumption.]]></description>
<pubDate>2024/6/11 9:17:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[蔡伟伟,龙  洗,杨乐平]]></author>
</item>
<item>
<title><![CDATA[Review of key technologies for autonomous homing of paraoil systems]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302210000003]]></link>
<description><![CDATA[In order to explore the key technologies of parafoil systems, including modeling, trajectory planning, and trajectory tracking control, to support their autonomous homing in large-scale equipment airdrop replenishment, carrier rocket booster recovery, and natural disaster rescue applications. Through research on the development of parafoil systems both domestically and internationally, a comparative analysis and summary of the basic principles, commonly used methods, and cutting-edge technologies of the three key technologies were conducted, with a focus on the flexible modeling technology of parafoil systems in complex environments, trajectory planning technology in obstacle spaces, and trajectory tracking technology based on intelligent control strategies. A summary and outlook were made on the future development trends of key technologies for autonomous homing of parafoil systems, which can help researchers gain a comprehensive understanding of the research progress and development trends in autonomous homing of parafoil systems, and provide inspiration and reference value for further research in this area.]]></description>
<pubDate>2024/6/11 9:16:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈增强,孙昊,孙青林,杨金山]]></author>
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<title><![CDATA[Security Evaluation of Midori128 Cryptographic Algorithm Based on Integral Fault Analysis]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204120000004]]></link>
<description><![CDATA[To research the security of the Midori128 cryptographic algorithm against integral fault attacks, the analysis in this paper finds that: by establishing the relationship between integral distinguisher equilibrium position, faulty ciphertext and round key, the last round key of the algorithm can be recovered through key search, and then the master key can be recovered by using the key extension algorithm. Theoretical analysis shows that the time complexity of recovering the correct key by using the 3-round integral distinguisher is 221 when the active byte fault is injected in the penultimate round 4; the time complexity is 224 when the active byte fault is injected at any time after the penultimate round 6 and before the penultimate round 5. In this paper, we simulate the attack process using accuracy, success rate and elapsed time for the penultimate 4th round injection fault, and the experimental results show that the average probability of successfully recovering the master key using two ciphertext sets is 94.7%, and the probability of success using three ciphertext sets is 100%. In this paper, two sets of fault security analysis schemes are derived that the round function of the Midori128 algorithm is vulnerable to the integral fault attack, and additional protection such as fault detection is needed for at least the last six rounds when the algorithm is running.]]></description>
<pubDate>2024/6/5 19:42:38</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[贺水喻,,,魏悦川]]></author>
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<title><![CDATA[High Precision Frequency Estimation Algorithm Based on Autocorrelation Weighted Fusion]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204120000002]]></link>
<description><![CDATA[In order to ensure the performance of radar countermeasure reconnaissance system in complex electromagnetic environment, a multi-segment signal frequency estimation algorithm based on autocorrelation weighted fusion is proposed. First, perform autocorrelation processing on each segment of the noisy signal to obtain a high SNR sinusoidal signal with zero initial phase and the same frequency as the original signal, then use the arcsine operator to construct a support matrix to perform real-time weighted fusion of the autocorrelated signals, and finally, the reference signal is established on the basis of the rough estimation, and the high-precision frequency estimation result is obtained by minimizing the error function. The simulation results show that, compared to existing algorithms, the algorithm in this paper not only improves the accuracy significantly, but also has stable estimation performance under the conditions of different SNRs, signal lengths and signal anomalies, while satisfying the low computational cost, which provides a reference for radar countermeasures intelligence reconnaissance based on multi-sensors.]]></description>
<pubDate>2024/6/5 19:41:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈昌孝,何明浩,李争,刘康,曾莎]]></author>
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<title><![CDATA[Inversion of submarine steady electric field based on point-type current source and Tikhonov regularization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204100000002]]></link>
<description><![CDATA[In order to evaluate the distribution characteristics of submarine underwater corrosion steady electric field, a method is proposed based on equivalen point-type current source and Tikhonov regularization. The forward model of submarine underwater corrosion steady electric field is established by the equivalent point-type current source theory. And the current intensity of the equivalent point-type current sources is solved by Tikhonov regularization according to the measured electric field data. The effectiveness of the proposed method is verified by commercial finite element software COMSOL. The electric field value error from the depth of 38 m to the depth of 42.5 m and 32.5 m is less than 6%. Even if the calculated depth reaches 45 m, the relative root mean square error is still less than 21%. When the noise standard deviation is 0.1 times the maximum value of the actual electric field, the inversion error is still less than 10%, with high accuracy and high military value.]]></description>
<pubDate>2024/6/5 19:41:17</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[刘春阳,张建春,]]></author>
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<title><![CDATA[Influences of Design Parameters on Shock Isolation Performance of Integrated Quasi-zero Stiffness Isolator]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204210000002]]></link>
<description><![CDATA[The shock isolation performance of the integrated quasi-zero stiffness isolator (as also be called "integrated isolator") was studied in this paper. The attenuation period, oscillation frequency, maximum acceleration ratio and maximum displacement of shock response were selected as evaluation indexes, respectively. The influences of linear stiffness ratio and geometric design parameters on the shock isolation of the integrated isolator under half-sine pulse acceleration excitation were emphatically studied by using the fourth-order Runge-Kutta method. The calculation results show that the integrated isolator has better acceleration attenuation performance than the linear isolator after the shock with a long duration. The smaller outer wall height s and the larger wall thickness th are beneficial to improve the shock isolation performance. The relevant research can provide guidance for the engineering application of the integrated quasi-zero stiffness isolator.]]></description>
<pubDate>2024/6/5 19:40:40</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[丁伯森,刘海平,朱冬梅]]></author>
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<title><![CDATA[Online identification method on aerodynamics and thrust of supersonic cruise vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202306140000001]]></link>
<description><![CDATA[To accurately predict the aerodynamic and thrust characteristics of supersonic cruise missile during flight, an integrated online identification method for aerodynamic and thrust parameters was proposed. Motion model of supersonic cruise missile powered by a solid rocket ramjet engine in the longitudinal plane was established, and a polynomial model of aerodynamic and thrust coefficients in the cruise phase was established. The unscented Kalman filtering method was used to conduct online identification and simulation verification of aerodynamic and thrust parameters. The identification performance was compared and verified based on flight test data. Research had shown that the integrated identification of aerodynamic and thrust parameters for supersonic cruise missile was necessary and effective, and the proposed method can be applied to online parameter identification during flight.]]></description>
<pubDate>2024/6/5 19:39:59</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[江振宇]]></author>
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<title><![CDATA[Adaptive Antidromic Window Moving Method for  Spacecraft Maneuver Detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204110000001]]></link>
<description><![CDATA[An adaptive method using antidromic window moving for detecting maneuvers of space objects is proposed in this paper. The proposed method took two-line elements (TLE) as data source. Adaptive window configuration model was established to get detection window for different objects. Meanwhile, cross arc prediction was integrated in order to obtain the maneuver time more precisely. Applying antidromic window moving method, the maneuver in the latest epochs can be detected. The results were compared with those of real maneuvers and those of existing literatures. It is shown that the proposed method can adapt to the window configuration of maneuvering detection of space objects on different orbits. Besides, the detection success rate can reach more than 90% under the given simulation conditions. Moreover, the accuracy of maneuver time estimation is observably higher than that of existed method. Simulations of the approach proposed have demonstrated good performance in near-real-time maneuver detecting.]]></description>
<pubDate>2024/6/5 19:39:25</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李海阳,李泽越,罗亚中,杨震]]></author>
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<title><![CDATA[Experimental study on effects of carbon dopants on the beam divergence angles of solid propellants]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202311170000001]]></link>
<description><![CDATA[Two kinds of carbon doped particles, graphene and toner, were used to directionally modify solid propellant. The influence of different doping ratios and working conditions on the divergence angle of the modified propellant was comparedand analyzed by high-speed photography technology and a self-built beam divergence angle measurement system, so as to determine the optimal doping ratios and working conditions of the doped particles. It is found that the optimal doping ratio of graphene and carbon powder is 7%, and the beam divergence angle of graphene is smaller, and the response time of generating stable plasma flow is shorter. At the same time, graphene is more suitable for the working conditions under the small laser energy supply, and carbon powder is more suitable for the working conditions under the large laser energy supply.]]></description>
<pubDate>2024/6/5 19:39:01</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[OU Yang,,]]></author>
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<title><![CDATA[Deterministic robust backstepping motion tracking controller for a proportional valve-controlled pneumatic cylinder system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204280000001]]></link>
<description><![CDATA[In order to achieve high-precision robust control of pneumatic cylinder motion trajectory, the mathematical model of proportional valve-controlled pneumatic cylinder system was established, and a non-linear deterministic robust controller was designed based on the backstepping method, which can effectively suppress the effects of system model parameter uncertainty, unmodelled dynamics and external disturbances. The Simulink module in MATLAB was used to construct a simulation model of the pneumatic cylinder motion trajectory tracking control system. The simulation results show that the designed controller is feasible. A real-time control system for pneumatic cylinder motion trajectory based on a non-linear deterministic robust controller was developed using xPC-Target in MATLAB/Simulink. The test results show that the controller can effectively track the reference trajectory, with a maximum tracking error of 0.89 mm for a 0.3 Hz sinusoidal trajectory, which is about 2.97% of the amplitude, and 1.02 mm for a 0.4 Hz sinusoidal trajectory, which is 3.4% of the amplitude.]]></description>
<pubDate>2024/6/5 19:38:19</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[何  迪,刘  磊,浦晨玮,钱鹏飞]]></author>
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<title><![CDATA[Path planning of a multiple AGV system in unmanned warehouse with bottom passable shelves]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303310000004]]></link>
<description><![CDATA[In this paper, an improved A* algorithm is proposed to solve a path planning problem on a multiple AGVs (automatic guided vehicles) system in unmanned warehouse with bottom passable shelves. The multiple AGV system is prone to conflict, collision and deadlock in the process of carrying. Therefore, the A* algorithm is improved by introducing multi-valued grid and traffic rules to solve the path planning problem for the multiple AGV system. To improve handling efficiency of the multiple AGV system, the planned path is optimized by adding shelf recall mechanism, turning cost and heat cost. A binary heap data structure is also used to improve calculation speed of the path planning. Finally, the improved A* algorithm and the path optimization strategy are simulated and verified by a visual quadrilateral grid unmanned warehouse model built by Python.]]></description>
<pubDate>2024/6/5 19:36:09</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[程富阳,李洪波,杨洪玖,赵国威]]></author>
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<title><![CDATA[Research on Single-Event Effect for a Bandgap Reference in Bulk CMOS Technologies]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204020000003]]></link>
<description><![CDATA[A bandgap reference (BGR) test chip is designed in 65nm and 28nm commercial bulk CMOS technologies. Pulsed-laser experiments are adopted to investigated single-event radiation characteristics, and the experimental results show that the output voltage of BGR significantly increases after irradiation with high enough energy, and the voltage cannot recover after annealing, this indicates that single-event hard damage (SHD) presents in the BGR. Further studies indicate that the bipolar junction transistor (BJT) in BGR is the sensitive device to induce hard damage. The investigation proposed important information for SHD hardened design for BGR in commercial bulk CMOS technology.]]></description>
<pubDate>2024/6/4 15:15:02</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[陈建军,池雅庆,梁斌,文溢,邢海源,姚啸虎]]></author>
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<title><![CDATA[Inversion modeling method utilizing ship’s internal magnetic field]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203150000001]]></link>
<description><![CDATA[The integral equation method is widely used in ship’s magnetic field inversion modeling, but the model requires enough measurement points to obtain the ship’s magnetic field at a specific depth. To address the problem that the integral equation method uses the near-field magnetic field to model with poor accuracy, an improved measure by adding constraint equation was proposed. The numerical simulation of the magnetic field of a thin steel plate model and a 3D ship model was carried out respectively. The finite element method was used to initialize the selection of the ship’s internal measurement points. The inversion model was constructed based on the measured values of the internal magnetic field of the ship and the singular value decomposition method is used to solve the magnetic source parameters and predict the external space magnetic field. It shows that the root mean square error of the prediction results of the external space magnetic field of the ship is less than 12%. The magnetic field measurement experimental verification of the ship cabin model shows that the root mean square error of the prediction of the external magnetic field from the internal magnetic field of the cabin is about 13%, which proves the effectiveness of the proposed method and can improve the instability and insufficient accuracy of the traditional inversion model. The research results can provide ideas for the algorithm design of closed-loop degaussing of ships.]]></description>
<pubDate>2024/6/4 15:13:17</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[何保委,刘胜道,唐烈峥,张俊洪,周国华,宗敬文]]></author>
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<title><![CDATA[FREE VIBRATION OF CYLINDRICAL FUNCTIONALLY GRADED TUBES ON BI-PARAMETER FOUNDATION BASED ON A HIGHER-ORDER BEAM THEORY]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208250000001]]></link>
<description><![CDATA[Free vibration of functionally graded (FG) tubes on Winkler--Pasternak foundation with radial inhomogeneity and on Winkler--Pasternak foundation was studied using a higher-order shear deformation beam theory. The shear correction coefficient was is not needed and shear stress-free condition on the inner and outer surfaces are automatically satisfied. An auxiliary function was introduced to convert two coupled governing equations for the deflection and rotation into a one single governing equation. For typical end boundary conditions, the characteristic equations were derived and natural frequencies are determined exactly. By comparing the calculated results with those existing on literature, the accuracy of the obtained results is verified. This paper provides  an one-dimensional elastic theoretical solution for Winkler-Pasternak elastic foundation beams with high accuracy. The evaluated numerical results show that gradient index and elastic foundation stiffness remarkably affect the natural frequencies of free vibration. Compared with higher-order frequencies, the influences of the stiffness coefficients of elastic foundation on lower-order frequencies are more remarkable.]]></description>
<pubDate>2024/6/4 9:54:42</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔辉如,李显方,马维力,彭帆,申柳雷,王诗琦]]></author>
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<title><![CDATA[Sensorless control of permanent magnet synchronous motor in full speed range]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204160000001]]></link>
<description><![CDATA[When the IF controlled starting strategy is adopted to realize the sensorless control of permanent magnet synchronous motor in the full speed range, there are some problems in the starting process, such as irregular forward and reverse jitter of speed, weak starting torque ability and slow starting speed. Therefore, in this paper, the high-frequency pulse voltage injection method is used to complete the zero low-speed start of the motor, and combined with the effective flux linkage method in the medium and high-speed region, a position sensorless composite control strategy in the full speed range is formed. In order to realize the smooth switching between high-frequency pulse voltage injection method and effective flux linkage method, a hysteresis switching strategy based on the combination of speed transition region and state machine is proposed in this paper. The proposed strategy divides the full speed range into zero low speed region, transition region and medium high speed region. When the motor enters the transition region from the high speed region, the high-frequency pulse voltage injection method is turned on in advance to stabilize its position estimation process and prepare for switching. In addition, in order to reduce the impact of injected high-frequency voltage on the position estimation process of effective flux linkage method, soft switching is used in the speed transition zone to realize the input and exit of high-frequency pulse voltage injection method. Furthermore, aiming at the coupling problem of two position estimation methods working at the same time in the speed transition zone, a double synchronous rotating coordinate system is set up to realize the decoupling control of rotor position estimation. Finally, the effectiveness of the proposed method is verified on a three-phase permanent magnet synchronous motor.]]></description>
<pubDate>2024/6/4 9:53:08</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[付康壮,,刘计龙,麦志勤,]]></author>
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<title><![CDATA[Analysis of linearity and correlation of acoustic spread spectrum signal in multipath reverberation channel]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202305160000002]]></link>
<description><![CDATA[To analyze the correlation and linearity of acoustic spread spectrum signals in shallow water multipath channels, a virtual source calculation model for Pekeris waveguides in shallow waters with frequency attenuation and seabed loss was established. Pulse signals and spread spectrum signals in shallow seas were simulated, and the linearity of spread spectrum signals in a multipath reverberation environment was preliminarily investigated through experiments conducted in a reverberation chamber. The simulation results show that the frequency domain solution of the virtual source method is consistent with that of the normal mode method, and the same low-frequency mode dispersion phenomenon as the normal mode method can be obtained through the virtual source method, verifying that the virtual source method is suitable for low-frequency problems in ideal shallow water waveguides and Pekeris waveguides; when modal dispersion occurs, the correlation performance of low-frequency spread spectrum signals is better than that of high-frequency signals under the same conditions. The experimental results show that when the time-domain waveform of a low-frequency pulse is distorted and broadened, the spread spectrum signal of the same frequency can accurately measure the geometric delay of the reflected signal, demonstrating that the low-frequency multipath effect can still be regarded as the linear superposition of all "path" signals.]]></description>
<pubDate>2024/6/3 15:40:50</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[纪刚,吕晓军,唐永壮,谢志勇,周其斗]]></author>
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<title><![CDATA[Time-delay estimation tracking control of flexible-joint space robot based on low-pass filter]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203040000002]]></link>
<description><![CDATA[In order to solve the joint tracking control and vibration problem of flexible-joint space robot system in the pre-grasping stage when the position and pose are not controlled, the dynamic equations of a free-floating three-bar flexible-joint space robot system are established using the Lagrangian equation in conjunction with the principle of momentum conservation. In order to improve the equivalent stiffness of flexible-joint, a joint flexible compensation method was introduced. According to the flexible-joint space robot system was divided into slow and fast systems by singular perturbation theory. On this basis, a sliding mode control method with time delay estimation as the main framework was designed for the slow variable systems, while combining it with a low-pass filter to eliminate the system chattering problem caused by sliding mode control; A linear velocity difference feedback control system was designed for the fast-changing system to suppress the flexible vibration problems introduced by the flexible joints. Simulation verification demonstrates that the space robotic arm is capable of quickly and steadily tracking the desired trajectory within a limited time, confirming that the control scheme possesses good robustness and reliability.]]></description>
<pubDate>2024/6/3 12:27:24</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈力,徐河振,于潇雁,张宇涵]]></author>
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<title><![CDATA[Research on fault tolerant control of launch vehicle active phase considering thrust loss]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204120000001]]></link>
<description><![CDATA[The launch vehicle is prone to power system faults such as thrust drop in the ascending stage, and the traditional control method is difficult to meet the requirements of high precision and high stability control in the case of large interference. In this research, The adaptive augmented control and fuzzy PD control of launch vehicle are studied, and their control characteristics are analyzed. A dynamic switching control algorithm based on fuzzy rules is proposed, By calculating the output weight of adaptive PD control and fuzzy PD control, the optimal control scheme of the system is obtained. The control torque reconstruction and dynamic switching control algorithm are combined to carry out fault-tolerant control under rocket thrust loss, The results show that the dynamic switching control algorithm based on fuzzy rules can effectively improve the attitude control quality. Compared with other control methods, the maximum yaw angle deviation is reduced by 20%, the system response time is 15% faster, and there is no oscillation in the control process.]]></description>
<pubDate>2024/6/3 10:08:02</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[程玉强,谢昌霖,杨述明]]></author>
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<title><![CDATA[Analysis of temperature control mechanism of a novel semi-active cooling device for high-speed flight vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210130000003]]></link>
<description><![CDATA[Aiming at the thermal control problem of high temperature components in special cabin of advanced aircraft, a new semi-active temperature control principle was proposed. Based on this principle, a new semi-active cooling device was designed and tested. The heat transfer performance and temperature control mechanism of the new semi-active cooling device under different working conditions were analyzed and compared. It can be found from the presented results that the thermal control performance of the new semi-active cooling device was significantly better, especially for the semi-active cooling device filled with 100 % infiltrated aerogel, the hot end temperature is 272 ℃ at 3000 s, which was 102 ℃ lower than that under the passive heat transfer condition, and the peak efficiency was up to 68%. With increasing of the outlet pressure of the cooling device, the time for the coolant to reach the boiling point is longer. Filling infiltration aerogel can effectively prolong the vaporization time of the coolant, and the weight is lighter.]]></description>
<pubDate>2024/6/3 8:58:26</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭庆阳,李世斌,马锐]]></author>
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<title><![CDATA[Infrared small target detection method based on improved non-convex estimation and asymmetric spatial-temporal regularization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205190000001]]></link>
<description><![CDATA[With the wide application of infrared technology in early warning system and space-based surveillance system, infrared small target detection has become a hot research issue at home and abroad. Aiming at infrared dim and small targets detection in complex background, this paper based on the non-convex tensor low-rank estimation with asymmetric spatio-temporal regularization constraint algorithm proposed a new kernel norm estimation method to replace the original estimation method. Then, an adaptive weight tensor based on structure tensor and multi-structure element top-hat filtering is proposed to constrain the target tensor in this paper, which has enhanced the sparsity and suppressed the remaining strong edge structures of the target tensor.Experimental results show that the improved algorithm can better eliminate the influence of strong edge structure on the detection results, and has a lower false alarm rate than the original algorithm under the condition of ensuring the detection rate.]]></description>
<pubDate>2024/5/22 8:20:19</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[胡亮,杨德贵]]></author>
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<title><![CDATA[Adaptive control techniques in the shock wave/turbulence boundary layer interaction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111220000001]]></link>
<description><![CDATA[In order to prompt the development of the flow control technique, starting with the shock wave/ turbulence boundary layer interac-tion (SWTBLI) mechanism and the urgent requirements of the flow control, the research progress of the adaptive control techniques in the shock wave/ turbulence boundary layer interaction from four aspects was summarized, namely adaptive vortex generator, adaptive bump, adaptive micro jets and adaptive secondary recirculation jet. Analysis shows that developing adaptive flow control techniques, combined with AI technology, realizing local flow acceleration/deceleration, aerodynamic thermal protection, aerody-namic control and other functions in different areas of the hypersonic vehicle by adjusting external excitation, establishing control feedback loop according to flow field parameters and accelerating intelligent control schemes can be used as an important technical means for wide-speed flight of the new generation hypersonic vehicle.]]></description>
<pubDate>2024/4/8 8:35:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杜兆波,黄  伟,柳  军,吴  瀚,钟翔宇]]></author>
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<title><![CDATA[Optimal design for the high-speed and lightweight transmission system of SpaceFibre node]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112020000001]]></link>
<description><![CDATA[An optimal design of SpaceFibre node was proposed to meet the lightweight, high bandwidth and high reliability requirements for the satellite payload data transmission system. The incremental calculation based on frame was used to reduce circuit complexity. Benefitting from four-stage pipeline, error detection module operated at different rates. The module had lower hardware resources by sharing CRC. To improve reliability, the design adopted a two-layer control strategy with complete response. Resource-optimized FSM and storage architecture were built to simplify the implementation of the retransmission algorithm. A verification system at board-level with two nodes was implemented in XC7Z100FFG900-2 FPGA. The results show that the design satisfies the functions stipulated by the standard. The maximum frequency is increased by 1.5 times, and the rate up to 6.25Gbps. And resources of registers and lookup tables are reduced. Hence, the design provides a reference for the development of an efficient SpaceFibre CODEC.]]></description>
<pubDate>2024/4/8 8:35:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安军社,郑静雅]]></author>
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<title><![CDATA[Suppression of nonlinear flutter for a wing with freeplay in high speed airflow using nonlinear energy sink]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112020000004]]></link>
<description><![CDATA[Aiming at the subcritical problem of wing flutter system with freeplay nonlinear, the nonlinear energy sink (NES) technology is introduced into the flutter system to improve the critical velocity of limit cycle oscillation of freeplay nonlinear flutter system. The dynamic model of flutter system with NES control for wings with freeplay nonlinear is established, and the effects of NES parameters such as mass ratio, frequency ratio, damping ratio and relative position on the limit cycle oscillation suppression of flutter system are analyzed.SThe results show that the larger the damping ratio is, the system can enter the stable region at a smaller natural frequency ratio, but the position of NES needs to be closer to the leading edge of the wing.SThe smaller the damping ratio, the smaller the NES mass required for the limit cycle vibration response of the flutter system to enter the stable region. The influence of NES parameters on the critical velocity of limit cycle oscillation of flutter system is discussed.SWhen the NES position is close to the leading edge of the wing, increasing the natural frequency ratio will significantly improve the limit cycle oscillation suppression effect.SThe increase of mass ratio can significantly improve the suppression effect of limit cycle oscillation and improve the critical speed of limit cycle oscillation.SThe smaller the damping ratio of NES, the better the suppression effect of limit cycle oscillation of flutter system.]]></description>
<pubDate>2024/4/8 8:35:15</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[黄伟,钮耀斌,王中伟]]></author>
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<item>
<title><![CDATA[Pyramid progressive fusion low-illumination image enhancement network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201060000001]]></link>
<description><![CDATA[Since existing low-illumination image enhancement networks have insufficient ability to perceive and express feature information of different scales, this paper proposes a low-illumination image enhancement network model based on pyramid progressive fusion. The network performs multiple down-sampling operations on the image to form a feature pyramid. Then, it fuses the feature maps at different scales by adding skip connections to three different branches of the feature pyramid. The fine recovery module further extracts the refined information, and finally restores the feature map to a normal light image. The network model not only effectively enhances the brightness of the overall low-illumination image, but also maintains the detailed information and clear edge contours of the objects in the image. Moreover, it can effectively suppress the dark noise, and make the overall enhanced image realistic and natural.]]></description>
<pubDate>2024/4/8 8:35:11</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[何鹏浩,李淼,徐超越,杨昊,余映]]></author>
</item>
<item>
<title><![CDATA[Chinese cross-domain NL2SQL algorithm enhanced by auxiliary task]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201180000001]]></link>
<description><![CDATA[NL2SQL(natural language to structured query language) task aims to translate natural language queries into SQL(structured query language) executable by the database. A Chinese cross-domain NL2SQL algorithm enhanced by auxiliary tasks was proposed. Core idea was to perform multi-task training and improve the accuracy of the model by adding auxiliary tasks in the decoder and combining the prototype model. Auxiliary task was designed by modeling the database schema into a graph, predicting the dependency relations between the natural language queries and the nodes in the database schema graph, and explicitly modeling the dependency relations between the natural language query and the database schema. Through the improvement of auxiliary tasks, the model could better identify which tables/columns in the database schema were more effective for predicting the target SQL for specific natural language queries. Experimental results on the Chinese NL2SQL dataset DuSQL show that the algorithm after adding auxiliary tasks has achieved better results than the prototype model, and can better handle cross-domain NL2SQL task.]]></description>
<pubDate>2024/4/8 8:35:07</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[胡亚红,刘鹏杰,刘亚冬,朱正东]]></author>
</item>
<item>
<title><![CDATA[Joint design method of transmit-receive for transmit beamspace MIMO-STAP radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111240000001]]></link>
<description><![CDATA[The joint design of transmit beamforming and receiving filter for airborne multiple-input multiple-output (MIMO) radar in the background of signal-dependent clutter is studied. MIMO radar transmit beamspace space-time adaptive processing (STAP) signal model is established. In order to ensure the target detection performance in clutter environment, the signal-to-interference-plus-noise ratio (SINR) is maximized and a new iterative optimization algorithm based on the maximization minimization (MM) framework is designed to solve the joint design problem. By properly finding the lower bound of the objective function, the convergence speed of the proposed algorithm is effectively improved and the running time of the proposed algorithm is reduced. In addition, compared with the traditional phased array radar and MIMO radar, the optimized transmit beamforming and receive filter can significantly improve the output SINR. Simulation results demonstrate the effectiveness of the proposed method.]]></description>
<pubDate>2024/4/8 8:35:04</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[刘方正,毛云祥,潘继飞,石树杰,周青松]]></author>
</item>
<item>
<title><![CDATA[Detail perception fusion algorithm Based on Multi-scale decomposition for Extreme exposure images]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204120000003]]></link>
<description><![CDATA[Aiming at the problem of the low dynamic range of extreme exposure images, such as underexposure and overexposure images, a detail perception image fusion algorithm based on multi-scale decomposition is proposed. After detail enhancement, the underexposed image is roughly fused with the overexposed image. Wavelet transform is used to decompose the brightness component of the image after detail enhancement, and a special high-frequency and low-frequency fusion strategy is designed to realize the fine fusion of brightness components; The hue and saturation components of the coarse fusion image are recombined with the brightness components of the fine fusion image to obtain the final fusion result. Based on abundant testing data, the experimental results show that the visual effect of this method is excellent. The index of averaged MEF-SSIM is 0.9854, and the index of averaged SSIM is 0.6508, which is superior to the existing mainstream algorithms.]]></description>
<pubDate>2024/4/8 8:34:59</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈溅来,黄俊彬,梁步阁,杨德贵,张俊超,赵党军]]></author>
</item>
<item>
<title><![CDATA[Research on cooperative acquisition control strategy of geocentric very high orbit constellation configuration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208030000001]]></link>
<description><![CDATA[Aiming at the problem of cooperative acquisition and control of the constellation configuration in the Earth-centered very high orbit, a cooperative capture control strategy is designed based on virtual formation. Firstly, the optimal trajectory planning algorithm for multi-pulse burnup is used to coordinately plan the configuration capture trajectory; then the adaptive full-scale integral sliding mode controller is used to track and control the respective transfer trajectories of the satellites. Finally, the simulation verification is carried out by taking the configuration capture of the Samsung constellation at an orbital height of 100,000 kilometers as an example. The simulation results show that the strategy can be effectively applied to the constellation configuration capture control of the geocentric very high orbit, and can make the satellites in the constellation reach the self-supplied nominal position at the same time with less burnup, and at the same time have high accuracy.]]></description>
<pubDate>2024/4/8 8:34:54</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[吕健康,罗宇飞,孟云鹤]]></author>
</item>
<item>
<title><![CDATA[Delayed accumulation combined with AR filtering for naval axial frequency electric field signal processing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202130000001]]></link>
<description><![CDATA[In order to improve the signal-to-noise ratio of the target axial frequency electric field, a coherent accumulation method combined with AR filtering is proposed to process the array electric field signal for the application scenario of using an array of electric field sensors to measure the electric field of a ship. Finally, the accumulated signals are filtered using the AR model parameters. In order to verify the effectiveness of the proposed method under low SNR conditions, the measured array electric field signals are processed, and the results show that the proposed method can effectively suppress the noise spectrum and preserve the axial frequency line spectrum with an S/N ratio of -25.39 dB, and the S/N ratio is improved by about 21.92 dB after processing.Keywords: shaft-rate electric field, array signal processing, delayed accumulation, AR filtering]]></description>
<pubDate>2024/4/3 1:25:31</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[程锦房,谢昌奇,喻鹏,张伽伟]]></author>
</item>
<item>
<title><![CDATA[Microwave Frequency Measurement based on Dual Optical Frequency Combs and Stimulated Brillouin Scattering]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203100000001]]></link>
<description><![CDATA[A novel high-accuracy microwave frequency measurement based on dual coherent optical frequency combs (OFCs) and stimulated Brillouin scattering (SBS) is investigated. The unknown signal and the sweep signal are modulated by two dual parallel Mach–Zehnder modulators as the signal optical and the pump signal which are lunched into the dispersion shift fiber (DSF). Using the coherent dual OFCs and the sweep signal with shifted frequencies, the proposed measurement system can realize the wave-division and time-division multiplexing simultaneously. Besides, the coherent dual OFCs brings about a series of SBS gain responses at the same time. Then, the frequency of the unknown signal can be estimated by measuring the output optical power of the multiple channels. Furthermore, in order to improve the frequency measurement accuracy, the measured optical power values are employed to generate an amplitude comparison function (ACF) which can be utilized for error correction. Finally, the proposed scheme is verified via numerical simulations with a measurement error less than ±2.5MHz.]]></description>
<pubDate>2024/4/3 1:25:07</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[安康,梁涛,乔晓强,张先玉]]></author>
</item>
<item>
<title><![CDATA[Automatic Extraction Method of TIN-DDM Terrain Feature Line Supported by Rolling Ball Transform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202120000001]]></link>
<description><![CDATA[In view of the problems in the traditional GRID-DDM terrain feature line extraction method, such as the threshold is difficult to be adjusted quantitatively, the connection mode cannot be adjusted adaptively, and the type of terrain feature line is incomplete, this paper presents an automatic extraction method of TIN-DDM terrain feature line based on rolling ball transformation model. Based on the decision for terrain feature points associated with the critical rolling sphere radius, the concept of terrain shape boundary points is introduced, and the automatic extraction model of terrain feature lines based on subdivision unit is established according to the modeling idea of reverse engineering. Combined with the multi-scale expression characteristics of the terrain type judgment criteria and the terrain feature optimization model considering water depth values, an automatic extraction method of terrain feature lines that can be expressed at multiple scales and complete types is proposed. The experimental results show that compared with the classical surface water simulation method, this method can automatically extract complete, continuous, subdivided and multi-scale TIN-DDM terrain feature lines, and the generated terrain feature lines have higher terrain reconstruction accuracy.]]></description>
<pubDate>2024/4/3 1:24:34</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[董箭,,,张志强,]]></author>
</item>
<item>
<title><![CDATA[Experiment on the sound reduction performance of gas-water cabin in the pipeline system of underwater vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205270000001]]></link>
<description><![CDATA[Pipeline system is an important interaction pathway between underwater vehicle and external surrounding environment. It is also one of the main propagation channels for noise radiation. And it is considered to be an important factor influencing on the stealth properties of underwater vehicle. Reducing the radiation noise of pipeline system has become a key technology for developing quiet underwater vehicle. A new noise reduction method was proposed combining the characteristic of water muffler and water cabin in underwater vehicle. Making full use of the water cabin in underwater vehicle and charging certain gas to form an accumulator-type elastic-compressive expansion chamber for noise reduction. The acoustic experiment was accomplished to study and verify the performance of the gas-water cabin on noise reduction. The results indicated that the flow and pressure pulsation is effectively suppressed by the gas-water cabin, and the noise propagation pathway of the pipeline is blocked in special frequency range. This gas-water cabin provides a usefully approach on noise reduction.]]></description>
<pubDate>2024/4/3 1:22:29</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[暴春航,侯凌风,龙新平,秦子明,孙坤杰,张祖提]]></author>
</item>
<item>
<title><![CDATA[Development and verification of shape memory alloy self-resetting vibration damping device]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203030000001]]></link>
<description><![CDATA[In the continuous transonic wind tunnel test, the adjustable central flap mechanism deployed in the second throat can continuously change the effective throttling area and quickly fine-tune the Mach number of the test section. The dynamic performance of the adjustable central flap mechanism is one of the key factors affecting the stability and refinement of wind tunnel test data. In order to improve the flow induced vibration of the mechanism in the working state, a self-resetting vibration damping device which can meet the limited installation space of the central flap mechanism is designed and manufactured according to the biasing two-way driving principle of shape memory alloy (SMA). The SMA constitutive relation subroutine compiled by UMAT interface is used to realize the numerical analysis of the maximum pressing force of the damping device, and the error between the numerical analysis and the static test results is about 2.58%; A ground vibration reduction test platform was built to test the vibration reduction effect of SMA self-resetting vibration damping device in the separated and closed states. The vibration reduction test results show that the vibration response of the central flap mechanism is significantly reduced with SMA self-resetting damping device activated. An obvious damping rates appear in the frequency band of 0 Hz-100 Hz, especially, the damping rate in the range of low frequency to 55Hz is greater than 50%.]]></description>
<pubDate>2024/4/3 1:21:59</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈万华,陈振华,高鑫宇,李道奎,麻越垠,聂旭涛,张伟]]></author>
</item>
<item>
<title><![CDATA[Chemical Nonequilibrium Modeling Study of Inflatable Reentry Decelerator]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202130000004]]></link>
<description><![CDATA[In this paper, the air five species chemical kinetic model is used to study the flow characteristic of an inflatable reentry decelerator. The effects of shape deformation on flow temperature and pressure, heat flux along the wall are investigated, and the mole fractions of each species in the flow filed are presented. The modeling results show that the shape deformation of inflatable reentry decelerator has little influence on flow characteristic, and leads an increase of heat flux on the capsule surface. The study of species distribution shows that since N<sub>2</sub> is more difficult to dissociate than O<sub>2</sub>, the mole fraction of N is much lower than the mole fraction of O in the flow filed. Under the current calculation conditions, the ration of nitrogen and oxygen along the wall and axis is almost consistent with the incoming flow. The modeling studies in this paper fit well with experiments, which verify the reliability of the model.]]></description>
<pubDate>2024/4/3 1:21:15</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[董海波,冯瑞,何青松,黄明星,贾贺,王广兴]]></author>
</item>
<item>
<title><![CDATA[Analysis of the Research on the Flying-wing Aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203010000002]]></link>
<description><![CDATA[The development trajectory of the flying-wing aircraft was sorted out, encompassing the early evolutionary history to the current state of research, along with contemplation and forecasts regarding future directions. Meanwhile, several key control challenges associated with flying-wing aircraft were discussed, including attitude control in a wide-speed domain under nonlinear conditions, high-precision autonomous take off and landing control under multiple effect coupling, robust control issues with approximate aerodynamic models and under strong disturbances, as well as control allocation problems arising from multi-surface redundancy. Moreover, the discussion on flow control issues that were currently a focal point in flying-wing aircraft research were discussed in depth. The following research trend of active flow control technology was expounded.]]></description>
<pubDate>2024/4/3 1:20:45</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈清阳,鲁亚飞,王鹏,王玉杰,辛宏博,朱炳杰]]></author>
</item>
<item>
<title><![CDATA[Multi-spacecraft cooperative guard strategy based on reachable domain coverage]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303160000001]]></link>
<description><![CDATA[Cooperative guard of multi-spacecraft is an effective way for high-orbit spacecraft to deal with potential threat. Aiming at guarding high-orbit high-value targets, a multi-spacecraft cooperative guard strategy based on reachable domain coverage was proposed. The cooperative guard mission was described from the perspective of relative motion, and the multi-pulse reachable domain of the threat was modeled as a convex optimization problem. In the framework of receding optimization, the guard planes and points were designed based on the dynamically updated terminal reachable domain of threat, and a multi-spacecraft cooperative trajectory planning model was constructed with the guard points as terminal position constraints, the corresponding guard trajectories were generated. Simulation results show that the proposed method can quickly calculate the terminal reachable domain of the threat. The cooperative guard strategy can effectively prevent the threat in multiple scenarios, and the guard success rate increases with the maneuvering ability of the guard spacecraft.]]></description>
<pubDate>2024/4/3 1:16:34</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[蔡伟伟,杨乐平,张润德,朱彦伟]]></author>
</item>
<item>
<title><![CDATA[Chinese cross-domain NL2SQL algorithm enhanced by auxiliary task]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201180000001]]></link>
<description><![CDATA[NL2SQL(natural language to structured query language) task aims to translate natural language queries into SQL(structured query language) executable by the database. A Chinese cross-domain NL2SQL algorithm enhanced by auxiliary tasks was proposed. Core idea was to perform multi-task training and improve the accuracy of the model by adding auxiliary tasks in the decoder and combining the prototype model. Auxiliary task was designed by modeling the database schema into a graph, predicting the dependency relations between the natural language queries and the nodes in the database schema graph, and explicitly modeling the dependency relations between the natural language query and the database schema. Through the improvement of auxiliary tasks, the model could better identify which tables/columns in the database schema were more effective for predicting the target SQL for specific natural language queries. Experimental results on the Chinese NL2SQL dataset DuSQL show that the algorithm after adding auxiliary tasks has achieved better results than the prototype model, and can better handle cross-domain NL2SQL task.]]></description>
<pubDate>2024/4/2 18:01:02</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[胡亚红,刘鹏杰,刘亚冬,朱正东]]></author>
</item>
<item>
<title><![CDATA[Pyramid progressive fusion low-illumination image enhancement network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201060000001]]></link>
<description><![CDATA[Since existing low-illumination image enhancement networks have insufficient ability to perceive and express feature information of different scales, this paper proposes a low-illumination image enhancement network model based on pyramid progressive fusion. The network performs multiple down-sampling operations on the image to form a feature pyramid. Then, it fuses the feature maps at different scales by adding skip connections to three different branches of the feature pyramid. The fine recovery module further extracts the refined information, and finally restores the feature map to a normal light image. The network model not only effectively enhances the brightness of the overall low-illumination image, but also maintains the detailed information and clear edge contours of the objects in the image. Moreover, it can effectively suppress the dark noise, and make the overall enhanced image realistic and natural.]]></description>
<pubDate>2024/4/2 18:00:15</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[何鹏浩,李淼,徐超越,杨昊,余映]]></author>
</item>
<item>
<title><![CDATA[Suppression of nonlinear flutter for a wing with freeplay in high speed airflow using nonlinear energy sink]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112020000004]]></link>
<description><![CDATA[Aiming at the subcritical problem of wing flutter system with freeplay nonlinear, the nonlinear energy sink (NES) technology is introduced into the flutter system to improve the critical velocity of limit cycle oscillation of freeplay nonlinear flutter system. The dynamic model of flutter system with NES control for wings with freeplay nonlinear is established, and the effects of NES parameters such as mass ratio, frequency ratio, damping ratio and relative position on the limit cycle oscillation suppression of flutter system are analyzed.SThe results show that the larger the damping ratio is, the system can enter the stable region at a smaller natural frequency ratio, but the position of NES needs to be closer to the leading edge of the wing.SThe smaller the damping ratio, the smaller the NES mass required for the limit cycle vibration response of the flutter system to enter the stable region. The influence of NES parameters on the critical velocity of limit cycle oscillation of flutter system is discussed.SWhen the NES position is close to the leading edge of the wing, increasing the natural frequency ratio will significantly improve the limit cycle oscillation suppression effect.SThe increase of mass ratio can significantly improve the suppression effect of limit cycle oscillation and improve the critical speed of limit cycle oscillation.SThe smaller the damping ratio of NES, the better the suppression effect of limit cycle oscillation of flutter system.]]></description>
<pubDate>2024/4/2 17:59:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[黄伟,钮耀斌,王中伟]]></author>
</item>
<item>
<title><![CDATA[Optimal design for the high-speed and lightweight transmission system of SpaceFibre node]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112020000001]]></link>
<description><![CDATA[An optimal design of SpaceFibre node was proposed to meet the lightweight, high bandwidth and high reliability requirements for the satellite payload data transmission system. The incremental calculation based on frame was used to reduce circuit complexity. Benefitting from four-stage pipeline, error detection module operated at different rates. The module had lower hardware resources by sharing CRC. To improve reliability, the design adopted a two-layer control strategy with complete response. Resource-optimized FSM and storage architecture were built to simplify the implementation of the retransmission algorithm. A verification system at board-level with two nodes was implemented in XC7Z100FFG900-2 FPGA. The results show that the design satisfies the functions stipulated by the standard. The maximum frequency is increased by 1.5 times, and the rate up to 6.25Gbps. And resources of registers and lookup tables are reduced. Hence, the design provides a reference for the development of an efficient SpaceFibre CODEC.]]></description>
<pubDate>2024/4/2 17:59:09</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安军社,郑静雅]]></author>
</item>
<item>
<title><![CDATA[Adaptive control techniques in the shock wave/turbulence boundary layer interaction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111220000001]]></link>
<description><![CDATA[In order to prompt the development of the flow control technique, starting with the shock wave/ turbulence boundary layer interac-tion (SWTBLI) mechanism and the urgent requirements of the flow control, the research progress of the adaptive control techniques in the shock wave/ turbulence boundary layer interaction from four aspects was summarized, namely adaptive vortex generator, adaptive bump, adaptive micro jets and adaptive secondary recirculation jet. Analysis shows that developing adaptive flow control techniques, combined with AI technology, realizing local flow acceleration/deceleration, aerodynamic thermal protection, aerody-namic control and other functions in different areas of the hypersonic vehicle by adjusting external excitation, establishing control feedback loop according to flow field parameters and accelerating intelligent control schemes can be used as an important technical means for wide-speed flight of the new generation hypersonic vehicle.]]></description>
<pubDate>2024/4/2 17:58:59</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杜兆波,黄  伟,柳  军,吴  瀚,钟翔宇]]></author>
</item>
<item>
<title><![CDATA[Detail perception fusion algorithm Based on Multi-scale decomposition for Extreme exposure images]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204120000003]]></link>
<description><![CDATA[Aiming at the problem of the low dynamic range of extreme exposure images, such as underexposure and overexposure images, a detail perception image fusion algorithm based on multi-scale decomposition is proposed. After detail enhancement, the underexposed image is roughly fused with the overexposed image. Wavelet transform is used to decompose the brightness component of the image after detail enhancement, and a special high-frequency and low-frequency fusion strategy is designed to realize the fine fusion of brightness components; The hue and saturation components of the coarse fusion image are recombined with the brightness components of the fine fusion image to obtain the final fusion result. Based on abundant testing data, the experimental results show that the visual effect of this method is excellent. The index of averaged MEF-SSIM is 0.9854, and the index of averaged SSIM is 0.6508, which is superior to the existing mainstream algorithms.]]></description>
<pubDate>2024/4/2 17:57:56</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈溅来,黄俊彬,梁步阁,杨德贵,张俊超,赵党军]]></author>
</item>
<item>
<title><![CDATA[Joint design method of transmit-receive for transmit beamspace MIMO-STAP radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111240000001]]></link>
<description><![CDATA[The joint design of transmit beamforming and receiving filter for airborne multiple-input multiple-output (MIMO) radar in the background of signal-dependent clutter is studied. MIMO radar transmit beamspace space-time adaptive processing (STAP) signal model is established. In order to ensure the target detection performance in clutter environment, the signal-to-interference-plus-noise ratio (SINR) is maximized and a new iterative optimization algorithm based on the maximization minimization (MM) framework is designed to solve the joint design problem. By properly finding the lower bound of the objective function, the convergence speed of the proposed algorithm is effectively improved and the running time of the proposed algorithm is reduced. In addition, compared with the traditional phased array radar and MIMO radar, the optimized transmit beamforming and receive filter can significantly improve the output SINR. Simulation results demonstrate the effectiveness of the proposed method.]]></description>
<pubDate>2024/4/2 17:57:43</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[刘方正,毛云祥,潘继飞,石树杰,周青松]]></author>
</item>
<item>
<title><![CDATA[Research on cooperative acquisition control strategy of geocentric very high orbit constellation configuration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208030000001]]></link>
<description><![CDATA[Aiming at the problem of cooperative acquisition and control of the constellation configuration in the Earth-centered very high orbit, a cooperative capture control strategy is designed based on virtual formation. Firstly, the optimal trajectory planning algorithm for multi-pulse burnup is used to coordinately plan the configuration capture trajectory; then the adaptive full-scale integral sliding mode controller is used to track and control the respective transfer trajectories of the satellites. Finally, the simulation verification is carried out by taking the configuration capture of the Samsung constellation at an orbital height of 100,000 kilometers as an example. The simulation results show that the strategy can be effectively applied to the constellation configuration capture control of the geocentric very high orbit, and can make the satellites in the constellation reach the self-supplied nominal position at the same time with less burnup, and at the same time have high accuracy.]]></description>
<pubDate>2024/4/2 17:55:46</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[吕健康,罗宇飞,孟云鹤]]></author>
</item>
<item>
<title><![CDATA[Spare parts demand fuzzy prediction model based on data and knowledge]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210100000002]]></link>
<description><![CDATA[The uncertainty of spare parts demand impact on the prediction model significantly. Fuzzy mathematics is an effective means to deal with uncertainty. Knowledge-driven model is based on the rules defined by domain experts, but limited by the scarcity of domain experts' knowledge. Data-driven model is with the advantages of big data and the prediction accuracy, but with low interpretability and insufficient security. The fuzzy prediction model of spare parts demand of this paper is based on fuzzy clustering algorithm and Fuzzy Network method, which is driven by data and knowledge. Fuzzy clustering algorithm generates rules from data and experts generate rules from knowledge. The two kinds of rules are merged by Fuzzy network method, and the fuzzy set parameters of rules are optimized by genetic algorithm(GA). The proposed model overwhelm fuzzy clustering algorithm in interpretability, transparency and accuracy.]]></description>
<pubDate>2024/4/2 17:51:21</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[魏曙寰]]></author>
</item>
<item>
<title><![CDATA[Reinforcement learning of ballistic maneuver adjustment strategy after missile penetration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201150000001]]></link>
<description><![CDATA[In order to solve the problem of trajectory maneuver adjustment caused by large deviation of flight trajectory after midcourse penetration of ballistic missile, an optimization model of maneuver adjustment timing strategy was established. A reverse sequence Q learning algorithm for maneuver adjustment was designed, and a tile coding approximator encoding was used to encode the state characteristics space, and the space was linearly approximated. A reverse-order update strategy mechanism combining Q-learning algorithm and Monte Carlo method was constructed, the optimal timing of missile maneuvering adjustment was trained. The simulation results show that the strategy obtained by training 10 000 generations of reinforcement learning algorithm can reliably control the adjustment decision of flight trajectory after missile penetration with the minimum maneuver times under given scenario parameters, which verifies the effectiveness of the method.]]></description>
<pubDate>2024/4/2 17:51:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[樊博璇,韩磊,李冰]]></author>
</item>
<item>
<title><![CDATA[Translational Tracking Strategy of Two-Test-Mass Drag-Free Spacecraft Based on Geocentric Orbit in Gravitational Waves Detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207280000003]]></link>
<description><![CDATA[Inquire into the approach of drag-free control technic to detect gravitational waves is proposed in this study, the basic elements of gravitational-wave detection mission based on geocentric orbit is introduced, and then the dynamics modeling of the two-test-mass drag-free system is established, including the relative motion dynamics and coupling property among the spacecraft and test masses, furthermore, the requirements and disturbance of this system are analyzed, and according to this, control law based on H-infinity theory is designed for spacecraft-tracking loop and suspension loop of test masses, finally, different tracking strategy is analyzed with the control law, and we get the preliminary conclusion with results of a nonlinear time-domain simulation, strategy without defined drag-free point can give a feasible solution without suspension along non-sensitive axes, not only the performance in the frequency domain is achieved, but also the offset of each test mass is limited to a micrometer order, and the inertial reference point is obtained.]]></description>
<pubDate>2024/4/2 17:51:21</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[郝立维,孙玥,王继河,张锦绣,张谕]]></author>
</item>
<item>
<title><![CDATA[Film cooling characteristics analysis of the turbine blade tip in transonic flow]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201120000001]]></link>
<description><![CDATA[To grasp the film cooling characteristics of the turbine blade tip in transonic flow. The Pressure Sensitive Paint technique was used to experimentally obtian the effects of the tip clearance gap and mass flow ratio on the film cooling performance of the blade tip.The cascade exit Mach numbers was 1.05. The results indicate that at the low mass flow ratio, increasing the tip clearance gap could significantly improve the film cooling performance of the tip mid-chord region, whereas, changing the tip clearance gap has a slight effect on the film cooling performance of the tip mid-chord region. In the tip mid-chord region, increasing the mass flow ratio decreases With the mass flow ratio increasing, the film cooling effectiveness in the tip mid-chord region decreases under the small tip clearance gap condition. Increasing the mass flow ratio from 0.1%+0.05% to 0.14%+0.07% shows positive effect on the film cooling performance in the tip mid-chord region at large tip clearance gap.]]></description>
<pubDate>2024/4/2 17:51:21</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[胡其高,夏军,张博伦,朱惠人]]></author>
</item>
<item>
<title><![CDATA[Acceleration scheme and mesoscopic numerical simulation for rarefied gas dynamics]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111140000001]]></link>
<description><![CDATA[Abstract: To overcome the difficulty that DVM(discrete velocity method) for solving the Boltzmann equation has extremely slow convergence speed and high computational resource consumption in the slip flow and early transition flow regimes, an acceleration scheme which coupling the mesoscopic and macroscopic the equations in full field was proposed. Boltzmann model equation could be solved based on the DVM using finite difference method at the mesoscopic level, and the moment equations could be solved based on the semi-implicit-method for pressure linked equations using finite volume method at the macroscopic level. It is well known that the macroscopic equations are highly efficient in the low Knudsen number regime, and this character can be utilized to accelerate the solutions of the Boltzmann equation. The data transfer between the macroscopic and the mesoscopic equations was based on the velocity distribute function, which can be reconstructed from the high-order Hermite polynomial function. The simulation results indicate that: the acceleration scheme shows great potential in the slip and early transition regime, which is able to save up to 95.28% computational time cost. However, it performs less efficient for large Knudsen numbers.]]></description>
<pubDate>2024/4/2 17:51:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨伟奇]]></author>
</item>
<item>
<title><![CDATA[Staged Lookup: Accelerating Path Lookup in Virtual File System of Linux]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112100000001]]></link>
<description><![CDATA[The conventional Linux kernel traverses a hierarchic path in steps to index a file. With the gap between persistent storage devices and main memory lessening gradually, the cost of this indexing strategy is increasingly prominent. Staged Lookup was proposed to speed up path lookups by dynamically caching popular directories and further reducing access latencies to files. The core of Staged Lookup was to cache commonly accessed dentries, to avoid redundant path walks that traversed directory trees from the root. Staged Lookup also enriched backward path walks to perform path-lookups from a closer cached dentry instead of the root. A prototype of Staged Lookup was implemented and integrated into Linux Kernel v3.14 and v5.4. Experimental results show that Staged Lookup offers up to 46% performance gain compared to ordinary path lookup schemes. Furthermore, Staged Lookup shows small performance overheads compared to the original kernel implementation.]]></description>
<pubDate>2024/4/2 17:51:21</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[殷树,邹彦良]]></author>
</item>
<item>
<title><![CDATA[Review on Analysis and Evaluation of Anti-damage Capability for Launching Vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110140000002]]></link>
<description><![CDATA[With the rapid development of various advanced reconnaissance and detection technologies, the battlefield situation of modern war is becoming more and more transparent. Various long-range precision guided transport carriers carry high-performance advanced warheads, which bring severe challenges to the anti-damage ability and battlefield survivability of ground equipment such as missile launchers. Articles around the launcher anti-damage ability of analysis and evaluation technology, firstly analyzes the launcher may face the threat of damage and damage mechanism of from the point of view of an anti-damage ability evaluation of application of shock wave penetration, thermal radiation and electromagnetic radiation, the kinetic energy is the research status of four types of damage, and put forward different damage types in the anti-damage ability of analyze and evaluate the application of direction; Secondly, based on the vulnerability analysis space theory, the development process of equipment vulnerability analysis is summarized. It is considered that the logical transfer relationship from physical space to performance space is the key to the vulnerability analysis of launchers at present. The research trends of vulnerability criteria are introduced from the physical criteria, performance criteria and classification criteria. Finally, the research concept and the main problems in the analysis method of the anti-damage ability of the launcher are described. The research conclusions can provide references for the analysis and evaluation of the anti-damage ability of the missile launcher.]]></description>
<pubDate>2024/4/2 17:51:21</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[高蕾,高钦和,黄通,钱秉文,沈飞,王冬]]></author>
</item>
<item>
<title><![CDATA[Analysis of the most sensitive region of single-event transient in 22-nm FDSOI devices]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112240000001]]></link>
<description><![CDATA[Based on 3D-TCAD simulations, the sensitivity region of single-event transient (SET) effect in 22-nm fully depleted silicon-on-insulator (FDSOI) devices are investigated. This work studied the SET-sensitive region of both single transistor and inverter of 22-nm FDSOI process to analyze the influence of the heavy ion strike locations on SET sensitivity in silicon circuits. Difference between single transistor and invertor is explained by charge collection mechanism. An in-depth analysis shows that the parasitic bipolar amplification effect in FDSOI device is related to the heavy ion strike location, which is the root cause of different SET sensitivity at different regions in transistors. And the increased SET sensitivity in drain region, when the drain of the single transistor connected to a constant voltage source, leads to the different conclusion between single transistor and inverter. This research improves the research method of studying SET sensitive regions of the devices under FDSOI process. The simulation result of inverter is more in line with the actual situation than single transistor, which will provide theoretical guidance for SET hardening.]]></description>
<pubDate>2024/4/2 17:51:00</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[方亚豪,梁斌,刘小年,张博翰]]></author>
</item>
<item>
<title><![CDATA[A Sequential Censored Probability Circle Test Method for Hit Accuracy]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201060000002]]></link>
<description><![CDATA[For the calculation difficulty directly of the circular error probability test, a sequential censored probability circle test method is proposed in this paper. The paper defines the basic decision rules of the test method, and gives the calculation methods of the developer risk, the consumer risk, and the average number of tests, and puts forward two different optimization models about decision threshold on this basis. Numerical simulation is used to analyze the different results derived from the two different calculation methods of the decision threshold in the test scheme. The results show that the optimization model of minimizing the average number of tests has better practicability in engineering.]]></description>
<pubDate>2024/4/2 17:51:00</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨华波,张士峰]]></author>
</item>
<item>
<title><![CDATA[Experimental investigation of rotating detonation ramjet with different expansion angles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204070000003]]></link>
<description><![CDATA[A series of direct-connected tests were conducted on a rotating detonation ramjet engine with a cylindrical isolator-combustor configuration, under the conditions of a total temperature of 860 K and Mach 2 inflow. This study aimed to investigate the influence of combustor front expansion angle (θ=30°、45°、60°, and 90°) on the detonation wave propagation characteristics, operating range, and pressure distribution. The results indicate that the combustion mode is consistently deflagration when the expansion angle is 90°. As the expansion angle gradually decreases, the combustion mode transitions towards sawtooth and hybrid mode (including single wave stage). When the expansion angle is 30°, the rotating detonation exhibits the widest self-sustaining operating range and highest combustor pressure. Additionally, as the expansion angle decreases, the lower limit of the equivalence ratio for achieving the hybrid mode decreases. Furthermore, the study analyzed the impact of combustion modes on the inflow and found that the periodic high-frequency pressure oscillation in the sawtooth wave/hybrid mode could cause the positioning of leading edge of the shock train in the isolator to move upstream. The hybrid mode has the most significant impact on supersonic inflow.]]></description>
<pubDate>2024/4/2 17:51:00</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘世杰,刘卫东,彭皓阳,王光宇,张海龙]]></author>
</item>
<item>
<title><![CDATA[Fast incremental one-class support vector machine algorithm for rocket engine fault detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111200000001]]></link>
<description><![CDATA[In order to solve the problem of imbalance between positive and negative samples in liquid rocket engine fault diagnosis, and to enable adaptive fault detection during engine steady working state, a anomaly detection model based on fast incremental one-class support vector machine was estab-lished. Feature engineering method was adopted to extract features from sensor-obtained multivari-ate time series. Through incremental leaning, the one-class support vector machine model was im-proved and applied to iquid rocket engine anomaly detection. The one-class support vector machine detection model was endowed with adaptability for various engine individuals and multiple working conditions, while increasing computing speed. A number of tests data analysis show that the model is effective, fast-training and practically valuable.]]></description>
<pubDate>2024/4/2 17:51:00</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[卢哲,薛薇,张箭,张楠,张万旋]]></author>
</item>
<item>
<title><![CDATA[Image denoising algorithm based on weighted kernel norm minimization and improved wavelet threshold function]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112300000003]]></link>
<description><![CDATA[In view of the structural residual noise in the weighted nuclear norm minimization (WNNM) algorithm and the inability to maintain the edge structure of the image, a denoising method that minimizes the weighted kernel norm and improves the wavelet threshold is adopted.. Use the total variation (TV) model to perform preliminary denoising of the noise image, Use the noisy image to subtract the preliminary denoised image, and use an improved wavelet threshold function to denoise the noise difference image obtained after subtraction. The denoised residual image is superimposed with the preliminary denoised image, and the superimposed image is finally denoised using an iterative weighted kernel norm minimization algorithm based on the residual noise level. Compared with the more popular denoising algorithms, the PSNR(peak signal-to-noise ratio) and SSIM(structural similarity)  processed by this algorithm are improved, the texture structure of the image can be maintained, and the effect is better in a high-noise environment.]]></description>
<pubDate>2024/4/2 17:51:00</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[程超,郭昕刚,霍金花,许连杰]]></author>
</item>
<item>
<title><![CDATA[Deep Learning for Visual Speech Generation: A Survey]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206090000004]]></link>
<description><![CDATA[The goal of this paper is to further advance the development of visual speech learning. The task definition and research significance of visual speech generation was expounded and the difficulties and challenges were deeply analyzed in this field; Besides, the current status and development level of visual speech generation research was introduced, and the recent mainstream methods were sorted, classified and commented based on the difference of generation frameworks; At the end of the paper, the potential problems and possible research directions of visual speech generation were discussed.]]></description>
<pubDate>2024/4/2 17:51:00</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[刘 丽,盛常冲,]]></author>
</item>
<item>
<title><![CDATA[Radar deception jamming detection method with digital radio frequency memory]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205110000002]]></link>
<description><![CDATA[The transponder deception jamming with digital radio frequency memory (DRFM) is highly coherent with real radar echoes, which makes it difficult for radar to distinguish real radar echoes and jamming. To address this issue, this paper proposes a DRFM-based deception jamming detection method based on Hough transform. Firstly, the jamming signal model based on linear frequency modulation is established and the spectrum of the jamming harmonics is analyzed subsequently. Then, the short-time Fourier transform and two-dimensional CFAR detector are used to extract the features of the jamming signal. In doing so, the Hough transform is used to complete deception jamming detection. The proposed method is based on the characteristics of DRFM deception jamming itself, and does not depend on prior information and application scenario. Moreover, it has low computational complexity and good detection performance under the condition of low signal-to-noise. The effectiveness of the proposed method is verified through simulations.]]></description>
<pubDate>2024/4/2 17:51:00</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈爽,,张顺生]]></author>
</item>
<item>
<title><![CDATA[High-precision acquisition method of spacecraft orbit based on Equilibrium flight theory]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208030000002]]></link>
<description><![CDATA[The space gravitational wave detection system in geocentric orbit consists of three identical satellites, which move in the same orbit with a phase difference of 120°. The high accuracy of gravitational wave detection requires the accuracy of satellite orbit parameters and the stability of constellation configuration. In this paper, an equilibrium flight theory based on continuous micro-thrust control is proposed to solve the problem of precise orbit capture, and the spacecraft orbit control strategy is given analytically. Firstly, the concept of balanced flight is proposed, and the analytical solution of flight under special conditions is given. Then, the optimal control strategy of orbit acquisition can be calculated analytically, and the objectives of orbit eccentricity adjustment, orbit height adjust-ment and satellite angular velocity adjustment can be further achieved, and finally the high-precision acquisition of constellation configuration can be achieved. Simulation results show that the proposed method can achieve high precision orbit shape adjustment and satellite angular velocity adjustment, and meet the requirements of gravita-tional wave detection mission for detector orbit accuracy.]]></description>
<pubDate>2024/4/2 17:51:00</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[侯佳睿,罗宇飞,孟云鹤]]></author>
</item>
<item>
<title><![CDATA[Operation analysis and preliminary experiment of the gyromagnetic nonlinear transmission lines]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202080000002]]></link>
<description><![CDATA[In the past decades, the wideband high power microwave sources which combine the advantages of high-power density of narrow-band sources and wide spectrum of ultra-wideband sources have drawn much attention. As a kind of wideband source, the gyromagnetic nonlinear transmission lines (GNLTL) have the characteristics of high center frequency, easily implementation of frequency adjustment, high repetition frequency, etc. The physical essence of the GNLTL’s ability to generate microwaves is related to the damped precession of magnetic moment, but the application of GNLTL is different from the traditional situations which means the traditional theory is not completely applicable. It is difficult to explain the principle of the GNLTL quantitatively in theory due to the complicated working mechanism. In this paper, we try to qualitatively explain the physical mechanism and working process of the GNLTL. A test experiment was developed, and then the design and construction of the GNLTL were introduced. Microwaves were generated in the experiment with a center frequency of 750 MHz, a 3 dB bandwidth of 12% and a peak power of 245 kW.]]></description>
<pubDate>2024/4/2 17:49:04</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[崔言程,黄立洋,孟  进,袁玉章,朱丹妮]]></author>
</item>
<item>
<title><![CDATA[Current status and trends of drag-free technology for space-based gravitational wave detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207280000004]]></link>
<description><![CDATA[To detect space gravitational waves in the ultra-low frequency of in the milli hertz range, we need to provide them with a purely quiet space environment, the drag-free spacecraft system is used as a space science platform for the detection of space-based gravitational waves, drag-free control is one of the key technologies to realize the ultra-static and ultra-stable operation of science platform for gravitational wave space detection. At present, the dynamics and control of the spacecraft system have been studied deeply by various research institutions at domestic and overseas, and different detection tasks have been proposed according to the requirements of different detection frequency bands. The design and control of spacecraft formation are introduced and analyzed in detail, and the principles and theoretical methods of drag-free control and attitude control, high-precision inertial sensors and actuators involved are deeply dissected. In this paper, the overall situation of demonstration and verification of drag-free spacecraft in orbit for space gravitational wave detection is detailed and analyzed. On this basis, the key problems required to be solved at present in the research of follow-up related were presented, and the research hotspots and trends in the methods of future dynamics and control of drag-free spacecraft systems were also pointed out.]]></description>
<pubDate>2024/4/2 17:48:43</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[连晓斌,,,,,]]></author>
</item>
<item>
<title><![CDATA[Frequency and phase revision technique of DS/FH signal tracking]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202180000002]]></link>
<description><![CDATA[Tracking procedure of DS (direct sequence)/FH (frequency hopping) spread spectrum signal is effected by Doppler effect and ionospheric effect seriously, which makes it hard to be used for the anti-interference field of satellite navigation. To solve this issue, a RLS (recursive least square) based filtering was proposed to improve this stability of DS/FH signal tracking. The carrier Doppler estimation with variable center frequency in different channel was converted to the estimation with the center frequency of the DS/FH signal, and the estimates are filtered. The NCO (numerically controlled oscillator) of carrier was revised according to the predicted Doppler frequency as the frequency hops. TEC (total electron content) was estimated in real time by observing the carrier phase and code phase mutations, and the carrier phase and code phase was revised as the frequency hops. Simulations experiment demonstrate the proposed method is effective to eliminate the frequency and phase discontinuity of the DS/FH signal tracking, whose tracking accuracy can be the same level as DS signal.]]></description>
<pubDate>2024/4/2 17:48:23</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[张波]]></author>
</item>
<item>
<title><![CDATA[Distributed fixed time convergence cooperative guidance law against communication delay]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202220000001]]></link>
<description><![CDATA[In order to make multiple missiles effectively complete the simultaneous attack of maneuvering targets in the presence of communication delay, a fixed-time convergence distributed cooperative guidance law against communication delay was proposed. Based on the framework of fixed time control technology, the guidance law could stabilize the time boundary independent of the initial state of multiple missile system and improved the control efficiency of multiple missile system. A fast non-singular terminal sliding mode and virtual leader were used to realize the guidance law's robustness against communication delay. Lyapunov stability theory was used to prove the consistency in fixed time. Simulation results show that under the condition of communication time delay, multiple missiles can effectively attack the target simultaneously based on the designed distributed cooperative guidance law.]]></description>
<pubDate>2024/4/2 17:47:33</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[戴可人,,,于航,张合,郑技平]]></author>
</item>
<item>
<title><![CDATA[Research of altitude control of powered parafoil based on wind feedforward and active disturbance rejection control]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211100000002]]></link>
<description><![CDATA[Powered parafoil has huge advantage on its cost performance and duration of flight. Thus, it shows wide application perspective on the battle reconnaissance, electronic warfare and airdrop supply. However, the lift force of the parachute systems is determined by the airspeed which is larged influenced by the external wind. The external wind is also the main disturbance on the altitude control of the powered parafoil. To solve this problem, in this paper, an eight-DOF dynamical model of the parafoil is built. Then, based on the traditional active disurbance rejection control (ADRC), an improved disturbance rejection controller is designed based on the wind feedforward compensation unit. Under this condition, the external wind will be compensated directly, and the powered parafoil can realize the accuracy altitude. Then, after the preliminary verification of the controller in the detailed simulation experiment, the flight test is carried out. In the windy environment, the average vertical tracking error is less than 2 meters. The correctness of the proposed controller is verified.]]></description>
<pubDate>2024/4/2 17:46:25</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[卢伟涛,孙  昊,孙青林]]></author>
</item>
<item>
<title><![CDATA[Wall boundary condition for the R13/R26 moment method at the mesoscopic level]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201040000001]]></link>
<description><![CDATA[Wall boundary conditions for the macroscopic equations, i.e. the NSF(Navier-Stokes-Fourier) equations, R13/R26 moment equations, the middle and high Knudsen number regimes, lose their accuracy dramatically and is easy to diverge. .To overcome these difficulties, a wall boundary condition for the R13/R26 moment method was proposed at the mesoscopic level. The velocity distribution function could be reconstructed and feedback into the Boltzmann model equation in the near-wall region, and the wall boundary condition for the R13/R26 moment method could be calculated based on solving the Boltzmann equation with the discrete velocity method. Results indicate that: the proposed wall boundary condition is able to increase the computational accuracy up to 59.84% compared with the classical approach. Meanwhile, it is able to get the steady-state solution for the Knudsen number up to 1.0.]]></description>
<pubDate>2024/4/2 17:43:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨惠,杨伟奇]]></author>
</item>
<item>
<title><![CDATA[Bending and buckling behavior analysis of the carbon nanotubes  reinforced composites Timoshenko beams]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203140000001]]></link>
<description><![CDATA[The bending and buckling behavior of the macro carbon nanotubes reinforced composites (CNTRCs) was studied considering the scale effect of carbon nanotubes (CNTs). Firstly, based on the Eshelby-Mori-Tanaka (EMT) method and using nonlocal theory to characterize the scale effect of CNTs, the nonlocal EMT constitutive model was established. According to the Timoshenko beam theory, the static differential equations and boundary conditions of CNTRCs beams were derived through Hamilton principle. Then the bending response and ultimate buckling load of CNTRCs beams at simply supported edges were obtained and compared with the literature to verify the correctness of the proposed model and solution method. Finally, the influence of the scale effect parameters and volume fraction of CNTs and the slenderness ratio of composite beams on the bending response and ultimate buckling load of CNTRCs beams was analyzed. The results show that the equivalent stiffness of the CNTRCs beam is weakened by considering the scale effect of CNTs, and the volume fraction of CNTs and scale effect parameter both have a great impact on the bending response and ultimate buckling load of the CNTRCs beam with a large slenderness ratio.]]></description>
<pubDate>2024/4/2 17:42:39</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[雷勇军,吴栋,于宝石,张大鹏]]></author>
</item>
<item>
<title><![CDATA[A situation analysis method based on level set for spacecraft pursuit-evasion game]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303140000001]]></link>
<description><![CDATA[Recently, spacecraft pursuit-evasion game has drawn increasing attention from scholars. In the paper, the qualitative spacecraft pursuit-evasion game is studied in order to provide feasibility support for strategy design, and a situation analysis method for scenarios in close range is proposed by comprehensively using dimension-reduction dynamics and backwards reachability set. A dimension-reduction dynamic model is derived in the line-of-sight rotation coordinate system, and the pursuit-evasion qualitative model of the game system is determined to reduce state space dimension. The backwards reachable set of the target set is used to divide the pursuit-evasion state space and describe the capture zone. A time-dependent Hamilton-Jacobi-Isaacs (HJI) partial differential equation (PDE) is established to describe the evolution of backwards reachable set in the dimension-reduction dynamics, based on level set method, and a WENO-TVD solver is designed to numerically calculate the viscous solution of the final value problem of the HJI PDE. These measures achieve the accurate description of target set and avoid the terminal singularity. The effectiveness of the method and batch processing function are demonstrated by numerical simulations of several pursuit-evasion scenarios with different thrust configurations.]]></description>
<pubDate>2024/4/2 17:41:30</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨傅云翔,杨乐平,张乘铭,朱彦伟]]></author>
</item>
<item>
<title><![CDATA[Survey on dynamics and control problems in spacecraft orbital pursuit-evasion game]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303140000003]]></link>
<description><![CDATA[With the rapid development of spacecraft rendezvous and proximity operation technology, the problem of orbital pursuit-evasion has gradually become a research hotspot in the aerospace field. From the perspective of dynamics and control, the research status of spacecraft orbital pursuit-evasion was reviewed. The general form of the orbital pursuit-evasion problem model based on quantitative differential games was given, and various types of orbital pursuit-evasion problems were systematically sorted out. For the solution of pursuit and escape strategies, the advantages and disadvantages of various methods were analyzed for closed-loop strategy and open-loop strategy. Focusing on the combination of artificial intelligence algorithm and orbital pursuit and escape problem, the research status of orbital pursuit and escape strategy based on deep neural network and reinforcement learning was expounded. Regarding future prospects, development directions has been proposed, including pursuit-evasion game situation analysis, multi-spacecraft game control, game dynamics and control under three-body problem.]]></description>
<pubDate>2024/4/2 17:40:10</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨傅云翔,杨乐平,张乘铭,朱彦伟]]></author>
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<title><![CDATA[Spacecraft orbital pursuit-evasion strategy for rendezvous based on receding horizon optimization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303140000002]]></link>
<description><![CDATA[As a key technology of space close control, orbital pursuit-evasion attracts more and more researchers' attention. In this paper, the free-time orbital pursuit-evasion game for rendezvous was studied. Given the uncertainty such as measurement error in the process, a high-efficiency strategy based on receding horizon optimization was proposed. The saddle point control strategy of the game was derived according to differential games, and the equivalent transformation of the problem was carried out. By solving open-loop saddle point strategy off-line in advance, the initial states of the problem and the corresponding solutions were taken as samples for neural network training, and the trained network structure can quickly obtain the approximate solution. In order to better deal with the measurement noise in the game environment, a receding horizon optimization framework was designed based on the neural network structure. By periodically solving the problem, the rendezvous of the pursuer and evader was finally realized. Numerical simulation shows that the proposed strategy can effectively deal with the uncertainty of measurement noise, and compared with the existing strategy in the literature, the calculation time in this paper can be reduced from minutes to several seconds.]]></description>
<pubDate>2024/4/1 11:16:17</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨傅云翔,杨乐平,张乘铭,朱彦伟]]></author>
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<title><![CDATA[Evaluation of Damage Effect Against Irregular Area Target by Multiple Missiles under Uncertainty]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207140000003]]></link>
<description><![CDATA[A key challenge in missile operational research lies in enhancing the credibility of damage evaluation for multiple missiles striking irregular surface targets under information scarcity. The evaluation model of the damage effect against irregular area targets by multiple missiles with given parameters was developed by the Monte Carlo method. Belief degree distributions was used to describe uncertainties in damage evaluation. The evaluation result showed a high level of uncertainty in damage effect. The contribution of uncertainty in each attribute to the uncertainty in the damage effect was analyzed based on belief entropy. By reducing the uncertainty of the high-contribution attributes, the uncertainty of the damage effect could be reduced iteratively. The simulation results showed that the uncertain range of the effective damage rate of the area target was significantly reduced. This study can provide useful guidance on the work to reduce uncertainty in damage evaluation.]]></description>
<pubDate>2024/4/1 11:14:03</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[胡剑文,,,]]></author>
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<title><![CDATA[Preferred Plane Bank-to-Wind Technology for Plane-symmetric Launch Vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203020000003]]></link>
<description><![CDATA[The control force can be mismatched on pitch and yaw plane for plane-symmetric launch vehicle, a control method named Bank to Wind (BTW) was proposed to solve the problem, which adjusts the windward side according to rolling program angle to decrease the maximum engine deflection. The off-line method of BTW control was studied, the analytical solution of the theoretical value of BTW control rolling program angle was derived, and it was proved that the deviation of the theoretical value is the same order as the flight attitude deviation. A fitting algorithm based on Fourier series with weights was proposed to modify the rolling program angle, ensuring engineering feasibility. Six-degree-of-freedom flight dynamics simulations were conducted to analyze the impact of BTW control on control forces, aerodynamic loads, and the tracking quality of the program angle, thereby verifying the effectiveness of BTW control. By comparing the simulation results of different fitting base frequencies, it is concluded that excessively high fitting frequencies can affect control quality. From an engineering perspective, the "smoothness" of the rolling program angle is more important than its "fitting accuracy."]]></description>
<pubDate>2024/4/1 11:12:23</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杜昊昱,唐攀,王紫扬,张普卓,赵永志]]></author>
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<title><![CDATA[Dynamic response analysis of rocket joint structure considering discrepancy of bolt preloads]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202210000001]]></link>
<description><![CDATA[In order to address the problem that the dynamic response characteristics of the bolted flange connection structure, which is widely used in aerospace rocket structures, are significantly affected by bolt preload, the static and dynamic response characteristics of the rocket connection structure were studied taking into account the discrepancy of bolt preloads under different conditions. A method was proposed to analyze these responses of the rocket connection structure with difference of bolt preloads, which was based on finite element analysis and impact tests of the specific bolted flange connection shell structure. By investigating the response characteristics of the connection structure with a loose bolt, a new bolt loosening detection procedure based on the complementary ensemble empirical mode decomposition algorithm is proposed which can quantify the characteristics of the increase of the frequency response amplitude in the middle and high frequency bands of the connection structure when the loosening happens, and can quickly identify the occurrence of loose conditions without damage.]]></description>
<pubDate>2024/4/1 11:11:09</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[关振群,潘嘉诚,孙伟程,曾岩]]></author>
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<item>
<title><![CDATA[On design of intelligent security and reliable payment system based on blockchain technology]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201200000001]]></link>
<description><![CDATA[Internet payment system provides a service guarantee platform for transactions between different users on the internet. However, there are still a series of security problems in the existing system, which poses a great threat to the development of the third-party payment industry. The blockchain technology uses the decentralized structure, by sharing data and consensus mechanism, to ensure the authenticity and integrity of the data and realize the trust among members; The blockchain technology has key advantages including decentralization, programmability and security, and it is particularly suitable for constructing a programmable monetary system. An intelligent security and reliable payment system is designed based on block chain technology. The system combines blockchain technology, state secret algorithm and payment system to provide a more secure guarantee for the traditional internet payment system. it uses the point-to-point characteristics of blockchain technology to solve the problems of payment efficiency, data security, etc. With the help of big data technology of internet, credit rating is provided to users and credit services are provided. Using trans-chain technology, the data of different blockchains can be shared to figure out a better solution to the liquidity of funds.]]></description>
<pubDate>2024/4/1 11:09:40</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈颖,,刘天野,张黎仙,]]></author>
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<title><![CDATA[A System-of-system Design and Simulation Evaluation Methodon the Unmanned Swarm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209020000002]]></link>
<description><![CDATA[The unmanned swarm combat is becoming a new type of style that changes the form of warfare. As the relatively independent testing of unmanned equipment and the lack of integrated closed-loop design and integrated verification methods, a system-of-system (SoS) design and simulation evaluation method is proposed in this paper. The method includes five stages: the combat concept modeling and demand analysis, the SoS design concept and SoS design, the infield simulation experiment and scheme exploration, the system prototype development and evaluation optimization, the completion of integrated testing and comprehensive decision-making. In addition, we innately develop the theoretical methods, tool links, and integrated environment of the SoS design, simulation tests, evaluation and optimization, where provide theoretical and technical support for the systematization, intelligence, and actual combat level of unmanned equipment.]]></description>
<pubDate>2024/3/29 17:21:30</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[井田,李小波,王维平,杨松,周鑫]]></author>
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<title><![CDATA[Evolution permutation optimal Latin hypercube design method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204260000002]]></link>
<description><![CDATA[Latin hypercube design is one of the most commonly used computer experimental design methods. However, most of the existing Latin hypercube design methods are one-time sampling methods, and it is hard for them to take into account the spatial uniformity and computational efficiency of the design. In this paper, an experimental design method of permutation evolution Latin hypercube is proposed. Through the evolution and permutation inheritance of a small-scale design, the update and optimization of Latin hypercube design are realized with less computation. In addition, this method gives consideration to the relationship between existing samples and new added samples and realizes the sequence expansion of samples, which is very convenient in the actual approximate modeling process. Finally, through several groups of numerical experiments, the advantages of this method in space filling quality and calculation efficiency are verified.]]></description>
<pubDate>2024/3/29 12:34:33</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[文谦,武泽平,杨家伟,张为华,]]></author>
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<item>
<title><![CDATA[Infrared small target detection method based on improved non-convex estimation and asymmetric spatial-temporal regularization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205190000001]]></link>
<description><![CDATA[With the wide application of infrared technology in early warning system and space-based surveillance system, infrared small target detection has become a hot research issue at home and abroad. Aiming at infrared dim and small targets detection in complex background, this paper based on the non-convex tensor low-rank estimation with asymmetric spatio-temporal regularization constraint algorithm proposed a new kernel norm estimation method to replace the original estimation method. Then, an adaptive weight tensor based on structure tensor and multi-structure element top-hat filtering is proposed to constrain the target tensor in this paper, which has enhanced the sparsity and suppressed the remaining strong edge structures of the target tensor.Experimental results show that the improved algorithm can better eliminate the influence of strong edge structure on the detection results, and has a lower false alarm rate than the original algorithm under the condition of ensuring the detection rate.]]></description>
<pubDate>2024/3/29 10:51:07</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[胡亮,杨德贵]]></author>
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<title><![CDATA[Improved ADC model for launcher vehicle survivability in typical combat flow and graded environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110080000001]]></link>
<description><![CDATA[In order to comprehensively evaluate the survivability of launch vehicles in combat, the differences and relations of four levels of weapon equipment parameters-performance- capability -effectiveness and evaluation space were defined. In view of the survivability assessment of launch vehicles, graded 5 types of natural environment, 3 levels of threat environment and 3 kinds of combat flow status, the impact of external environment was taken as the necessary conditions of effectiveness evaluation, and an evaluation framework of three dimensions of content, level and object was constructed.The detection probability and damage probability were used to characterize the camouflage ability and anti-damage protection ability of launch vehicles, and the continuous transfer probability matrix of launch vehicles' combat status was established. A comprehensive evaluation model of launch vehicle based on improved ADC model under typical operational flow and standard environment was proposed. Through simulation analysis, the survivability of various launch vehicles varies significantly in different environments and combat status, the model can dynamically evaluate the survivability of launch vehicles from multiple dimensions of performance space, environment space and combat flow space, and put forward optimization and quantitative suggestions for the performance design and battlefield application of launch vehicles.]]></description>
<pubDate>2024/1/15 16:22:39</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[刘志浩,]]></author>
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<title><![CDATA[Optimizing Operator Computation of MiniGo on a High-Performance Heterogeneous Accelerator]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212150000002]]></link>
<description><![CDATA[An efficient parallel computing method based on the characteristics of the high-performance heterogeneous accelerator and the training mode of MiniGo was proposed. The on-chip computing resources were reasonably planned to achieve pipelining parallel optimization between heterogeneous devices. The shared memory programming was designed according to the existence of shared storage segments between heterogeneous devices to reduce data transmission costs. According to the characteristics of multiple computing resources in a DSP cluster, combined with the computing-memory access feature of the operators, different optimization strategies were designed. At the same time, this method provides an easy-use high-performance operator library for TensorFlow. The experimental results show that this method realizes the multi-core parallel computing of operators. The speedup of convolution was 24.69 compared with that was achieved on a single core. Compared with the cropped version of the 8-core FT2000+ CPU, the speedup of training and selfplay execution on this method were 3.83 and 1.5, respectively.]]></description>
<pubDate>2024/1/5 17:20:36</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[贺周雨,姜晶菲,李荣春,乔  鹏]]></author>
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<title><![CDATA[Parallel Optimization of Convolution Algorithm on Multi-core DSPs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209200000002]]></link>
<description><![CDATA[Convolution is one of the basic operations in neural networks at present, and its optimization is a research hotspot in academia and industry. According to the characteristics of the heterogeneous multi-core DSP chip independently developed by National University of Defense Technology and the characteristics of the convolution algorithm, a high-performance multi-core parallel convolution implementation scheme for multi-core DSP architecture is proposed in this paper. A feature graph level multi-core parallel scheme is proposed for  convolution. For convolutions with kernels larger than 1, a window level multi-core parallel optimization design is proposed, and an element-wise vectorization based intra-core parallel optimization implementation is proposed. The experimental results show that the maximum efficiency of the proposed parallel optimization method can reach 64.95%. When the bandwidth is limited, the parallel expansion efficiency of multi-core can still reach 48.36% ~ 88.52%. Compared with E5-2640 CPU, the execution performance on the typical network resnet50 achieves 5.39x performance acceleration.]]></description>
<pubDate>2024/1/5 11:10:37</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[高蕾,姜晶菲,李东升,李荣春,李娅琳,王庆林,许金伟]]></author>
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<title><![CDATA[Joint Optimization for Heterogeneous Multi-UAV Configuration and Mission Planning within SEAD Scenarios]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203270000001]]></link>
<description><![CDATA[Suppression of enemy air defenses (SEAD) is a typical application scenario of multi-UAV cooperation. a heterogeneous UAV fleet vehicle routing problem model was established by taking UAV configuration as a decision variable based on the mission planning problem and fully characterizing multiple constraints of the target, mission and UAV. A two-layer joint optimization method was designed to handle UAV configuration and mission planning in a hierarchical manner: the upper layer was designed with the connection impact indicator to accurately assess the quantitative requirements of various types of UAVs.The lower layer improves the genetic algorithm, which could efficiently handle multiple coupling constraints and can accurately adjust the mission plan in conjunction with UAV configuration changes. The two layers coordinated with each other to obtain a UAV configuration and mission execution plan that meet the requirements. Simulation results show that the method can obtain a reasonable UAV configuration plan without traversing various UAV configurations, while obtaining an efficient and feasible mission execution plan.]]></description>
<pubDate>2023/12/19 15:54:13</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭正,侯中喜,贾高伟,王建峰,辛宏博]]></author>
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<title><![CDATA[A consistency adjustment method for pairwise comparison matrix in analytic hierarchy process based on weights]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111090000001]]></link>
<description><![CDATA[In the Analytic Hierarchy Process (AHP), it is usually necessary to adjust the pairwise comparison matrix (PCM) to meet the consistency requirements, however, the influence of the inconsistency of the PCM on weights after adjustment is ignored, and the calculated weights cannot retain the information of the original PCM to the maximum extent. Therefore, a method for PCM modulation based on the weights was proposed. The method constructs a completely consistent matrix according to the properties of weights, and the matrix is fitted by the AdaGrad method, so as to minimize the total change of the matrix relative to the original PCM. Then, takes its corresponding weights as the calculation result of the matrix. Numerical results show that this method can significantly improve the retention of original PCM information compared with other methods and does not require repeated consistency checking.]]></description>
<pubDate>2023/12/5 8:54:04</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[耿正霖]]></author>
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<title><![CDATA[Evaluation of Electro-Optical Protection Combat Effectiveness Based on ANP]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109230000001]]></link>
<description><![CDATA[Rapid and accurate evaluation of electro-optical protection combat effectiveness is the basis of implementing electro-optical protection for key target. Considering the deficiency of AHP in evaluation of electro-optical protection combat effectiveness, ANP was proposed to evaluate, toke analyze of the independence、correlation and feedback of the interior of the element hierarchy as entry point, putted forward the main index dictionary of electro-optical protection combat effectiveness, set up the evaluation model, according to setting up the matrix、calculating、obtaining the weights, complete the evaluation. Validated the model by an example, provided theory-reference for evaluation of electro-optical protection combat effectiveness.]]></description>
<pubDate>2023/12/5 8:53:49</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[王宇]]></author>
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<title><![CDATA[Performance Analysis of SMI based GNSS STAP under Distributed Intermittent Interferences]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109270000001]]></link>
<description><![CDATA[Considering the distributed intermittent interference threat faced by GNSS receiver, this paper comprehensively and accurately analyzes the anti-jamming performance of space-time adaptive processing based on Sample Matrix Inversion (SMI) method. Based on the performance analysis model, according to the mismatch of sampling covariance matrix caused by intermittent interferences, the performance of Space-Time Adaptive Processing (STAP) under different conditions is comprehensively analyzed through classification evaluation, combing induction and theoretical derivation. The analysis results show that when the sampling length is less than the scintillation period and the pre-sample method is used, the missed sampling will occur and the interference suppression performance will decrease sharply, and the frequency of missed sampling is the sum of the scintillation frequencies of each interference. Numerical and simulation analyses verify the results of analysis. The optimal design of STAP in the face of distributed intermittent interference is discussed. This paper provides an important reference for dealing with the distributed intermittent jamming threat.]]></description>
<pubDate>2023/12/5 8:53:49</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[王解]]></author>
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<item>
<title><![CDATA[Multi-reference-station based Relative Positioning Method and Impact Analysis of the Biases in the A Priori Baseline Vectors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110060000001]]></link>
<description><![CDATA[In order to improve the reliability of the single-station-based relative positioning solutions over short baselines, the multi-reference-station-based relative positioning method is explored in this contribution. Firstly, the a priori baseline information between the reference stations is integrated into the observable model, thus giving the functional and stochastic models of the multi-reference-station-based relative positioning. Based on that, the closed-form formula of the ambiguity dilution of precision for the positioning is derived so that the influence of the number of reference stations on the float ambiguity precision is revealed. Then the impacts of the biases in the a priori baseline information on the integer ambiguity resolution are analyzed theoretically. It is shown that the integer ambiguity resolution can barely be influenced on the condition that the bias is less than a few centimeters. Finally, the multi-reference-station-based relative positioning method is validated with both the simulated and real data sets. The numerical results show that, increasing the number of reference stations not only improves the single-epoch, single-frequency ambiguity resolution success rate and convergence rate, but also restrains the biases in the a priori baseline information. For example, the ambiguity resolution success rate is still larger than 92% even when the biases of the baseline components attain 4 cm in the field tests. This contribution provides the theoretical foundation for special scenarios such as the rapid construction of temporary airport in wartime.]]></description>
<pubDate>2023/12/5 8:53:49</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[范波,侯振伟,伍劭实,张良,钟季龙]]></author>
</item>
<item>
<title><![CDATA[Multi-block moving window slow feature analysis fault diagnosis method based on KL divergence]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109140000003]]></link>
<description><![CDATA[A KL(Kullback Leibler) divergence multi-block moving window slow feature analysis method is proposed to solve the problems that the variable feature information cannot be fully utilized by the traditional block segmentation method based on experience, the local information is ignored by a single modeling method, and the off-line model cannot adapt to the time-varying characteristics. KL divergence was used to measure the distance between variables in the normal working condition data set, and the minimum error sum criterion was introduced to cluster, which was divided into two sub-blocks with the minimum distance. On this basis, the slow feature analysis method was utilized to model each sub-block, and the optimal model was obtained by updating the sampled data with moving window. Monitoring statistics were calculated respectively, and the fault monitoring results were fused with support vector data description to achieve fault diagnosis. The proposed method is applied to the monitoring of Tennessee Man process, and higher fault detection rate and lower false alarm rate are obtained, verify the feasibility and effectiveness of this method.]]></description>
<pubDate>2023/12/5 8:53:49</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[程超,郭昕刚,霍金花,许连杰]]></author>
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<title><![CDATA[Spatial domain collocation interference cancellation method based on auxiliary array in integrated platform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201050000001]]></link>
<description><![CDATA[The integrated platform integrates multiple high-power frequency-using devices in a limited space. Due to the overlap of frequency bands, the local transmitter (Tx) will cause serious collocation interference to the receiver (Rx), causing the saturation of Rx antenna interface and failing to work normally. In response to the above problems, this paper proposes a collocation interference cancellation method based on auxiliary array, establishes a collocation interference cancellation system model, derives the expression of minimum residual interference (RI) power, and proposes channel conditions that need to be satisfied for collocation interference cancellation. In addition, the location of the auxiliary is analyzed when Tx array is non-cooperative, and the relationship of the locations of arrays is analyzed when the Tx array is cooperative. Theoretical and simulation results show that the collocation interference cancellation method based on auxiliary array can effectively cancel collocation interference at the Rx antenna interface without affecting the transmission efficiency of the local Tx array.]]></description>
<pubDate>2023/12/5 8:53:48</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[杜林松,李彤,潘文生,邵士海,时成哲]]></author>
</item>
<item>
<title><![CDATA[Study of the Intelligent Prediction Modelfor Ammunition Storage Microenvironment Temperature]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109150000001]]></link>
<description><![CDATA[Temperature is one of the main factors affecting the storage life of ammunition. It is the key for evaluating and prolonging the life of ammunition to acquire the temperature variation law of ammunition storage microenvironment efficiently and accurately. However, it takes a long time for traditional test method, and it also has a low universal and high coat. More importantly, traditional test cannot predict the future temperature variation. So, with the help of the neural network and the heat transfer theory, a model for predicting the microenvironment of ammunition storage is studied, and based on the model, a corresponding temperature prediction software is developed. Finally, the relevant test is in progress to verify the software correctness and parameter optimization in Dunhuang and Mohe.]]></description>
<pubDate>2023/12/5 8:51:20</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈阳,杜琴,王竟成,谢兰川,张云,张志明]]></author>
</item>
<item>
<title><![CDATA[GaN Power Devices and Their Radiation Effects for Space Applications]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204260000001]]></link>
<description><![CDATA[Compared with traditional materials such as silicon (Si) and gallium arsenide (GaAs), the third-generation semiconductor material gallium nitride (GaN) has the advantages of large band gap, high breakdown voltage, high electron saturation drift velocity, and high temperature resistance. It can be used to fabricate high-temperature, high-frequency and high-power electronic devices, showing broad application prospects in space communication and power electronic systems under complex radiation environment. This paper introduces the main structures of GaN power electronic devices at present, and analyzes the working principles of GaN devices with different structures. The research progress of total ionizing dose effect and single event effect of GaN power devices in recent years has been reviewed. The degradation and damage mechanisms of GaN devices caused by radiation effects are analyzed and discussed.]]></description>
<pubDate>2023/12/5 8:49:11</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[毕津顺,曹爽,,沈立志,孙毅,于庆奎]]></author>
</item>
<item>
<title><![CDATA[An Efficient RNN Inference Engine on Very Long Vector Processor]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211070000002]]></link>
<description><![CDATA[Recurrent neural network（RNN） is one of the commonly used deep learning algorithms in the field of natural language processing. With the increasing depth and complexity of the model, the computational requirements of RNN increases dramatically. On the other hand, due to the inconsistent length of processing sequences, the performance optimization of RNN on different processors makes it difficult to researchers. In this paper, an efficient RNN acceleration engine is implemented for the self-developed long vector processor FT-M7032. This engine proposed a row-first matrix vector multiplication algorithm and a data-aware multi-core parallel method to improve the computational efficiency of matrix vector multiplication. It proposed a two-level kernel fusion optimization method to reduce the overhead of temporary data transmission. The optimized handwritten assembly codes for multiple operators are integrated to further tap the performance potential of long vector processors.  Experiments show that the RNN engine for long-vector processors is efficient, when compared with the multi-core ARM FT2000+ and Intel Golden CPU, the RNN-like model LSTM can achieve a performance acceleration of up to 62.68 times and 3.51 times, respectively.]]></description>
<pubDate>2023/12/5 8:48:19</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈抗抗,苏华友,杨乾明]]></author>
</item>
<item>
<title><![CDATA[Hybrid WCNS scheme with new discontinuity detector applied to discontinuous inviscid compressible flows]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202305230000001]]></link>
<description><![CDATA[In supersonic inviscid compressible flow calculations, high-order accurate schemes are supposed to robustly capture shock waves and obtain high fidelity simulation results of the flow field, which usually contains discontinuities and small-scale vortex structures. Based on combinations of sub-stencil derivatives, smoothness measurement algorithms were studied, and a new discontinuity detector was developed to balance accuracy and robustness, making troubled-cell recognition highly resolved for small-scale vortices. Hybrid WCNS methods were studied, which could solve smooth and discontinuous regions in the flow field using linear and nonlinear weighting schemes respectively, to overcome the difficulty of a single nonlinear scheme in achieving design accuracy in smooth areas. Numerical results show that the hybrid WCNS scheme with new discontinuity detector performs well in simulating one-dimensional and two-dimensional Euler equations, and has higher computational efficiency compared to the original WCNS method that uses local characteristic decomposition in the entire flow field.]]></description>
<pubDate>2023/12/5 8:46:55</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[邓小刚,]]></author>
</item>
<item>
<title><![CDATA[Optimizing Yinyang K-means Algorithm on Many-core CPUs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209060000001]]></link>
<description><![CDATA[Traditional Yinyang K-means algorithm is computationally expensive when dealing with large-scale clustering problems. An efficient parallel acceleration implementation of Yinyang K-means algorithm was proposed based on the architectural characteristics of typical many-core CPUs. This implementation was based on a new memory data layout, used vector units in many-core CPUs to accelerate distance calculation in Yinyang K-means, and targeted memory access optimization for NUMA(non-uniform memory access) characteristics. Compared with the open source multi-threaded version of Yinyang K-means algorithm, this implementation could achieve the speedup of up to 5.6 and 8.7 approximately on ARMv8 and x86 many-core CPUs, respectively. Experients show that the optimization successfully accelerate Yinyang K-means algorithm in many-core CPUs.]]></description>
<pubDate>2023/12/5 8:46:00</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[郝若晨,李荣春,刘杰,梅松竹,王庆林,尹尚飞,周天阳]]></author>
</item>
<item>
<title><![CDATA[The influence of forecasting wind intensity on rocket maximum aerodynamic load accuracy and modeling analysis]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109100000002]]></link>
<description><![CDATA[The prediction accuracy of upper wind has an important impact on the flight safety of the launch vehicle, which is mainly manifested in the impact on the accuracy of the maximum aerodynamic load; however, there are very few research literatures on the accuracy of different forecast wind intensity and the corresponding accuracy of the maximum aerodynamic load forecast value. Based on the actual wind in a certain area, the accuracy characteristics of different forecast wind intensity and the corresponding maximum aerodynamic load forecast value are respectively analyzed. And use the multiple linear regression method to establish a revised model. The results show that within 1-11days of forecasting days, The greater the forecast wind intensity, the higher the forecast wind accuracy and the corresponding maximum aerodynamic load forecast value accuracy; Using multiple linear regression method can improve the accuracy of the maximum aerodynamic load forecast, and the smaller the forecast wind intensity, the more obvious the improvement of the forecast accuracy of the maximum aerodynamic load. These findings have reference value in the flight assurance and safety decision-making of rocket launch.]]></description>
<pubDate>2023/12/5 8:39:37</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[程胡华]]></author>
</item>
<item>
<title><![CDATA[Experimental Study on Space Charging Effectof Flexible Thermal Control Films of Spacecraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109260000001]]></link>
<description><![CDATA[The charged characteristics of flexible thermal control films have been tested under 10-70KeVelectron irradiation according to the structural characteristics of conductive-insulating multilayer composite and micro/nano-size of thickness, and the key parameters such as surface charging potential and electrostatic discharge frequency are obtained. The transport law of irradiated electrons in multilayer thin films is studied by Monte Carlo method. The results show that there is no electrostatic discharge when the irradiated electron energy is 10KeV due to the particularity of the structure of the film. With the continuous increase of the electron energy, the surface potential amplitude of the film material increases first and then decreases with the electrostatic discharge frequency and the space charging effect is the most significant when the electron energy is 25KeV.]]></description>
<pubDate>2023/12/4 10:44:14</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈益峰,冯娜,韩炎晖,季启政,柳青,秦晓刚,王金晓,杨生胜]]></author>
</item>
<item>
<title><![CDATA[Improved ADC model for launcher vehicle survivability in typical combat flow and graded environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110080000001]]></link>
<description><![CDATA[In order to comprehensively evaluate the survivability of launch vehicles in combat, the differences and relations of four levels of weapon equipment parameters-performance- capability -effectiveness and evaluation space were defined. In view of the survivability assessment of launch vehicles, graded 5 types of natural environment, 3 levels of threat environment and 3 kinds of combat flow status, the impact of external environment was taken as the necessary conditions of effectiveness evaluation, and an evaluation framework of three dimensions of content, level and object was constructed.The detection probability and damage probability were used to characterize the camouflage ability and anti-damage protection ability of launch vehicles, and the continuous transfer probability matrix of launch vehicles' combat status was established. A comprehensive evaluation model of launch vehicle based on improved ADC model under typical operational flow and standard environment was proposed. Through simulation analysis, the survivability of various launch vehicles varies significantly in different environments and combat status, the model can dynamically evaluate the survivability of launch vehicles from multiple dimensions of performance space, environment space and combat flow space, and put forward optimization and quantitative suggestions for the performance design and battlefield application of launch vehicles.]]></description>
<pubDate>2023/12/4 10:44:13</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[刘志浩,]]></author>
</item>
<item>
<title><![CDATA[On-chip Cache Design Method Based on Cooperative Memory Compilation and Layout]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111010000003]]></link>
<description><![CDATA[In order to improve the speed of on-chip cache and reduce the area and power consumption, this paper proposes an on-chip cache design method based on cooperative memory compilation and layout. This method estimates the timing margin of the memory based on their different spatial positions, uses the exhaustive combination of various configuration parameters, including splitting / merging, increasing / decreasing size, threshold replacement and deformation to compile the memory. Then the best SRAM memory compilation configuration is selected according to the timing margin. This method is integrated with the existing physical design steps into a complete design flow. Experimental results show that this method can reduce the power consumption by about 9.9% and the critical path delay by 7.5%.]]></description>
<pubDate>2023/12/4 10:44:10</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[刘必慰,宋雨露,熊琪,杨茗]]></author>
</item>
<item>
<title><![CDATA[High-throughput LDPC decoder on GPU for 5G New Radio]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204290000001]]></link>
<description><![CDATA[We proposed a GPU-based QC-LDPC decoder for 5G New Radio(NR). Different from existing LDPC decoders based on GPUs, our decoder achieved high throughput when decoding LDPC codes with high code rates. Moreover, we implemented the shortening and puncturing techniques which are exploited by 5G NR. The decoding algorithm Min-Sum approximation algorithm(MSA) was optimized to implement efficient parallel decoding on the GPU. In order to save the on-chip and the off-chip bandwidth, we proposed the two-level quantization scheme and implement data packing on the GPU. We also analyzed the optimum thread assignment for different code rates based on our implementation. By using the optimum settings on the GPU, the decoding throughput achieves 1.38 Gbps in the case of (2080,1760), r=5/6 on Nvidia RTX 2080Ti.]]></description>
<pubDate>2023/12/4 10:44:08</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李荣春,乔鹏,王庆林,周鑫]]></author>
</item>
<item>
<title><![CDATA[Motion model of spherical fragments penetrating gelatin and sensitivity analysis of fragment parameters]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207120000003]]></link>
<description><![CDATA[To reveal the injury mechanism of spherical fragments to human tissue, gelatin was used as a substitute for human tissue. Based on the theory of dynamic cavity expansion, the segmental motion theoretical model of spherical fragments penetrating gelatin was established by considering the velocity attenuation of spherical fragments in the stage of incomplete entering stage, to study the motion law of spherical fragments penetrating gelatin. The correctness of the model was verified by the experiments of steel balls and tungsten balls penetrating gelatin, and the optimal drag coefficients in the model were solved. The sources of errors in the theoretical calculation process were analyzed, and the expression of dimensionless penetration depth was derived. A sensitivity analysis of the influence of spherical fragment parameters (diameter, density and velocity) on the penetration depth was carried out by using the sobol' method. The results show that the motion model can well simulate the motion law of spherical fragments. The velocity attenuation of low-density spherical fragments in the incomplete entering stage cannot be ignored. The sensitivity of spherical fragment parameters to the effect of penetration depth is in descending order of velocity, density and diameter.]]></description>
<pubDate>2023/12/4 10:44:05</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈莉,蒋明飞,刘坤,吴志林,赵磊]]></author>
</item>
<item>
<title><![CDATA[A quantization and pruning optimization method for attention mechanism]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210170000002]]></link>
<description><![CDATA[Attention-based mechanism deep neural network models have achieved remarkable results in many tasks such as natural language processing and computer vision, but model inference also contains huge computation and memory access overhead, which poses a challenge to the computing power and efficiency of the computing platform. To solve the problem of efficient processing of attention-based models, studies the model compression technology of co-optimization of quantization and pruning, and proposes a symmetric linear fixed-point quantization method for four activations in attention mechanism, namely query, key, value, and probability. At the same time, a probability matrix pruning method and a progressive pruning strategy are proposed to effectively reduce the loss of pruning accuracy. The experimental results on different datasets show that for the typical attention model BERT, in the case of low or no accuracy loss this optimization method can achieve 4-bit or 8-bit fixed-point quantization, 0.93-0.98 sparsity, greatly reduces the calculation amount of the model, and lays a good foundation for accelerating the calculation of the quantized sparse model.]]></description>
<pubDate>2023/12/4 10:44:03</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[何源宏,姜晶菲,许金伟]]></author>
</item>
<item>
<title><![CDATA[Numerical dissipation of flux splitting schemes and its induced error at contact discontinuity]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111040000001]]></link>
<description><![CDATA[Numerical dissipation and its generation mechanisms of three kinds of flux splitting schemes for calculating contact discontinuity problems under different flow field parameters are given, and the numerical results and theoretical derivation show that when the FVS scheme is used for contact discontinuity calculation, if there is a subsonic region in the flow field, numerical disturbance errors moving at the characteristic velocity will be induced during the generation of density dissipation. These errors have no effect on the numerical dissipation, but it will affect the velocity and pressure distributions, thus changing the structure of the flow field. In two-dimensional flow fields, the mutual interference of the induced errors will produce numerous complex small-scale structures, which brings difficulties to the flow field structure identification. Meanwhile, in the flow field with linear distribution of density parameters, if the object reconstructed by the spatial discrete scheme is convective flux, using FVS scheme to calculate the flow field will generate numerical errors, making it difficult to reach the second order of computational accuracy.]]></description>
<pubDate>2023/12/4 10:43:58</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[韩芳,刘君,魏雁昕]]></author>
</item>
<item>
<title><![CDATA[Research on the fast prediction algorithm of the flight pipeline of the reentry capsule]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209280000002]]></link>
<description><![CDATA[To meet the computational requirements of safe airspace and the expected landing location in the recovery mission of the reentry capsule, a fast prediction algorithm of flight pipeline based on the Koopman operator approach was proposed for the reentry capsule together with the safe airspace determination process for the rescue helicopter. The body-parachute dynamic model was constructed. A group of discrete state points was uniformly selected from therandom state space by using the Halton sampling method, and the multiple possible trajectory was calculated. Based on the back pulling mechanism of Koopman operator, the initial probability density value was associated with the current state to obtain the flight pipeline and desired trajectory of the reentry capsule and its separation parts under uncertain conditions. The numerical analysis shows that the fast prediction algorithm of flight pipeline based on the Koopman operator approach is significantly better than the Monte Carlo method in terms of convergence speed and accuracy. After using the flight pipeline calculation results to plan the flight route of the rescue helicopter, the collision risk is reduced by 54% at most and the corresponding search time is reduced by 70%. The proposed algorithm has been successfully applied to the Chang'e-5 recovery mission.]]></description>
<pubDate>2023/12/4 10:40:24</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[禄晓飞,涂国勇,杨涛,,张青斌,]]></author>
</item>
<item>
<title><![CDATA[Structural optimization for composite wings of tail-sitter electric aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207200000001]]></link>
<description><![CDATA[According to the requirements of material delivery platform in the complex terrain area, the research on the structural design of the composite wing of the tail-sitter electric aircraft is carried out. Based on the load analysis, the structural configuration and lay out designs were studied, and the structural design scheme of the composite wing was proposed. The finite element model of the composite wing was developed and the static strength analyses under different operating conditions were completed. The distributions of structural stresses and deformations were obtained, and the structural strength was evaluated with the Tsai-Wu failure criterion employed. The structural optimal analysis of the composite wing was performed based on the stepwise optimization strategy with the layer thicknesses and angles as design variables. The optimal results show that the structural mass is reduced by 47.77% under the constraints of structural stiffness and strength, which can provide the important reference for the design and development of the tail-sitter electric aircraft structure.]]></description>
<pubDate>2023/12/1 15:21:46</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[麻震宇,张琪,张祎桀]]></author>
</item>
<item>
<title><![CDATA[Modeling and numerical simulation of constant-height flight by air-lifting gas mixing for aerostats]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206290000004]]></link>
<description><![CDATA[Abstract: According to the floating weight balance characteristics and the ideal gas state equation, a method to control the height of the aerostat’s flat flight height by gas mixing was explored, and the overall design research of constant-height flight by air-lifting gas mixing was carried out. Considering the importance of thermodynamic characteristics to the ascent process and the flat flight process of the aerostat, combined with the thermophysical properties of mixed gas in engineering thermodynamics, the super-pressure balloon was taken as the research object, and the thermal environment was coupled with the dynamic model of the sphere ascent and the flight process. On this basis, the mechanical simulation of the ascent and level flight process of the balloon is carried out, and the changes in altitude, speed, gas temperature and pressure during the ascent of the balloon are obtained, so as to verify the feasibility of the theoretical model of constant-height flight by air-lifting gas mixing, and provide guidance for the subsequent aerostat flight test.]]></description>
<pubDate>2023/12/1 15:21:46</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[曹胜鸿,宋林,杨燕初,赵荣,祝榕辰]]></author>
</item>
<item>
<title><![CDATA[Impact of transceiver IQ imbalances on cooperative jamming suppression in confidential communications]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111290000006]]></link>
<description><![CDATA[A CJ(cooperative jamming) masked secure communication architecture was proposed in this article for communication environmentsconfidential communications where when malicious interference and illegal eavesdropping coexist. Thereinto, the FH(frequency-hopping) technology was adopted in the transceiver to avoid malicious interference, and the CJ technology was employed to block illegal eavesdropping. Nevertheless, the proposed architecture employs a wide frequency bandwidth, which will raise nonnegligible IQ(in-phase and quadrature) imbalances at the transceiver oscillators. In view of this, based on the proposed secure communication architecture, mathematical modeling was conducted on the signal distortion caused by the imbalance of the receiving and transmitting IQ channels; A, a mathematical expression for SDNR(the signal to distortion-plus-noise ratio) at the receiver was provided to measure the degree of signal distortion caused by the imbalance of the transmitting and receiving IQ channels; A, and a closed- form expression for the system CJSR(CJ suppression ratio) was givenderived to evaluate the CJ suppression capability of the proposed architecture in the presence of imbalanced transmit and receive IQ channels. The sSimulation results show that the power of the signal distortion raised by transceiver IQ imbalance is much greater than that of the thermal noise. Besides, both the SDNR and CJSR will decline sharply as the transceiver IQ imbalance deteriorates, and when the magnitude and phase imbalance are 0.95 and п/50 respectively, both the SDNR and CJSR performance will deteriorate 47 dB.]]></description>
<pubDate>2023/12/1 15:21:46</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈雯雯,邵士海,宋长庆,唐友喜,赵宏志]]></author>
</item>
<item>
<title><![CDATA[Study of high-power microwave protection technology based on plasma]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112010000001]]></link>
<description><![CDATA[Plasma has a unique protective effect against high-power microwave attack. In this paper, based on the plasma fluid approximation method, the time dependent evolution of the incident electric field during the interaction between high-power microwaves and columnar plasma arrays is studied using COMSOL software, and the physical process and mechanism of plasma protection against high-power microwaves are analysed. The results show that the incident high-power microwave will change the plasma parameters drastically, especially the electron density will increase sharply, so that the plasma will show metal-like electromagnetic properties to the incident high-power microwave, and finally realize the effective protection against the incident high-power microwave. In addition, the plasma protection against high-power microwaves is experimentally verified by using columnar plasma arrays generated by high-frequency glow discharge. Finally, the main problems to be solved for plasma-based high-power microwave protection technology are summarized.]]></description>
<pubDate>2023/12/1 15:21:46</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[陈宗胜,李志刚,刘丽萍,邱志楠,汪家春,王俊儒]]></author>
</item>
<item>
<title><![CDATA[Autonomous Configuration Planning for Intelligent Search and Rescue Robots in Rough Terrains]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302280000001]]></link>
<description><![CDATA[In order to solve the configuration planning problem for intelligent search and rescue robots with assisted flippers to achieve autonomous obstacle crossing, a novel method for planning robot configuration during obstacle crossing is proposed that can be applied to complex terrains. The core of the proposed method was an adaptable and efficient robot pose model prediction algorithm. By representing the terrain as a series of discrete point sets, a mathematical model for predicting the one-sided pose of the tracked robot was established; further, a fast solver for this model was proposed, which can predict 1000-1500 poses per second. Based on this, the evaluation metrics of the robot's state and action in the obstacle-crossing process were established, and an optimization-based real-time flippers action planner was realized using the dynamic programming algorithm and rolling optimization. The simulation and real-robot experiments show that the proposed approach enables the robot to control the flippers to cross rough terrains autonomously. It performs more smoothly than the reinforcement-learning method and manual operation when crossing obstacles.]]></description>
<pubDate>2023/12/1 15:21:46</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈柏良,黄开宏,卢惠民,潘海南,吴文启,肖军浩]]></author>
</item>
<item>
<title><![CDATA[Analysis of high-speed railway network delay propagation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109230000002]]></link>
<description><![CDATA[Noted the limitation of existing methods to study the delay propagation mechanism in high-speed railway network, the Bayesian network is used to analyze delay dependencies between stations based on high-speed train operation data and schedule data. The percolation theory of complex network is applied to study the evolution of delay propagation clusters. Nanjingnan Railway Station in the largest delay propagation cluster and Changshanan Railway Station in the second largest delay propagation cluster are taken as examples to analyze the network at percolation threshold. Based on core delay propagation clusters, the station delay state prediction model is established. The results show that stations can be divided into 3 categories, namely, delay generator, delay mediator and delay absorber according to their characteristic in the aspect of delay propagation. Delay generator can not only spread the delay to stations close to them, but also spread the delay to the far away stations through delay propagation chain, which makes the network taking part of the delay generator as the center and spreading delay to the delay mediator and the delay absorber in a radiational delay propagation mode.]]></description>
<pubDate>2023/12/1 15:21:46</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[郭宝,谭淮锐,王璞,周慧]]></author>
</item>
<item>
<title><![CDATA[Research progress of  irradiation effect of MRAM]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203140000003]]></link>
<description><![CDATA[The novel non-volatile magnetic random access memory (MRAM) has the advantages of fast read and write speed, long data retention time and low power consumption, which has attracted wide attention from researchers. Its excellent anti-irradiation capabilities have been explored in depth, and further applications in aerospace and other fields are expected. The industrial development, technological changes and applications of MRAM are reviewed, the mature MRAM products of recent years are listed, and the advantages and disadvantages of different generations of MRAM are analyzed. The radiation effects of magnetic tunnel junction, and read/write circuit based Complementary Metal Oxide Semiconductor (CMOS) were discussed. Summary of recent achievements in anti-radiative hardening design for MRAM. The development prospect of anti-irradiation MRAM in aerospace field and even nuclear energy field is prospected, and it is considered that it has broad application prospect]]></description>
<pubDate>2023/12/1 15:21:46</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[]]></author>
</item>
<item>
<title><![CDATA[Life Estimation and Experimental Verification of the Grids of 30cm Diameter Ion Thruster]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109220000001]]></link>
<description><![CDATA[In order to estimate the overall life of the existing three gate module of 30cm diameter ion thruster, the grid gap under thermal equilibrium state and the erosion velocity of different regions of the grids were simulated and calculated by FEM (finite element method) and PIC-MCC (particle-in-cell-Monte Carlo collision) method respectively. The results show that when the thruster reaches the thermal equilibrium, the overall deformation of the decelerator grid presents central area depression characteristics, and the overall deformation of the accelerator grid presents a uniform protruding. In the center area of the grids with the diameter of 0~70mm, the mean gap between the two grids decreases by 0.057mm. Meanwhile, in the annular region with the diameter of 70~140mm, the mean gap between the two grids increases by 0.129mm. The erosion velocity of the apertures at the edge of the decelerator grid reaches 6.25×10-14 kg/s within 1500h, and which of the aperture at 5700h decreases 15.4% compared with 1500h. The erosion velocity of the apertures at the center and edge of the accelerator grid, and the apertures at the center of the decelerator grid decreases 8.0%，4.1% and 3.6%, respectively. The results of 5700 hours life test show that the erosion of the apertures at the center of the decelerator grid, and the apertures at the center and edge of the accelerator grid is basically linear, and the comparison error between the simulation and test is within 10%.]]></description>
<pubDate>2023/12/1 15:21:46</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[耿海,孙明明,杨俊泰,岳士超]]></author>
</item>
<item>
<title><![CDATA[Analysis of flow field characteristics of S-bend inlet with dual synthetic jets]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209270000002]]></link>
<description><![CDATA[S-bend inlet leads to obvious flow separation and apparent total pressure distortion in unmanned aerial vehicle. An active flow control method based on synthetic double jets was proposed accordingly. The numerical simulation model of S-bend inlet with synthetic double jets was established. The results show that synthetic double jets can effectively suppress the boundary layer flow separation near the separation point of S-bend inlet through ‘blowing’ and ‘suction’ in the whole jet cycle, and effectively improve the total pressure recovery coefficient. The effects of different injection angle, injection velocity and injection frequency on the flow field control characteristics of S-bend inlet were studied. The analysis shows that the smaller the angle between the synthetic double jet and the main stream is, the better the flow separation control effect will be. The larger the injection speed will form a ‘blocking’ effect on the main stream, resulting in no obvious control effect. The closer the injection frequency is to the characteristic frequency of the flow field, the more obvious the control effect will be.]]></description>
<pubDate>2023/12/1 15:21:10</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[罗振兵,彭文强,周昕润,周岩,朱寅鑫]]></author>
</item>
<item>
<title><![CDATA[Analysis of flow field characteristics of S-bend inlet with dual synthetic jets]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209270000002]]></link>
<description><![CDATA[S-bend inlet leads to obvious flow separation and apparent total pressure distortion in unmanned aerial vehicle. An active flow control method based on synthetic double jets was proposed accordingly. The numerical simulation model of S-bend inlet with synthetic double jets was established. The results show that synthetic double jets can effectively suppress the boundary layer flow separation near the separation point of S-bend inlet through ‘blowing’ and ‘suction’ in the whole jet cycle, and effectively improve the total pressure recovery coefficient. The effects of different injection angle, injection velocity and injection frequency on the flow field control characteristics of S-bend inlet were studied. The analysis shows that the smaller the angle between the synthetic double jet and the main stream is, the better the flow separation control effect will be. The larger the injection speed will form a ‘blocking’ effect on the main stream, resulting in no obvious control effect. The closer the injection frequency is to the characteristic frequency of the flow field, the more obvious the control effect will be.]]></description>
<pubDate>2023/12/1 15:21:10</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[罗振兵,彭文强,周昕润,周岩,朱寅鑫]]></author>
</item>
<item>
<title><![CDATA[Cascade control for depth tracking of supercavitating vehicles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111290000008]]></link>
<description><![CDATA[To enhance the stability of the supercavitating vehicle caused by the nonlinear planing force between the cavitation and the vehicle, a cascade control method for the depth tracking is proposed based on the circle criterion theory and the Nelder-Mead (NM) algorithm. The mathematical model of the supercavitating vehicle and the circle criterion theorem are introduced. The cascade error state equation of the supercavitating vehicle is established based on the model, and the absolute stability of the inner-loop is studied using the circle criterion. The inner-loop feedback parameters are further optimized through the NM algorithm. The simulation analysis results show that the control method proposed in this paper is convenient for feedback parameter tuning, and can realize the accurate depth tracking effectively.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈增强,孙明玮,张建宏,周瑜]]></author>
</item>
<item>
<title><![CDATA[Scaled similarity analysis of aerodynamic characteristics and wind tunnel test for stratospheric airship]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211290000002]]></link>
<description><![CDATA[This paper describes in detail the analysis and design method of the sky-ground scaled similarity of aerodynamic characteristics for stratospheric airship. The similarity criteria for the rigid and flexible models to complete the wind tunnel tests are given. Two kind of scaled models and wind tunnel test are completed. By analyzing the wind tunnel experimental data for scaled models, it is found that the aerodynamic characteristics of the stratospheric airship under different inflatable internal pressures are basically same, but the rigid-body model is obviously different. The aerodynamic drag coefficient under flexible characteristics is significantly higher than that of rigid body, and even twice as high as that under zero attack angle, which leads to the essential changes of the rolling aerodynamic torque characteristics, such as stability and divergence. It has important engineering application value for evaluating flexible aerodynamic characteristics of stratospheric airship, especially under low pressure state. And it overcomes the disadvantages of using rigid-body aerodynamic characteristics data or engineering estimation method in the airship overall design of "dynamic-resistance balance".]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[史智广,杨玉洁,左宗玉]]></author>
</item>
<item>
<title><![CDATA[The near-field Frequency Domain Imaging Algorithm about the Aircraft’s scattering characteristics Diagnosis]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203290000001]]></link>
<description><![CDATA[The traditional methods of aircraft stealth performance test have the disadvantages of long test cycle and high test cost. The flexibility of UAV in structural style and material composition makes it have more space for stealth performance optimization than the manned aircraft, so it was urgent to carry out near-field imaging indoors or outdoors. Based on the imaging geometry of aircraft turntable, a general signal model of near-field turntable imaging was established, and a near-field frequency-domain imaging algorithm for aircraft electromagnetic scattering feature diagnosis was proposed. Under the constraint of sub aperture imaging setting, the slant plane spectrum was approximately processed as the horizontal plane spectrum; This paper analyzes the applicable conditions of the algorithm, generates simulation data around typical near-field imaging geometry and aircraft size, and completes near-field imaging in the range of 600MHz ~ 35GHz. Good imaging results confirm the correctness of the theoretical analysis and the proposed algorithm.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[贾高伟,邵帅,阴鹏]]></author>
</item>
<item>
<title><![CDATA[Weighted Sum Rate Optimization for Intelligent Reflecting Surface-aided Wireless Network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204100000001]]></link>
<description><![CDATA[For the transmission design problem in an IRS (intelligent reflecting surface)-enabled network, by jointly designing the transmit beamforming and IRS reflecting coefficient, the goal of this paper was to maximize the weighted sum rate for mul-tiply ground users, subject to the transmit power and the unit modulus constraint. To solve the non-convex objective, we developed an alternating optimization method, where the phase shifter optimization was solved by the RMG (Riemannian manifold gradient) algorithm, and the beamforming was obtained by the bisection search method. Furthermore, an ele-ment-wise block coordinate descent-based method was proposed to reduce the complexity of the RMG method. Simulation results verify the effectiveness of the proposed algorithm, and demonstrate that IRS can significantly improve the spectrum efficiency, when the reflecting coefficients are properly optimized.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[林志,牛和昊,王磊,王勇,赵青松]]></author>
</item>
<item>
<title><![CDATA[Semi-supervised generative adversarial network framework for modulation recognition of communication signals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111260000001]]></link>
<description><![CDATA[Aiming at the problem that the accuracy of the existing modulation signal recognition model is low under the condition of weak supervision with only a small amount of labeled data, a semi supervised learning framework based on generated countermeasure network is proposed. By performing a redundant spatial transformation on the communication signals, the method can adapt to the generative adversarial network model and retain rich signal adjacent features; Through the introduction of Wasserstein generative adversarial network-gradient penalty, a semi-supervised learning framework suitable for electromagnetic signal processing is constructed to realize the effective utilization of unlabeled signal samples. In order to verify the effectiveness of the proposed algorithm, sufficient experiments are conducted on the RADIOML 2016.04C dataset. Experimental results show that the proposed method can train an efficient classifier under semi-supervised conditions and obtain excellent modulation recognition results.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[楼财义,沈伟国,王巍,徐杰,郑仕链,周华吉]]></author>
</item>
<item>
<title><![CDATA[State of the Art and Prospects of Neural Architecture Search]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202190000001]]></link>
<description><![CDATA[Neural architecture search is a task that aims to automatically search for the optimal neural network structure for different tasks, which is of great importance and inevitability in the joint development of deep learning and computer vision to the current stage. A comprehensive review of the research on neural network search was provided. In specific, the definition and significance of neural architecture search were introduced, and the difficulties and challenges faced in relevant research were deeply analyzed. Based on this, the mainstream search strategies was elaborate and summarize; Finally, the potential problems and possible future research directions were summarized and discussed to promote further development in this field.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[盛常冲,]]></author>
</item>
<item>
<title><![CDATA[The Evaluation Models of Close-range Patrol Mission in Space Based on Multiple Factors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202305180000001]]></link>
<description><![CDATA[Space close-range patrol can be used to carry out close-range observation and monitoring of targets for identifying the target’s types and working states, which is of great significance for military and civilian fields such as in orbit services. The study analyzed the general forms of space close-range patrol tasks. Furthermore, based on the optical observations of close-range patrol, the multifactor observation task effectiveness evaluation models were constructed, including a constraint model for observation, a relative distance evaluation model, an effective observation time evaluation model, and a target observation angle evaluation model. This solves the effectiveness evaluation problem for the complete process of patrol tasks, which can support the design of patrol strategies and patrol trajectories better based on the evaluation results. In addition, based on the numerical simulation analysis and semi-physical experiments, the proposed evaluation model was verified. The result shows that the actual observation effect is consistent with the model evaluation result.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[侯志璞,]]></author>
</item>
<item>
<title><![CDATA[Power output characteristics of high-rate pulse-discharged lithium battery]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109260000002]]></link>
<description><![CDATA[Due to the existence of internal resistance and polarization, there will be a large voltage drop at the discharging moment of the lithium battery, especially the high-rate pulse-discharged lithium battery. In this paper, the power characteristics of high-rate pulse-discharged lithium battery are studied, as well as the influence rules of temperature, state of charge (SOC) and aging on battery power performance. Concretely, the power characteristic curve of lithium battery is defined, a high-rate battery test plat-form is built, and experimental research is carried out from three impedance sensitive factors: temperature, SOC and aging. The research methods and conclusions are of certain significance for the peak power evaluation and power curve prediction of lithium battery system.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[焦绍光,,]]></author>
</item>
<item>
<title><![CDATA[Scaled similarity analysis of aerodynamic characteristics and wind tunnel test for stratospheric airship]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211290000002]]></link>
<description><![CDATA[This paper describes in detail the analysis and design method of the sky-ground scaled similarity of aerodynamic characteristics for stratospheric airship. The similarity criteria for the rigid and flexible models to complete the wind tunnel tests are given. Two kind of scaled models and wind tunnel test are completed. By analyzing the wind tunnel experimental data for scaled models, it is found that the aerodynamic characteristics of the stratospheric airship under different inflatable internal pressures are basically same, but the rigid-body model is obviously different. The aerodynamic drag coefficient under flexible characteristics is significantly higher than that of rigid body, and even twice as high as that under zero attack angle, which leads to the essential changes of the rolling aerodynamic torque characteristics, such as stability and divergence. It has important engineering application value for evaluating flexible aerodynamic characteristics of stratospheric airship, especially under low pressure state. And it overcomes the disadvantages of using rigid-body aerodynamic characteristics data or engineering estimation method in the airship overall design of "dynamic-resistance balance".]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[史智广,杨玉洁,左宗玉]]></author>
</item>
<item>
<title><![CDATA[The near-field Frequency Domain Imaging Algorithm about the Aircraft’s scattering characteristics Diagnosis]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203290000001]]></link>
<description><![CDATA[The traditional methods of aircraft stealth performance test have the disadvantages of long test cycle and high test cost. The flexibility of UAV in structural style and material composition makes it have more space for stealth performance optimization than the manned aircraft, so it was urgent to carry out near-field imaging indoors or outdoors. Based on the imaging geometry of aircraft turntable, a general signal model of near-field turntable imaging was established, and a near-field frequency-domain imaging algorithm for aircraft electromagnetic scattering feature diagnosis was proposed. Under the constraint of sub aperture imaging setting, the slant plane spectrum was approximately processed as the horizontal plane spectrum; This paper analyzes the applicable conditions of the algorithm, generates simulation data around typical near-field imaging geometry and aircraft size, and completes near-field imaging in the range of 600MHz ~ 35GHz. Good imaging results confirm the correctness of the theoretical analysis and the proposed algorithm.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[贾高伟,邵帅,阴鹏]]></author>
</item>
<item>
<title><![CDATA[Weighted Sum Rate Optimization for Intelligent Reflecting Surface-aided Wireless Network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204100000001]]></link>
<description><![CDATA[For the transmission design problem in an IRS (intelligent reflecting surface)-enabled network, by jointly designing the transmit beamforming and IRS reflecting coefficient, the goal of this paper was to maximize the weighted sum rate for mul-tiply ground users, subject to the transmit power and the unit modulus constraint. To solve the non-convex objective, we developed an alternating optimization method, where the phase shifter optimization was solved by the RMG (Riemannian manifold gradient) algorithm, and the beamforming was obtained by the bisection search method. Furthermore, an ele-ment-wise block coordinate descent-based method was proposed to reduce the complexity of the RMG method. Simulation results verify the effectiveness of the proposed algorithm, and demonstrate that IRS can significantly improve the spectrum efficiency, when the reflecting coefficients are properly optimized.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[林志,牛和昊,王磊,王勇,赵青松]]></author>
</item>
<item>
<title><![CDATA[Semi-supervised generative adversarial network framework for modulation recognition of communication signals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111260000001]]></link>
<description><![CDATA[Aiming at the problem that the accuracy of the existing modulation signal recognition model is low under the condition of weak supervision with only a small amount of labeled data, a semi supervised learning framework based on generated countermeasure network is proposed. By performing a redundant spatial transformation on the communication signals, the method can adapt to the generative adversarial network model and retain rich signal adjacent features; Through the introduction of Wasserstein generative adversarial network-gradient penalty, a semi-supervised learning framework suitable for electromagnetic signal processing is constructed to realize the effective utilization of unlabeled signal samples. In order to verify the effectiveness of the proposed algorithm, sufficient experiments are conducted on the RADIOML 2016.04C dataset. Experimental results show that the proposed method can train an efficient classifier under semi-supervised conditions and obtain excellent modulation recognition results.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[楼财义,沈伟国,王巍,徐杰,郑仕链,周华吉]]></author>
</item>
<item>
<title><![CDATA[State of the Art and Prospects of Neural Architecture Search]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202190000001]]></link>
<description><![CDATA[Neural architecture search is a task that aims to automatically search for the optimal neural network structure for different tasks, which is of great importance and inevitability in the joint development of deep learning and computer vision to the current stage. A comprehensive review of the research on neural network search was provided. In specific, the definition and significance of neural architecture search were introduced, and the difficulties and challenges faced in relevant research were deeply analyzed. Based on this, the mainstream search strategies was elaborate and summarize; Finally, the potential problems and possible future research directions were summarized and discussed to promote further development in this field.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[盛常冲,]]></author>
</item>
<item>
<title><![CDATA[The Evaluation Models of Close-range Patrol Mission in Space Based on Multiple Factors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202305180000001]]></link>
<description><![CDATA[Space close-range patrol can be used to carry out close-range observation and monitoring of targets for identifying the target’s types and working states, which is of great significance for military and civilian fields such as in orbit services. The study analyzed the general forms of space close-range patrol tasks. Furthermore, based on the optical observations of close-range patrol, the multifactor observation task effectiveness evaluation models were constructed, including a constraint model for observation, a relative distance evaluation model, an effective observation time evaluation model, and a target observation angle evaluation model. This solves the effectiveness evaluation problem for the complete process of patrol tasks, which can support the design of patrol strategies and patrol trajectories better based on the evaluation results. In addition, based on the numerical simulation analysis and semi-physical experiments, the proposed evaluation model was verified. The result shows that the actual observation effect is consistent with the model evaluation result.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[侯志璞,]]></author>
</item>
<item>
<title><![CDATA[Power output characteristics of high-rate pulse-discharged lithium battery]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109260000002]]></link>
<description><![CDATA[Due to the existence of internal resistance and polarization, there will be a large voltage drop at the discharging moment of the lithium battery, especially the high-rate pulse-discharged lithium battery. In this paper, the power characteristics of high-rate pulse-discharged lithium battery are studied, as well as the influence rules of temperature, state of charge (SOC) and aging on battery power performance. Concretely, the power characteristic curve of lithium battery is defined, a high-rate battery test plat-form is built, and experimental research is carried out from three impedance sensitive factors: temperature, SOC and aging. The research methods and conclusions are of certain significance for the peak power evaluation and power curve prediction of lithium battery system.]]></description>
<pubDate>2023/12/1 15:20:20</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[焦绍光,,]]></author>
</item>
<item>
<title><![CDATA[Cascade control for depth tracking of supercavitating vehicles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111290000008]]></link>
<description><![CDATA[To enhance the stability of the supercavitating vehicle caused by the nonlinear planing force between the cavitation and the vehicle, a cascade control method for the depth tracking is proposed based on the circle criterion theory and the Nelder-Mead (NM) algorithm. The mathematical model of the supercavitating vehicle and the circle criterion theorem are introduced. The cascade error state equation of the supercavitating vehicle is established based on the model, and the absolute stability of the inner-loop is studied using the circle criterion. The inner-loop feedback parameters are further optimized through the NM algorithm. The simulation analysis results show that the control method proposed in this paper is convenient for feedback parameter tuning, and can realize the accurate depth tracking effectively.]]></description>
<pubDate>2023/12/1 15:20:08</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈增强,孙明玮,张建宏,周瑜]]></author>
</item>
<item>
<title><![CDATA[Spatial domain collocation interference cancellation method based on auxiliary array in integrated platform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201050000001]]></link>
<description><![CDATA[The integrated platform integrates multiple high-power frequency-using devices in a limited space. Due to the overlap of frequency bands, the local transmitter (Tx) will cause serious collocation interference to the receiver (Rx), causing the saturation of Rx antenna interface and failing to work normally. In response to the above problems, this paper proposes a collocation interference cancellation method based on auxiliary array, establishes a collocation interference cancellation system model, derives the expression of minimum residual interference (RI) power, and proposes channel conditions that need to be satisfied for collocation interference cancellation. In addition, the location of the auxiliary is analyzed when Tx array is non-cooperative, and the relationship of the locations of arrays is analyzed when the Tx array is cooperative. Theoretical and simulation results show that the collocation interference cancellation method based on auxiliary array can effectively cancel collocation interference at the Rx antenna interface without affecting the transmission efficiency of the local Tx array.]]></description>
<pubDate>2023/12/1 9:59:55</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[杜林松,李彤,潘文生,邵士海,时成哲]]></author>
</item>
<item>
<title><![CDATA[Influence of blade number on performance of a hubless pump-jet thruster]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110200000001]]></link>
<description><![CDATA[Noise is an important index to evaluate the performance of hubless pump-jet thruster. The noise induced by pressure pulsation is the main noise source during the operation of hubless pump-jet thruster. In order to enrich the optimization theory of hubless pump-jet thruster noise performance, the influence of blade number on the performance of hubless pump-jet thruster was studied in this paper, and the variation law of pressure pulsation in hubless pump-jet thruster with different number of blades was emphatically investigated. Based on the finite volume element method of computational fluid dynamics, the Reynolds average equation (RANS equation) was discretized, and the calculation model was closed by using RNG k-? turbulence model, coupling the pressure-velocity by using the SIMPLEC algorithm. The unsteady numerical simulation of the flow field inside the hubless pump-jet thruster with different number of blades was carried out, and the calculated results were compared and analyzed in detail. The study results show that with the increase of blade number, the hzeead, efficiency and thrustSof hubless pump-jet thruster model increase gradually. The pressure distribution on the blade surface becomes more uniform. The pressure pulsations of the impeller rim and the middle part decreased obviously. The amplitude of pressure pulsations at the main frequencies of impeller inlet and outlet decreases gradually from rim to center.]]></description>
<pubDate>2023/11/29 12:30:57</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[刘厚林,,谈明高,]]></author>
</item>
<item>
<title><![CDATA[Weight-optimized WENO-Z schemes with reorganized stencil]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110100000001]]></link>
<description><![CDATA[For developing high-order scheme with low dissipation and low dispersion to accurately simulate the flow field with complex structures such as shock wave, a method of stencil reorganization was proposed based on the fifth-order finite difference WENO-Z scheme. A four-point central stencil recombined by three-point stencils is introduced in the calculation of nonlinear weight in order to optimize the weight allocation of each template in the original format, and two improved WENO-Z schemes were proposed. The dispersion and dissipation properties of the WENO schemes were compared and analyzed via the approximate dispersion relation analysis, which shows that the dissipation of the two improved schemes decreases at different extent. The numerical experiments show that the improved schemes have better shock capture property and higher resolution for small-scale flow structures.]]></description>
<pubDate>2023/11/29 12:29:10</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[易贤]]></author>
</item>
<item>
<title><![CDATA[Protocol of Neighbor Discovery in Directional Millimeter Wave Wireless Networks]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210110000004]]></link>
<description><![CDATA[Aiming at the problem that it is difficult to discover neighbors without prior information between nodes in the directional millimeter wave network, a neighbor discovery protocol base on blind rendezvous algorithm is proposed and the theoretical relationship among slot length, the number of sectors and the time of neighbors discovery is derived in this paper. Furthermore, in order to shorten the time of neighbor discovery base on blind rendezvous algorithm, a neighbor discovery protocol based on location prediction is proposed. The simulation results show that the longest discovery time of neighbor discovery protocol base on blind rendezvous algorithm is less than ODND protocol and average discovery time of neighbor discovery protocol base on blind rendezvous algorithm is less than ODND protocol when the number of sectors N is close to 2^n（2^n-1<N≤2^n，n>1,n∈Z）。In addition, neighbor discovery protocol based on location prediction can effectively shorten neighbor discovery time.]]></description>
<pubDate>2023/11/28 12:54:03</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[梁仕杰,赵海涛]]></author>
</item>
<item>
<title><![CDATA[Trajectory Planning and Control of Continuous Observation Missions for Geostationary Spacecraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109140000001]]></link>
<description><![CDATA[For high-definition observation of geosynchronous (GEO) spacecraft, the optical satellite approaches the GEO spacecraft with continuous low-thrust and flies around the GEO spacecraft without thrust. On the deviation of Clohessy-Wiltshire (CW) equations, CW equations are improved by accommodating the non-spherical perturbation, and the quadratic terms of the nonlinearity in the differential gravitational acceleration. The secular growth of the nonlinear deviation and the most perturbation deviation have been accommodated in the improved CW（ICW） equations. On trajectory planning, we calculate the initial phase angle interval of the fly-around trajectory to ensure that the optical satellite can take pictures of the GEO spacecraft with favorable observation angles throughout the entire fly-around mission. Simulations are conducted based on CW equations and ICW equations, respectively. The simulation based on the CW equations fails, but the simulation based on the ICW equations succeeds. The total thrust required is only 4.67 m/s, which is highly feasible in engineering.]]></description>
<pubDate>2023/11/27 9:31:46</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李智,王浩,王伟林,张海涛,张雅声]]></author>
</item>
<item>
<title><![CDATA[Optimizing Operator Computation of MiniGo on a High-Performance Heterogeneous Accelerator]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212150000002]]></link>
<description><![CDATA[An efficient parallel computing method based on the characteristics of the high-performance heterogeneous accelerator and the training mode of MiniGo was proposed. The on-chip computing resources were reasonably planned to achieve pipelining parallel optimization between heterogeneous devices. The shared memory programming was designed according to the existence of shared storage segments between heterogeneous devices to reduce data transmission costs. According to the characteristics of multiple computing resources in a DSP cluster, combined with the computing-memory access feature of the operators, different optimization strategies were designed. At the same time, this method provides an easy-use high-performance operator library for TensorFlow. The experimental results show that this method realizes the multi-core parallel computing of operators. The speedup of convolution was 24.69 compared with that was achieved on a single core. Compared with the cropped version of the 8-core FT2000+ CPU, the speedup of training and selfplay execution on this method were 3.83 and 1.5, respectively.]]></description>
<pubDate>2023/11/27 8:37:37</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[贺周雨,姜晶菲,李荣春,乔  鹏]]></author>
</item>
<item>
<title><![CDATA[Parallel Optimization of Convolution Algorithm on Multi-core DSPs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209200000002]]></link>
<description><![CDATA[Convolution is one of the basic operations in neural networks at present, and its optimization is a research hotspot in academia and industry. According to the characteristics of the heterogeneous multi-core DSP chip independently developed by National University of Defense Technology and the characteristics of the convolution algorithm, a high-performance multi-core parallel convolution implementation scheme for multi-core DSP architecture is proposed in this paper. A feature graph level multi-core parallel scheme is proposed for  convolution. For convolutions with kernels larger than 1, a window level multi-core parallel optimization design is proposed, and an element-wise vectorization based intra-core parallel optimization implementation is proposed. The experimental results show that the maximum efficiency of the proposed parallel optimization method can reach 64.95%. When the bandwidth is limited, the parallel expansion efficiency of multi-core can still reach 48.36% ~ 88.52%. Compared with E5-2640 CPU, the execution performance on the typical network resnet50 achieves 5.39x performance acceleration.]]></description>
<pubDate>2023/11/21 17:18:25</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[高蕾,姜晶菲,李东升,李荣春,李娅琳,王庆林,许金伟]]></author>
</item>
<item>
<title><![CDATA[Multimodal cross-decoupling for few-shot learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206210000001]]></link>
<description><![CDATA[In the current Few-Shot Learning (FSL) scenarios, it is difficult to classify samples of same categories correctly with a small number of labeled samples when visual representations of categories are abundant and diverse. Multimodal few-shot learning utilizes easy-to-obtain and relatively independent semantic information to guide the extraction of attribute-agnostic category features. However, the existing approaches neglect the various effects of differences between multi-attributes on correct identification of sample categories. To address this problem, we propose a multimodal cross-decoupling method which could decouple semantic features with different attributes and reconstruct the essential category features of samples, aiming to alleviate the impact of category attribute differences on few-shot classification. Extensive experiments on two benchmark few-shot datasets MIT-States and C-GQA with large attribute discrepancy indicate that the proposed method outperforms the existing approaches, which verifies its effectiveness.]]></description>
<pubDate>2023/11/21 17:16:02</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[冀中,王思迪,于云龙]]></author>
</item>
<item>
<title><![CDATA[Influence of satellite differential code bias on BDS-3 dual-frequency precision point positioning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110130000002]]></link>
<description><![CDATA[To explore the influence of BDS-3(BeiDou navigation satellite system phase Ⅲ) different frequency combination satellite DCB(differential code bias) on PPP(precise point positioning), the BDS-3 different frequency ionospheric-free combined satellite DCB correction model was derived and performed DCB correction experiments by seven different dual-frequency combinations based on the observation data of four MGEX stations during seven consecutive days. The results show that the DCB correction has a significant improvement of the PPP accuracy in the initial epoch, which helped to converge the filtering and improve the RMS of the single-day solution, but weakly in the final positioning accuracy. Although the positioning accuracy and the B2a/B3I and B2b/B3I combinations’ convergence speed are considerably thinner than other combinations, it still enhances after DCB correction. Otherwise, the positioning accuracy and convergence time of the other 5 combinations are equivalent after correction. The RMS of the static PPP single-day solution is about 5.50 cm, 2.50 cm, and 6.25 cm in the E, N, and U directions, which are approximately 20%~65% higher than before. The average convergence time, an increase of about 6%, is 38 minutes, and the kinematic PPP, an increase of about 20%, is 59 minutes. The final positioning accuracy is better than 5 cm in the horizontal component and 7 cm in the elevation component.]]></description>
<pubDate>2023/11/21 17:07:52</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杜彦君,贾小林,许瑾,姚顽强]]></author>
</item>
<item>
<title><![CDATA[Development status and technology challenges of high-altitude long-endurance solar-powered aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206230000001]]></link>
<description><![CDATA[High-altitude long-endurance (HALE) solar-powered aircrafts are the research frontiers, they can staying airborne for several months, and can form new application ability named ‘long-endurance + station-keeping’. The three-stage development process of HALE solar-powered aircrafts is systematically summarized, including early exploration stage, rapid development stage and operational capability demonstration stage, and typical development plans aboard are introduced. Key technology challenges are analyzed, including aerodynamic configuration design, energy storage battery, high altitude propulsion, large scale structure and flight control, and suggestions for research directions are proposed. All those can provide reference for innovation development of HALE solar-powered aircrafts.]]></description>
<pubDate>2023/9/28 19:01:40</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭正,侯中喜,杨希祥]]></author>
</item>
<item>
<title><![CDATA[Analysis of flow field characteristics of S-bend inlet with dual synthetic jets]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209270000002]]></link>
<description><![CDATA[S-bend inlet leads to obvious flow separation and apparent total pressure distortion in unmanned aerial vehicle. An active flow control method based on synthetic double jets was proposed accordingly. The numerical simulation model of S-bend inlet with synthetic double jets was established. The results show that synthetic double jets can effectively suppress the boundary layer flow separation near the separation point of S-bend inlet through ‘blowing’ and ‘suction’ in the whole jet cycle, and effectively improve the total pressure recovery coefficient. The effects of different injection angle, injection velocity and injection frequency on the flow field control characteristics of S-bend inlet were studied. The analysis shows that the smaller the angle between the synthetic double jet and the main stream is, the better the flow separation control effect will be. The larger the injection speed will form a ‘blocking’ effect on the main stream, resulting in no obvious control effect. The closer the injection frequency is to the characteristic frequency of the flow field, the more obvious the control effect will be.]]></description>
<pubDate>2023/9/26 15:09:43</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[罗振兵,彭文强,周昕润,周岩,朱寅鑫]]></author>
</item>
<item>
<title><![CDATA[Multi-block moving window slow feature analysis fault diagnosis method based on KL divergence]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109140000003]]></link>
<description><![CDATA[A KL(Kullback Leibler) divergence multi-block moving window slow feature analysis method is proposed to solve the problems that the variable feature information cannot be fully utilized by the traditional block segmentation method based on experience, the local information is ignored by a single modeling method, and the off-line model cannot adapt to the time-varying characteristics. KL divergence was used to measure the distance between variables in the normal working condition data set, and the minimum error sum criterion was introduced to cluster, which was divided into two sub-blocks with the minimum distance. On this basis, the slow feature analysis method was utilized to model each sub-block, and the optimal model was obtained by updating the sampled data with moving window. Monitoring statistics were calculated respectively, and the fault monitoring results were fused with support vector data description to achieve fault diagnosis. The proposed method is applied to the monitoring of Tennessee Man process, and higher fault detection rate and lower false alarm rate are obtained, verify the feasibility and effectiveness of this method.]]></description>
<pubDate>2023/9/26 15:08:05</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[程超,郭昕刚,霍金花,许连杰]]></author>
</item>
<item>
<title><![CDATA[Multi-reference-station-based Relative Positioning Method and Impact Analysis of the Biases in the A Priori Baseline Vectors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110060000001]]></link>
<description><![CDATA[In order to improve the reliability of the single-station-based relative positioning solutions over short baselines, the multi-reference-station-based relative positioning method is explored in this contribution. Firstly, the a priori baseline information between the reference stations is integrated into the observable model, thus giving the functional and stochastic models of the multi-reference-station-based relative positioning. Based on that, the closed-form formula of the ambiguity dilution of precision for the positioning is derived so that the influence of the number of reference stations on the float ambiguity precision is revealed. Then the impacts of the biases in the a priori baseline information on the integer ambiguity resolution are analyzed theoretically. It is shown that the integer ambiguity resolution can barely be influenced on the condition that the bias is less than a few centimeters. Finally, the multi-reference-station-based relative positioning method is validated with both the simulated and real data sets. The numerical results show that, increasing the number of reference stations not only improves the single-epoch, single-frequency ambiguity resolution success rate and convergence rate, but also restrains the biases in the a priori baseline information. For example, the ambiguity resolution success rate is still larger than 92% even when the biases of the baseline components attain 4 cm in the field tests. This contribution provides the theoretical foundation for special scenarios such as the rapid construction of temporary airport in wartime.]]></description>
<pubDate>2023/9/26 15:07:27</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[范波,侯振伟,伍劭实,张良,钟季龙]]></author>
</item>
<item>
<title><![CDATA[Performance Analysis of SMI based GNSS STAP under Distributed Intermittent Interferences]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109270000001]]></link>
<description><![CDATA[Considering the distributed intermittent interference threat faced by GNSS receiver, this paper comprehensively and accurately analyzes the anti-jamming performance of space-time adaptive processing based on Sample Matrix Inversion (SMI) method. Based on the performance analysis model, according to the mismatch of sampling covariance matrix caused by intermittent interferences, the performance of Space-Time Adaptive Processing (STAP) under different conditions is comprehensively analyzed through classification evaluation, combing induction and theoretical derivation. The analysis results show that when the sampling length is less than the scintillation period and the pre-sample method is used, the missed sampling will occur and the interference suppression performance will decrease sharply, and the frequency of missed sampling is the sum of the scintillation frequencies of each interference. Numerical and simulation analyses verify the results of analysis. The optimal design of STAP in the face of distributed intermittent interference is discussed. This paper provides an important reference for dealing with the distributed intermittent jamming threat.]]></description>
<pubDate>2023/9/26 15:06:57</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[王解]]></author>
</item>
<item>
<title><![CDATA[Spatial domain collocation interference cancellation method based on auxiliary array in integrated platform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201050000001]]></link>
<description><![CDATA[The integrated platform integrates multiple high-power frequency-using devices in a limited space. Due to the overlap of frequency bands, the local transmitter (Tx) will cause serious collocation interference to the receiver (Rx), causing the saturation of Rx antenna interface and failing to work normally. In response to the above problems, this paper proposes a collocation interference cancellation method based on auxiliary array, establishes a collocation interference cancellation system model, derives the expression of minimum residual interference (RI) power, and proposes channel conditions that need to be satisfied for collocation interference cancellation. In addition, the location of the auxiliary is analyzed when Tx array is non-cooperative, and the relationship of the locations of arrays is analyzed when the Tx array is cooperative. Theoretical and simulation results show that the collocation interference cancellation method based on auxiliary array can effectively cancel collocation interference at the Rx antenna interface without affecting the transmission efficiency of the local Tx array.]]></description>
<pubDate>2023/9/26 15:05:56</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[杜林松,李彤,潘文生,邵士海,时成哲]]></author>
</item>
<item>
<title><![CDATA[Evaluation of Electro-Optical Protection Combat Effectiveness Based on ANP]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109230000001]]></link>
<description><![CDATA[Rapid and accurate evaluation of electro-optical protection combat effectiveness is the basis of implementing electro-optical protection for key target. Considering the deficiency of AHP in evaluation of electro-optical protection combat effectiveness, ANP was proposed to evaluate, toke analyze of the independence、correlation and feedback of the interior of the element hierarchy as entry point, putted forward the main index dictionary of electro-optical protection combat effectiveness, set up the evaluation model, according to setting up the matrix、calculating、obtaining the weights, complete the evaluation. Validated the model by an example, provided theory-reference for evaluation of electro-optical protection combat effectiveness.]]></description>
<pubDate>2023/9/26 15:00:03</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[王宇]]></author>
</item>
<item>
<title><![CDATA[Energy management strategy based on fuzzy logic control for hybrid electric propulsion system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206170000001]]></link>
<description><![CDATA[By the optimization of secondary power system, hybrid electric technology can heighten the utilization efficiency of energy, which has great potential and advantage in development of general electric aviation. An energy management strategy based on fuzzy logic control for hybrid electric propulsion system is presented in this paper. By setting the fuzzy membership function of Vertical Take-Off and Landing (VTOL) aircraft’s power requirement, internal-combustion-engine (ICE)-generator’s output power, and the state of charge (SOC) of battery,  the output power of generator and battery were dynamic optimal allocated.  So as to increase the fuel economy and aircraft range effectively. According to the model establishment, the energy system changes of 100kg scale VTOL aircraft were simulated, and simulation results demonstrated that the algorithm was practical. The paper can provide design thoughts and analysis method for energy control and arrangement of hybrid electric propulsion system.]]></description>
<pubDate>2023/9/26 14:58:38</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[李建奇,朱炳杰,朱莹涛]]></author>
</item>
<item>
<title><![CDATA[Life Estimation and Experimental Verification of the Grids of 30cm Diameter Ion Thruster]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109220000001]]></link>
<description><![CDATA[In order to estimate the overall life of the existing three gate module of 30cm diameter ion thruster, the grid gap under thermal equilibrium state and the erosion velocity of different regions of the grids were simulated and calculated by FEM (finite element method) and PIC-MCC (particle-in-cell-Monte Carlo collision) method respectively. The results show that when the thruster reaches the thermal equilibrium, the overall deformation of the decelerator grid presents central area depression characteristics, and the overall deformation of the accelerator grid presents a uniform protruding. In the center area of the grids with the diameter of 0~70mm, the mean gap between the two grids decreases by 0.057mm. Meanwhile, in the annular region with the diameter of 70~140mm, the mean gap between the two grids increases by 0.129mm. The erosion velocity of the apertures at the edge of the decelerator grid reaches 6.25×10-14 kg/s within 1500h, and which of the aperture at 5700h decreases 15.4% compared with 1500h. The erosion velocity of the apertures at the center and edge of the accelerator grid, and the apertures at the center of the decelerator grid decreases 8.0%，4.1% and 3.6%, respectively. The results of 5700 hours life test show that the erosion of the apertures at the center of the decelerator grid, and the apertures at the center and edge of the accelerator grid is basically linear, and the comparison error between the simulation and test is within 10%.]]></description>
<pubDate>2023/9/26 11:15:59</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[耿海,孙明明,杨俊泰,岳士超]]></author>
</item>
<item>
<title><![CDATA[Research progress of  irradiation effect of MRAM]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203140000003]]></link>
<description><![CDATA[The novel non-volatile magnetic random access memory (MRAM) has the advantages of fast read and write speed, long data retention time and low power consumption, which has attracted wide attention from researchers. Its excellent anti-irradiation capabilities have been explored in depth, and further applications in aerospace and other fields are expected. The industrial development, technological changes and applications of MRAM are reviewed, the mature MRAM products of recent years are listed, and the advantages and disadvantages of different generations of MRAM are analyzed. The radiation effects of magnetic tunnel junction, and read/write circuit based Complementary Metal Oxide Semiconductor (CMOS) were discussed. Summary of recent achievements in anti-radiative hardening design for MRAM. The development prospect of anti-irradiation MRAM in aerospace field and even nuclear energy field is prospected, and it is considered that it has broad application prospect]]></description>
<pubDate>2023/9/26 11:15:27</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[]]></author>
</item>
<item>
<title><![CDATA[Analysis of high-speed railway network delay propagation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109230000002]]></link>
<description><![CDATA[Noted the limitation of existing methods to study the delay propagation mechanism in high-speed railway network, the Bayesian network is used to analyze delay dependencies between stations based on high-speed train operation data and schedule data. The percolation theory of complex network is applied to study the evolution of delay propagation clusters. Nanjingnan Railway Station in the largest delay propagation cluster and Changshanan Railway Station in the second largest delay propagation cluster are taken as examples to analyze the network at percolation threshold. Based on core delay propagation clusters, the station delay state prediction model is established. The results show that stations can be divided into 3 categories, namely, delay generator, delay mediator and delay absorber according to their characteristic in the aspect of delay propagation. Delay generator can not only spread the delay to stations close to them, but also spread the delay to the far away stations through delay propagation chain, which makes the network taking part of the delay generator as the center and spreading delay to the delay mediator and the delay absorber in a radiational delay propagation mode.]]></description>
<pubDate>2023/9/26 11:14:54</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[郭宝,谭淮锐,王璞,周慧]]></author>
</item>
<item>
<title><![CDATA[Autonomous Configuration Planning for Intelligent Search and Rescue Robots in Rough Terrains]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302280000001]]></link>
<description><![CDATA[In order to solve the configuration planning problem for intelligent search and rescue robots with assisted flippers to achieve autonomous obstacle crossing, a novel method for planning robot configuration during obstacle crossing is proposed that can be applied to complex terrains. The core of the proposed method was an adaptable and efficient robot pose model prediction algorithm. By representing the terrain as a series of discrete point sets, a mathematical model for predicting the one-sided pose of the tracked robot was established; further, a fast solver for this model was proposed, which can predict 1000-1500 poses per second. Based on this, the evaluation metrics of the robot's state and action in the obstacle-crossing process were established, and an optimization-based real-time flippers action planner was realized using the dynamic programming algorithm and rolling optimization. The simulation and real-robot experiments show that the proposed approach enables the robot to control the flippers to cross rough terrains autonomously. It performs more smoothly than the reinforcement-learning method and manual operation when crossing obstacles.]]></description>
<pubDate>2023/9/26 11:14:17</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈柏良,黄开宏,卢惠民,潘海南,吴文启,肖军浩]]></author>
</item>
<item>
<title><![CDATA[Study of high-power microwave protection technology based on plasma]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112010000001]]></link>
<description><![CDATA[Plasma has a unique protective effect against high-power microwave attack. In this paper, based on the plasma fluid approximation method, the time dependent evolution of the incident electric field during the interaction between high-power microwaves and columnar plasma arrays is studied using COMSOL software, and the physical process and mechanism of plasma protection against high-power microwaves are analysed. The results show that the incident high-power microwave will change the plasma parameters drastically, especially the electron density will increase sharply, so that the plasma will show metal-like electromagnetic properties to the incident high-power microwave, and finally realize the effective protection against the incident high-power microwave. In addition, the plasma protection against high-power microwaves is experimentally verified by using columnar plasma arrays generated by high-frequency glow discharge. Finally, the main problems to be solved for plasma-based high-power microwave protection technology are summarized.]]></description>
<pubDate>2023/9/26 11:13:40</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[陈宗胜,李志刚,刘丽萍,邱志楠,汪家春,王俊儒]]></author>
</item>
<item>
<title><![CDATA[Impact of transceiver IQ imbalances on cooperative jamming suppression in confidential communications]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111290000006]]></link>
<description><![CDATA[A CJ(cooperative jamming) masked secure communication architecture was proposed in this article for communication environmentsconfidential communications where when malicious interference and illegal eavesdropping coexist. Thereinto, the FH(frequency-hopping) technology was adopted in the transceiver to avoid malicious interference, and the CJ technology was employed to block illegal eavesdropping. Nevertheless, the proposed architecture employs a wide frequency bandwidth, which will raise nonnegligible IQ(in-phase and quadrature) imbalances at the transceiver oscillators. In view of this, based on the proposed secure communication architecture, mathematical modeling was conducted on the signal distortion caused by the imbalance of the receiving and transmitting IQ channels; A, a mathematical expression for SDNR(the signal to distortion-plus-noise ratio) at the receiver was provided to measure the degree of signal distortion caused by the imbalance of the transmitting and receiving IQ channels; A, and a closed- form expression for the system CJSR(CJ suppression ratio) was givenderived to evaluate the CJ suppression capability of the proposed architecture in the presence of imbalanced transmit and receive IQ channels. The sSimulation results show that the power of the signal distortion raised by transceiver IQ imbalance is much greater than that of the thermal noise. Besides, both the SDNR and CJSR will decline sharply as the transceiver IQ imbalance deteriorates, and when the magnitude and phase imbalance are 0.95 and п/50 respectively, both the SDNR and CJSR performance will deteriorate 47 dB.]]></description>
<pubDate>2023/9/26 11:12:36</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈雯雯,邵士海,宋长庆,唐友喜,赵宏志]]></author>
</item>
<item>
<title><![CDATA[Modeling and numerical simulation of constant-height flight by air-lifting gas mixing for aerostats]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206290000004]]></link>
<description><![CDATA[Abstract: According to the floating weight balance characteristics and the ideal gas state equation, a method to control the height of the aerostat’s flat flight height by gas mixing was explored, and the overall design research of constant-height flight by air-lifting gas mixing was carried out. Considering the importance of thermodynamic characteristics to the ascent process and the flat flight process of the aerostat, combined with the thermophysical properties of mixed gas in engineering thermodynamics, the super-pressure balloon was taken as the research object, and the thermal environment was coupled with the dynamic model of the sphere ascent and the flight process. On this basis, the mechanical simulation of the ascent and level flight process of the balloon is carried out, and the changes in altitude, speed, gas temperature and pressure during the ascent of the balloon are obtained, so as to verify the feasibility of the theoretical model of constant-height flight by air-lifting gas mixing, and provide guidance for the subsequent aerostat flight test.]]></description>
<pubDate>2023/9/26 11:11:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[曹胜鸿,宋林,杨燕初,赵荣,祝榕辰]]></author>
</item>
<item>
<title><![CDATA[Structural optimization for composite wings of tail-sitter electric aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207200000001]]></link>
<description><![CDATA[According to the requirements of material delivery platform in the complex terrain area, the research on the structural design of the composite wing of the tail-sitter electric aircraft is carried out. Based on the load analysis, the structural configuration and lay out designs were studied, and the structural design scheme of the composite wing was proposed. The finite element model of the composite wing was developed and the static strength analyses under different operating conditions were completed. The distributions of structural stresses and deformations were obtained, and the structural strength was evaluated with the Tsai-Wu failure criterion employed. The structural optimal analysis of the composite wing was performed based on the stepwise optimization strategy with the layer thicknesses and angles as design variables. The optimal results show that the structural mass is reduced by 47.77% under the constraints of structural stiffness and strength, which can provide the important reference for the design and development of the tail-sitter electric aircraft structure.]]></description>
<pubDate>2023/9/26 11:10:01</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[麻震宇,张琪,张祎桀]]></author>
</item>
<item>
<title><![CDATA[Power output characteristics of high-rate pulse-discharged lithium battery]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109260000002]]></link>
<description><![CDATA[Due to the existence of internal resistance and polarization, there will be a large voltage drop at the discharging moment of the lithium battery, especially the high-rate pulse-discharged lithium battery. In this paper, the power characteristics of high-rate pulse-discharged lithium battery are studied, as well as the influence rules of temperature, state of charge (SOC) and aging on battery power performance. Concretely, the power characteristic curve of lithium battery is defined, a high-rate battery test plat-form is built, and experimental research is carried out from three impedance sensitive factors: temperature, SOC and aging. The research methods and conclusions are of certain significance for the peak power evaluation and power curve prediction of lithium battery system.]]></description>
<pubDate>2023/9/26 8:47:31</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[焦绍光,,]]></author>
</item>
<item>
<title><![CDATA[The Evaluation Models of Close-range Patrol Mission in Space Based on Multiple Factors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202305180000001]]></link>
<description><![CDATA[Space close-range patrol can be used to carry out close-range observation and monitoring of targets for identifying the target’s types and working states, which is of great significance for military and civilian fields such as in orbit services. The study analyzed the general forms of space close-range patrol tasks. Furthermore, based on the optical observations of close-range patrol, the multifactor observation task effectiveness evaluation models were constructed, including a constraint model for observation, a relative distance evaluation model, an effective observation time evaluation model, and a target observation angle evaluation model. This solves the effectiveness evaluation problem for the complete process of patrol tasks, which can support the design of patrol strategies and patrol trajectories better based on the evaluation results. In addition, based on the numerical simulation analysis and semi-physical experiments, the proposed evaluation model was verified. The result shows that the actual observation effect is consistent with the model evaluation result.]]></description>
<pubDate>2023/9/26 8:47:11</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[侯志璞,]]></author>
</item>
<item>
<title><![CDATA[State of the Art and Prospects of Neural Architecture Search]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202190000001]]></link>
<description><![CDATA[Neural architecture search is a task that aims to automatically search for the optimal neural network structure for different tasks, which is of great importance and inevitability in the joint development of deep learning and computer vision to the current stage. A comprehensive review of the research on neural network search was provided. In specific, the definition and significance of neural architecture search were introduced, and the difficulties and challenges faced in relevant research were deeply analyzed. Based on this, the mainstream search strategies was elaborate and summarize; Finally, the potential problems and possible future research directions were summarized and discussed to promote further development in this field.]]></description>
<pubDate>2023/9/26 8:46:51</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[盛常冲,]]></author>
</item>
<item>
<title><![CDATA[Semi-supervised generative adversarial network framework for modulation recognition of communication signals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111260000001]]></link>
<description><![CDATA[Aiming at the problem that the accuracy of the existing modulation signal recognition model is low under the condition of weak supervision with only a small amount of labeled data, a semi supervised learning framework based on generated countermeasure network is proposed. By performing a redundant spatial transformation on the communication signals, the method can adapt to the generative adversarial network model and retain rich signal adjacent features; Through the introduction of Wasserstein generative adversarial network-gradient penalty, a semi-supervised learning framework suitable for electromagnetic signal processing is constructed to realize the effective utilization of unlabeled signal samples. In order to verify the effectiveness of the proposed algorithm, sufficient experiments are conducted on the RADIOML 2016.04C dataset. Experimental results show that the proposed method can train an efficient classifier under semi-supervised conditions and obtain excellent modulation recognition results.]]></description>
<pubDate>2023/9/26 8:46:33</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[楼财义,沈伟国,王巍,徐杰,郑仕链,周华吉]]></author>
</item>
<item>
<title><![CDATA[Weighed Sum Rate Optimization for Intelligent Reflecting Surface-aided Wireless Network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204100000001]]></link>
<description><![CDATA[For the transmission design problem in an IRS (intelligent reflecting surface)-enabled network, by jointly designing the transmit beamforming and IRS reflecting coefficient, the goal of this paper was to maximize the weighted sum rate for mul-tiply ground users, subject to the transmit power and the unit modulus constraint. To solve the non-convex objective, we developed an alternating optimization method, where the phase shifter optimization was solved by the RMG (Riemannian manifold gradient) algorithm, and the beamforming was obtained by the bisection search method. Furthermore, an ele-ment-wise block coordinate descent-based method was proposed to reduce the complexity of the RMG method. Simulation results verify the effectiveness of the proposed algorithm, and demonstrate that IRS can significantly improve the spectrum efficiency, when the reflecting coefficients are properly optimized.]]></description>
<pubDate>2023/9/26 8:46:11</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[林志,牛和昊,王磊,王勇,赵青松]]></author>
</item>
<item>
<title><![CDATA[The Performance Analysis of near-field Frequency Domain Imaging Algorithm about the Aircraft’s scattering characteristics Diagnosis]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203290000001]]></link>
<description><![CDATA[The traditional methods of aircraft stealth performance test have the disadvantages of long test cycle and high test cost. The flexibility of UAV in structural style and material composition makes it have more space for stealth performance optimization than the manned aircraft, so it was urgent to carry out near-field imaging indoors or outdoors. Based on the imaging geometry of aircraft turntable, a general signal model of near-field turntable imaging was established, and a near-field frequency-domain imaging algorithm for aircraft electromagnetic scattering feature diagnosis was proposed. Under the constraint of sub aperture imaging setting, the slant plane spectrum was approximately processed as the horizontal plane spectrum; This paper analyzes the applicable conditions of the algorithm, generates simulation data around typical near-field imaging geometry and aircraft size, and completes near-field imaging in the range of 600MHz ~ 35GHz. Good imaging results confirm the correctness of the theoretical analysis and the proposed algorithm.]]></description>
<pubDate>2023/9/26 8:45:45</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[贾高伟,邵帅,阴鹏]]></author>
</item>
<item>
<title><![CDATA[Scaled similarity analysis of aerodynamic characteristics and wind tunnel test for stratospheric airship]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211290000002]]></link>
<description><![CDATA[This paper describes in detail the analysis and design method of the sky-ground scaled similarity of aerodynamic characteristics for stratospheric airship. The similarity criteria for the rigid and flexible models to complete the wind tunnel tests are given. Two kind of scaled models and wind tunnel test are completed. By analyzing the wind tunnel experimental data for scaled models, it is found that the aerodynamic characteristics of the stratospheric airship under different inflatable internal pressures are basically same, but the rigid-body model is obviously different. The aerodynamic drag coefficient under flexible characteristics is significantly higher than that of rigid body, and even twice as high as that under zero attack angle, which leads to the essential changes of the rolling aerodynamic torque characteristics, such as stability and divergence. It has important engineering application value for evaluating flexible aerodynamic characteristics of stratospheric airship, especially under low pressure state. And it overcomes the disadvantages of using rigid-body aerodynamic characteristics data or engineering estimation method in the airship overall design of "dynamic-resistance balance".]]></description>
<pubDate>2023/9/26 8:45:19</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[史智广,杨玉洁,左宗玉]]></author>
</item>
<item>
<title><![CDATA[Cascade control for depth tracking of supercavitating vehicles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111290000008]]></link>
<description><![CDATA[To enhance the stability of the supercavitating vehicle caused by the nonlinear planing force between the cavitation and the vehicle, a cascade control method for the depth tracking is proposed based on the circle criterion theory and the Nelder-Mead (NM) algorithm. The mathematical model of the supercavitating vehicle and the circle criterion theorem are introduced. The cascade error state equation of the supercavitating vehicle is established based on the model, and the absolute stability of the inner-loop is studied using the circle criterion. The inner-loop feedback parameters are further optimized through the NM algorithm. The simulation analysis results show that the control method proposed in this paper is convenient for feedback parameter tuning, and can realize the accurate depth tracking effectively.]]></description>
<pubDate>2023/9/26 8:44:06</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈增强,孙明玮,张建宏,周瑜]]></author>
</item>
<item>
<title><![CDATA[Carrier phase tracking loop for long update period satellite navigation signal suitable for GPU processing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208240000001]]></link>
<description><![CDATA[In view of this contradiction that the GPU processing efficiency is limited under the short update interval and the traditional tracking loop is not robust under the high dynamic scenario under the long update interval, a carrier phase tracking algorithm with long update period for high dynamic scenes was proposed. In this algorithm, a low complexity LFM signal parameter estimation algorithm was designed to estimate Doppler and its rate of change at the initial stage of tracking, thereby eliminating most signal dynamics, and during the tracking process, 4-order Kalman filter was used to precisely track the residual signal phase and dynamic. It is verified by simulation that under the 200ms update interval, fast and stable tracking of the carrier phase can be realized in sinusoidal motion scenes with Doppler primary/secondary change rates of 800Hz/s and 64Hz/s2, respectively. The convergence can be achieved with only one update, and the tracking sensitivity is as low as 23dBHz; the phase tracking accuracy is far better than the traditional third-order phase locked loop.]]></description>
<pubDate>2023/9/20 17:05:17</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄龙,林红磊,鲁祖坤,肖志斌]]></author>
</item>
<item>
<title><![CDATA[Modulation Classification Method For OFDM Subcarrier under Carrier Frequency Offset]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109020000001]]></link>
<description><![CDATA[Modulation recognition algorithm based on signal amplitude distribution and higher-order spectral characteristics was presented. The algorithm mainly utilized the amplitude distribution of orthogonal frequency division multiplexing subcarrier signal after orthogonal demodulation by inverse Fourier transform, realized multiplexing phase shift key and orthogonal amplitude modulation recognition by histogram statistics, and the modulation order in the multiplexing phase shift key class was recognized by multi-spectral analysis. Compared with the classical modulation recognition algorithm based on high-order cumulant, it has better adaptability to carrier frequency residual deviation, and the recognition rate is improved by nearly 20% under the condition of CFO; Compared with the cyclostationary method, it has better signal-to-noise ratio adaptability. The simulation results show the effectiveness of this method. Under the same recognition rate, the adaptability is improved by 5dB. The simulation results show the effectiveness of this method.]]></description>
<pubDate>2023/9/7 15:23:30</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[朱立为]]></author>
</item>
<item>
<title><![CDATA[Design of Ultra-Tight Coupling GNSS Receiver Tracking Loop in Spinning Vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107160000003]]></link>
<description><![CDATA[The spinning vehicles are typical applications of GNSS (global navigation satellite system) receivers. When the GNSS carrier spins, the rotation will introduce higher order dynamics making the traditional tracking loop out of lock. On the other hand, coupling with the INS (inertial navigation system) can effectively compensate the high order dynamic of signal carrier phase. In this case, a design of ultra-tight coupling GNSS tracking loop, which used the solutions of INS to aid the tracking of GNSS signal, was proposed. Besides, the relationship among the aiding rate of INS, the angle rate of spinning vehicle and the error of signal carrier phase was also analyzed. The simulation results show that the proposed tracking loop structure can effectively deal with the problem of signal tracking in the spinning vehicle, and significantly enhance the precision of position compared to the single GNSS navigation results.]]></description>
<pubDate>2023/9/1 18:17:13</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[陈飞强,刘瀛翔,王飞雪,谢郁辰]]></author>
</item>
<item>
<title><![CDATA[Asynchronous and non-stationary interference mitigation method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210140000004]]></link>
<description><![CDATA[To address the problem of mitigating asynchronous non-stationary interference in single-channel conditions, a data-driven sparse component analysis method is proposed. The aim of this method is to recover the desired signal from the received mixed signals. This method used the powerful modeling ability of deep Convolutional Neural Network to model the complex mapping between the input and output data, and realized the adaptive selection of sparse domain of target signals, the adaptive learning of sparse representation of target signals in sparse domain, and the automatic recovery of target signals. Unlike the previous interference mitigation algorithms, the proposed method completed the "end-to-end" signal waveform recovery in the time domain, and had no prior requirement for aliasing observation, which was more universal than the existing methods. Simulation experiments verify the effectiveness of the proposed interference mitigation method under different environmental noise and interference signal strength and generalization test conditions, and the interference mitigation performance is significantly better than the existing algorithms.]]></description>
<pubDate>2023/8/28 8:49:04</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈梁栋,戴定川,,黄知涛,王翔]]></author>
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<item>
<title><![CDATA[Research on Simulation of Water Entry Motion of Convolutional Projectile]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303140000008]]></link>
<description><![CDATA[In order to study the influence of motion parameters and warhead shape on the oblique entry process of a projectile into water, adopting Volume of Fraction of gas-liquid two-phase flow and water vapor cavitation model. The three-dimensional kinematics and dynamics of the rigid body were coupled by nested grids, and the motion process of the projectile in the stage of speed 80~100m/s tilting into water and opening cavitation process was simulated. According to the literature experiments, the prediction errors of the velocity and displacement of the underwater projectile are 0~6% and -8%~0, and the rotation angle error is - 6%~0. Through the simulation study of the water entry velocity and angle of entering water under multiple working conditions, it is found that with the increase of the water entry velocity, the axial impact load of the projectile increases. The maximum load is linearly related to the square of the speed, and the nonlinear attenuation rate of the velocity is large. The larger the angle of entry, the smaller the angular rate of rotation of the projectile body, the stronger the stability of movement. But the velocity decay rate is not affected by the angle of entry.The projectile body adopted a stepped head modification ,compared with the conical nose projectile, the average velocity decay rate, rotation angular rate and maximum axial impact load of the body after the head stepped modification are reduced to 66.7%, 40% and 77.2% respectively. The motion stabtility is improved significantly .]]></description>
<pubDate>2023/8/18 8:46:32</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[胡欣康,赵旭]]></author>
</item>
<item>
<title><![CDATA[Overview of Cognitive Electronic Warfare]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202306300000001]]></link>
<description><![CDATA[Cognitive electronic warfare (CEEW) is usually defined as a form of electronic warfare that is based on electronic warfare equipment with cognitive performance and focuses on autonomous interactive electromagnetic environment learning capability and dynamic intelligent confrontation task processing capability. Since it was first proposed, it has attracted extensive attention from researchers and scholars at home and abroad for its advantages of accurate perception, strong reasoning and fast decision-making. With the continuous emergence of new concepts, technologies and applications of artificial intelligence, cognitive electronic warfare has stepped into a brand new stage of development. In order to capture its future development direction, we summarize and enrich the connotation of the concept of cognitive electronic warfare from the perspective of artificial intelligence, sort out the development of cognitive electronic warfare and typical foreign projects, build the framework and architecture of cognitive electronic warfare system, conduct a comprehensive and systematic review of the key technologies of cognitive electronic warfare from the aspects of perception, judgment, decision-making, etc., and summarize the challenges and development trends of cognitive electronic warfare.]]></description>
<pubDate>2023/8/10 10:27:07</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[王翔]]></author>
</item>
<item>
<title><![CDATA[Intelligent detection method of ROP chain using two-dimensional feature of byte pattern]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302230000003]]></link>
<description><![CDATA[ROP attack is an important method for network attackers to break through the protection of operating system and realize network attacks, and ROP chain is the main component of ROP attack. An intelligent detection method with good generalization performance was proposed for automatically extracting features of ROP chains in network traffic. The sequential extraction method was adopted to divide the measured network traffic into multiple sequences, one-dimensional traffic data was converted into two-dimensional feature vectors by using sliding window and numerical quantization, and the detection of ROP chain was realized based on the convolution neural network model. Different from the existing static detection methods, the proposed method did not rely on the context information of the program memory address, was simple to implement, easy to deploy, and had excellent detection performance. The experimental results show that the highest accuracy rate of the model is 99.4%, the false negative rate is 0.6%, the false positive rate is 0.4%, the time cost is within 0.1s, and the false negative rate for the real ROP attack traffic is 0.2%.]]></description>
<pubDate>2023/8/7 8:30:05</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄恺杰,]]></author>
</item>
<item>
<title><![CDATA[BRAM Anti-irradiation Design Method for Satellite Payloads using Time-sharing Refreshing and Location Constraint]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201250000001]]></link>
<description><![CDATA[In order to solve the problem of lightweight and high-reliability anti-irradiation hardening for block random access memory(BRAM) in static random access memory-based field programmable gate array（FPGA）under the strict limitation of space-borne resources, the paper proposed BRAM anti-irradiation hardening design method based on time-sharing refreshing and location constraint. The time-sharing refreshing of the BRAM was realized through monitoring time slot of algorithm execution, and location constraint was added to effectively reduce the probability of simultaneous anomalies of two modules under the design of triple modular redundancy, effectively improving the reliability of BRAM radiation resistance with less resource consumption. The results of heavy ion acceleration test show that after adopting the time-sharing refreshing and location constraint hardening methods, the single event function interruption cross section of a certain type of satellite payload in our laboratory has decreased by about 84%. The BRAM anomaly on navigation satellites has been reduced from 3 stars, which occurred 3 times in 2 years, to 25 stars that have not occurred in 2 years, and the reliability of radiation resistance has been greatly improved.]]></description>
<pubDate>2023/7/19 12:30:18</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄仰博,刘旭辉,楼生强,毛二坤,孙鹏跃,张书政]]></author>
</item>
<item>
<title><![CDATA[High-efficiency data loading and output buffering strategy for sparse convolutional computing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206080000002]]></link>
<description><![CDATA[In view of the problems such as inefficient data loading, insufficient utilization of multiply-accumulates resources, complex output buffering and addressing logic in existing neural network accelerators when processing sparse neural networks, it proposed a high-efficiency data loading and output buffering strategy for sparse convolutional computing. It performed an all-to-all multiply-accumulates operation on the non-zero input feature map data and the non-zero weights belonging to the same input channel, which reduced the difficulty of non-zero data pairing and improved the utilization of multiply-accumulates resources; By using input stationary calculation and intensive cyclic loading of IFM data, it significantly reduced the number of data off-chip fetches; It  optimized the output buffer design and solved the problems of address access contention and storage congestion during output buffering in existing solutions. Experimental results show that, when compare to Fine-Grained Systolic Accelerator with similar architectures, the process element area of the proposed architecture is decreased by 21.56%; the data loading speed is increased by 117.71% on average; the utilization of multiplier is increased by 11.25%, reaching 89%.]]></description>
<pubDate>2023/7/19 12:29:20</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[陈长林,刘彪,刘思彤,唐励勤,于红旗,张宇飞]]></author>
</item>
<item>
<title><![CDATA[Complex Multitask Bayesian Compressive Sensing using Modified Laplace Priors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105250000001]]></link>
<description><![CDATA[Bayesian compressive sensing (BCS) is an important sub-class of sparse signal reconstruction algorithms. It has been demonstrated that BCS has been widely applied in many signal processing fields. To extend the existing real-valued BCS framework to the complex-valued one, we developed a complex multitask Bayesian compressive sensing algorithm using modified Laplace priors (CMBCS-MLP), and further derived a fast algorithm based on sequential operations. It is demonstrated by numerical examples that the developed CMBCS-MLP algorithm is more accurate and robust than the existing algorithms in the complex sparse signal reconstructions.]]></description>
<pubDate>2023/7/19 12:28:28</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[孙斌,张启雷]]></author>
</item>
<item>
<title><![CDATA[Power resource allocation method for CMIMO radar based on high dynamic characteristics of RCS]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303270000002]]></link>
<description><![CDATA[Aiming at the problem that the tracking accuracy of the collocated MIMO radar is not high due to the high dynamic variation of the target electromagnetic scattering cross-sectional area RCS, a collocated MIMO radar power resource adaptive allocation method based on the high dynamic characteristics of the target RCS is proposed.. Firstly, the static RCS database under different polarization is constructed. Then the untracked Kalman is used for tracking, and the dynamic RCS of the target is calculated by predicting the time-varying direction of the target kinemic mation and the line of sight. The larger polarization of the RCS was selected. On this basis, a tracking posterior Kramer lower bound including radar emission parameters is derived to measure the multi-target tracking performance, and a tracking accuracy optimization model under strong power constraints is constructed. Finally, the above multivariate optimization problem is solved, and the power adaptive scheduling is realized. Simulation experiments show: the proposed algorithm can effectively combine the dynamic diversity characteristics of RCS in different directions to achieve effective power allocation in the practical tracking scenarios. Compared with the traditional RCS model allocation scheme, the proposed algorithm solves the mismatch problem between the allocation scheme and the actual tracking scene, and improves the multi-target tracking performance of the collocated MIMO radar.]]></description>
<pubDate>2023/7/19 12:27:31</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[丁瑞,蒋李兵,王壮,杨庆伟,郑舒予]]></author>
</item>
<item>
<title><![CDATA[Influence Analysis of the Filter Order on Time-domain Interference Suppression of Navigation Receiver]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109290000002]]></link>
<description><![CDATA[Filter order is the core parameter affecting the time-domain adaptive anti-jamming performance and the computational complexity of satellite navigation receivers.  In order to solve the problem of the current order selection is heavily dependent on engineering experience and the impact of the analysis is insufficient, this paper analyzes the impact of the filter order on the time-domain adaptive anti-jamming performance of navigation receivers, providing theoretical research for low-complexity time-domain anti-jamming. The analysis was oriented to different interference environments. The filter amplitude-frequency response and signal carrier-to-noise ratio were used as evaluation indicators. The simulation experiments and practical tests verified the traditional least mean square(LMS) algorithm and the improved LMS algorithm. Finally, an adaptive design method for optimal filter order based on digital filter was proposed. Experimental data analysis shows that by appropriately increasing the filter length, the anti-interference performance of the time-domain adaptive filter can be effectively improved. In practical applications, the filter order can be optimized by constraining the carrier-to-noise ratio loss.]]></description>
<pubDate>2023/7/19 12:24:10</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[郭海玉,李柏渝,鲁祖坤,宋捷,孙广富,肖志斌]]></author>
</item>
<item>
<title><![CDATA[Convolutional Codes Recognition Base on Joint Learning of Matrix Transformation Features and Code Sequences]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210140000003]]></link>
<description><![CDATA[Existing deep learning based convolutional code recognition methods still have shortcomings such as large parameter sizes and weak recognition performance. Aiming at this problem, this paper proposed a convolutional code recognition method based on joint learning of matrix transform features and code sequences. This method first arranged the received codeword sequence into a matrix form, and used soft information to eliminate the codewords with low reliability. Then, a new matrix transformation algorithm was used to obtain the feature matrix. During the recognition process, the original matrix of code words and the matrix of features were fed into a network model with a joint learning capability for multimodal data.  The feature extraction fusion and convolution code recognition were completed in the neural network. The simulation results show that the recognition performance of the proposed method is significantly better than the existing recognition methods based on deep learning, especially for high bit rate convolutional codes. When the rate is low, the proposed method is also better than traditional methods. When the signal-to-noise ratio reaches 5dB, the recognition rate of 25 convolutional codes with different parameters can reach 100%.]]></description>
<pubDate>2023/7/19 12:22:15</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄知涛,刘伟松,满欣,明亮,王垚,尤红雨]]></author>
</item>
<item>
<title><![CDATA[Radar target tracking algorithm in the framework of interacting  multiple model with glint noise]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207120000004]]></link>
<description><![CDATA[Aiming at the problem of the performance degradation of the traditional tracking algorithm when confronted with glint noise, a robust filtering method named as IMM-CKF is proposed by integrating the cubature Kalman filter (CKF)  into the framework of interacting multiple model (IMM). In the proposed algorithm, the target state is modeled as Gaussian distribution, the glint noise is modeled as Gaussian mixture distribution, and the occurrence probability of the glint noise is modeled as the first-order Markov process. An IMM framework is then used to implement model-matched filtering for each Gaussian component. To further mitigate the impact of nonlinear observation condition on tracking accuracy, the CKF is utilized as Gaussian approximation filter to realize recursive prediction and update of the target state. Simulation results show that the proposed method not only has higher tracking accuracy than traditional algorithms such as Gaussian sum filter and particle filter, but also has better real time ability. Additionally, the IMM-CKF can effectively estimate the existence of glint noise.]]></description>
<pubDate>2023/7/19 9:56:55</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李祖检,滕书华,占荣辉]]></author>
</item>
<item>
<title><![CDATA[An Accelerated Fault Injection Algorithm for SRAM-based FPGA using Whole Frame Upset]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107160000002]]></link>
<description><![CDATA[UR-SB (unrecoverable-sensitive bits), which cannot be corrected by regular refresh, will cause long-term interruption of on-orbit service of satellite load. Thus, the impact of UR-SB needs to be evaluated and improved deeply by the fault injection tests. However, the propor-tion of UR-SB is extremely low. If the traditional bit-by-bit upset fault injection method is adopted, the fault injection tests would take too long time, and the efficiency is extremely low. This paper proposes a fault injection acceleration algorithm for SRAM-based FPGA based on whole frame upset, which can quickly filter out the configuration frames without UR-SB through whole frame upset fault injection. By taking dichotomy on the configuration frames with UR-SB, the precise positioning process of UR-SB can be speeded up effectively. Taking the commonly used XQR2V3000 device as an example, the simulation results indicate that the test efficiency can be improved by 207 times under the poor conditions, and the real data experimental results of the signal generation load in our group are increased by 949 times. These results demonstrate the validity of the acceleration algorithm proposed in this article.]]></description>
<pubDate>2023/7/19 9:56:32</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈雷,黄仰博,楼生强,吕晟莱,毛二坤,孙鹏跃,张书政,周欢]]></author>
</item>
<item>
<title><![CDATA[Research and implementation of high planar resolution penetrating imaging radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110260000001]]></link>
<description><![CDATA[Penetrating imaging radar technology uses the characteristics that the electromagnetic wave can penetrate the medium, to get high-resolution image of discontinuities in the non-metallic medium. In order to realize millimeter high plane resolution, high detection efficiency and high portability of the radar system, a high plane resolution penetration imaging radar system was designed. Continuous wave system and fast scanning spatial sampling scheme were adopted to ensure miniaturization and high imaging performance. An integrated radar RF front-end was realized. Data processing methods such as autofocus imaging processing under the condition of unknown parameters were proposed. A prototype of penetrating imaging radar system was developed, which weighs only 2.5 kg and can be operated by one person and one hand. The experimental tests of imaging resolution and penetration ability are carried out to verify the feasibility and effectiveness of the scheme.]]></description>
<pubDate>2023/7/19 9:55:36</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈诚,何志华,黄春琳,金光虎,刘涛,宋晓骥,粟毅]]></author>
</item>
<item>
<title><![CDATA[A Novel Digital Stretch Implementation Method Based on Cascading Segmented Fast Fourier Transform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202250000001]]></link>
<description><![CDATA[To resolve the problem of high hardware consumption and difficulty in engineering implementation in digital Stretch processing with large decimation multiples, a new method based on cascading segmented FFT processing is proposed. The data sequence after digital mixing is cascading segmented and reorganized, and then the digital Stretch processing is realized by using the less points FFT operation. The experimental results based on the measured data prove the effectiveness of the presented strategy. The resource consumption analysis demonstrates that the proposed method can implement digital Stretch more hardware-efficiently compared with the conventional method.]]></description>
<pubDate>2023/7/19 9:55:01</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[林钱强,莫璨瑜,秦正阳]]></author>
</item>
<item>
<title><![CDATA[Fast frequency-sweep interference mitigation based on pulse blanking for GNSS receivers]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207120000002]]></link>
<description><![CDATA[A low-complexity method based on pulse blanking for fast frequency-sweep interference mitigation in satellite navigation receivers was proposed in this paper. This method converted the continuous wave interference into pulse interference through a low-pass filter, and then pulse detection and blanking were used to mitigate the interference.  The interference was blanked as a pulse when it located in the passband of the low-pass filter. Otherwise, it was suppressed as an outband interference when it located in the stopband of the low-pass filter. Theoretical analysis and experimental results show that the computation complexity of this method is reduced by an order of magnitude compared with that of traditional method, and it can achieve similar interference suppression performance.]]></description>
<pubDate>2023/7/19 9:54:32</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈飞强,黄龙,刘哲,鲁祖坤]]></author>
</item>
<item>
<title><![CDATA[Overview of GNSS/INS Ultra-tight integrated navigation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209200000005]]></link>
<description><![CDATA[GNSS/INS ultra-tight integrated navigation system has become a research hotspot in the field of integrated navigation due to its high positioning accuracy, excellent dynamic performance and strong anti-jamming ability. The principle of GNSS/INS ultra-tight integration was introduced, and the advantages and features of ultra-tight integration mode relative to other integration modes were compared based on the analysis of the technical principle. The domestic and international research status was introduced, represented by ultra-tight integration under high dynamics and MIMU/GNSS ultra-tight integration. The key technologies such as fault-tolerant control technology, neural network assistance, and multi-sensor assisted ultra-tight integration were summarized, and the prospect of GNSS/INS ultra-tight integration towards low cost, high precision and strong stability was prospected.]]></description>
<pubDate>2023/7/19 9:53:58</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[邓 丁,李诗扬,倪少杰,谢郁辰]]></author>
</item>
<item>
<title><![CDATA[The Multilevel Real-time Visualization Technology for Large-scale Geographic Vector Linestring Data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303200000001]]></link>
<description><![CDATA[Geographic vector data visualization plays a vital role in the geographic information system, the mainstream methods adopt the data-driven calculation way, which is difficult to support the multilevel real-time visualization of large-scale geographic vector linestring data. The paper proposes a multilevel real-time visualization technique for large-scale geographic vector linestring data. An adaptive visualization model for multilevel tile rendering was established, and a pixel-quad-R (PQR) tree spatial index structure and an adaptive visualization algorithm for geographic vector line data based on PQR-tree were designed to support the data organization and visualization of the model, respectively. Experiments on billion-scale datasets show that the visualization results at any zoom level can be obtained by real-time calculation without caching. The technology can well support multilevel real-time visualization of large-scale geographic vector linestring data in a single machine, and the visualization performance is far superior to the current mainstream methods, which have a high application prospect in the field of exploration and analysis of spatial big data.]]></description>
<pubDate>2023/7/19 9:53:21</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈荦,景宁,刘泽邦,马梦宇,杨岸然,钟志农]]></author>
</item>
<item>
<title><![CDATA[Universal adversarial attack method for communication modulation identification using principal component analysis]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202210140000001]]></link>
<description><![CDATA[Existing studies show that deep learning is easily attacked by adversarial examples. Taking communication modulation recognition as an example, adding adversarial perturbations to the transmitted signal can effectively prevent non-cooperative users from utilizing the deep learning method to recognize the modulation of the signal. Thus, adversarial perturbations can help enhance communication security. To address the problem that the existing adversarial attack techniques are difficult to meet the adaptive and real-time problems, the universal adversarial perturbation applicable to the whole dataset is obtained by principal component analysis of the adversarial perturbation generated by a small part of the data extracted from the dataset. The computation of the universal adversarial perturbation can be carried out under offline conditions and then added to the signal to be transmitted in real time, which can satisfy the real-time requirements of communication and realize the purpose of reducing the accuracy of non-cooperative party modulation recognition. Experimental results show that the method proposed in this paper has better deception performance relative to the baseline method.]]></description>
<pubDate>2023/7/19 9:46:19</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[邓寿云,黄知涛,柯达,卢超奇]]></author>
</item>
<item>
<title><![CDATA[Multi-Memristor-Array Interconnection Structure for Large Scale CNN Acceleration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206130000001]]></link>
<description><![CDATA[To address the problems of inefficient data loading and readout and poor flexibility of array collaboration in existing multi-memristor-array based Convolutional Neural Network (CNN) accelerators, a highly efficient and flexible multi-array interconnection architecture is proposed. The data loading strategy of the architecture supports data reuse in multiple weight mapping modes, reducing the need for off-chip data access; the readout network supports flexible combination of multiple processing units to achieve different scales of convolutional operations, as well as fast accumulation and readout of computation results, thus improving chip flexibility and overall computing power. Simulation experiments performed on the NeuroSim platform with running VGG-8 networks indicate a 146% increase in processing speed than that of the MAX2 neural network accelerator, with only a 6% increase in area overhead.]]></description>
<pubDate>2023/7/18 14:39:08</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[陈长林,,,,,,张宇飞]]></author>
</item>
<item>
<title><![CDATA[Multi-Memristor-Array Interconnection Structure for Large Scale CNN Acceleration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206130000001]]></link>
<description><![CDATA[To address the problems of inefficient data loading and readout and poor flexibility of array collaboration in existing multi-memristor-array based Convolutional Neural Network (CNN) accelerators, a highly efficient and flexible multi-array interconnection architecture is proposed. The data loading strategy of the architecture supports data reuse in multiple weight mapping modes, reducing the need for off-chip data access; the readout network supports flexible combination of multiple processing units to achieve different scales of convolutional operations, as well as fast accumulation and readout of computation results, thus improving chip flexibility and overall computing power. Simulation experiments performed on the NeuroSim platform with running VGG-8 networks indicate a 146% increase in processing speed than that of the MAX2 neural network accelerator, with only a 6% increase in area overhead.]]></description>
<pubDate>2023/7/18 12:22:27</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[陈长林,,,,,,张宇飞]]></author>
</item>
<item>
<title><![CDATA[Compression method for three-dimensional point cloud deep model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202108110000001]]></link>
<description><![CDATA[With the widespread application of computer three-dimensional vision, point cloud processing algorithms based on deep learning have attracted a lot of research in recent years, however, the time and storage consuming characteristics have greatly restricted its deployment and application on the mobile terminal devices. Based on the general idea of improving the loss function, a new point cloud deep model compression framework is proposed, and the knowledge distillation method is introduced into the binary quantization model, at the same time, considering the speciality of the point cloud aggregation operation, an auxiliary loss item is introduced. The improved loss function includes three parts: prediction loss, distillation loss and auxiliary loss. The experimental results show that, compared with the existing algorithms, the proposed algorithm can obtain higher accuracy, meanwhile, the application to current mainstream point cloud deep network models could also achieve good scalability.]]></description>
<pubDate>2023/7/18 11:32:52</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[马燕新,万建伟,许可,赵志]]></author>
</item>
<item>
<title><![CDATA[The effect of signal power enhancement on the performance of GNSS anti-jamming receiver with null-steering antenna]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110110000002]]></link>
<description><![CDATA[Due to the low transmitting power and large transmission loss, the satellite signal reaching the GNSS receiver is extremely weak, and easy to be interfered. In order to deal with the threat of interference, taking measures at both the system and user level is a good choice. In this paper, a model estimating the interference suppression ability of adaptive antenna arrays is established. The effect of satellite signal power enhancement on performance of adaptive antenna array receivers is analyzed. The results show that, the interference mitigation capability of the receiver can be improved by 3-4 dB per 10 dB signal power enhancement. The performance (carrier-to-noise ratio, ranging and positioning accuracy, etc.) is the best when the signal power is enhanced by about 15-20 dB considering the non-limiting conditions. The research result could guide the optimization of the signal power enhancement and anti-jamming design of receivers.]]></description>
<pubDate>2023/7/18 11:10:58</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈飞强,欧钢,孙一凡,唐小妹]]></author>
</item>
<item>
<title><![CDATA[Clustering Sparse Fitting Scheme for GNSS Multipath Channel Simulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202040000001]]></link>
<description><![CDATA[A GNSS multipath channel sparse fitting scheme based on K-medoids clustering was proposed to tackle the problem of a large amount of simulation computation and hardware resource overhead for GNSS channels, which is inconvenient for real-time performance evaluation and practical engineering applications. The equivalent reduced channel impulse response (CIR) parameters were extracted using a sparse fitting method based on K-medoids clustering CIR parameters extraction, and the channel simulation were realized using a sparse tapped-delay-line structure. The proposed method sparsely fits the original GNSS multipath channel model under the constraint of retaining multipath error by employing tapped-delay-line structure filter with fewer taps, which can decrease the complexity of simulation without requiring huge hardware resources. Simulation results show that the proposed scheme is effective by sparse fitting the CIR parameters generated by the reference channel model.]]></description>
<pubDate>2023/7/18 10:57:01</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[欧钢,唐小妹,周顺]]></author>
</item>
<item>
<title><![CDATA[Specific emitter identification using reconstructed attractors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209170000001]]></link>
<description><![CDATA[Aiming at solving problems of high dimension and poor robustness faced by the existing reconstructed phase space-based methods, a nonlinear dynamic SEI framework based on reconstructed attractors was proposed in this paper. Based on the proposed framework, a novel SEI method was developed by adopting Isometric Mapping (Isomap) to reconstructing attractors from the reconstructed phase space. This method reconstructed emitter attractors, which strengthens dynamic characteristics from a lower dimension perspective. In addition, experiments verified that the proposed method could achieve higher accuracy, better robustness, and higher efficiency.]]></description>
<pubDate>2023/7/18 10:43:54</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄知涛,宋川江,王翔,赵雨睿]]></author>
</item>
<item>
<title><![CDATA[Proposal of a geometric correction method based on equivalent bias angle sparse measurement for sequential observation image of area-array sensor]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202304200000002]]></link>
<description><![CDATA[The imaging process of space-based optical sensor is easily influenced by a variety of errors on orbit and the raw images contain many image distortions. The geometric correction of raw images for improving positioning accuracy is necessary before the processing of subsequent applications. At present, the Sequential images with small size and high frame frequency which obtained by the Area-array sensor are hardly meet the requirements of the number and spatial distribution of control points for the traditional geometric correction, meanwhile the way of frame-by-frame solution has a huge amount of computation. To overcome these shortcomings of traditional methods, this paper proposes a geometric correction method based on equivalent bias angle sparse measurement for sequential observation image of area-array sensor. The problem of parameters solution for each frame has been converted to the problem of equivalent bias angle recovery under the Time-domain sparse measurement in the geometric correction processing. Due to using the time-frequency information of equivalent bias angle signal, the proposed method can effectively reduce the requirement for the number and spatial distribution of control points. Meanwhile, the real image data from the area-array sensor of Gaofen-4 satellite is used to verify the validity and low computation of the proposed method.]]></description>
<pubDate>2023/7/18 10:29:16</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安成锦,陈  军,樊建鹏,李  振,马  晨]]></author>
</item>
<item>
<title><![CDATA[Memristive Neuromorphic Computing Approach Combining Calibration Method and In-memory Training]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106160000002]]></link>
<description><![CDATA[Memristor based neuromorphic computing architecture has achieved good results in image classification, speech recognition and other fields, but when the memristor array has the problem of low yield, the performance declines significantly. In this paper, a method combining memristive neuromorphic computing based calibration method with in-situ training was proposed, which increased the accuracy of multiplicative accumulation calculation by using the calibration method and reduced the training error by using the in-situ training method. In order to verify the performance of the proposed method, a multi-layer perceptron architecture is used for simulation. From the simulation results, the accuracy of the neural network is improved obviously (nearly 40%). Experimental results show that compared with the single calibration method, the precision of the network trained by the proposed method is improved by about 30%, and the precision of the network trained by the proposed method is improved by 0.29% compared with other mainstream methods.]]></description>
<pubDate>2023/7/18 10:12:11</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[杜湘瑜,刘海军,彭杰]]></author>
</item>
<item>
<title><![CDATA[Task allocation of multiple UAVs under heterogeneous resource types]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202208110000001]]></link>
<description><![CDATA[In view of the large scale of UAVs in the process of task allocation of heterogeneous multi-UAVs and the requirements of heterogeneous targets for different resource types and quantities, CBBA  based on heterogeneous resource clustering and subtask generation is proposed. The large-scale task allocation problem is decomposed into several sub problems to be solved. Firstly, considering the conditions of mission value, mission execution time window and range cost, the task allocation model of multi-UAVs ground reconnaissance and strike is established. Secondly, k-medoids clustering analysis method is used to cluster multiple UAVs based on carrying resource balance, so as to meet the requirements of multiple UAVs for heterogeneous resource types. Finally, the sub task of the strike task is generated, and the improved CBBA is used to solve the established task allocation model. Simulation results show that this method can successfully solve the task allocation problem of multiple UAVs with heterogeneous resource requirements under various constraints, and has significant advantages in task allocation of large-scale UAVs.]]></description>
<pubDate>2023/6/2 16:43:05</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[魏兆恬]]></author>
</item>
<item>
<title><![CDATA[Research on online evolution of parallel simulation model for equipment useful life prediction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203150000002]]></link>
<description><![CDATA[Based on the research of parallel simulation technology for equipment remaining life prediction, the state equations under different degradation states is unified, the construction method of prediction model library is proposed, and the specific workflow of online model evolution is designed. The simulation experiment verifies that online model evolution under the workflow designed in this paper can achieve better simulation results.]]></description>
<pubDate>2023/6/2 16:42:20</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[邸彦强,,李  婷,]]></author>
</item>
<item>
<title><![CDATA[Multi-objective Action Control of Equipment Maintenance Support Force in Wartime]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212180000001]]></link>
<description><![CDATA[Aiming at the problems that the wartime equipment maintenance support task is heavy, the repair time is limited, and the type of maintenance support force does not match the damage demand of the equipment to be repaired, which makes it difficult to achieve accurate battlefield support, the multi-objective action control of wartime equipment maintenance support force is studied. Considering complex constraints such as repair time window, equipment damage state, types of maintenance support forces, changes of maintenance support capabilities and non-traversal, a multi-objective action control model of maintenance support forces is established, which aims at the sum of equipment importance, the sum of repaired equipment and the sum of time beyond the repair time window. The non-dominated sorting genetic algorithm Ⅱ (NSGA-Ⅱ) with elite strategy is improved, and the variable neighborhood search, VNS) algorithm is combined to strengthen the local search ability of the algorithm. The improved VNSGA-Ⅱ hybrid algorithm is designed to solve the model, and the rationality and effectiveness of the model and algorithm are verified by examples.]]></description>
<pubDate>2023/6/2 16:41:46</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[曹军海,陈春良,郭一鸣,刘彦,张闯]]></author>
</item>
<item>
<title><![CDATA[The Modified Criteria for Jet Direction of Bubbles Above a Rigid Boundary]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303090000001]]></link>
<description><![CDATA[The Blake criterion, which predicts the bubble jet direction above a wall, was obtained through the Kelvin impulse theory. However, the theoretical model has lower prediction accuracy under certain parameters. Therefore, a modified judgment criterion for the bubble jet direction was proposed by considering the bubble pressure variation and the boundary effect, verified by the boundary element method. Meanwhile, the prediction results of the modified model and the traditional Blake criterion were compared, and the influence of dimensionless strength parameters on the prediction results of the modified model was investigated. The results show that the modified model has higher prediction accuracy than the traditional Blake criterion. The modified theoretical model provides a valuable reference for underwater explosion, seabed geophysical exploration, and related fields.]]></description>
<pubDate>2023/6/2 16:41:17</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[陈启航,李帅,张阿漫]]></author>
</item>
<item>
<title><![CDATA[Research on Simulation of Water Entry Motion of Convolutional Projectile]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303140000008]]></link>
<description><![CDATA[In order to study the influence of motion parameters and warhead shape on the oblique entry process of a projectile into water, adopting Volume of Fraction of gas-liquid two-phase flow and water vapor cavitation model. The three-dimensional kinematics and dynamics of the rigid body were coupled by nested grids, and the motion process of the projectile in the stage of speed 80~100m/s tilting into water and opening cavitation process was simulated. According to the literature experiments, the prediction errors of the velocity and displacement of the underwater projectile are 0~6% and -8%~0, and the rotation angle error is - 6%~0. Through the simulation study of the water entry velocity and angle of entering water under multiple working conditions, it is found that with the increase of the water entry velocity, the axial impact load of the projectile increases. The maximum load is linearly related to the square of the speed, and the nonlinear attenuation rate of the velocity is large. The larger the angle of entry, the smaller the angular rate of rotation of the projectile body, the stronger the stability of movement. But the velocity decay rate is not affected by the angle of entry.The projectile body adopted a stepped head modification ,compared with the conical nose projectile, the average velocity decay rate, rotation angular rate and maximum axial impact load of the body after the head stepped modification are reduced to 66.7%, 40% and 77.2% respectively. The motion stabtility is improved significantly .]]></description>
<pubDate>2023/6/2 16:40:51</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[胡欣康,赵旭]]></author>
</item>
<item>
<title><![CDATA[Progress in internal wave theory for two-layer and three-layer fluid systems]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303240000001]]></link>
<description><![CDATA[Internal waves, occurring in stratified ocean, are ubiquitous in the world oceans. It is of great significance for our country's marine development to study the generation and evolution of internal waves. Based on the internal wave theory of two-layer and three-layer fluid systems, the Korteweg-de Vries internal wave theory, Miyata-Choi-Camassa (MCC) internal wave theory, High-Level Green-Naghdi (HLGN) internal wave theory and Dubreil-Jacotin-Long internal wave theory, which were widely used at home and abroad, were selected to review their research progress. The advantages and limitations of different internal wave theories were discussed from mathematical models, theoretical research and numerical simulations. In the view of mathematical derivation, it is proved that MCC internal wave theory is equivalent to the first-level HLGN internal wave theory.]]></description>
<pubDate>2023/6/2 16:40:41</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[杜辉,段文洋,王战,张天钰,赵彬彬]]></author>
</item>
<item>
<title><![CDATA[Research Progress and Prospect of Operational Reliability of Civil Aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302210000002]]></link>
<description><![CDATA[Operation reliability evaluation and analysis, as one of the key technologies to be broken through in the whole life cycle reliability management of aircraft, is an effective means to improve the safe, reliable and stable operation of aircraft. Based on the technical status and development trend of civil aircraft operation reliability research, the requirements of civil aircraft operation reliability research are expounded according to the current type design, development and actual situation of in-service aircraft. By reviewing the research progress and engineering application status of civil aircraft operational reliability theory, the research status and problems of civil aircraft operational reliability are elaborated from six aspects: data acquisition technology, operational reliability analysis method, operational reliability prediction feedback, operational reliability design, maintenance support based on operational reliability, and life-cycle management platform. The future development direction of operation reliability research of civil aircraft is prospected.]]></description>
<pubDate>2023/6/2 16:40:18</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[冯蕴雯,刘佳奇,路成,潘维煌]]></author>
</item>
<item>
<title><![CDATA[A novel frequency selective surface-loaded dual-polarized ultra-wideband tightly coupled array antenna]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303140000005]]></link>
<description><![CDATA[Tightly coupled array antenna is a kind of ultra-wideband phased array technology. To achieve better electromagnetic characteristics and more stable radiation properties within an ultra-wide band, a novel dual-polarized ultra-wideband tightly coupled array antenna loaded with wide-angle impedance matching layer on a strip frequency selective surface was proposed. The array elements were studied and analyzed through the truncation by the periodic boundary conditions in high frequency electromagnetic simulation software CST. After investigating its electromagnetic properties of array impedance and radiation, a 6 × 6 array antenna was designed, manufactured for actual measurement. The measurement results show that the standing wave ratio of the antenna in the frequency band of 2~12GHz is less than 3. The impedance bandwidth is 10GHz. Moreover, the antenna has stable radiation within frequency band, more electromagnetic energy is concentrated in the mainlobe, and the cross polarization is small. In the operating frequency band, the maximum gain can reach 13dB. This kind of array antennas can be applied in the ultra-wideband phased array domain.]]></description>
<pubDate>2023/6/2 16:39:31</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[方艺忠,王少植,吴微微,颜雨晨,袁乃昌]]></author>
</item>
<item>
<title><![CDATA[Filtered pressure model in large eddy simulation/probability density function method for compressible flows]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202212210000001]]></link>
<description><![CDATA[The subgrid species-temperature correlation term significantly affects the accuracy of large eddy simulation of reactive flows. A new filtered pressure model is developed by using the basic characteristics of probability equivalence in the probability density function method, which can well close the subgrid species-temperature correlation term. Firstly, the probability density function and its coupling solution method are introduced. Then, a new filtered pressure model is derived based on previous models. Finally, numerical tests of different filtered pressure models were carried out in a three-dimensional supersonic hydrogen/air temporally evolving reactive mixing layer. The results show that, compared with the traditional filtered pressure model, the new filtered pressure model can significantly improve the simulation accuracy. In particular, based on the new filtered pressure model, the large eddy simulation/probability density function method can better simulate minor species in the chain reaction such as hydrogen peroxide, which is expected to more effectively reproduce complex combustion phenomena such as self ignition.]]></description>
<pubDate>2023/6/2 16:37:51</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[梁剑寒,孙明波,王翼,张林]]></author>
</item>
<item>
<title><![CDATA[Study on fatigue reliability of FRC steel embedded T-joint based on Weibull distribution]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201140000003]]></link>
<description><![CDATA[T type joint of FRC/steel by was made by vacuum forming process and suture technology, carry out tension-tension fatigue test. According to the fatigue test results, the initial damage characteristics and damage evolution of T joints were analyzed under the action of fatigue load. In addition, the fatigue life distributions under different stress levels are fitted based on two-parameter Weibull distribution, and the fatigue reliability function of the joints at different stress levels and the double logarithm curve of stress/life under the specified reliability are given(R-lnS-lnN).]]></description>
<pubDate>2023/6/2 9:02:11</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[陈国涛,梅志远,祝 熠]]></author>
</item>
<item>
<title><![CDATA[The effect of microwave pulse on the carrier-to-noise ratio of navigation receiver tracking loops]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202206200000001]]></link>
<description><![CDATA[To clarify the optimal interference parameters of microwave pulses to navigation receivers, by analyzing theoretically the tracking loop correlation processing of navigation receiver under microwave pulse interference, a interference classification method was proposed based on the relationship between microwave pulse spectral lines, spread spectrum code spectral lines and coherent integration time, the correlation output power and carrier-to-noise ratio under microwave pulse interference with different parameters was further derived, finally experimental verification was carried out. Theoretical analysis and experimental results show that when the microwave pulse width is greater than or equal to the spreading code period and less than the coherent integration time, a spreading code spectral line is interfered with multiple microwave pulse spectral lines which enters the bandwidth of the coherent integrator, the microwave pulse has the best interference effect on navigation receivers, and is better than continuous wave interference; with the increase of the number of interference spectral lines, the correlation output power is increased, the carrier-to-noise ratio is decreased, and the interference effect is enhanced.]]></description>
<pubDate>2023/6/2 9:01:50</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈亚洲,赵敏,周星]]></author>
</item>
<item>
<title><![CDATA[Analysis of electric field protection effect and cathodic protection performance of pump-jet propulsion submarine]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201130000002]]></link>
<description><![CDATA[In order to explore the protective effect of pump-jet propulsion submarine under the two typical working modes of electric field protection and impressed current cathodic protection, the boundary element method was used to establish the corrosion-related electrostatic field model of the submarine. The influence of fairing and guide vane on the electric field protection and cathodic protection performance was simulated and analyzed. The results show that compared with the traditional propulsion mode, the peak-to-peak value of electric field of pump-jet propulsion submarine in seawater is reduced by about 38%, and it can achieve better electric field protection effect with only about 50% current value. In addition, no matter whether the whole boat coating is intact or not in the cathodic protection process, the peak electric field at the pump-jet propulsion device is reduced to a certain extent, indicating that the pump-jet propulsion device has better electric field stealth performance. However, in the process of impressed current cathodic protection for pump-jet propulsion submarines, good protection effect can only be achieved at the hull and the major axis. The impeller and guide vane inside the fairing are difficult to reach the protection potential, which is in an under-protection state, so local corrosion protection still needs to be strengthened.]]></description>
<pubDate>2023/6/2 9:01:31</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[胡育诚,柳 懿,唐炜豪,汪石川,王向军]]></author>
</item>
<item>
<title><![CDATA[Modeling and analysis of muzzle vibration of wheeled assault gun firing on the move and stability control]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303230000003]]></link>
<description><![CDATA[In order to investigate the impact laws of road unevenness, fire line height, and stabilizer on the muzzle vibration of a wheeled assault gun, A multi-body dynamic model of the wheeled assault gun firing on the move is established and verified with experimental results. A road-surface spectrum model is built by using the harmonic superposition method, and the dynamic model is calculated under different road conditions and different fire line heights. The influence of the road-surface level and fire line heights on the muzzle vibration of the wheeled assault gun is obtained. The model of a vertical stabilizer is set up, and the co-simulation of dynamics and control is carried out. The influence of the stabilizer on the muzzle vibration is analyzed by comparing muzzle vibration with and without stabilizers. The research results show that muzzle vibration amplitude increases with the increase of road roughness. The influence of fire line heights on muzzle vibration is nonlinear. The vertical stabilizer can effectively control muzzle vibration of the wheeled assault guns during firing on the move, reducing the vibration amplitude and quickly restoring to the stable state. This research has certain reference significance for the overall design and engineering application of the wheeled assault gun.]]></description>
<pubDate>2023/6/2 9:01:13</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[邓远泊,,,,]]></author>
</item>
<item>
<title><![CDATA[Jacobi-Ritz time domain semi-analytic method and characteristic analysis of cylindrical shell vibro-acoustic radiation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303150000007]]></link>
<description><![CDATA[Considering the deficiency in the research on transient Vibro-Acoustic characteristics of cylindrical shell structures, a Jacobi-Ritz semi-analytic method for forced vibration sound radiation of cylindrical shells in time domain was proposed by combining Newmark-β integral method and Kirchhoff boundary element integral equation in time domain. Based on the theory of first-order shear deformation and the idea of element method, a calculation and analysis model of vibration acoustic radiation of cylindrical shell was established. Jacobi polynomial and Fourier series were used to represent the allowable functions of axial and circumferential displacement. The time domain response of forced vibration of cylindrical shell was calculated based on Rayleigh-Ritz method and Newmark-β integral method. Based on Kirchhoff integral equation, the time domain response of radiated noise was solved, and the acoustic radiation characteristics of forced vibration of cylindrical shell were analyzed. Compared with Finite Element Method/Boundary Element Method numerical results, the proposed method has the characteristics of good convergence and high precision. The peak value of acoustic response of cylindrical structures shifts to the left with the weakening of the boundary condition stiffness, and the vibration acoustic response decreases with the increase of the thickness. When the peak frequency of random load is close to the natural frequency of the structure, strong characteristic line spectrum appears in the acoustic response of the structure.]]></description>
<pubDate>2023/6/2 9:00:36</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[高聪,李海超,庞福振,张明,郑嘉俊]]></author>
</item>
<item>
<title><![CDATA[Transfer of oxygen concentrator life prediction model based on LSTM-fine-tune]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202205100000001]]></link>
<description><![CDATA[To transfer the life prediction model, this paper proposed an LSTM-fine-tune model. The model is trained by using experimental data under ideal conditions. During the transfer process, part of the LSTM network layer is frozen, and other parts of the network are modified by using data in actual service environment. In order to verify the generalization ability of the model, this paper uses sinusoidal functions with different phases and amplitudes to generate data and obtains the knowledge of the sinusoidal function, and applies it to the regression of other sinusoidal functions. The results show that the LSTM-fine-tune model can be fitted quickly, and the average mean square error is only 1.0335. It is significantly lower than the direct prediction error 1.5368. In order to test the generalization ability of this method through actual monitoring data, this paper obtains the data of oxygen concentrators under test conditions and actual service environment respectively and verifies the generalization ability of the model. The results show that the prediction accuracy of the training set is improved by 43.0% and that of the test set is improved by 20.2%.]]></description>
<pubDate>2023/6/2 9:00:31</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[崔展博,焦晓璇,景博,潘晋新,王生龙]]></author>
</item>
<item>
<title><![CDATA[Application of Wasserstein distance in fault detection for liquid-propellant rocket engines]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303130000002]]></link>
<description><![CDATA[Health monitoring can effectively improve the reliability of liquid-propellant rocket engines. Aiming at the problem of fault detection in health monitoring for liquid-propellant rocket engines, a method based on Wasserstein distance was proposed and verified using ground hot test data of an LOX/LH2 rocket engine. The core idea was to use Wasserstein generative adversarial network to simulate the sample distribution of normal data, and used its discriminator to calculate the Wasserstein distance between the test sample and the simulated distribution, so as to achieve fault detection. The results show that the proposed method can overcome the difficulty of insufficient fault data, detect the faults in the steady-state process effectively without false alarm, and is sensitive to early anomalies. In the case of a small number of training samples, when the Wasserstein distance threshold is set to 3 standard deviation ranges, the method is sensitive to early anomalies during the start-up transient. Starting fault can still be effectively detected with the threshold of 5 standard deviation ranges, with a false alarming rate of 12.5%.]]></description>
<pubDate>2023/6/2 8:59:30</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[程玉强,邓凌志]]></author>
</item>
<item>
<title><![CDATA[Survey on Converged Networks of High-performance Computing Network and Data Center Network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302210000001]]></link>
<description><![CDATA[With the convergence trend of high performance computing, big data processing, cloud computing and artificial intelligence computing, the boundary between high-performance computers and data centers is becoming more and more blurred. The converged network of high-performance computing network and data center network becomes an important trend, so that the infrastructure can be used to support high performance computing, big data processing, cloud computing and artificial intelligence computing, meeting the needs of multiple fields of applications. The current research status of converged network was analyzed, representative converged networks were described in detail to comprehensively show the latest technologies and trends. The challenges faced by the converged network were put forward, and the trends of converged network were proposed, including the convergence and differentiation coexistance of the converged network protocols, performance acceleration of the converged network based on in-network computing, and performance optimization of the converged network for emerging applications.]]></description>
<pubDate>2023/6/2 8:59:18</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[董德尊,,陆平静,,,]]></author>
</item>
<item>
<title><![CDATA[The coupling effects of multi-spindled interconnected hydropneumatics suspension of  launch vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303130000003]]></link>
<description><![CDATA[The heavy-duty missile launcher has the characteristics of high load and strong cross-country performance, Hydropneumatics suspension(HPS) are used in heavy-duty missile launcher because of their nonlinear characteristics of stiffness and damping. It can better adapt to the changes of external load excitation. In the multi-spindled interconnected HPS, there is the interconnection of the front and rear suspensions, which leads to the non-linear characteristics of the interconnected HPS that is different from the independent HPS. the simulation models of an interconnected HPS of two-axles and four-axles were built based on the mathematic model and AMESim software. Based on this, the influence of the coupling effect of the multi-axis connected twin-accumulator HPS system was analyzed under several different excitation frequencies. The results show that even under low-frequency excitation, the multi-axis interconnected HPS has obvious damping characteristics. Compared with the two-axis interconnected HPS system, the external characteristics of the four-axis interconnected HPS system have advantages. The external characteristics of the connected HPS system are more intense when excited by low frequency and good when excited by high frequency, indicating that the system can attenuate the asynchronous vibration of the system when it is in a high frequency environment.]]></description>
<pubDate>2023/6/2 8:58:45</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[刘洋佐,马大为,任杰]]></author>
</item>
<item>
<title><![CDATA[Research Progress in Damage Mechanism of Nickel-Based Single Crystal Superalloys under Service Conditions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303140000004]]></link>
<description><![CDATA[Nickel-based single crystal superalloys are widely used in aeroengine turbine blades and gas turbine blades due to their excellent comprehensive mechanical properties at high temperature. In recent years, domestic and overseas researchers have carried out a large number of research on the failure and damage mechanism of nickel-based single crystal superalloys under service conditions in order to improve the service life of nickel-based single crystal blades and solve the key technology of "the two turbines". It is concluded that the research achievements and progress of fatigue, creep and thermomechanical fatigue damage mechanism of nickel-based single crystal superalloys under service conditions. In addition, in view of the time and cost increase caused by a large number of experiments, it is also summarized the research works and achievements in life prediction methods of nickel-based single crystal superalloys in recent years, and proposed the difficulties and challenges in life evaluation and failure analysis of nickel-based single crystal superalloys.]]></description>
<pubDate>2023/6/2 8:58:05</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[沈将华,王秀霞,周宇亭]]></author>
</item>
<item>
<title><![CDATA[A multi-scale implicit scheme for steady flows of diatomic gases in all flow regimes]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303160000002]]></link>
<description><![CDATA[The application of unified gas kinetic scheme is greatly hindered by the huge requirements of computing resources. Based on Boltzmann-Rykov model equation, a conservative implicit scheme for steady flows in all flow regimes was developed by adopting macroscopic prediction technique, and the macroscopic equation and microscopic equation were solved collaboratively to accelerate the convergence. At the cell interface, a simplified and efficient multi-scale numerical flux iwas directly constructed from the characteristic difference solution of kinetic model equation. The adoption of non-uniform, unstructured velocity space and velocity space adaptive technology further reduce the requirement of computation and improve computational efficiency. The applications of unstructured discrete velocity space and adaptive discrete velocity space reduced the number of velocity mesh significantly and made the present method be rather efficient. The accuracy and effectiveness of the proposed method were confirmed by the simulations of rarefied supersonic and hypersonic flows over a flat plate, supersonic and hypersonic flows over a sphere. Numerical results indicate that the proposed method can accurately solve two - dimensional and three - dimensional diatomic gas multi-scale flow problems, and it is about one orders of magnitude faster than the explicit discrete unified gas kinetic scheme method.]]></description>
<pubDate>2023/6/2 8:57:54</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈健锋,刘沙,张瑞,钟诚文,卓丛山]]></author>
</item>
<item>
<title><![CDATA[A computation-for-communication distributed task scheduling method for networked UAV swarm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303190000001]]></link>
<description><![CDATA[Aiming at the problem of autonomous coordination of networked UAV swarm and the advantages and disadvantages of market bidding method, the idea of 'computation-for-communication' and its corresponding distributed task scheduling method are proposed. By analyzing explicit and implicit conflicting tasks, a set of task-related agents is established. A local optimization method based on task suppression is proposed to resolve some task conflicts in advance, so as to reduce the number of algorithm iterations. An agent position inference method based on historical bidding information is designed to provide necessary information input for local optimization. Monte Carlo simulation experiments were carried out based on the networking simulation platform and the swarm rescue scenario. The results show that compared with the representative CBBA algorithm and PI algorithm in the market bidding method, the proposed method can obtain fewer iterations, shorter convergence time and better scheduling performance.]]></description>
<pubDate>2023/6/2 8:57:18</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[李杰,]]></author>
</item>
<item>
<title><![CDATA[Combining Multi-view Learning and Consistent Representation for Face Forgery Detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302170000001]]></link>
<description><![CDATA[Most of the existing face forgery detection methods usually achieve acceptable detection performance on known attacks, but still face the risk of overfitting and fail to maintain good detection capability when dealing with unknown scenes. To solve this problem, an effective face forgery detection framework based on multi-view learning and consistent representation was proposed. To capture more comprehensive forgery traces, the input image was transformed into two complementary views and a dual-stream backbone network was used for multi-view feature learning. The consistency metric was introduced to explicitly constrain the similarity of local features output from different viewpoints in a patch-level supervised manner. To improve the detection accuracy of the model, the feature decomposition strategy further optimized the forgery-relevant feature to reduce the interference of irrelevant factors, and the decision made from the forgery-relevant feature space was used as the final prediction. Extensive experiments on benchmark datasets show that the proposed method outperforms the existing mainstream approaches with good cross-domain generalization capability.]]></description>
<pubDate>2023/6/2 8:57:12</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[杨佳鑫,于淼淼,张军]]></author>
</item>
<item>
<title><![CDATA[Modeling and solving for flexible procurement pricing of emergency material]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204070000002]]></link>
<description><![CDATA[As  the risk of "over-storage" or "under-storage" still exists in the emergency equipment reserve， in order to improve the reserve efficiency,  it put forward the flexible procurement strategy of emergency equipment, taking the economic benefit of enterprises and the military procurement cost as the optimization target. By establishing the model of optimizing enterprise reserve strategy and military procurement pricing, the optimal flexible pricing of the military and the corresponding enterprise optimal reserve strategy under the external environmental factors such as the probability of the outbreak of war and the price range of equipment spot market were solved. The decision conclusion was verified by an example analysis. The result shows that the implementation of the optimal strategy would be beneficial for the military and enterprises to share the risk of emergency equipment quantity reserve.]]></description>
<pubDate>2023/6/2 8:55:00</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[杜海东,何成铭,刘旭阳,汪琳]]></author>
</item>
<item>
<title><![CDATA[Dynamic loading technology for Mullins effect of rubber elastomer used in aeronautical tires]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202303100000002]]></link>
<description><![CDATA[The rubber elastomers, widely used in aeronuatrical tires, are subject to experience severe dynamic cycling loading during their engineering service. In order to obtain their mechanical characteristics and potential damage mechanisms under those conditons, a dynamic loading methodology was proposed for performing Mullins effect experiments based on stress wave loading. According to the characteristics of stress wave propagation, its each unit was designed and configured based on Hopkinson pressure bar principle. An experimental system was then built for rubber elastomer materials, and the dynamic cyclic behavior was obtained of styrene-butadiene rubber used in tires. The analyses on the experimental original signals demonstrated that the system can obtain the increasing maximum strain during each cycle, which menifested the system can achieve the dynamic loading of Mullins effect for elastomer. Finally, the loading system specificaitons are discussed for obtaining controllable loading and unloading parameters after finely adjusting systme components.]]></description>
<pubDate>2023/6/2 8:50:16</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[杜文轩,苗应刚,殷建平]]></author>
</item>
<item>
<title><![CDATA[Current status and trend of dynamic atomization characteristics of swirl injector under oscillating environment in liquid rocket]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105140000001]]></link>
<description><![CDATA[In order to master the atomization characteristics of oscillating spray and its relationship with unstable combustion,   research and development of gas-liquid coaxial swirl injectors and liquid-liquid coaxial swirl injectors, which are widely used in liquid rocket engines, are reviewed from three aspects of excited oscillation, self-pulsation, and interactions of spray oscillation with combustion stability, so as to deepen our understanding of them. According to the review, for the excited oscillation, the research on the upstream pressure oscillation caused by flow oscillation of supply system under normal temperature and pressure conditions is relatively sufficient. However, the research on the backpressure oscillation caused by pressure oscillation in the combustion chamber and the research on the excited oscillation of spray under supercritical conditions are lack. For the self-pulsation, the current research is focused on the liquid-centered coaxial swirl injectors. There are few studies on the gas-centered coaxial swirl injectors and liquid-liquid coaxial swirl injectors. The optical diagnosis technology is far from enough to extract the single combustion flow field information.]]></description>
<pubDate>2023/5/17 17:32:41</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[姜传金,,,,]]></author>
</item>
<item>
<title><![CDATA[Line Spectrum Unsteady Thrust Prediction and Test Verification of the of Pump Jet]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109090000002]]></link>
<description><![CDATA[In order to predict the unsteady thrust of the interaction line spectrum of the pump-jet propeller rotor and the periodic leading vane wake, ignore the thickness of the pump-jet propeller rotor blades, and simplify the pump-jet rotor into an annular cascade. According to the "sheet theory", the radius is The segment of the pump jet rotor is intercepted at r, and the change of the flow field parameters along the segment radial is ignored, so that the annular cascade segment can be regarded as a plane cascade, which is the basis of the interaction response function of the harmonic and the plane In the above, considering the periodic leading vane and wake inflow, the unsteady thrust prediction formula of the line spectrum of the pump-jet propeller is deduced, and the formula is verified by comparison with experimental and numerical results. Finally, the influence of changes in flow field parameters on the unsteady thrust of the propeller rotor line spectrum is analyzed. The research obtained, the ratio of the leading vane-rotor spacing to the chord length of the leading vane, the result is similar to the result of the trailing vane. When the ratio of the current guide vane-rotor distance to the chord length of the front guide vane is greater than 1, the rotor-rear guide vane distance has almost no effect on the line spectrum thrust of the rear guide vane.]]></description>
<pubDate>2023/3/31 8:23:39</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[程功,何升阳,靳栓宝,王东,魏应三,武星宇,翟硕]]></author>
</item>
<item>
<title><![CDATA[Residual connection image restoration based on parallel generation convolution]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106290000001]]></link>
<description><![CDATA[In order to solve the defects of edge artifacts and semantic discontinuity when large and irregular areas are missing in images with complex background and fine texture, a residual connection image restoration algorithm based on parallel generation convolution was proposed. Firstly, the damaged image was inputted into a two-column parallel convolutional coarse inpainting network to obtain two image components with different sizes of reception fields. The two image components were combined by the shared decoding and the L1 loss of the output was calculated to optimize the network. Subsequently, the output of the coarse network was sent into the fine inpainting network which contained the residual connection and the attention mechanism to improve the ability of repairing fine details. Finally, the global and local discriminators and VGG19 were used to calculate the loss and to enhance the global and local consistency of the inpainted result. Experimental results show that the proposed algorithm can effectively repair large and irregular missing areas under complex background and fine texture, improve the authenticity and integrity of image details, semantics and structure. Its peak signal-to-noise ratio and structural similarity are superior than the state of the arts.]]></description>
<pubDate>2023/3/30 18:11:03</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[晁艳静,郭磊,李海江,李海燕,李红松]]></author>
</item>
<item>
<title><![CDATA[Flow field structures and mode decomposition analysis of impinging dual synthetic jets]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107280000002]]></link>
<description><![CDATA[Dual synthetic jet impingement cooling is a compact and efficient cooling technology with the characteristics of simple structure, small volume, low energy-consumption and rich vortex structure. Large eddy simulation method was used to numerically study the flow field characteristics of impinging dual synthetic jets. The Lagrangian coherent structure of the flow field was identified based on finite-time lyapunov exponents , and the results are compared with the vorticity results in the Euler frame. It was found that vortex structure of the jet core area of dual synthetic jets was exceeding complex and rich under the alternating action of periodical jets, and there was a pair of stable vortex structure far away from the core. Lagrangian coherent structures were well corresponding to the vorticity. Proper orthogonal decomposition analysis wa performed on the flow field of dual synthetic jets. The results showed that the first-order mode was approximately symmetrical about the central axis of the exit of the actuator, and its energy accounted for 35% of the total energy, and the first 6 modes accounted for 80%. According to the characteristics of the flow field reflected by the first 6 modes, the flow field of dual synthetic jets impinging plate had a high degree of symmetry.]]></description>
<pubDate>2023/3/30 18:09:54</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[程盼,邓  雄,刘  强,罗振兵,王秋旺]]></author>
</item>
<item>
<title><![CDATA[Video behavior recognition network using multi time-scale convolution]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106010000002]]></link>
<description><![CDATA[The behavior recognition network based on 2D convolutional usually integrates classification results of multiple video frames to recognize different behaviors, but it can’t extract space-time feature using the 2D convolution kernels. To solve this problem, multi time-scale convolution (MTSC) was proposed based on TSM, which contains convolution kernels of different scales to fuse the space-time feature from different time scales. By controlling the position that inserting MTSC into ResNet50 network and the parameter setting of MTSC, the optimal behavior recognition network based on MTSC was discussed in this article Through training network with PyTorch and carrying out experiments on Something-Something v2 data set, the behavior recognition network based on MTSC achieves 59.47% Top-1 accuracy, and outperform TSM and other behavior recognition networks.]]></description>
<pubDate>2023/3/30 12:59:15</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈西江,,梁全恩]]></author>
</item>
<item>
<title><![CDATA[Motor bearing fault diagnosis by combining vibration feature optimization and GWOA-XGBoost]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107290000003]]></link>
<description><![CDATA[In order to solve the problem that it is difficult to identify the fault state of motor bearings, which results in low diagnosis accuracy, a motor bearing fault diagnosis model was proposed based on signal feature extraction and Extreme Gradient Boosting algorithm (XGBoost). First, the optimized variational mode decomposition (VMD) is used to obtain the IMF components of the vibration signal, and then the MSE value of each IMF component is calculated based on the multi-scale entropy theory for feature reconstruction. Secondly, the whale optimization algorithm (WOA) is improved by introducing the selection, crossover and mutation operation of genetic algorithm (GA). Finally, the improved WOA algorithm is used to optimize the hyperparameters of XGBoost, and obtain the hyperparameter combination that helps XGboost achieve the best classification effect. The vibration signals of 7 different types of faults are reconstructed and input into the optimized XGBoost model for fault diagnosis. Experimental results show that the motor bearing fault diagnosis accuracy of the proposed model can reach 97.1%, which significantly improves the performance compared with the traditional diagnosis method.]]></description>
<pubDate>2023/3/30 12:57:26</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[樊清川,,于飞]]></author>
</item>
<item>
<title><![CDATA[Electrical power system important node evaluation algorithm inspired by internet thinking]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109010000001]]></link>
<description><![CDATA[Effective identification of important nodes in power system effectively was helpful to improve robustness of system and reduce the probability of accidents by applying additional protection or changing the topology of important nodes under limited resources. Inspired by the Web page sorting algorithm, we proposed an algorithm called E-SALSA (electrical stochastic approach for link structure analysis) for evaluating important nodes in power system. Taking into account the influence of power system topology, power flow and other factors on nodes, this algorithm could effectively reflect the true situation of power system, and its features were more in line with the background of power system. In the IEEE300 node power system, we compared E-SALSA algorithm with the electrical median algorithm and the MBCC-HITS (model based on cocitation hypertext induced topic search) algorithm by using the two indexes of the scale of load loss and the maximum subgroup size. The results show that E-SALSA algorithm has advantages over electrical betweenness algorithm in both indicators. Compared with MBCC-HITS algorithm, E-SALSA algorithm can use all factors more comprehensively on the impact of nodes, which further proves its rationality and effectiveness.]]></description>
<pubDate>2023/3/30 12:56:56</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[方粮,耿俊琪,曲延滨,宋蕙慧,孙贤明,许诺]]></author>
</item>
<item>
<title><![CDATA[Design of extended mission to fly by multi small celestial bodies using the lunar probe]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106280000003]]></link>
<description><![CDATA[For a full utilization of the probe after the lunar exploration, the extended mission using the probe for flybys of small celestial bodies was considered from the Moon or Earth orbit. Combined with the flight status of the probe after the lunar exploration mission, the energy requirement for escaping from the Moon or the Earth was analyzed, together with other necessary conditions for the flyby mission, such as the brightness of small bodies, the capacity of onboard equipment, etc. The methods of selecting small bodies and trajectory design were studied. Aiming at the problems of large number of targets and consequently large amount of computation and hard optimization of target sequences, the algorithm of multi-layer optimal selection of small bodies was designed. The extended mission of flyby of small celestial bodies was proposed for the Chang’e-5 orbiter. The result shows that the orbiter can approach up to five asteroids under given constraints, including the large Asteroid 12923. This study can be used for the Chang’e-5 extended mission, and provide beneficial reference for the future missions of Moon and small celestial bodies.]]></description>
<pubDate>2023/3/30 12:55:02</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈明,刘磊,张尧]]></author>
</item>
<item>
<title><![CDATA[Optimization of voltage zero crossing switching strategy for 5L-ANPC inverter considering absorption circuit]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106080000001]]></link>
<description><![CDATA[The topology of five-level active-neutral-point-clamped(5L-ANPC) converter has a simple structure, which can be directly supplied by the common DC bus, and is easy to realize energy feedback. It is very suitable for the 5-10kV propulsion variable frequency speed regulation in the integrated power system of ship. The topology and basic working principle of 5L-ANPC were briefly introduced. Based on the analysis of four commutation circuits of 5L-ANPC topology and considering the assembly and adaptability of the snubber circuit, a single capacitor integrated snubber circuit was designed. The over-voltage problem of internal switch in 5L-ANPC topology with absorption circuit using traditional voltage zero crossing strategy was analyzed and an improved output voltage zero crossing switching strategy was proposed，which ensure the safety of switching device and avoid the abnormal voltage jump. The effectiveness and correctness of the improved strategy are verified by simulation and experiment.]]></description>
<pubDate>2023/3/30 8:59:09</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[蒋林飞,肖飞]]></author>
</item>
<item>
<title><![CDATA[Review of the detection and removal methods of raindrops attached to the lens surface]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107100000001]]></link>
<description><![CDATA[Visual system is an important part of autonomous unmanned system. The raindrops attached to the surface of the camera lens will produce artifacts in the image, resulting in the degradation of image quality, which will significantly affect the performance of the visual system. The detection and removal methods of attached raindrops in recent years were comprehensively and deeply researched. The essence of the problem was condensed, and the existing raindrop imaging models were summarized. Different technical methods were sorted out from three directions: model-based, data-driven and camera system-based, then the development of deep network model was summarized from two aspects of network architecture and loss function. The existing datasets of attached raindrops were summarized, and the performance of some algorithms was compared through the experimental results. The main problems in the task of raindrop detection and removal were discussed, and the possible development direction in this field was prospected.]]></description>
<pubDate>2023/3/30 8:57:55</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[欧阳斌,,]]></author>
</item>
<item>
<title><![CDATA[Influence of third harmonic of air gap flux density on motor vibration and noise]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107010000002]]></link>
<description><![CDATA[Aiming at the problem of electromagnetic vibration and noise of motor, it is found that improving the sinusoidal characteristic of air gap flux density does not necessarily reduce the vibration and noise of motor. In view of this, the order and frequency of the main force wave causing the vibration and noise of the motor are analyzed, and the specific functional relationship between the third harmonic of air gap flux density and the vibration and noise of the motor is explored. In order to analyze the order and frequency of the main force wave which causes the vibration and noise of the motor, the force wave table is eliminated based on the analytical method, and the main noise source is determined. In order to explore the influence of the third harmonic of air gap flux density on motor vibration and noise, the mathematical models of air gap flux density and radial force wave are established, and the optimal amplitude of the third harmonic of air gap flux density is solved by genetic algorithm. The analysis results show that improving the sinusoidal air gap flux density does not necessarily reduce the vibration noise of the motor, and the third harmonic of air gap flux density has an optimal value in a certain range to minimize the vibration noise of the motor. The analysis results provide a reference for the design of low noise motor.]]></description>
<pubDate>2023/3/30 8:50:06</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[卢希浩,乔鸣忠,张弛]]></author>
</item>
<item>
<title><![CDATA[The false alarm interference laws of dual frequency electromagnetic radiation in band to stepped frequency continuous wave radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106060000001]]></link>
<description><![CDATA[In order to master the false alarm laws of dual frequency electromagnetic radiation in band to radar, the stepped frequency continuous wave radar was taken as the research object, based on the theoretical analysis and effect test, the level change law, waveform characteristics and location law of false alarm target were studied. The results show that: under the effect of dual frequency electromagnetic radiation in the band, the tested radar can generate at most two "hill type" false alarm targets with random positions without considering intermodulation interference, and the distance difference is related to the frequency difference of dual frequency interference. The two components of the dual frequency interference signal suppress each other, that is, if the intensity of one component is constant, with the enhancement of another component, the level of the false alarm target formed by the former decreases slowly and the final deceleration is basically constant, while the level of the false alarm target formed by the latter increases gradually until the level is constant. If the strength of the two components of the dual frequency interference signal increases in the same proportion, the levels of both two false alarm targets rise approximately linearly at the initial stage, and then the growth rate gradually decreases to zero.]]></description>
<pubDate>2023/3/30 8:14:05</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[崔燕舞,魏光辉,赵凯]]></author>
</item>
<item>
<title><![CDATA[Multi-subband radar signal fusion noise suppression method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106240000001]]></link>
<description><![CDATA[All-pole model constructs a linear model of the signal, and various parameters of the estimated signal can be obtained through the order and calculation of the model, so as to realize signal prediction. Before sub-band fusion, coherence processing is required, which can be solved by means of coherence function and so on. Since root-MUSIC algorithm is not robust in pole selection in a low signal- noise ratio(SNR) environment, it will cause the model to judge the order incorrectly. Method for estimating characteristics of ultra-wideband radar from multi-subband radar signal based on the all-pole model proposed by Cuomo et al. has a low signal-to-noise ratio, a multi-subband all-pole model fusion method based on noise suppression is proposed. Weighting the main diagonal singular value matrix of the signal Hankel matrix to eliminate noise components. It is proposed to use the overall forward prediction matrix to obtain the pole value and the pole amplitude of the Multi-subband fusion signal. From this estimate the multi-subband fusion signal at low signal-to-noise ratio. The results show that the proposed method has better estimation results than the traditional pole-model scheme when the signal-noise ratio is -20dB to 10dB in simulation environment.]]></description>
<pubDate>2023/3/30 8:13:17</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[蒋伊琳,陆满君,唐三强,张莉婷]]></author>
</item>
<item>
<title><![CDATA[Design of ultra-wideband energy selective surface for protection of high intensity EM fields]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106200000001]]></link>
<description><![CDATA[In order to deal with the threat of strong electromagnetic pulses to electronic information systems, an ultra-wideband strong energy selection surface (ESS) with transceiver compatibility has been designed, effectively expanding the operating bandwidth and frequency of the ESS, and can provide no less than 14 dB protection effect in L/S/C-band. The ESS is a periodic structure, with each unit containing a pair of arrow-shaped structures and a switching diode. It can adaptively switch the reflection/transmission state according to the energy density of external irradiated electromagnetic waves, thereby achieving strong electromagnetic protection and compatibility with working signal transmission and reception. Simulation research shows that the insertion loss of this new ESS in the L/S/C band is less than 1 dB, and its protection effectiveness reaches 22 dB. Finally, the performance of the designed sample was verified in the waveguide. The results show that the average insertion loss of the sample in the waveguide is 1 dB, and the protection effectiveness reaches 14 dB, which preliminarily verifies the low insertion loss and high protection effectiveness of the designed structure.]]></description>
<pubDate>2023/3/30 8:13:17</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[刘培国,,]]></author>
</item>
<item>
<title><![CDATA[Model Agnostic Federated Mutual Learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106300000001]]></link>
<description><![CDATA[The mainstream Federated Learning methods require gradient interaction and the ideal assumption of the independently identically distribution, which brings additional communication overhead, privacy leakage, and data inefficiency. We proposed a new FL framework called Model Agnostic Federated Mutual Learning (MAFML). MAFML only used a small amount of low-dimensional information (for example, the soft labels output of the neural network in the image classification task) for sharing to achieve cross-participants "mutual learning and mutual education". Moreover, MAFML did not need a shared global model. Users could customize their own private models without restricting the model structure and parameters. At the same time, MAFML used a general approach for avoiding gradient interference so that each participant's model could be well generalized to other domains without reducing the performance of its own domain data. Experiments on multiple cross-domain datasets show that MAFML can provide a promising solution for alliance business facing the "competition and cooperation" dilemma.]]></description>
<pubDate>2023/3/30 8:12:34</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈曙晖,丁博,李艺颖,周伟]]></author>
</item>
<item>
<title><![CDATA[Research and Verification of Numerical Calculation Method for Submarine's Floating Movement]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106300000003]]></link>
<description><![CDATA[摘  要：预报潜艇上浮运动是探索研究潜艇上浮运动控制规律以及潜艇安全上浮的前提，本文详细介绍了潜艇上浮运动的数值计算方法和计算流程，对数值计算方法中的湍流模型及离散格式等进行了优选，并基于模型上浮试验结果，对数值计算的不确定度进行了分析和对数值计算结果进行了验证，证明了该数值计算的可靠性，并发现数值计算结果与试验结果具有较好的吻合度，从而验证了该数值计算方法的可行性和准确性，该数值计算方法和试验可为潜艇上浮运动的研究提供参考和借鉴。]]></description>
<pubDate>2023/3/30 8:12:34</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[魏可可]]></author>
</item>
<item>
<title><![CDATA[Reliability analysis for a k-out-of-n system with one repairman having variant vacations]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107010000001]]></link>
<description><![CDATA[Aiming at the impact of maintenance scheduling on equipment training and reliability in equipment support, the maintenance work of multiple ships supported by the detachment-level repair station is abstracted into a single maintenance station to support the dispatching and distribution of maintenance forces for multiple systems, the variable vacation strategy of repairman is introduced to describe it. Take the common n out of k system in the equipment structure as the research object, aiming at the problem of excessively strict model constraints caused by typical distributions such as exponential distributions in previous studies, continuous Phase type (PH) distribution is used to describe the system-dependent random variables and build system reliability analysis model.Finally, the model applicability is verified using numerical application, and it is analyzed the influences of whether the repairman is on vacation, the changes of system components numbers, and the effect of repairman vacation rate and maintenance rate on system reliability. Numerical example results show that the reliability model can be effective retrieval the influence of maintenance forces scheduling on the reliability of k-out-of-n system, it can provide theoretical basis and practical reference for the reasonable arrangement of the number of repairman vacation and the optimal configuration of the number of system components.]]></description>
<pubDate>2023/3/30 8:11:19</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[黄晓颖,吴晶,]]></author>
</item>
<item>
<title><![CDATA[Research on Key Parameters in Engineering Design of Anode Gas Supply Ring of Low Power Hall Thruster]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107060000002]]></link>
<description><![CDATA[In order to improve the uniformity of the neutral atom distribution in the discharge channel of the low-power Hall thruster, the finite element method is used to optimize the key structural parameters of the anode gas supply ring. Aiming at the current mainstream dual-chamber anode gas supply ring structure, the influence of key parameters such as the number of diversion holes in the upper and lower buffer chambers and the volume ratio of the upper and lower buffer chambers on the uniformity of anode gas outlet is analyzed. The research results show that the difference rate of the mass flow rate of the vent holes and the number of diversion holes between the partitions show the characteristics of a bathtub curve. The number of diversion holes is in the range of 10-12, and the gas outflow from the vent holes has good uniformity. The maximum difference rate is better than 0.8%; as the volume ratio of the upper and lower buffer chambers increases, the maximum deviation rate and the average deviation rate of the anode gas supply ring outlets both decrease first and then increase, and the maximum is when the volume rate k=1 The deviation rate is only 0.48%. At this time, the anode gas supply ring has the best circumferential uniformity. The research results of this paper can provide theoretical support for the engineering design of the anode gas supply ring of the Hall thruster.?]]></description>
<pubDate>2023/3/30 8:11:13</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[龙建飞,罗威]]></author>
</item>
<item>
<title><![CDATA[Experimental analysis on early stage frosting characteristics of Ni-based GH3536 superalloy plate]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201110000001]]></link>
<description><![CDATA[Ni-based GH3536 superalloy smooth plate and micro-holed plate with a hydrophobic surface were used as test samples, and the early stage frosting characteristics of the surface were studied. The impact of surface temperature, relative humidity, and surface wettability on crystal shape and growth rate were investigated quantitatively. The results indicate that with the decrease of the surface temperature, the initial time of crystal formation is shortened, the growth rate of crystal is enlarged, and four types of crystal shapes are captured. The increase of relative humidity can increase the number of crystals and enhance the crystal growth slightly, while the condensation and freezing time of droplets are independent of it. When the variation of relative humidity changes the crystal shape, a significant difference is found in crystal height and growth rate. The hydrophobic surface made of micro-holes structures can evidently delay the formation of the crystal. However, the impacts on crystal growth and shape are negligible.]]></description>
<pubDate>2023/3/30 8:09:00</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[柳军,汪  元,袁雪强,岳晓菲,张  多]]></author>
</item>
<item>
<title><![CDATA[Characteristics of Corrosion Electric Field Model and Analysis of the Genesis of Singular Peaks in Submarine Propeller Area]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106080000002]]></link>
<description><![CDATA[Aiming at the problem that the boundary conditions affect the characteristics of the electric field signal by the boundary element method and result in the phenomenon of singular peaks in the propeller area,  the polarization curves of 921 alloy steel and nickel bronze propeller materials were used as the modeling boundary conditions, and the electric field characteristics under constant potential and nonlinear boundary conditions were analyzed. By establishing the equivalent circuit of hull propeller electrochemical impedance under the parameters of impedance spectrum, the reason of the singular peak in the propeller area of submarine corrosion electric field was analyzed. The simulation results show that the characteristic distribution of submarine electric field and the phenomenon of singular peak in propeller area are related to the electrochemical polarization state of submarine material, and setting the nonlinear polarization boundary parameters reasonably can achieve the effect of weakening the singular peaks and smoothing the corrosion of the electric field model.]]></description>
<pubDate>2023/3/30 8:05:26</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[何芳,王向军,王晓蓓]]></author>
</item>
<item>
<title><![CDATA[Calculation of ground proximity warning envelopebased on flight simulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109050000001]]></link>
<description><![CDATA[The ground proximity warning envelope in TSO-C151b standard is a general model design without considering the characteristics of the aircraft. In order to accurately give the warning envelope of excessive descent rate of a certain aircraft, the alarm mechanism was analyzed by combining the aerodynamic characteristics and control characteristics of the aircraft, and a six degree of freedom simulation program was established. Based on the aircraft engine data, aerodynamic data and quality characteristics data, simulation models and operation procedures were established to simulate the operation response process of each rudder surface, as well as the motion attitude and flight path of the aircraft in real time. The loss height pulled up by the aircraft at different descent rates was calculated, and the ground proximity warning envelope was designed. Combined with the actual flight test data, the model design is reasonable and the calculation results are accurate. The alarm envelope obtained by simulation is compared with TSO-C151b, and the suggestions for the use of the ground proximity warning envelope are given to ensure the flight safety of the aircraft.]]></description>
<pubDate>2023/3/30 8:05:12</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李泽华,刘琛,魏涛,郑峰敏]]></author>
</item>
<item>
<title><![CDATA[Research progress of energy and actuator for micro-soft robots]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202207200000003]]></link>
<description><![CDATA[Deeply integrated by smart materials and electromechanical control technologies, micro-sSoft robots  have a wide range of application prospects in complex environments such as pipeline maintenance and battle field reconnaissance due to their high compliance,  low energy consumption and high-energy density. As the key factors of micro-soft robot, energy and actuator play a decisive role in their motion modes and performances. In order to make more researchers understand the research progresses of the existing flexible driving technology and their energy sources, the typical driving methods based on physical energy driving, chemical energy driving and biological hybrid driving were summarized and analyzed. The shortcomings and future development of the existing flexible driving technology and thire energy sources were discussed and summarized, which can provide reference for the development and improving performance of the flexible drive technology of soft robots in the future.]]></description>
<pubDate>2023/3/30 7:58:14</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[洪  阳,蒋涛,林泽宁,罗自荣,尚建忠,杨  云]]></author>
</item>
<item>
<title><![CDATA[Analysis of the influence of rocket exit area in the RBCC engine under the ejector mode]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302130000006]]></link>
<description><![CDATA[Abstract: In order to improve the performance of the rocket-based combined-cycle engine, the influence of the rocket exit area under the ejector mode is studied. Through numerical simulation research, the mass flow of captured air is mainly affected by the entrainment performance under the condition of low flight Mach number. The larger the rocket exit area, the better the entrainment performance. However, with the increase of flight Mach number, the kinetic energy of the entrainment air increases, and there is flow choking in the isolator. The mass flow of captured air is mainly limited by the geometric size of the isolator, independent of the rocket exit area. Under subsonic conditions, the smaller the rocket exit area is, the lower the specific impulse of the engine is, and when the exit area is 3.15, the rocket plume will expand and impact the wall, which could cause a sudden reduction in performance. Under supersonic conditions, the smaller the rocket exit area, the higher pressure in the combustor, and the better performance of the rocket-based combined-cycle engine.]]></description>
<pubDate>2023/3/20 14:45:49</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安彬,陈纪凯,顾瑞,黄玉辉,李梦磊,李佩波,孙明波,王教儒,王泰宇,姚轶智]]></author>
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<title><![CDATA[Research on the evaluation model of third-party service organization of equipment price based on gray correlation and neural network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202302140000002]]></link>
<description><![CDATA[Abstract: In order to scientifically and reasonably select the third-party service organizations of equipment price, the evaluation model was constructed by gray correlation analysis and neural network. The research data was obtained in the form of a questionnaire survey. The gray correlation method was used to analyze the correlation between the evaluation index and the comprehensive score. It was found that the two primary evaluation indicators of service attitude and system construction were more important, with a correlation degree of more than 0.74. Using effective secondary indicators and comprehensive scores as input and output data, the evaluation model based on a neural network was built. Finally, through the verification and analysis of the rationality of the method, it is found that the prediction accuracy probability of the discovery neural network model is 75%, and the probability of meeting the requirements is 25%, which meets the actual user needs and can provide suggestions for the competent departments to select third-party institutions.]]></description>
<pubDate>2023/3/20 11:00:52</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[孙胜祥,杨黎峰,]]></author>
</item>
<item>
<title><![CDATA[Regional coverage satellite constellation optimization algorithm fused with genetic ant colony algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104070000001]]></link>
<description><![CDATA[In order to optimize the design of satellite constellations with specific area coverage and intensive revisits, a design scheme of regression orbit and co-substellite point trajectory constellation was adopted, and a method to optimally solve the satellite constellation orbit parameters by integrating genetic ant colony algorithm with the weight ranking coverage of key areas in specific area was proposed. The design requirements of the regional coverage constellation were analyzed, a regression orbit coverage area model was established, the optimal orbit root number was calculated using the genetic ant colony algorithm, and all the constellation parameters were solved using the co-substellite point trajectory constellation solution algorithm. The simulation results show that the optimized constellation meets the coverage time and revisit frequency requirements for the area target, and provides focused coverage and revisits of important locations in order of weight, which verifies the feasibility of the algorithm.]]></description>
<pubDate>2023/2/2 17:07:48</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈志明,华冰,王培源,吴云华]]></author>
</item>
<item>
<title><![CDATA[Hardware-accelerated Consistent Computing Structure for Signal Processing and Deep Learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104080000001]]></link>
<description><![CDATA[In the edge devices and mobile terminals, the traditional signal processing and deep learning tasks must be supported simultaneously in order to implement end-to-end processing, a variety of typical signal processing algorithms and deep learning algorithms are analyzed and modularized from the calculation requirements level. Then the common modules, which is suitable for hardware acceleration parallelly in the two types of applications are extracted. A consistent computing model for signal processing and deep learning is proposed, and then a hierarchical processing element and arrayed processing structure are proposed based on the consistent computing model in which the control part and computation part are separated. By the software definition of different application computing processe, the consistent hardware-accelerated computation of signal processing and deep learning can be realized flexibly. Finally, based on Zynq computing platform, the consistency computing model and computing structure were verified from two aspects of reconstruction efficiency and computing performance, and the validation results indicate that software-defined reconfigurable computing structures based on consistency computing models have high computational performance and reconstruction efficiency.]]></description>
<pubDate>2023/2/2 17:07:18</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[高彦钊,陶常勇]]></author>
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<item>
<title><![CDATA[Evaluation and Analysis of Concolic Execution Optimizations in Hybrid Fuzzing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104090000001]]></link>
<description><![CDATA[Traditional hybrid fuzzing research focuses more on enhancing the fuzzing part by static and dynamic analysis, however, neglects the performance problem of concolic execution itself. Based on the balance-point mode proposed in this paper, we analyze the popular concolic execution tools firstly, including taint-assist fuzzing, hybrid fuzzing, and concolic execution, and induce 6 optimization patterns. Then we implement 6 optimization patterns on concolic execution, using platform Triton, and perform experiments on 10 real-world software applications. The optimization techniques are evaluated by three metrics, including efficiency, memory consumption, and coverage. Experiment results show that all of the optimization patterns can basically reduce the unnecessary constraints. However, the reduction of constraints can cause information loss and lead to coverage decrease. Finally, according to the experiment results, a performance sequence of 6 optimization patterns is proposed as a reference to method selection in the application field.]]></description>
<pubDate>2023/2/2 17:06:44</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陶静,,]]></author>
</item>
<item>
<title><![CDATA[Design and implementation of high speed parallel Gardner algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104100000001]]></link>
<description><![CDATA[With the gradual increase of space exploration tasks and the increasing tension of space channel spectrum resources, the traditional Gardner timing synchronization algorithm can no longer meet the demand of high throughput and high reliability of high-speed data transmission system. In order to improve the throughput and correctable error range of Gardner timing synchronization algorithm, a high-speed parallel Gardner algorithm is proposed. To ensure the interpolation accuracy and reduce the multiplier consumption, a parallel piecewise parabolic interpolation filter is designed; to facilitate the parallel pipeline design and optimal sampling point selection, a counting module and a timing cache adjustment module are built; to improve the equivalent throughput rate, the pipelined parallel loop filter structure and the pipelined parallel numerically controlled oscillator (NCO) structure are reconstructed. The results show that the equivalent throughput rate of the algorithm can reach 1739.13Msps (Million sample per second), the Digital Signal Processor (DSP) resource consumption can be reduced by 44%, and the timing error of 2000ppm (parts per million) can be corrected.]]></description>
<pubDate>2023/2/2 17:06:09</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈轩,胡婉如,梅如如,王竹刚,张颖]]></author>
</item>
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<title><![CDATA[Research on characteristics of air-to-air wireless channel in sea scenario]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105110000002]]></link>
<description><![CDATA[For the remote communication scenario of UAV at sea, the received power is measured based on the wireless communication link between UAVs. In terms of large-scale path loss, the logarithmic distance linear model is used to fit the measurement data. The characteristics of remote air-to-air wireless channel at sea are analyzed, and the path loss index is obtained. The ray tracing method is used to simulate and verify the measurement results. Through the simulation of channel impulse response, the reasons for the rapid change of received power are analyzed in terms of multipath delay and power. Three kinds of distribution functions are used to fit the measured data, and the small-scale distribution characteristics of air-to-air wireless channel under sea surface and inshore communication conditions are analyzed.]]></description>
<pubDate>2023/2/2 17:05:31</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[董宇良,黄英,雷菁,李为]]></author>
</item>
<item>
<title><![CDATA[Prescribed performance control for hypersonic vehicle based on constrained command filter]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105120000001]]></link>
<description><![CDATA[For the tracking performance problem of hypersonic vehicle with actuator constraints of amplitude and rate. A prescribed performance control scheme based on constrained command filter is proposed. In order to improve the transient and steady state performance of the system, a prescribed performance backstepping controller is designed. And a new performance function is designed to reduce the tracking error overshot. Then, a command filter is introduced to solve the problem of difficult derivation in the design of backstepping controller. For the problem of limited input, a constrained command filter is constructed to constrain the control law of the system, which guarantees that the control input meet the limit requirements of amplitude and rate, and the corresponding theoretical proof is carried out. In addition, the linear extended state observer (LESO) is used to observe and compensate the system parameter uncertainties and external disturbances. Based on Lyapunov stability theory, it is proved that all tracking errors of the system are ultimately uniformly bounded. Finally, the effectiveness of the proposed method is verified by simulation.]]></description>
<pubDate>2023/2/2 17:04:38</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[方登建,李海燕,李静,韦俊宝]]></author>
</item>
<item>
<title><![CDATA[A Spectrum Map Construction Method by Using Monitoring Data and Its Verification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105210000001]]></link>
<description><![CDATA[Spectrum map can be used to quantitatively describe and visually present electromagnetic environment information from multiple dimensions including time, space, frequency and energy, which is the basis of cognition and utilization of electromagnetic space. In this paper, a spectrum map construction method based on general regression neural network fitting and clustering Kriging is proposed, in which the path-loss and shadowing components are estimated by general regression nerual network for trend-surface fitting to improve the construction accuracy. Moreover, in order to improve construction efficiency and guarantee the accuracy meanwhile, monitoring data clustering and optimal neighborhood selection are utilized to reduce the amount of calculated data. The proposed method can realize the accurate and fast construction without prior information by only using limited amount electromagnetic environment monitoring data. A spectrum map prototype verification system is designed and implemented, real measured data from vehicle-based collection system is utilized for testification of the feasibility and performance of the proposed method.]]></description>
<pubDate>2023/2/2 17:04:08</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[查淞,黄纪军,李冰,刘继斌,马晨,夏海洋]]></author>
</item>
<item>
<title><![CDATA[The ballistic performance of double-arrow  negative Poisson"s ratio structure]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105270000001]]></link>
<description><![CDATA[The penetration performance of the double-arrow negative Poisson’s ratio multicellular structure against bullet penetration is studied by numerical simulation method.The penetration behaviors of bullets and the damage forms of the double-arrow negative Poisson"s ratio structure under the three bullet target conditions of top-edge impact,hinge-point impact and side-impact were compared and analyzed.The results show that the negative Poisson"s ratio effect of the double-arrow negative Poisson"s ratio structure is not significant when the bullet impacts the structure at a high velocity;the bullet directly penetrates the structure at topside impact and hinge point impact,the damage of the cell element is small and the anti-intrusion performance of the double-arrow negative Poisson"s ratio multi-cell structure is poor at this time;the bullet does not penetrate the multi-cell structure at side impact,and the damage of the cell element is large;the double-arrow negative Poisson"s ratio structure relies on its double-Poisson"s ratio structure to deflect the bullet at side impact.The double-arrow negative Poisson"s ratio structure relies on its double triangular structure to deflect and roll the bullet during side impact,which significantly increases its penetration resistance.Finally, the effect of the change in the angle of incidence of the bullet during topside impact on the intrusion resistance of the double-arrow negative Poisson"s ratio structure is analyzed,it is found that there is a 30° angle of incidence and a 60° angle of incidence.The double-arrow negative Poisson"s ratio multi-cell structure has some resistance to penetration when the bullet is near these two incidence angles.]]></description>
<pubDate>2023/2/2 17:03:24</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[刘洋佐,马大为,任杰,赵昌方,仲健林]]></author>
</item>
<item>
<title><![CDATA[Modified Sage-Husa Adaptive Filter Based Three-Dimensional Localization for Moving Target Using Two UAVs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105310000001]]></link>
<description><![CDATA[A three-dimensional intersection localization method for moving target using two vision-based UAVs, which does not rely on the distance information from the target point to the UAV, was proposed in this paper. An interacting multiple model (IMM) estimator was adopted to the localization method to solve the problem of not knowing the motion form of the target. A modified Sage-Husa adaptive filtering algorithm that synthesized the covariance matching technique and the positive definiteness judgment was used to improve the accuracy of localization. To assess the performance of these approaches, a set of simulations that carried out under realistic conditions were presented. Results show that the method proposed in this paper can get the accurate three-dimensional coordinates of the target. The modified Sage-Husa adaptive filtering algorithm can improve the localization accuracy significantly, with the average estimation error reduced from 27.1m to 14.6m under the intersection angle of 90°. The influence of the intersection angle on localization was studied in the simulation, which shows that too small intersection angle is not conductive to the improvement of localization accuracy, a larger intersection angle is good for the localization method without filtering, but the effect on the method with the modified Sage-Husa adaptive filtering algorithm is not significant.]]></description>
<pubDate>2023/2/2 17:02:54</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭正,侯中喜,鲁亚飞,吴岸平]]></author>
</item>
<item>
<title><![CDATA[Experimental study of multi-point injection air/ethanol gas generator]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106160000004]]></link>
<description><![CDATA[In order to effectively solve the shortcomings of the existing gas ejection source, as well as meet the needs of large mass flowrate and miniaturization of an injection system, a gas generator with multi-point injection structure using air and alcohol as propellants was developed based on the comprehensive analysis of various gas injection source schemes, and the experimental research under various working conditions was carried out. Research results show as bellows: the multi-point injection scheme greatly improves the space utilization rate, which effectively meets the miniaturization requirements of ejection system. Spray performance is good, and the spray cone angle and particle diameter are superior to the index requirements. Ignition reliability is high, which solves the shortcomings of low ignition reliability of the existing gas generator in the field. The operation curve indicates a rapid ignition, stable combustion and uniform temperature field of gas generator. The excess air coefficient range for stable operation is 2.52～4.34, showing a wide mass flow-rate range. In addition, efficient film cooling on the combustion liner inner wall effectively ensures the long time operation of the gas generator.]]></description>
<pubDate>2023/2/2 16:58:51</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[赵芳]]></author>
</item>
<item>
<title><![CDATA[A survey on key technologies of UAV advanced ground stations]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204250000001]]></link>
<description><![CDATA[The novel UAV (unmanned aerial vehicle) ground station with advanced control capabilities such as immersive display, intelligent assistance, and naturalized human-computer interaction has become a hot research topic in the field of UAV control.  To analyze the technical aspects, the functional points and designs concepts of a series of advanced ground stations for UAVs at home and abroad were systematically compared.   The technical system composition from the OODA (observe, orient, decide and act) loop of UAV ground station command and control were summarized and refined.   The key techniques such as task environment construction, battlefield situation immersive display, intelligent assisted decision and naturalized human-computer interaction were analyzed and pointed out.  The main research methods of various techniques were deeply analyzed.  The current challenges and future development trends of UAV advanced ground stations were also studied and judged.  In addition, it provides guidance and reference for the development of novel ground stations.]]></description>
<pubDate>2023/2/2 16:58:02</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[牛轶峰,谭 沁,唐邓清,王 菖,相晓嘉,周 晗]]></author>
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<item>
<title><![CDATA[Review of visual-inertial navigation system initialization method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202211010000002]]></link>
<description><![CDATA[Visual-inertial navigation systems (VINS) solves a series of parameters required for state estimation through initialization at the initial stage of the system, such as scale, gravity vector, velocity, inertial measurement unit’s bias, etc., to improve the accuracy of navigation positioning and environmental perception of the system. The initialization methods of VINS can be divided into three categories according to the sensing information fusing mode: joint initialization, disjoint initialization and semi-joint initialization. Based on the existing research work, the current mainstream initialization methods of VINS were reviewed from four aspects: basic theory, development and classification, existing methods, performance evaluation, and the future development trends were summarized, which is helpful to have a general understanding of VINS initialization methods and grasp its development direction.]]></description>
<pubDate>2023/2/2 16:53:57</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李睿豪,刘  哲,史殿习,杨绍武]]></author>
</item>
<item>
<title><![CDATA[Mass transit data crowd profiling algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102260000001]]></link>
<description><![CDATA[Crowd profiling of massive transit data is valuable for analyzing the travel characteristics and traffic trends of urban groups, but the processing of the data is time-consuming, low-quality and difficult to interpret. A systematic solution for crowd profiling of massive public transport data was proposed, firstly, based on the PageRank algorithm to filter out the trajectories of people passing through important stations, which greatly reduces the trajectory data of the target population; then, we proposed a textual analysis method for trajectories to improve the interpretability of crowd profiling; finally, we analysed and determined the K-means algorithm based on cosine distance as the clustering algorithm for crowd profiling. The experiments on 30 million passengers" transit data show that the proposed algorithm can solve the problem of crowd profiling in massive transit data in a more systematic way, while the K-means algorithm based on cosine distance has the best clustering effect and the accuracy rate is about 80%. The results are consistent with real-world crowd behavioural characteristics..]]></description>
<pubDate>2023/1/30 17:42:34</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[郭芊,汪飞,张建忠,张锦]]></author>
</item>
<item>
<title><![CDATA[Analysis of anti-spoofing performance of GNSS multi-beam anti-jamming receiver]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105110000001]]></link>
<description><![CDATA[In order to analyze the anti-spoofing performance of the GNSS multi-beam anti-jamming receiver in the scene of spoofing interference in the navigation system, the theoretical formula for the power of the real signal and the spoofed signal is deduced after the multi-beam anti-jamming receiver adopts the MVDR algorithm processing under the condition of limiting the number of snapshots, the influence of the power of the spoofed signal arriving at the antenna array on the output power of the real signal and the spoofed signal is analyzed in detail, and the anti-spoofing performance of the receiver is measured by the output deception suppression ratio. The analysis shows that even if the power of the spoofed signal is below the noise level, the multi-beam anti-jamming receiver using the MVDR algorithm can still suppress the spoofing interference. When the spoofed signal-to-noise ratio is high, the suppression effect is more obvious. Finally, the correctness of the conclusion is verified by simulation and hardware platform measurement.]]></description>
<pubDate>2023/1/30 17:12:34</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈飞强,冯晓超,高立朝,倪少杰,任彬彬]]></author>
</item>
<item>
<title><![CDATA[Design Research of Gas Distribution System for Annular Connecting Straight Cylinder Engine]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104090000003]]></link>
<description><![CDATA[The design of gas distribution system is an indispensable part of the successful development of the engine. The annular connecting straight cylinder engine has many advantages such as high-power density, low inertia force and so on. However, the cylinder rotors always rotate along the circumferential direction of the output shaft during operation, which makes the traditional static gas distribution method no longer applicable. Therefore, it is of great significance to research and design a new type of gas distribution system that meets the intake and exhaust requirements of this type of engine. In view of the unique annular connecting structure and differential velocity motion characteristic of the engine, the volume change law of each rotor cylinder is analyzed; The relationship between the intake and exhaust phases of each rotor cylinder and the rotor rotation angle is studied. On this basis, an innovative dynamic position gas distribution system with airway reuse feature is designed. According to the two-stroke gas distribution scheme, the parts of the gas distribution system were designed and processed. The air blow experiment show that the engine can run stably at 92 rpm when the driving air pressure is 1MPa, which effectively verifies the feasibility of the gas distribution system.]]></description>
<pubDate>2023/1/29 17:07:45</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[唐源江,徐海军,徐小军,杨聪楠]]></author>
</item>
<item>
<title><![CDATA[Application of EEMD+BiGRU combination model in short-term traffic flow prediction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104220000001]]></link>
<description><![CDATA[Aiming at the problems of high random fluctuation of urban traffic flow and high noise in data, which lead to the decline of prediction accuracy, a combined traffic flow prediction model based on EEMD (ensemble empirical mode decomposition) and BiGRU (bidirectional gated recurrent unit) was proposed, which can effectively improve the accuracy of short-term traffic flow prediction. EEMD algorithm was used to decompose the original data, and the noise energy map was drawn according to the IMF component to remove the noise in the component. The denoised IMF components were trained as the input of BiGRU network. And the results of training were reconstructed and added to obtain the final prediction result. The experimental results show that compared with the EMD-LSTM model, LSTM model and EEMD-LSTM model proposed in references, the mean absolute percentage errors are improved by 42.36%, 61.82% and 30.95% when the IMF components containing noise are not abondoned during reconstruction; after abandoning the IMF component containing noise, the mean absolute percentage error is improved by 56.62% compared with the reconstruction of all IMF components.]]></description>
<pubDate>2023/1/29 17:04:29</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[郝  俊,张玺君]]></author>
</item>
<item>
<title><![CDATA[Warship firefighting system intelligent reconfiguration decision-making and its application based on battle damage]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105210000003]]></link>
<description><![CDATA[The fire-fighting system is widely distributed in the whole warship space, and the damage probability due to weapon attack is relatively high. If the system isn’t isolated and reconstructed in time, it will have a serious impact on the survivability and combat capability of the warship. Aiming at the problem of isolated information of monitoring points and low degree of intelligent decision-making in the current warship fire-fighting system, a node-based fire-fighting system functional logic model is constructed. The intelligent decision algorithm of fire-fighting system damage isolation and reconstruction based on combat damage employment is put forward. The intelligent monitoring system for fire-fighting was developed. The results of case comparison calculation and system inspection show that the intelligent decision-making algorithm and intelligent monitoring system have effectively improved the speed and accuracy of analysis and decision-making, significantly improved the efficiency of command and control, and provided effective support for the water fire fighting system under combat damage condition.]]></description>
<pubDate>2023/1/29 16:52:22</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[龚 立,侯岳,王康勃]]></author>
</item>
<item>
<title><![CDATA[Coordinated control method of active power cooperation for high power flexible interconnected equipment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104150000001]]></link>
<description><![CDATA[In order to solve the problem that the capacity of line transformer in AC power network interconnected by conventional bus switch can not be utilized reasonably, a coordinated control strategy for active power of AC power grid on both sides is proposed, which relies on a new type of high-power flexible interconnection equipment composed of back-to-back voltage source converter. Firstly, the topological structure and basic control principle of the flexible interconnection equipment are introduced, and then a method of generating active power reference is developed to realize the reasonable capacity of the transformers on both sides of the line. Finally, a simulation example is built based on PSCAD/EMTDC to verify the basic control of the flexible interconnection equipment and the proposed coordinated control method of active power cooperation. The simulation results show that when the flexible interconnection equipment adopts the proposed method, the cooperation of active power of AC lines on both sides can be realized, and the problem that the capacity of line transformer can not be allocated reasonably is solved.]]></description>
<pubDate>2023/1/29 15:11:09</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[王洪达,杨曼]]></author>
</item>
<item>
<title><![CDATA[Research on influence factors and coping strategies about the space transmission of particle beam]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104070000002]]></link>
<description><![CDATA[The space transmission of charged particle beam is a very complex physical problem, there are many affecting factors, including the initial beam distribution, divergence, energy divergence and the  geomagnetic field. In the paper, the effects of initial beam distribution, divergence, energy divergence and geomagnetic field on the spatial transmission of particle beams were comprehensively analyzed, and the numerical modeling of electrostatic diffusion and geomagnetic deflection effects was carried out. The simulation result shows that the electrostatic diffusion effect of the particle beam can be weakened by increasing the initial radius, and the exact direction of beam can be accurately predicted through accurate measurement of magnetic field. It can be seen that research on self-consistent force of charged particle beam and its interaction with external field is great significant to the study of generation, transport characteristics and engineering application of the particle beam.]]></description>
<pubDate>2023/1/29 15:02:48</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[黄惠军,彭忠,任三孩,邢艳军]]></author>
</item>
<item>
<title><![CDATA[The Prophet Method of GNSS vertical time series Prediction Considering the Influence of Noise]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104230000001]]></link>
<description><![CDATA[GNSS vertical time series are non-stationary, non-linear and noisy. Based on the in-depth study of Prophet prediction model, we propose a combined prediction method of "noise reduction-decomposition-prediction" by introducing Empirical Mode Decomposition (EMD) for the good prediction effect of Prophet prediction model for trend signal and periodic signal. The combined prediction method of "noise-reduction-decomposition-prediction" is proposed. The original time series is firstly subjected to EMD noise reduction, and then the decomposition of the noise-reduced series is predicted, and finally reconstructed into the final prediction series. The experimental results show that the average signal-to-noise ratio after noise reduction is 10.30 dB, and the average energy percentage is 88.75%; the prediction results of the prediction method constructed in this paper are improved by 26.41% and 14.88% on average in root mean square error, and 18.92% and 7.91% on average in average percentage error, respectively, which verifies the short-term prediction effectiveness and This validates the effectiveness and practicality of the method.]]></description>
<pubDate>2023/1/29 14:38:49</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[程远明,贺小星,鲁铁定,陶蕊,周子琪]]></author>
</item>
<item>
<title><![CDATA[Optimization of sparse rectangular planar array using modified integer genetic algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202103240000001]]></link>
<description><![CDATA[In order to reduce the peak sidelobe level (PSLL) of sparse rectangular array with fixed sparse ratio and fixed aperture, an modified integer genetic algorithm (MIGA) is proposed. On the basis of integer genetic algorithm, the crossover strategy of equal interval sampling, multi-point mutation strategy and excellent gene recombination strategy are proposed. In order to improve the diversity of the population and avoid falling into the local optimum, the multi-point mutation strategy is adopted; the excellent gene recombination technology is adopted to accelerate the convergence speed of the algorithm. Simulation results show that, compared with the traditional binary and real coding, integer coding is more direct and efficient; Compared with the related algorithms for sparse rectangular array optimization, the proposed algorithm obtains the better sidelobe level, which proves the effectiveness and superiority of the algorithm.]]></description>
<pubDate>2023/1/29 14:07:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[国强,戚连刚,王亚妮,袁鼎]]></author>
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<item>
<title><![CDATA[Isodamage Curves Characterization Methods of Anti-damage Capability for Multi-axle Special Vehicle Tire System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104190000001]]></link>
<description><![CDATA[In order to explore the survival probability of multi-axle special vehicle tire system under battlefield threat and quantitatively characterize the anti-damage capability of tire system, a new method based on isodamage curves was proposed to characterize the battlefield anti-damage capability of the tire system. Aiming at the influence of tire damage on the whole vehicle, the mechanical characteristics of tire system were quantitatively characterized based on vehicle dynamics, and the calculation model of tire system functional damage was established. Based on the damage theory, the collision and quantitative analysis of shock wave overpressure field were carried out, and the calculation model of tire system physical damage was established. According to the position relationship between the burst core and the vehicle, the calculation model of the tire system isometric line was established by using the characteristic line for the vehicle in the whole area. A five-axle special vehicle was taken as an example to verify the characterization method. The results show that this characterization method can be applied to the characterization of the anti-damage capability of the multi-axle special vehicle tire system under battlefield threat, which lays a model foundation for the improvement of maneuvering avoidance and protection ability in the future.]]></description>
<pubDate>2023/1/29 12:13:01</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[黄通]]></author>
</item>
<item>
<title><![CDATA[Analysis of the difference between probability distribution of conditional aloft wind speed and normal distribution]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105260000001]]></link>
<description><![CDATA[The aloft wind affects the flight loads, trajectory and posture of aerocraft, as an important uncertainty factor in Multidisciplinary Optimization Design of aerocraft, the statistical characteristics of aloft wind should be acquired accurately. The probability distribution of conditional aloft wind speed is unique, in order to facilitate the use of probability model of aloft wind for uncertainty design, reduce the amount of calculation, an analysis method of difference between probability distribution of conditional aloft wind speed and normal distribution was proposed, the applicable condition for simplifying the distribution of probability distribution of conditional aloft wind speed to normal distribution was given. Within 24.3oN～42.2oN latitude, in the numerical simulations, the differences in probability density in different regions were trumpet-shaped in the range of 2km～30km above sea level, the conditional aloft wind speed can be approximately assumed to be normally distributed near the altitude of 15km.]]></description>
<pubDate>2023/1/29 10:09:00</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[蔡毅鹏,常汉江,王 乐]]></author>
</item>
<item>
<title><![CDATA[Deterministic scheduling method with low latency for SpaceFibre]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104090000002]]></link>
<description><![CDATA[In order to achieve the deterministic transmission of diverse data streams in a short time on the SpaceFibre network, the fine-grained low-latency deterministic scheduling algorithm with classification was proposed. According to the different requirements for QoS, space tasks were divided into three types; for the efficient allocation of resources, the extended time-slot was introduced; the uniform distribution of time-slot without conflict reduced the average delay of data packets; to be suitable for the end-to-end network, the method generated scheduling vectors based on the network topology. The simulation model of the SpaceFibre network in OPNET was built to verify the effectiveness of the method. Experimental results show that the scheduling scheme generated by the method has better certainty; with the increment of the number of time slots, the average delay and jitter of each traffic are reduced. Therefore, the method plays an important pole in constructing the deterministic SpaceFibre network.]]></description>
<pubDate>2023/1/19 23:28:17</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安军社,郑静雅]]></author>
</item>
<item>
<title><![CDATA[Reliability Evaluation of the Coil Spring for Fuse with Multiple Performance Characteristics]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202103210000001]]></link>
<description><![CDATA[As a common energy storage component in fuse, spring is an important part which affects the reliability of fuse. The failure of fuse will cause serious hidden danger. In order to accurately predict the change of reliability of the spring for fuse during storage, a multivariate normal reliability evaluation method based on modified Arrhenius model is proposed. Taking the stress loss rate and permanent deformation rate as performance parameters, the constant stress accelerated test was designed to obtain the degradation data of spring at 120℃, 130℃, 150℃ and 160℃. Anderson darling statistics are used to verify that the optimal distribution of degradation is normal distribution. According to the modified Arrhenius model, the degradation trajectory curve of spring at storage temperature is obtained. Based on multivariate normal distribution, the storage reliability model of spring was established, and the change characteristics of spring reliability during storage were analyzed. Compared with other reliability models, the prediction results of this model are more accurate, which provides a theoretical basis for the condition-based maintenance of fuse.]]></description>
<pubDate>2023/1/11 15:55:35</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[顾晓辉,潘守华,杨承强]]></author>
</item>
<item>
<title><![CDATA[Analysis of Electromagnetic Force and Power Loss Characteristics of Electric-controlled Booster Pump High-speed Solenoid Valve]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102250000001]]></link>
<description><![CDATA[The finite element analysis method was used to establish a 3D static magnetic field simulation model of the high-speed solenoid valve of the electronic-controlled booster pump, and the accuracy of the model was verified by the experimental data. Through numerical simulation analysis, the characteristics of the electromagnetic force and power loss of the solenoid valve of the electric-controlled booster pump were studied by driving current and structural parameters (the number of coil turns, magnetic pole’s radius, working air gap), and the weight influence of each parameter on the electromagnetic force and power loss of the solenoid valve was obtained and the quantitative analysis was made. The results show that the radius of major and vice magnetic poles accounts for 38.15% of the electromagnetic force, followed by the driving current which accounts for 31.08%, the number of coil turns which accounts for 17.06%, and the working air gap which accounts for 13.71% of the electromagnetic force. From the perspective of power loss, the ratio of driving current, coil turns, radius of major and vice poles and working air gap of electric-controlled booster pump solenoid valve is analyzed. The ratio of coil turns, radius of major and vice magnetic poles and working air gap is the highest, 54.85%, followed by driving current, 44.99%, and the minimum ratio of radius of major and vice magnetic poles and working air gap is only 0.16%.]]></description>
<pubDate>2022/12/2 16:23:14</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[聂涛,吴 昕,杨 昆,曾凡明,赵建华,周磊]]></author>
</item>
<item>
<title><![CDATA[Deterministic figuring method by abrasive belt for high-precision shaft parts]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102250000002]]></link>
<description><![CDATA[In order to improve the machining accuracy of the metal shaft parts, the vibrating abrasive belt polishing method was innovatively applied to the deterministic figuring of high-precision shaft parts based on the principle of optical deterministic figuring. In this method, the abrasive belt covered the outer surface of the contact wheel, and the elastic contact wheel contacted the shaft workpiece under a certain pressure to form a rectangular grinding area. The removal of materials could be achieved by the axial vibration of the contact wheel. The contour of the shaft’s surface can be measured by cylindricity meter, and the error’s distribution could be obtained. The dwell time of the contact wheel at different positions on cylindrical surface was calculated by pulse iteration method. The material removal quantity at different positions of workpiece was different by servo control of the machine tool’s spindle, thus the cylindricity error could be corrected deterministically. After the simulated machining, the deterministic figuring experiment was carried out on the cylindrical surface of a AISI 1045 steel shaft. The experimental results show that the average roundness error of the workpiece converges from 0.42μm to 0.11μm, and the cylindricity error of the workpiece improves from 0.76μm to 0.35μm. The shape accuracy after machining is better than that of the ultra-precision cylindrical grinder, which verifies the feasibility of high-precision deterministic figuring on the cylindrical surface of shaft parts.]]></description>
<pubDate>2022/12/2 16:22:11</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈学蕾,戴一帆,关朝亮,胡皓,孙梓洲]]></author>
</item>
<item>
<title><![CDATA[Binocular vision measurement of sabot discard of shell piercing projectile]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012180000002]]></link>
<description><![CDATA[The sabot discard process of shell piercing projectile has significance on the flight stability and strike efficiency of it. Aiming at the six degrees of freedom movement process of shell piercing projectile after leaving the chamber,  a measurement method of sabot discard angle based on the principle of binocular vision was proposed. By setting some markers on the surface of projectile and sabot, the recognition and tracking of the markers were realized with the image processing and tracking algorithms. The spatial locations of these marker were calculated by combining with the binocular calibrated space parameters, and the discard angle of sabot relative to the projectile was obtained. Meanwhile, the accuracy of the method above was validated by experiment which was proved to be 2%. Taking the shell piercing projectile launching at initial velocities of 1550m/s and 1750m/s conducted in the laboratory as an example, the discard trajectories under different muzzle velocity were measured and analyzed. The results show that the faster the discard initial velocity is, the closer the discard trajectory is to the projectile.]]></description>
<pubDate>2022/12/2 16:21:42</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[程龙,李松乘,李湘平,鲁军勇,张晓]]></author>
</item>
<item>
<title><![CDATA[Influence of polarization state on electric field model of submarine propeller disturbance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106050000001]]></link>
<description><![CDATA[The electric field distribution of submarine had been affected by the degradation of coating properties during service. With material polarization as boundary condition, three electrostatic field models were established by using boundary element method，including submarine coating performance deterioration, coating penetration corrosion and coating local damage polarization. The propeller disturbance electric field model was analyzed from time domain and frequency domain characteristics. The results show that electrochemical polarization state has a significant effect on the potential and harmonic of propeller disturbance electric field. Under the three boundary conditions of constant potential, linear polarization and nonlinear polarization, when the propeller rotates at the same frequency to disturb the electrostatic field, the proportion of frequency components of each model is significantly different. Under the nonlinear boundary condition, the difference between the disturbance frequency and the ratio of twice disturbance frequency is the largest. Under the linear boundary condition, the difference between the disturbance frequency and the ratio of twice disturbance frequency is the smallest. Under three kinds of boundary conditions, the harmonic range of the electric field model above three times of the disturbance frequency will change. The harmonic range of the electric field model is the smallest under the constant potential boundary condition, and the harmonic range is the largest under the nonlinear boundary condition.]]></description>
<pubDate>2022/12/2 16:19:53</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[王向军]]></author>
</item>
<item>
<title><![CDATA[Co-simulation platform of reliability optimization design for turbine disk’s fatigue life with its core optimization strategy]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102220000001]]></link>
<description><![CDATA[Turbine disk is one of the main components of aero-engine. Once a critical failure occurs, it will lead to serious consequences. Co-simulation platform of reliability optimization with high-low cycle compound fatigue life for turbine disk was designed by Matlab. The uncertain factors affecting high-low cycle complex fatigue life of turbine disks are full considered in the platform. Based on the common requirements of lifetime function and lifetime reliability analysis limit state function, a strategy of sharing training sample points in adaptive construction of lifetime function Kriging model and lifetime reliability limit state surface Kriging model in the process of optimization iteration was proposed. Meanwhile, a learning function for constructing Kriging model of lifetime function was proposed. The high-low cycle complex fatigue life reliability optimization of turbine disk center and mortise were completed using the co-simulation platform. The local maximum stress of the optimal result is significantly reduced, the average life-cycle is increased, and the reliability constraints are satisfied.]]></description>
<pubDate>2022/12/2 16:16:16</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[吕震宙,张文鑫]]></author>
</item>
<item>
<title><![CDATA[Blast resistant and shock absorption design for missile-canister system in silo]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012300000002]]></link>
<description><![CDATA[To improve the survival ability of cold launch missile in silo, the research on blast resistant and shock absorption design had been performed. Finite element models were established for missile-canister system in different shock absorption ways. The dynamic responses under blast-induced ground shock were calculated.  The vibration reducing performances of several shock absorption systems were compared, including vertical suspension mode, lower supporting mode and slant suspension mode. Meanwhile, the influences of stiffness and damping on the shock absorbing performance were investigated. The results show that the vibration reducing performance of vertical suspension mode is slightly better than that of lower supporting mode, and that of slant suspension mode is worst. The vibration reducing performance of vertical suspension shock absorption system can be significantly improved by properly decreasing its stiffness and damping.]]></description>
<pubDate>2022/12/2 16:15:54</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭振,姜人伟,李道奎,周岸峰,周仕明]]></author>
</item>
<item>
<title><![CDATA[SSC Shift-frequency Jamming Suppression Based on GeneralizedS Transform and Tsallis Cross Entropy Threshold Segmentation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102010000003]]></link>
<description><![CDATA[Spectrum Spread and Compression(SSC) shift-frequency jamming can produce forward and backward false target by controlling the delay parameter which avoids the exact estimation to the frequency modulation rate. According to the time-frequency distribution difference between jamming and echo, a jamming suppression method based on Generealized S transform and Tsallis cross entropy threshold segmentation is proposed. The jamming principle of SSC shift-frequency jamming is analyzed and the jamming signal model after dechirp processing is constructed firstly. And then the generalized S transform, which is of good time-frequency concentration performance, is utilized to acquire the time-frequency image. Based on the related gray-scale image of time-frequency image, the minimum Tsallis cross entropy is utilized to obtain the optimal segmentation threshold and the time-frequency filter is constructed according to the segmentation threshold to suppress jamming. The simulation results show that the proposed method is of good jamming suppression performance to the false targets produced by SSC shift-frequency jamming and the jamming suppression ratio can be bigger than 30 dB.]]></description>
<pubDate>2022/12/2 16:15:09</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李欣,罗富友,袁天]]></author>
</item>
<item>
<title><![CDATA[Evaluation of matrix multiplication convolution algorithm for multi-core digital signal processors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209130000001]]></link>
<description><![CDATA[The matrix multiplication-based convolutional algorithm, which can efficiently implement convolutions with different parameters, is the first choice of convolution performance optimization for a given chip. Based on the architecture of Phytium heterogeneous multi-core DSPs developed by National University of Defense Technology and the characteristic of the matrix multiplication-based convolutional algorithm, a parallel implementation of the matrix multiplication-based convolutional algorithm (called ftmEConv) for different convolutions on multi-core DSPs was proposed. ftmEConv consisted of four parallelized parts: input feature maps transformation, filter transformation  , matrix multiplication, and output feature maps transformation, all of which were optimized for multi-core DSPs, and the performance of each part was improved by effectively exploiting the potential of all functional units in DSP cores. The experimental results demonstrate that ftmEConv achieved computational efficiency of up to 42.90%.Compared with other implementations of the matrix multiplication-based convolutional algorithm on heterogeneous chips, ftmEConvgett a speedup of up to 7.79 times.]]></description>
<pubDate>2022/12/2 16:14:06</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李东升,李荣春,廖林玉,梅松竹,裴向东,王浩旭,王庆林]]></author>
</item>
<item>
<title><![CDATA[Design and Verification of A Rotating-Magnet Based Mechanical Low-Frequency Antenna System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202103300000001]]></link>
<description><![CDATA[In order to achieve the miniaturization and low power consumption of the low-frequency electromagnetic transmitter, a system design and performance verification method based on multi-physics coupling simulation was proposed for the theoretical research and technical practice of RMBMA(rotating- magnet based mechanical antennas). A RMBMA system scheme including a permanent magnet source, a high-efficiency drive motor and its controller was designed. By developing an experimental prototype, the system performance and near magnetic field characteristics were tested experimentally, and the feasibility and effectiveness of the proposed design method and system scheme were verified. The results show that the main indexes of the prototype, such as magnetic field intensity and size, meet the requirements of the penetrating radio frequency technical area in the A MEchanically Based Antenna project of the United States, which provides a feasible idea for the scheme research and prototype design of RMBMA.]]></description>
<pubDate>2022/12/2 16:13:32</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[施伟,,,]]></author>
</item>
<item>
<title><![CDATA[Transmitting Main Lobe Jamming Adaptive Suppression Method for OFDM-MIMO Radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102020000001]]></link>
<description><![CDATA[Because of the high correlation between the forward jamming and the radar transmitting waveform, it is easy to cause serious jamming to the radar after being received by the radar main lobe. In order to solve the main lobe interference problem, the forward interference signal model of ofDM-MIMO radar main lobe was established, and the interference mechanism of ofDM-MIMO radar was analyzed. At the same time, based on the adaptive method processing theory, the analytical formula of ofDM-MIMO radar adaptive processing weight vector is derived, and an ofDM-MIMO radar forward main lobe interference adaptive suppression method based on range-dependent beam is proposed. Theoretical research and simulation results show that the proposed method can improve the output SINR and effectively suppress the forward main lobe interference.]]></description>
<pubDate>2022/12/2 16:08:15</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[Xiong Zhimin]]></author>
</item>
<item>
<title><![CDATA[Prediction and Parameter Study of the Unsteady Broadband Thrust for the Pump Jet]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102250000003]]></link>
<description><![CDATA[To predict the broadband unsteady force of the interaction between pump jet rotor and turbulence, the prediction formula of the rotor unsteady force is derived on the basis of the Sears function, considering the influence of the turbulence. On this basis, the prediction formula of propeller wide-frequency unsteady excitation force is derived, and the formula is verified by comparison with experimental values. Furthermore, considering the situation that the rotor of the pump-jet propeller works in the wake field of the leading vane, the turbulence wavenumber spectrum of the blade wake is established through the Gauss wake model, and the parameters of the blade wake field are calculated by empirical formulas. The steady-state excitation force prediction formula. The broadband unsteady excitation force calculated by the formula is similar to the numerical calculation result. Finally, the influence of changes in flow field parameters on the prediction results of the propeller rotor broadband radiation noise is analyzed. The research shows that the turbulence intensity only affects the amplitude of the broadband unsteady excitation force prediction results, and the turbulence integral scale has a greater impact on the amplitude and spectrum shape.]]></description>
<pubDate>2022/11/29 16:44:56</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[胡鹏飞,靳栓宝,孙方旭,王东,魏应三,武星宇,祝昊]]></author>
</item>
<item>
<title><![CDATA[Hartley block algorithm and experiment in adaptive control]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202103090000001]]></link>
<description><![CDATA[Aiming at the problem that the wavelet packet adaptive control subband contains a large number of convolution and correlation operations, which leads to the slow convergence speed of the algorithm, the wavelet packet adaptive control based on Hartley block (WPHB-LMS) is proposed. Firstly, fast Hartley transform is introduced into block algorithm to realize fast convolution and correlation operation in frequency domain. Secondly, Hartley block algorithm is used to generate control signals in the subband, and a wavelet packet filtered-x least mean square algorithm based on Hartley block (WPHB-FxLMS) is proposed through the overlapping reservation method. Finally, the vibration isolation performance and control effect under fixed frequency and fluctuant frequency working conditions are studied by simulation and experiment. The results show that the WPHB-FxLMS algorithm not only greatly reduces the convergence time, but also significantly improves the control precision, which has good robustness and stability, and can be applied in engineering practice well.]]></description>
<pubDate>2022/11/29 10:37:43</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[柴  凯,高伟鹏,刘树勇,朱石坚]]></author>
</item>
<item>
<title><![CDATA[Rule/intelligence coupling constraint training method for UAV swarm confrontation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202103170000002]]></link>
<description><![CDATA[Based on the concept of the intelligent combat of UAV (unmanned aerial vehicle) swarms, the UAV swarms intelligent combat simulation environment was established. Aiming at the problem that it is difficult to accurately control the speed and attack angle of UAVs in the confrontation process through reward signals in traditional reinforcement learning algorithms, a rule/intelligence coupling-constrained multi-agent deep deterministic policy gradient (RIC-MADDPG) algorithm was proposed. The algorithm used rules to constrain the actions of UAVs in reinforcement learning. The simulation results show that the wining-rate of red UAV swarm, trained by the method based on the RIC-MADDPG, can be improved from 53% to 79% . This proves that the strategy of “agent training - problem finding - rule making - agent training again- problem finding again - rule making again” is effective for optimization of agent combat strategy. The research results would be a reference for establishing the training system of the intelligent combat strategy of UAV swarms.]]></description>
<pubDate>2022/11/29 10:04:20</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[高显忠,侯中喜,贾高伟,王宝来,项磊]]></author>
</item>
<item>
<title><![CDATA[Investigation on the aging mechanism of HTPB propellantin SRM long-term storage]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012020000002]]></link>
<description><![CDATA[In order to recognize aging mechanism of HTPB solid propellant, a solid rocket motor was dissected which had been storage more than 19 years, and the propellant were sampled from bonded grain’s different position in radical direction. The SEM, EDX, cross-ling density, infrared absorption spectrum and Raman spectrum were used to characterized these samples. The test results show that the aging degree of propellant were different in different position of bonded grain, the worse aging and the closer case of SRM. The analysis suggests that the Al+ion catalyzed additive reaction of C=C and Cl or water, and the C-Cl or secondary alcohol were generated which increase the glass transition temperature of HTPB. And the Al+ion migration and heterogeneity generated unevenness aging speed. Moreover, the results was of great significance to the design and improvement the recipe of HTPB propellant, and investigation on the safeguard procedures.]]></description>
<pubDate>2022/11/29 9:47:44</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭宇,李海阳,李志杰,申志彬,张漩]]></author>
</item>
<item>
<title><![CDATA[Analysis of the thermal effect of electromagnetic pulse on high frequency structure]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102060000001]]></link>
<description><![CDATA[For Cerenkov-type devices, the thermal desorption caused by the temperature rise of the high-frequency structure can cause radio frequency breakdown, which in turn leads to a decrease in output power and a shortened pulse. Based on this, this article studies the heating temperature rise effect of electromagnetic pulses on the high-frequency structure, deduces the temperature rise formula of the high-frequency structure, points out the scope of application of the theoretical formula, and gives a numerical method to solve the temperature rise of the specimen. Taking the two-period 1MV/cm high-frequency structure as an example, the numerical calculation and simulation study of temperature rise have been carried out. The results show that the temperature rise effect of a single pulse with a pulse width of 100ns on the stainless steel specimen is significantly higher than that of other materials. When the system is working at a high repetition frequency, the temperature rise of electromagnetic pulses may cause the metal material to reach the threshold of gas desorption and cause the gas to desorb to form a local high pressure. The research in the thesis can provide reference for the research of gas desorption and radio frequency breakdown in highpower microwave sources.]]></description>
<pubDate>2022/11/29 9:44:11</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[崔言程,孟进,王海涛,袁玉章,朱丹妮]]></author>
</item>
<item>
<title><![CDATA[The influence of rain attenuation on the I/N distribution of the Q-band geostationary satellite orbit downlink]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104010000001]]></link>
<description><![CDATA[In view of the propagation characteristics of Q-band communication links that were severely affected by conditions such as rainfall, fog and atmospheric absorption, based on the analysis of the propagation loss of the Q-band geostationary satellite orbit downlink, the influence of rainfall attenuation on the I/N distribution under the interference scenario of the earth station co-location was studied. A method to calculate the propagation loss of Q-band downlink combined with rainfall distribution was proposed, and a functional model for I/N combined p% that the percentage of time when rainfall attenuation exceeds a threshold value was established. The influence of p% on the distribution of I/N was analyzed, and the average annual interference distribution was forecast. This method was used to analyze the influence of the CHINASAT-G-115.5E satellite network which was registered by the ITU, and the results show that the lower the p%, the more obvious the influence of rain attenuation on the communication link. When p＜0.5, the attenuation threshold changes faster. When the location of earth station and the orbit longitude of the interfering satellite are fixed, the smaller the p%, the smaller the minimum value of I/N in the annual average 1- p% time. This method can be applied to study the interference distribution of other orbital satellites, and provide a reference for interference avoidance.]]></description>
<pubDate>2022/11/28 15:23:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈托,董苏惠,高翔,孙云龙,王静,姚秀娟,智佳]]></author>
</item>
<item>
<title><![CDATA[Real-gas effects research associated with cryogenic transonic wind tunnel]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101310000003]]></link>
<description><![CDATA[The thermodynamic and calorific of the gas in wind tunnel will be imperfect when the wind tunnel operates under cryogenic temperature. In this case, the real gas effects should be considered for calculating flow parameters. The change laws of the compressibility factor and specific heart ratio for nitrogen gas under the ranges of pressures（1.0atm-4.5atm）and temperatures(100K～323K) were presented. By introducing isentropic expansion coefficient into one-dimensional perfect gas flow equations, the computational analysis model for cryogenic wind tunnel flow parameters was developed, and the operating envelope of transonic wind tunnel considering the gas liquefaction temperature and pressure under high speed was obtained. The analysis results show that for the ranges of pressures (115kPa～450kPa) and temperatures (110K to 323K) that cover the range of operation of transonic cryogenic wind tunnel, the maximum deviation of the various isentropic parameters from the ideal values is about 1 percent or less ,and this deviation would be insignificant for the aerodynamic designing of the cryogenic transonic wind tunnel.]]></description>
<pubDate>2022/11/28 13:07:34</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[黄知龙,廖达雄,史志伟,王宁]]></author>
</item>
<item>
<title><![CDATA[Optimal design of a novel self-adaptive climbing mechanism for landing in the amphibious bionic robot]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202103290000003]]></link>
<description><![CDATA[The amphibious bionic robot was an unmanned system which can work both underwater and on land, which has been widely used in the fields of disaster rescue, environmental detection and resource exploration. An amphibious robot compounded with wheel and fin with the ability of self-adaptive climbing was proposed in this paper. The kinematic and dynamic mechanics of the self-adaptive climbing process was analyzed. The torque required of the critical obstacle crossing point was set as the objective function, and the optimized design structural and operational parameters were obtained by applying the genetic algorithm. Meanwhile, the climbing ability of the amphibious robot in this work was compared with others. The results illustrate that the required torque of the amphibious robot was reduced by 718.4 N?mm. The robot compounded with wheel and fin could climb the vertical obstacle of a larger height. The self-adaptive climbing process was simulated by using the Adams. The simulation results illustrate that the variation of the propulsive velocity, the displacement and the torque in the processes of moving forward and climbing the obstacles. The experiments of the obstacle climbing was investigated for verifying the structural and operational parameters design.]]></description>
<pubDate>2022/11/28 13:05:01</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[罗自荣,尚建忠,宋震,王何,殷谦]]></author>
</item>
<item>
<title><![CDATA[Fast and accurate detection of infrared dim small target in low altitude complex scenes]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202103240000003]]></link>
<description><![CDATA[Aiming at the high difficulty and high false alarm rate of infrared dim small moving  target detection in low altitude and complex scenes, a precise detection method based on full convolution network and a low-latency parallel processing method based on field programmable gate array (FPGA) are proposed to meet the real-time processing application requirements of high frame rate images in the detection system. The method uses a lightweight full convolutional network to detect dim small targets in spatial domain, and then performs time domain trajectory correlation on suspected targets in adjacent frames to further reduce false alarms. The experimental results show that the detection rate and false alarm rate are  significantly improved compared with the five traditional methods. And the real-time processing of 100Hz image is completed on a single FPGA with the processing delay less than 1.8ms. This method realizes high-precision, high-robust and fast real-time detection of dim small targets in complex low altitude scene.]]></description>
<pubDate>2022/11/24 9:39:14</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[卞春江,李保权,王怀超,周海]]></author>
</item>
<item>
<title><![CDATA[Optimizing Parallel Matrix Transpose Algorithm on Multi-Core DSPs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209070000003]]></link>
<description><![CDATA[Matrix transpose is one of the common matrix operations, which is widely employed in various fields such as signal processing, scientific computing, and deep learning. With the popularization of Phytium heterogeneous multi-core DSPs developed by National University of Defense Technology, there is a strong demand for high-performance matrix transpose implementations for Phytium multi-core DSPs. Based on the architecture of multi-core DSPs and the characteristic of matrix transpose operations, a parallel matrix transpose algorithm (called ftmMT) for matrices with different element bit widths (8-byte, 4-byte, and 2-byte) is proposed. In ftmMT, the main optimizations include vectorization based on vector load/store functions, core-level parallelization based on matrix blocking, and overlapping between vectorization and memory access through implicit ping-pong methods. The experimental results show that ftmMT can significantly improve the performance of matrix transpose operations, and achieve a speedup of up to 8.99 times in comparison with the open-source transpose library HPTT running on CPU.]]></description>
<pubDate>2022/11/24 9:27:11</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李荣春,廖林玉,刘杰,梅松竹,庞征斌,裴向东,王庆林]]></author>
</item>
<item>
<title><![CDATA[Multi-channel power distribution anti-jamming based on asymmetric Colonel Blotto game]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102070000001]]></link>
<description><![CDATA[Aiming at the multi-channel power allocation problem of the communication system with a fix transmitting rate, which is undergoing intelligent jamming attack, an asymmetric Colonel Blotto game model is proposed. Under the condition of complete information, the equivalent optimal power allocation strategies at a single channel are deduced for the communication system and the jammer. Moreover, the only mixed Nash equilibrium strategy of them is proved, and the Nash equilibrium benefit is acquired. Based on the equivalent optimal power allocation strategies at a single channel, a direct column element exchange algorithm by multiple scanning is proposed to construct the multi-channel mixed power distribution matrix, which can adapt to more channels and wider power distribution range than the linear programming method. Finally, through numerical simulation, the effectiveness of the multi-channel mixed power allocation matrix construction algorithm and the optimality of the proposed power allocation strategies are verified.]]></description>
<pubDate>2022/11/22 17:27:25</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陆锐敏,骆俊杉,王世练,魏鹏]]></author>
</item>
<item>
<title><![CDATA[Enhanced hierarchy directed graph method for fault diagnosis of large-scale satellite ground station]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106120000001]]></link>
<description><![CDATA[To solve shortcomings of regular Hierarchy Directed Graph method when applied to satellite ground station fault diagnosis, Enhanced Hierarchy Directed Graph (EHDG) fault diagnosis method was proposed. In process of modeling, considering large number of fault symptoms, various fault symptoms of devices was categorized and combined according to their fault propagation paths to reduce the number of nodes in the model. Furthermore, the node effectiveness enabling function was added into the model to avoid the remodeling when the system structure was changed as the consequence of device switching caused by fault. In process of fault diagnosis reasoning, the search space of fault source was reduced by the combination of backtracking and forward reasoning method. The fault probability was calculated with the number of search hits of the nodes in fault source candidate set. All these designs accelerated the convergence of the model and enhance the efficiency. EHGD fault diagnosis method in single fault and multiple faults scenarios of BeiDou RDSS ground station system is verified, and the results demonstrate that EHDG method improves the accuracy and comprehensiveness in fault diagnosis.]]></description>
<pubDate>2022/11/22 13:38:22</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李井源,刘增军,孙广富,周 蓉]]></author>
</item>
<item>
<title><![CDATA[Design of landing impact test system and test verification of large rubber container]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202209090000001]]></link>
<description><![CDATA[In order to assure the transport airworthiness of large rubber container, the design of the landing impact test system was carried out according to the Civil Aviation Administration of China on the emergency landing overload requirements for transport category aircraft. The impact platform was simulated and verificated, the waveform generator was simulated and designed, the pendulun system and guiding menchanism were designed, while the landing impact test system was constructed. The payload reaches the order of 20t, and the maximum impact load reaches 400t. The large rubber container was selected as a typical air cargo for emergency landing test verification. The results show that the waveform of the impact test isapproximately triangular wave, which is simular to the waveform of thesimulation curve. The overload peak is 1.54g laterally and 3.06g, 9.02g, 16.20g heading respecrively. The maximum error with the target peak is less than 3%, and the corresponding time of the peak is more than 50ms. The test system meets the design requirements. The system will be used for the develeopment of airlift platform，which is great significance to ensure flight safety, reduce development risk and improve the airvorthiness of airlift platform.]]></description>
<pubDate>2022/11/11 10:06:28</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[刘冲冲,孟浩龙,易方]]></author>
</item>
<item>
<title><![CDATA[Joint resource allocation and dynamic task offloading scheme in vehicle multi-access edge network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101140000002]]></link>
<description><![CDATA[Aiming at the problem of task offloading failure caused by the excessively fast vehicle moving in the Internet of Vehicles, designs an effective task offloading risk assessment model, and puts forward a dynamic task offloading scheme with joint resource allocation, which models time, energy consumption and risk together for system utility, and maximizes system utility through joint optimization of offloading decision and resource allocation. The optimization problem is formulated as a mixed integer nonlinear programming (MINLP). Due to the problem is difficult to solve, we use convex optimization techniques to solve the computational resource allocation problem under a given offloading decision. Power allocation is through fractional programming Technology to optimize. The simulation analyzes the impact of vehicle mobility on system utility, which proves the rationality of our proposed scheme.]]></description>
<pubDate>2022/10/13 17:03:27</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[安亚宁,安悦,关向瑞,薛建彬]]></author>
</item>
<item>
<title><![CDATA[Trajectory optimization of single UAV for bearing-only target localization in urban environments]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011060000002]]></link>
<description><![CDATA[To solve the problem of radiation-source target localization for a single unmanned aerial vehicle in an urban environment, a new trajectory optimization algorithm for bearing-only target localization based on the environment prediction method is proposed. Interacting multiple model methods coupled with the extended Kalman filter is used to estimate the target localization in the line-of-sight and non-line-of-sight mixed environment. Based on the estimated target location and urban geographic information system, the electromagnetic signal occlusion region and multipath interference region are calculated using the line of sight tracking method. The predicted trajectories of unmanned aerial vehicle, which are generated under the framework of receding horizon method, use the maximum determinant of Fisher information matrix as the criterion in bearing-only target localization and also consider the influence of building obstacles avoiding and their occlusion and reflection effects in the localization process. In this way, the unmanned aerial vehicle is controlled to choose the optimal heading. The numerical simulation results show that the trajectory optimization algorithm enables the unmanned aerial vehicle to perform high-precision bearing-only target localization in the complex environment containing obstacles, signal occlusion, and multipath interference. The algorithm provides a new way to solve the problem of bearing-only target localization for single unmanned aerial vehicles in an urban environment.]]></description>
<pubDate>2022/10/8 15:58:42</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[陈方正,郝绍杰]]></author>
</item>
<item>
<title><![CDATA[Research on optimal configuration of energy storage in integrated power system with pulse load]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012140000001]]></link>
<description><![CDATA[The energy storage device (ESD) can support pulse power load on board, while improving the power quality of the integrated power system (IPS). However, considering the vessel environmental constraints and the requirements of pulsed load, it is necessary to rationally configure the ESD to improve the performance of the IPS. For this reason, based on the weighted minimal module ideal point method and analytic hierarchy process, a performance evaluation function of ESD is proposed, and the optimal configuration is carried out with this function. The proposed function fully considers the system requirements and pulse load characteristics, and takes the ESD volume, weight, and economy as the main components of the evaluation function. At the same time, it considers constraints such as power, energy, voltage, and SOC to establish an optimal configuration model. The differential evolution algorithm is adopted to solve it. Taking lithium battery and supercapacitor as example and the proposed model is solved. The results show that lithium battery has better performance under the given weight and are more suitable for IPS. Besides, the guiding configuration scheme is givenc.]]></description>
<pubDate>2022/10/8 15:58:16</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[付立军,高雪平,黄美娴,纪锋,张彦]]></author>
</item>
<item>
<title><![CDATA[Double Two-body Model using Geometrical Section Method and the Analysis of Trans-lunar Trajectory from Space Elevator]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012220000001]]></link>
<description><![CDATA[A geometrical representation method of double two-body model by using parameters in orbital plane of flight trajectory was proposed. The search space on three-dimensional sphere is reduced to be a two-dimensional circle formed by tangent of the orbital plane and the sphere of influence, the shape parameter of trans-lunar trajectory can be efficiently solved by one-parameter Brent root-finding algorithm and Lambert theory.  In order to avoid double calculation, the orbital multivariate search problem calculated by the transfer orbit window is decoupled into two sub-problems: the transfer orbit shape parameter solution problem and the transfer orbital plane space orientation problem, which reduces the solution dimension of the problem.  The two-stage method with parallel computing is approached in order to make full use of the nowadays computational power of PC with multi-core CPU. The simulation results show, the new parallel double two-body model with the use of geometrical section of orbital plane can be successfully applied to the analysis of the trans-lunar trajectory from space elevator.]]></description>
<pubDate>2022/10/8 15:57:53</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[童科伟]]></author>
</item>
<item>
<title><![CDATA[Open-Circuit Fault Diagnosis for Three-Phase Inverters Based on CNN and Analysis of its Sample Conditions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012290000001]]></link>
<description><![CDATA[In order to reasonable choose a sample condition which supports efficient intelligent diagnosis, and to overcome the problems of too many weights and weak local information extraction capability of intelligent traditional BP (back propagation) network, an open-circuit faults diagnosis method based on CNN(convolutional neural network) was studied. Moreover, by taking the typical three-phase two-level inverter as the specific object, the advantages of the CNN method on network weights number, network training stability and diagnosis effects under different conditions of sample durations and training sample numbers over the BP network method were analyzed quantitatively. The results show that the CNN method can build a deeper network model with much less weights than the BP network method, and it can achieve efficient and accurate model training and diagnosis with shorter and less samples.]]></description>
<pubDate>2022/10/8 15:56:45</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[艾胜,樊亚翔,罗毅飞,申皓澜,唐欣,肖飞]]></author>
</item>
<item>
<title><![CDATA[Construction of prediction model for electromagnetic force on electric-controlled booster pump high-speed solenoid valve]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012290000002]]></link>
<description><![CDATA[In order to scientifically predict the electromagnetic force performance of the electric-controlled booster pump high-speed solenoid valve for the ultra-high pressure common rail system , the Box-Benhnken Design response surface method was used to construct the electromagnetic force prediction model to achieve efficient prediction and optimization of its performance. First, a three-dimensional finite element simulation model of the high-speed solenoid valve for the electric-controlled booster pump was established and verified by experiments. Based on the idea of experimental design, key factors such as drive current, working air gap, armature thickness, number of coil turns, main magnetic pole radius, and orifice radius were selected. Box-Benhnken Design developed 54 sets of sample points of electromagnetic force numerical test research program. The electromagnetic force prediction model was constructed. After R test, and the simulation test verifies that the electromagnetic force prediction model has a maximum error of 1.3%, indicating that the model can accurately predict the high-speed solenoid valve of the electric-controlled booster pump Electromagnetic force provides a theoretical basis for the design and optimization of the ultra-high pressure common rail system control system.]]></description>
<pubDate>2022/10/8 15:56:06</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[刘金林,聂  涛,吴  昕,杨  昆,曾凡明,周  磊]]></author>
</item>
<item>
<title><![CDATA[Node real-time performance adaptive cluster resource scheduling algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101080000002]]></link>
<description><![CDATA[There are different types of user jobs, e.g., CPU intensive and memory intensive. The real-time performance of each node in one cluster varies greatly due to different configurations and the job running on it. To improve the cluster performance, NPARSA (Node Performance Adaptive Resource Scheduling Algorithm) was proposed. The real-time performance of a cluster node was represented by its configuration (such as the number of its CPU cores and memory) and the real-time state parameters (such as the residual of CPU, memory, and disk). NPARSA chose the attribute weights for a node according to the type of the job to be handled, and assigned nodes with higher priority to the job. Virtual machine experiments and physical cluster experiments prove the effectiveness of NPARSA. Compared with Spark's default scheduling algorithm, SDASA, and Difference, NPARSA can improve the performance of a cluster and shorten the execution time of user jobs.]]></description>
<pubDate>2022/10/8 15:55:45</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[胡亚红,吴寅超,朱正东]]></author>
</item>
<item>
<title><![CDATA[Research on the Evaluation Method of Electromagnetic Interference Situation of Satellite Navigation System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101250000004]]></link>
<description><![CDATA[In the complex electromagnetic environment of the battlefield, satellite navigation receivers are susceptible to electromagnetic interference (EMI) and cannot be positioned.  In response to this phenomenon, a method for evaluating the EMI situation of satellite navigation receivers based on unmanned aerial vehicle’s (UAV’s) environmental perception is proposed. The characteristic parameters of the EMI and the receiving state of the navigation receiver, when it is not interfered, are used as the input of the prediction, and when the receiver tracking loop is lost, the effect threshold is used as the observation target value to establish the XGBoost prediction model. Compared with the prediction methods of GPR and SVR, the results show that the XGBoost method has the better prediction accuracy. On this basis, the rank of the EMI situation of the navigation receiver is given, and the situation assessment method of the navigation receiver under single-source or dual-source are proposed. According to this prediction method, the comprehensive utilization of the technology schemes and the tactical schemes is beneficial to improving the adaptability of UAVs in complex electromagnetic environments.]]></description>
<pubDate>2022/10/8 15:54:14</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈亚洲,程二威,王玉明,张庆龙]]></author>
</item>
<item>
<title><![CDATA[Research on the failure mechanism of solid propellant under superimposed pressure]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106220000002]]></link>
<description><![CDATA[During the ignition state, the SRM (solid rocket motor) with wall pouring is in the state of superimposed pressure, while the circumferential direction of SRM inner bore is under tensile strain. In essence, the loading condition of solid propellant is actually a stretching process under superimposed pressure. It is urgent to carry out related research on the failure mechanism of propellant under superimposed pressure. In this paper, the mechanical behavior of solid propellant under coupling effect of superimposed pressure, temperature and strain rate is investigated through uniaxial tensile tests using self-developed superimposed pressure loading system. In addition, according to the mechanical response characteristics of the propellant under superimposed pressure, the failure modes of the propellant under superimposed pressure were further studied by means of meso-scale mechanical simulation. At the same time, the morphologic sectional features of the propellant specimens were analyzed by means of SEM (scanning electron microscope) test. The failure mechanism of the propellant under superimposed pressure was found out by means of combining test and simulation. The results show that the damage interfaces of propellant decrease significantly under superimposed pressure, and with the increasing of superimposed pressure, the damage form of propellant changes from particle "dewetting      dominated to particle breakage dominated.]]></description>
<pubDate>2022/10/8 15:52:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[申志彬,虞跨海,张  亮]]></author>
</item>
<item>
<title><![CDATA[New Polarimetric Calibration Scheme Using Passive Calibrator Set Including 22.5° Dihedral]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011250000001]]></link>
<description><![CDATA[Polarimetric calibration is the prerequisite of correct extraction and application of polarimetric information. In practical applications, the traditional Whitt passive point target calibration algorithm often leads to the problem of incorrect solution of polarimetric distortion matrix, which makes it impossible to calibrate the polarimetric distortion correctly. To solve this problem, on the basis of analyzing the cause of failure in solving the distortion matrix of the commonly used Whitt algorithm, a new polarimetric calibration method using 22.5° dihedral is proposed, including a new calibrator set, a preprocessing procedure for measured polarimetric scatter matrix and a new eigenvalue match rule, which can prevent wrong eigenvalue match result and thus wrong calibration result effectively. Simulation results verify its effectiveness and robustness.]]></description>
<pubDate>2022/10/8 15:52:00</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[张道明]]></author>
</item>
<item>
<title><![CDATA[A numerical and experimental study of the functioning of a typical linear pyrotechnic separation device]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105100000001]]></link>
<description><![CDATA[At present, the optimal design of linear pyrotechnic separation devices is mostly dependent on experiments, which is not only costly but also low efficient. Herein, a numerical model is developed with arbitrary Lagrangian-Eulerian method for a typical linear pyrotechnic separation device. The numerical model is validated via pyrotechnic separation experiments and photonic Doppler velocimetry (PDV), and is found to have reasonable accuracy. Then, the model is applied to study the mechanical mechanism of the transient separation process of the pyrotechnic separation device. The influence of multiple factors on the critical characteristic parameters is also studied quantitatively, such as effective plastic strain of the key areas of the device. It is found that the linear density of the detonating cord, the bottom radius of the v-notch of the separation plate have significant influence on the separation process. In addition, the material of the protection plate, the angle of the v-notch and the dimension of the rectangular notch of the separation plate also have a certain influence on the separation process, however, the influence is less than that exerted by the linear density of the detonating cord and the bottom radius of the v-notch. The study provides a foundation for optimal design of the typical linear pyrotechnic separation device.]]></description>
<pubDate>2022/10/8 15:50:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[王光宇,王晓鹏,王雨时,闻泉]]></author>
</item>
<item>
<title><![CDATA[Research on vibration interference and its suppressing method of underwater acoustic detection equipment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101140000003]]></link>
<description><![CDATA[Aiming at the problem that the carrier vibration of underwater detection system interferes with the micro-Doppler spectrum of target echo signal, the approximate multiplicative expression of interference was derived from the basic principle of interference generation. With obtaining vibration interference data, an interference suppression algorithm for multiplicative interference was proposed. Meanwhile, the error caused by the approximate algorithm was analyzed according to the approximate conditions when the multiplicative expression of interference was derived. The simulation results show that the proposed method can effectively suppress the interference which is derived from vibration of underwater acoustic detection system and imposed on the micro-Doppler spectrum, and the algorithm error can be ignored generally.]]></description>
<pubDate>2022/10/6 20:49:08</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[谭思炜,唐波]]></author>
</item>
<item>
<title><![CDATA[Cooperative airspace allocation of AEW and electronic jamming aircraft in attacking operation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011230000002]]></link>
<description><![CDATA[In this paper, the problem of cooperative airspace allocation of aircraft early warning (AEW) and electronic jamming aircraft in attacking operation was discussed. Firstly, based on the parameter treatment of multi-types Aircraft airspace allocation problem, and the basic principle of AEW and electronic jamming aircraft performing combat mission, the quantitative decision model of airspace allocation was constructed; Secondly, according to the characteristics of cooperative operation, the model of coordination efficiency evaluating was proposed and feasibility algorithm process was put forward. Finally, the relationship between angle of attack, vertical pattern factor of electronic jamming aircraft and cooperative airspace allocation was simulated, and the relevant conclusion with certain significance for practical guiding was drawn.]]></description>
<pubDate>2022/10/2 12:35:18</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[程东升,蒋伟,祁炜,武文]]></author>
</item>
<item>
<title><![CDATA[Task planning of heterogeneous UAV swarm based on balanced clustering market auction mechanism]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011300000001]]></link>
<description><![CDATA[Aiming at the global task planning problem of large-scale heterogeneous unmanned aerial vehicle (UAV), a task planning method based on balanced clustering market auction mechanism is proposed. Firstly, scene of completing tasks by collaborative UAVs is analyzed, and a task planning model with high generality is established by combining the advantages of task clustering and UAV coalition. Considering the demand of load balance of UAVs, a new balanced clustering market auction algorithm which comprehensively considers the travel consumption and task consumption is established by integrating and improving k-means algorithm and market auction mechanism. The balance parameter is introduced into the auction process to balance the load between UAV coalitions. By solving the traveling salesman problem to modify the balance parameter, the total cost can be continuously reduced while ensuring the load balance. The simulation results show that the proposed method can complete the complex task planning of heterogeneous multi-UAV in a short time, ensure the load balance of UAV coalitions, and have good performance in total cost and total time, exhibiting certain practical application value.]]></description>
<pubDate>2022/10/2 12:15:22</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[高东,潘登,郑建华]]></author>
</item>
<item>
<title><![CDATA[Magnus Effect of electromagnetic launch hypervelocity spinning projectile]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011300000002]]></link>
<description><![CDATA[Compared with the traditional gunpowder bullets, electromagnetic launch bullets have the advantages of high muzzle velocity and long fire range. However, the bullet shape is no longer axisymmetric because of the armature groove at the tail, resulting in unique aerodynamic characteristics. Based on the three-dimensional unsteady NS equation, the aerodynamic characteristics of electromagnetic projectile were analyzed by using the sliding grid technique. Results show that for the high-speedypervelocity spinning electromagnetic projectile, the Magnus effect comes from the interaction of shock layer distortion and the upwind area variation of the armature arm. The aerodynamic force and the moment varies periodically with the roll angle   due to the periodic variation of the upwind area of the armature arm, and the Magnus moment reaches the minimum and the maximum at the roll angle of 45° and 135°, respectively. The influence of the armature arm groove is remarkable, which not only worsens the Magnus effect (increased by more than 50% at 135°), but also makes the pressure center move forward periodically (the absolute forward amount is up to 5%). Furthermore, with the increase of spinning speed, the increase of the Magnus moment and the pressure center move-forward effect become more and more significant, which is harmful to the dynamic stability of the projectile.]]></description>
<pubDate>2022/9/30 17:10:16</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杜佩佩,冯军红,李开,李湘平,鲁军勇,张晓]]></author>
</item>
<item>
<title><![CDATA[Centimeter-level Ocean precise relative positioning by combining real-time data products and BeiDou short-message]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011120000002]]></link>
<description><![CDATA[In view of the wide demand for precision positioning in the Ocean and the high cost of traditional precision positioning services, it is proposed to use BeiDou short-message equipment to transmit navigation observation data, combined with real-time data products, to achieve low-cost centimeter-level precise relative positioning in the Ocean. In order to overcome the shortcomings of low transmission frequency of short messages, for the first time, the two technologies of fusion spatial relative positioning and precise point positioning are used to encrypt coordinates outside the minute interval. avoiding the accumulation of errors in the encrypted coordinates of the traditional time-relative method. Simulation experiments were carried out based on static and dynamic Ocean observation data. The results show that the new method can achieve centimeter level positioning in both horizontal and vertical directions, and whether it is 1 min interval or 5 min time interval the results show that the new method is not sensitive to the length of time interval.]]></description>
<pubDate>2022/9/30 13:40:49</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[董蔺,贺凯飞,姬生月,王振杰,杨浩]]></author>
</item>
<item>
<title><![CDATA[Real-time energy management strategy for electric drive armored vehicles with load power prediction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011100000003]]></link>
<description><![CDATA[Aiming at the lack of load power prediction function in electric drive armored vehicles leading to the lag of control action, a real-time energy management strategy with higher load power prediction accuracy was proposed. Based on analyzing the whole vehicle"s structure, each power source"s mathematical model was established using theoretical analysis and data fitting methods. Combining the two forecasting methods of auto regressive integrated moving average model and adaptive Markov chain, a combination forecasting method of non-stationary trend load power was designed. Under the framework of nonlinear model predictive control, a multi-objective optimization function was constructed, and the sequential quadratic programming method was utilized to solve the optimal control command in real-time in the finite time domain. The multi-power source was optimized and coordinated. Relying on the hardware-in-the-loop simulation platform, multi-road driving experiments were carried out, and energy management control effects with or without power prediction method were compared. The results show that the improved real-time energy management strategy has good predictability for future load power. It can significantly optimize the coordinated control process of multiple power sources, improve vehicle fuel economy, stabilize bus voltage and battery SOC (state of charge). Moreover, it has specific reference significance in engineering application scenarios under traditional model predictive control.]]></description>
<pubDate>2022/9/30 11:34:27</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈路明,廖自力,魏曙光,张  征]]></author>
</item>
<item>
<title><![CDATA[Research on coil support design and mechanical simulation of high magnetic field environment simulation system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101200000001]]></link>
<description><![CDATA[Strong electromagnetic impact environment is of great significance to test the reliability and safety of high-precision electromagnetic equipment in complex environments. The core actuator that generates a strong magnetic environment is the coil, whose performance directly restricts the quality of a strong magnetic environment. Therefore, in addition to ensuring the electromagnetic characteristics of the coil in the strong magnetic environment, it is also necessary to ensure that the coil bracket has sufficient mechanical characteristics. Based on the completion of the electromagnetic design of the coil, this paper establishes the finite element calculation model of the overall system of the coil support structure according to the three-dimensional structure diagram of the coil, material configuration, mass distribution, connection mode between components and coil fixation mode. The static and stability numerical calculation and analysis of the coil support system are carried out, and the strength of the connector is checked, which provides a reference for the coil support structure. For the first time, this paper designs and analyzes the overall mechanical structure of the coil used in the practical large-scale high-intensity magnetic impact system. The application background is relatively new, and the simulation calculation process is carried out in strict accordance with the actual size, which is highly consistent. It provides a solid foundation for the subsequent construction of the high-intensity magnetic environment generator, and fills the gaps in the mechanical structure analysis and actual construction of the large-scale high-intensity magnetic impact coil system in China.]]></description>
<pubDate>2022/9/30 11:29:20</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[刘琪,孙兆龙,武晓康,周国华]]></author>
</item>
<item>
<title><![CDATA[SOLAR RADIATION INTENSITY DISTRIBUTION COMBINED WITH STRATOSPHERIC AIRSHIP FLYING GESTURE]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101060000001]]></link>
<description><![CDATA[The distribution of solar radiation intensity on the upper surface of the stratospheric airship is an important factor affecting the output performance of photovoltaic arrays. The aim of this paper was to analysis the influence of the dynamic change of the flight attitude of the stratospheric airship on its upper surface solar radiation intensity distribution characteristics and establish a calculation model of interactive coupling between the airship dynamics model and the solar radiation physical model. By using this mode, a certain airship example was calculated, the solar radiation intensity distribution on the upper surface of the stratospheric airship was also proposed under flight yaw and pitch angle change, and the characteristics of solar radiation intensity affected by airship flight attitude. The result can be used to guide the optimized layout and array configuration of the solar array on the stratospheric airship.]]></description>
<pubDate>2022/9/30 11:04:29</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李兆杰,王旭巍,王岩,张衍垒]]></author>
</item>
<item>
<title><![CDATA[Application of incremental meta-learning IDBD algorithm in signal detection of shaft-rate electric field]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101150000001]]></link>
<description><![CDATA[In order to improve the detection ability of weak ship shaft-rate electric field in the background of marine environment electric field, the traditional adaptive line enhancement (ALE) based on Least Mean Square (LMS) algorithm is improved, and an ALE based on Incremental Delta-Bar-Delta (IDBD) algorithm is proposed. The algorithm is used to process the measured shaft-rate electric field signal data generated by the ship scale model. The results show that the algorithm can effectively separate the weak shaft-rate electric field signal from the broadband background noise under the condition of low signal-to-noise ratio(SNR). Compared with the ordinary ALE, this algorithm has a more significant effect in improving the SNR of the signal, and has a faster convergence speed and a smaller steady-state error, which greatly improves the ability to test shaft-rate electric field of the ship.]]></description>
<pubDate>2022/9/30 9:34:53</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[卞强,欧阳华,童余德,曾文仕]]></author>
</item>
<item>
<title><![CDATA[RESEARCH ON ELECTROMAGNETIC RADIATION CHARACTERISTICS OF TYPICAL EXPLOSIVES]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012020000001]]></link>
<description><![CDATA[A set of electromagnetic radiation measurement devices based on short-wave omnidirectional antennas and ultra-wideband omnidirectional antennas was designed to measure the electromagnetic radiation generated by TNT explosions, and the data was processed to obtain electromagnetic radiation characteristics.The results show that the explosive mass has a significant effect on the time domain characteristics of the electromagnetic radiation generated by the explosion. The greater the mass, the shorter the delayed response of the electromagnetic signal, the longer the duration, and the earlier the peak time. 60kg TNT explosion generated electromagnetic radiation signal frequency is mainly concentrated below 100 MHz, the most concentrated energy is in the 0-50 MHz band, the explosive composition has the largest effect on the spectrum distribution, and the electromagnetic radiation spectrum distribution generated by different components of the explosive explosion has obvious specificity. Electromagnetic radiation intensity generated by dynamite explosion shows a strong correlation with the distance from the burst center. The intensity decreases with the distance increasing, and the magnitude of the decrease is large. Charge configuration and detonation mode will change the geometric movement pattern of the explosive during the explosion process, resulting in the non-uniformity characteristics of the explosion electromagnetic radiation propagation.]]></description>
<pubDate>2022/9/29 14:45:02</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[崔元博,孔德仁,张学辉,张逸飞]]></author>
</item>
<item>
<title><![CDATA[Matrix Information Geometric Detector Based on Manifold Filter]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012080000001]]></link>
<description><![CDATA[Aiming at the problem of signal detection in small sample and nonhomogeneous clutter, a matrix information geometric detector based on manifold filter was proposed. The signal detection problem was transformed into a geometric problem on the matrix manifold. The correlation of each sample data was modeled as a Toeplitz positive definite matrix. On the basis, each matrix was replaced by a weighted smoothing filter of its surrounding matrices. The weighted smoothing filter removed part of the clutter energy and improved the discrimination between the target and the clutter. The geometric mean of a set of secondary sample data was calculated. By comparing the distance between the matrix under test and the geometric mean matrix with the detection threshold, the signal detection was realized. Simulation results demonstrate the superiority of the detection performance in small sample and nonhomogeneous clutter.]]></description>
<pubDate>2022/9/29 8:51:30</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[程永强,华小强,王宏强,王勇献]]></author>
</item>
<item>
<title><![CDATA[Variable-bandwidth design method of random vibration environmental test criteria for launch vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107230000001]]></link>
<description><![CDATA[A variable-bandwidth design method based on the principle of energy equivalence was proposed for the random vibration environmental test condition of launch vehicles. By adopting the fractional octave frequency band data processing method and keeping the RMS (root mean square) in every frequency band identical with the one of the original power spectral density, the exorbitant RMS problem of the traditional constant-bandwidth random vibration environmental test condition was avoided. To validate the capability of the method, random vibration simulations of a typical pipeline were conducted. The results indicate that the method is able to assess the product effectively rather than excessively. The proposed variable-bandwidth design method of the random vibration environmental test condition offers an efficient alternative for the conditions design in the random-vibration environment test of launch vehicles]]></description>
<pubDate>2022/9/28 18:56:57</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[姜人伟,李道奎,潘忠文,曾耀祥]]></author>
</item>
<item>
<title><![CDATA[The rarefaction effect on the stagnation heat flux in hypersonic cylinder flows]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203040000001]]></link>
<description><![CDATA[There are still obvious differences in the prediction of heat flow at the stagnation point of rarefied hypersonic due to different methods. The continuous method based on Fourier heat conduction law overestimates the heat flow, which is usually attributed to wall slip / jump and nonlinear heat conduction. The correction work based on the above two phenomena can not be well consistent with the results of direct simulation Monte Carlo (DSMC) method. In this paper, three heat flow expressions, Fay Riddell relation, DSMC method and Fourier heat transfer based on DSMC flow field temperature, are used to compare and study the results of different incoming Knudsen (Kn) numbers and different incoming mach (Ma) numbers respectively, in order to give a new understanding of overestimating stagnation point heat flow in rarefied flow region by classical continuous method from a micro perspective. The results show that the rarefaction effect of stagnation heat flow is reflected in three aspects: one is the temperature jump, which weakens the temperature gradient and reduces the stagnation heat flow; The second is translational nonequilibrium, which makes Fourier""s heat conduction law no longer applicable and underestimates heat flow; The third is the wall constraint, which makes Fourier""s heat conduction law overestimate the heat flow within 3 times the molecular average free path from the wall. In addition, based on micro statistics, this paper puts forward parameters that can quantitatively characterize the translational nonequilibrium degree, and obtains the share of nonequilibrium heat flow in stagnation heat flow. This part of heat flow is directly proportional to kn number and has a linear positive correlation with Ma number.]]></description>
<pubDate>2022/8/24 16:01:04</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[何淼生,李宪开,柳军,张志雨,朱斌镔]]></author>
</item>
<item>
<title><![CDATA[Prediction Method of Port Blocking Failure in High Performance Interconnection Networks]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011080000001]]></link>
<description><![CDATA[With the increase of system scale, chip power consumption and link rate, the overall failure rate of high-performance interconnection networks will continue to rise, and the traditional operation and maintenance methods will be difficult to sustain, bringing great challenges to the overall reliability and availability of HPC. In this paper, we propose a prediction model combining unsupervised classification algorithm and time series algorithm for serious interconnection network failures such as network port blocking. In this model, the symptomatic rules are extracted from the history information of the switch port status register and a new feature vector is formed. The K-means clustering algorithm is used to learn and classify the feature vectors. In the prediction, the DES algorithm is used to predict the port state in the future through a combination of the current state of the port, and a new feature vector is obtained and K-means algorithm is used to predict whether the port blocking failure will occur. On this basis, we can use the topology information to build independent sub prediction models with ToR switch ports and Spine switch ports respectively, so as to further improve the accuracy of prediction. The experimental results show that the prediction model can maintain the recall rate of 88.2%, and reach the accuracy rate of 65.2%. It can provide effective early warning and guidance for the operation and maintenance personnel in the actual system.]]></description>
<pubDate>2022/7/27 12:17:04</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[胡小弢,唐付桥,王  强,徐佳庆,杨汉芝,张  磊]]></author>
</item>
<item>
<title><![CDATA[The study on the digital transformation of defense advanced-research management: digital twin defense advanced-research]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202204290000004]]></link>
<description><![CDATA[In the era of digital economy, defense advanced-research management should actively face the trend of digital transformation and build a management system that is compatible with the development of the digital economy. By studying the lessons learned from civil R&D plans as well as the transformation property of digital economy, the main difficulties and requirements faced by the digital transformation of defense advanced research management are summarized and analyzed. Then, a new paradigm for improving defense advanced-research management - digital twin defense advanced-research, is put forward, in which digital twin is employed to help the digital transformation of defense advanced-research management. Furthermore, the compositions, features, capabilities, key technologies and construction stages are elaborated explicitly, in order that digital twin defense advanced-research can play a reference and promotion role for innovating the defense advanced-research management.]]></description>
<pubDate>2022/7/25 21:29:09</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[马亮,,,]]></author>
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<title><![CDATA[Research on the penetration resistances of ceramic/ thin steel composite targets impacted by high-velocity fragments]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109100000003]]></link>
<description><![CDATA[To explore the high-velocity-penetration resistant mechanism of ceramic/thin steel composite targets (hereafter called CS targets), the failure modes and penetration resistances of CS targets with 3mm-thick ceramic layer and 0.6mm-thick steel layer were analyzed through ballistic tests, and compared with the monolithic steel plates of identical areal densities. Based on the energy conservation principle, a theoretical prediction model for high-velocity penetration of CS targets was established. Comparison between predictions and testing results was conducted. Results show that the failure modes of rear thin steel layers in CS targets change from shear plugging to petalling due to the existence of front ceramic layers, which greatly promotes the anti-penetration energy-absorption efficiency of rear thin steel layers. Therefore, the overall penetration resistances of CS targets are superior to and above 15% higher than the monolithic steel counterparts. The predicted residual velocities of projectiles after perforation of CS targets correlate well with those experimental results, and the relative errors are all within 5%, which proves the rationality and validity of present theoretical mode.]]></description>
<pubDate>2022/7/25 21:28:34</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈长海,程远胜,万昌召,张瑞刚]]></author>
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<title><![CDATA[Defect quantification based on super-resolved ultrasonic image]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106300000002]]></link>
<description><![CDATA[Defect quantification based on the ultrasonic image is a key problem in the field of ultrasonic phased array imaging detection. Resolution is an important indicator to evaluate the quality of ultrasonic image. The higher the resolution, the better the quality of ultrasonic image, which can better evaluate the tested object. PC-MUSIC is introduced to study the defect quantification based on the super-resolved ultrasonic image. The ultrasonic array data can be collected via full matrix capture process, and then pre-processed to extract the scattered signals related with defect. The scattered signals are post-processed by PC-MUSIC to obtain the ultrasonic image with super resolution. The ultrasonic image is analyzed to extract the lateral cross section, the -6dB main lobe width of which is defined as the assessed length of defect. The experimental system has been built, and a block of Al with a 10mm-long slot has been machined as the tested object. It is shown that PC-MUSIC, under the proper dimension of signal subspace, can assess the length of defect, with an error less than 10%.]]></description>
<pubDate>2022/7/25 21:28:10</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[樊程广,高斌,杨磊,余孙全]]></author>
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<title><![CDATA[Comparison of Output 3.5 um Laser Propertiesby Optical Parametric Oscillation of BaGa4Se7 and KTiOAsO4]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011050000003]]></link>
<description><![CDATA[In order to compare the mid infrared laser performance output by the new nonlinear crystal BaGa4Se7 (BGSe) and the mature commercial nonlinear crystal KTiOAsO4 (KTA), the 1.06 μm laser was used to pump BGSe (56.3 °, 0 °, type-I) and KTA (90 °, 0 °, type-II-A) to output ~ 3.5 μm laser. The pump oscillation threshold of KTA and BGSe was 52.6 mJ (the theoretical value was 46.11mJ) and 20.6 mJ (the theoretical value was 18.32mJ) respectively when the pump wavelength was 1064nm, the pulse width was 13 ns, the beam diameter was 4 mm and the OPO cavity length was 90 mm. The  〖?λ〗_2/?T of BGSe and KTA was 3.20nm / ℃（the theoretical value was 2.49nm / ℃）and 0.073nm/℃（the theoretical value was 0.077nm / ℃）. The output linewidth of BGSe and KTA was 4.71nm and 2.45nm respectively. The experimental results of the pump oscillation threshold and the temperature tuning range fit the theoretical simulation well, and the results show that BGSe is better than KTA in these two aspects. But the output linewidth of KTA is narrower than that of BGSe. Our experimental results indicated that BGSe may find practical application in the future.]]></description>
<pubDate>2022/7/25 21:27:36</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[卞进田,孔辉,孙晓泉,徐海萍,叶庆]]></author>
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<title><![CDATA[Prediction of probability of successful water-exit for underwater vehicles under wave action]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011030000001]]></link>
<description><![CDATA[The method of predicting the success probability of water emergence of an underwater vehicle under measured waves has been studied, which is for submarine underwater operations. The calculation model of water-exit attitude parameters of the underwater vehicle is established based on Boundary element method (BEM). The water-exit attitude parameters of underwater vehicles under different wave conditions are calculated. The regular wave database is composed of water-exit attitude parameters under different wave conditions. The measured sea conditions in a certain period of time in the Bohai Bay are used as the launch environment. A wave height probability distribution model conforming to the Rayleigh distribution is established. the pitch angle of the tail touching water is taken as the judging condition. The prediction of probability of water-exiting success under measured waves is realized. The calculation results show that considering the worst conditions, the water pitch angle decreases with the increase of wave height , and with the same wave height, due to the influence of water phase, the change of pitch angle shows the law of cosine change The prediction method has certain reference value for submarine combat to determine the launch timing and provide reference for the successful probability of underwater launch.]]></description>
<pubDate>2022/7/25 21:27:04</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[孙龙泉,]]></author>
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<title><![CDATA[A Deep Learning Method for Multiplexing Hardware Counters]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201030000001]]></link>
<description><![CDATA[The accuracy of MPX results drops significantly when more hardware events need to be collected simultaneously. It is due to the mismatch between numerical fitting methods and hardware events. Therefore, we proposed a state-of-art deep learning method to achieve higher accuracy of MPX estimation. Firstly, by analyzing the similarity between the MPX results and the real data, we proved that hardware counts gained by running the same program is linear correlated. Secondly, by applying the MLP and Bi-GRU model, we fitted the MPX data. Finally, we proposed a new metric DTW-cost to judge the accuracy of MPX result based on dynamic time warping (DTW), which is a theory in time sequence analysis. The experiment results show that when sampling 15 hardware events simultaneously, average result of 13 High Performance Computing applications gained by the MLP model has a 10.53% higher relative accuracy than the fixed interpolation method. The MLP model has a 19.8% improvement at most. On the hardware events which MLP has a relatively poor performance, the Bi-GRU model improved relative accuracy score by 28.8% on average.]]></description>
<pubDate>2022/7/25 21:26:37</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[林新华,王鎏振,王一超]]></author>
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<title><![CDATA[Detection and Optimization Approaches for Synchronization Bottlenecks in Parallel Programs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112230000001]]></link>
<description><![CDATA[Improper locks in parallel programs may lead to performance bottlenecks. This paper proposes an approach called IdeSync to detect and optimize synchronization bottlenecks. IdeSync leverages the static analysis to obtain the synchronized methods and blocks, and then constructs a static synchronization dependency graph. It employs path-based dynamic analysis to build synchronization dependencies. A synchronization dependency graph is finally obtained. To find performance bottlenecks in the synchronization dependency graph, performance bottlenecks are detected by monitoring performance changes of a critical section by increasing the workload. Finally, optimized solution is recommended. The experimental results on 12 real-world projects show that a total of 72 synchronization bottlenecks is detected. All these bottlenecks are optimized based on IdeSync’s suggestion to achieve performance improvements, which shows that IdeSync can effectively detect and optimize synchronization bottlenecks.]]></description>
<pubDate>2022/7/25 21:26:12</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李柳旭,张杨]]></author>
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<title><![CDATA[HPC 2020 A Prediction Algorithm for Failed Batch Jobs in Co-located Cloud]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011230000001]]></link>
<description><![CDATA[Co-location is an important way for data centers to improve resource utilization. However, in co-located cluster, batch jobs may fail due to resource shortage and other troubles. If the failed jobs execute repeatedly in the cluster, resulting in the resource consumption cannot be ignored. Therefore, to carry out different batch jobs' failure risks, we first used k-means algorithm to divide batch jobs into four categories. Then, on the basis of classification, the two-layer nested classification model (TLNM) is proposed and the prediction algorithm based on TLNM is implemented. Experiment results based on Ali Trace 2018 data set show that the ROC curve of this algorithm is significantly better than other commonly used classifiers, and the area under the ROC curve (AUC) can reach 0.978, indicating that this algorithm has good classification performance. At the same time, the Recall can reach 0.951. Through the Confusion Matrix, it can be seen that the TLNM algorithm can accurately predict the failed batch jobs.]]></description>
<pubDate>2022/7/25 21:25:27</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[彭绍亮,石方,]]></author>
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<title><![CDATA[Synchrotron Radiation Source Image Compression Based on Difference and Neural Network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011170000001]]></link>
<description><![CDATA[The common image lossless compression methods cannot work well. Thus, a lossless compression method for synchrotron radiation source images based on image difference and neural network was proposed. Using the image difference method to reduce the linear correlations among images. Training the neural network to learn the nonlinear correlations in the images sequence, and compressing the pixel value with arithmetic coding using the predicted distribution. To reduce the predicting time and coding time, splitting the pixel value into two parts for parallel compression. The tests based on the images of Shanghai Synchrotron Radiation Facility show that our method can improve more than 20% in compression ratio compared to PNG/JPEG2000/FLIF, and the pixel value split can reduce 30% of the time in predicting and coding.]]></description>
<pubDate>2022/7/25 21:24:51</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈刚,程耀东,符世园,汪璐]]></author>
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<title><![CDATA[A GPU resource management for computational fluid dynamics]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201130000001]]></link>
<description><![CDATA[Aiming at the problem of low resource utilization of graphics processing unit (GPU) in the process of solving computational fluid dynamics (CFD), a CFD-oriented GPU resource optimization management scheme is proposed. Based on the characterization of the CFD and tasks running concurrently, a reasonable scheduling scheme is designed. By dynamically changing the startup scale and time of different tasks, our method is able to reduce resource competition while improving the effective use of GPU resources. The experimental results show that compared with the baseline method, the average speedup ratio of our proposed resource management scheme reaches 1.64x speedup under different task scales, and the use of GPU hardware resources has also been significantly improved.]]></description>
<pubDate>2022/7/25 21:23:20</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[卢宇彤,翁跃,张曦,张献伟]]></author>
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<title><![CDATA[Predicting the job running time with job name hierarchical clustering algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112280000001]]></link>
<description><![CDATA[Predicting the job running time is beneficial to improve the scheduling performance of the system. Traditional clustering algorithms are difficult to cluster similar job names.In order to better cluster similar jobs, the job name hierarchical clustering algorithm of letter-structure-number was constructed by analyzing the semantic importance of their components. Taking the real data of two supercomputers as an example, the data clustered by this algorithm was used to train the model. The experimental results show that the prediction accuracy of the model is better than that of the traditional method and the overall prediction accuracy is 70%~80%.]]></description>
<pubDate>2022/7/25 21:22:31</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[王桂娟,吴亚东,鲜港,杨文祥,喻杰,,,]]></author>
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<title><![CDATA[Wavefront aberration analysis for misaligned optical systems based on the coma-free pivot point]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104210000001]]></link>
<description><![CDATA[Based on the Nodal Aberration Theory, a special case of misalignments for reflective optical systems, which satisfying the condition of the coma-free pivot point, was studied. Under the effect of the special misalignments, the full field display aberration characteristics of the 3rd order coma and the 3rd order astigmatism were analyzed, the analytical calculation formula of the two nodes position of the 3rd order astigmatism was established. It was found that the 3rd order coma would not change, and one node of the 3rd order astigmatism would locate near the central field of view (FOV), which revealed the drawback of using only coma-zero in axial FOV as the criterion of perfect alignment during the traditional optical assembly. Based on the analysis of wavefront aberration, a method to judge whether the system is aligned well based on the variance of wavefront aberration in only one axial FOV after introducing quantitative misalignments was proposed. A type of two-mirror optical system was adopted to simulate the effect of misalignments on wavefront aberration, the results show that the model and the method established in this paper can quantitatively analyze the two nodes position of the 3rd order astigmatism and verified the validity of the proposed judgement method for system assembly.]]></description>
<pubDate>2022/7/24 23:58:24</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[白向娟,罗自荣,尚建忠,吴伟,于乃辉]]></author>
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<title><![CDATA[Autonomous Task decision-making method of robot ecosystem for unmanned scenes]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202203080000001]]></link>
<description><![CDATA[Based on the typical characteristics of natural ecosystems, we put forward the concept of robot ecosystem. Through the intelligent coordination and complex evolution of cluster robots, life features such as self-sustaining, self-replication and self-evolution emerge, enabling them to achieve long-term survival, reproduction and evolution under unmanned conditions, and perform specific tasks. According to the requirements of Autonomous Task decision-making in typical task scenarios of robot ecosystem, the characteristics of different machine learning task decision-making methods are analyzed, and the decision tree model and neural network model of Autonomous Task decision-making in robot ecosystem are established. The analysis shows that the accuracy of the two models is between 85%~90%, and both have good stability. The results show that the Autonomous Task decision-making problem of robot ecosystem can be well solved by machine learning methods such as decision tree and neural network, so as to provide technical support for task application in unmanned scenes.]]></description>
<pubDate>2022/7/24 23:30:58</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈小前,李泰博,刘红卫,徐磊,张育林]]></author>
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<title><![CDATA[HPC 2020-Software Crowdsourcing Tasks Assignment Supporting Fuzzy Measurement of Workers’ Qualification and Role Collaboration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011050000001]]></link>
<description><![CDATA[The existing researches on crowdsourcing task assignment do not involve in measuring the uncertainty of workers’ qualification, and not achieve the collaborative assignment in many-to-many mode between tasks and workers from the angle of crowdsourcing platform. Thus, an assignment approach of software crowdsourcing tasks is proposed supporting the fuzzy measurement of workers qualification and role collaboration. Integrating the past performance of workers and the expectation of tasks’ demands, this approach employs fuzzy interval numbers to evaluate the multiple attributes ability matching degree, and aggregates the comprehensive qualification via the fuzzy analytic hierarchy process method. By introducing the role-based collaboration theory, the many-to-many software crowdsourcing tasks assignment is formulated as a combinatorial optimization problem related to a task set and a worker group, and the constraints, including the tasks’ weights, quantity of workers and potential conflicts, are used to enhance the efficiency and success rate of tasks assignment. A solution based on the CPLEX package is presented to solve the problem. Simulation experiments show that this method can efficiently and accurately realize the collaborative allocation of crowdsourcing tasks under the premise of ensuring the best completion quality of global tasks.]]></description>
<pubDate>2022/7/24 23:23:12</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈跃鹏,黄卓轩,娄小平,马华,唐文胜]]></author>
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<title><![CDATA[Accelerating Parallel Reduction and Scan Primitives on ReRAM Architectures]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112270000001]]></link>
<description><![CDATA[Reduction and scan are two critical primitives in parallel computing. Thus, accelerating reduction and scan show great importance. However, the Von Neumann architecture suffers from performance and energy bottlenecks known as “memory wall” due to the unavoidable data migration. Recently, non-volatile memory (NVM) such as resistive random access memory (ReRAM), enables in-situ computing without data movement and its crossbar architecture can perform parallel matrix-vector multiplication (GEMV) operation naturally in one step. ReRAM-based architecture has demonstrated great success in many areas, e.g. accelerating machine learning and graph computing applications, etc. This paper proposed parallel acceleration methods for reduction and scan primitives on ReRAM-based Processing in memory (PIM) architecture and focused on the computing process in terms of GEMV and the mapping method on the ReRAM crossbar to reduce power consumption and improve performance. Compared with GPU, the proposed reduction and scan algorithm achieved substantial speedup by two orders of magnitude, and the average acceleration ratio could also reach two orders of magnitude. The case of segmentation could achieve up (on average) to five (four) orders of magnitude. Meanwhile, the power consumption decreased by 79%.]]></description>
<pubDate>2022/7/24 23:07:01</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[段懿洳,戢昊男,金洲,刘伟峰,伊恩鑫]]></author>
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<title><![CDATA[Parallel Job Characteristic Analysis Toolkit Based on Job Accounting Logs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112290000001]]></link>
<description><![CDATA[Workload analysis is an important direction in the field of high performance computing management research. Job accounting log analysis toolkit is the basis of workload analysis. However, popular job accounting log, such as ‘sacct’, does not support indexing by application name and cannot give statistical data of each application, which make it difficult to stat workload characteristics from application’s perspective. To solve this problem, an application name marking method of job accounting log based on keyword fuzzy matching was proposed, combined with a generalized job log data description model and a flexible extensible software architecture based on plugin mechanism. A parallel job feature statistical analysis tool JobCAT(Job Characteristic Analysis Toolkit) was implemented. Based on tests with 171038 actual job logs from a domestic peta-scale supercomputer system in operation, job log recognition ratio could reach up to 98.97%. Currently, JobCAT supports for generating parallel job’s data analysis report between arbitrary statistical interval with one click to run, includes 7 kind of plugins and 29 report tables, which lays a good foundation for further research on modeling and analysis of parallel job’s workload characteristics.]]></description>
<pubDate>2022/7/24 22:38:31</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[刘旭,罗红兵,莫则尧,田鸿运,武林平]]></author>
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<title><![CDATA[Experimental and numerical research on reducing resistance and increasing speed for a segmented-track amphibious vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012210000001]]></link>
<description><![CDATA[In order to study the hydrodynamic performance of a segmented-track amphibious vehicle, and realize reducing resistance and increasing speed, stern flaps were applied to the transom stern. Model towed tests and numerical simulations were carried out and both the results agreed well with each other. The longitudinal position of the center of gravity, the length and angle of the stern flap were studied and the resistance components were analyzed. The research results showed that with the longitudinal position of center of gravity between 540-560mm, the vehicle suffered least resistance. At the velocity between 3 and 5 m/s, the stern flap with a length of 156mm and an included angle of 10°with the horizontal plane has the most obvious drag reduction effect. Compared with the original naked vehicle body, the drag reduction rate is 34.3%. The installation of the stern flap can increase the hollow area at the rear of the vehicle, which is equivalent to increasing the length of waterline, thus increasing the length-to-width ratio. This research method shows that the drag reduction growth of amphibious vehicle can be effectively realized by properly adjusting the center of gravity and optimizing the parameters of wave plate.]]></description>
<pubDate>2022/7/24 21:58:59</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[郝军,孙承亮,唐源江,徐小军]]></author>
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<title><![CDATA[Optimizations of graph coloring method for unstructured finite volume Computational Fluid Dynamics on GPU]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011090000001]]></link>
<description><![CDATA[With rapid development of High Performance Computing, more and more GPGPU (general purpose graphic processing units) are used by Computational Fluid Dynamics (CFD) applications, due to high performance and low power consumption. Race condition is one the common issue in unstructured finite volume CFD GPU implementation, which could have major impact on the computational efficiency. Graph coloring is one of the efficient methods for resolving threads race condition. Graph coloring was used to address race condition for the two typical computing procedures, including the flux summation and the calculation of local maximum pressure. There were three optimizations were applied for graph coloring including shared memory, the reordering of volume and face indices, and the reordering of face variables. . The 3D aerodynamics application with a series of mesh sizes was used in the performance test by double and single precision floating point operations on GPU NVIDIA Tesla V100 and K80. The performance tests show that Shared memory is not obvious in performance. Furthermore, the reorder of volume and face indices reduces the performance of graph coloring. Finally, it is found that the reorder of face variables can increase performance remarkably. Specifically, the performance of graph coloring is increased by around 20% on V100 and 15% on K80.]]></description>
<pubDate>2022/7/24 11:39:10</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[Guo Xiaohu,杜云飞,刘杨,卢宇彤,孙旭,张曦]]></author>
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<item>
<title><![CDATA[Node Priority Optimization in Distributed Heterogeneous Clusters]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011220000001]]></link>
<description><![CDATA[Node priority is often used to evaluate the performance of cluster nodes, and it is of great importance providing suitable weight for each priority evaluation index. AHP (Analytic Hierarchy Process) was chosen to establish the evaluation index system of node priority, and the initial weight of each index was calculated. BP neural network was then used to optimize the weights obtained using AHP. The input of the BP neural network was a node"s performance index values collected during its execution using Ganglia, and the output of the network was the corresponding priority of the node. After the network training, the weight matrix was obtained and used to calculate the optimized weights. The experimental results show that the cluster node priority evaluation model based on AHP and BP can evaluate the node performance more accurately. Compared with the default resource allocation algorithm of Spark and the unoptimized weight SDASA algorithm, the cluster performance is improved effectively by using the node priority provided by this new model. When running the same kind of load with different amount of data, the average cluster performance increases by 16.64% and 9.76%; and when running different loads with the same amount of data, the average performance of the cluster increases by 12.49% and 6.54%, respectively.]]></description>
<pubDate>2022/7/23 22:10:28</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[胡亚红,毛家发,邱圆圆]]></author>
</item>
<item>
<title><![CDATA[Joint tracking and classification algorithm of non-ellipsoidal extended target]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201060000005]]></link>
<description><![CDATA[By making full use of the target size and shape information, a non-ellipsoidal extended target (NEET) joint tracking and classification (JTC) algorithm called NEET JTC is proposed in this paper based on random hypersurface model (RHM). In the proposed algorithm, the target extent state is modeled as star-convex shape, which is used as the feature for target classification. By modeling the target class-related prior information with vector form, constructing its relationship with the simultaneous extent state, and integrating it into the framework of Bayesian filter, the joint processing of tracking and classification is realized. In order to solve the implementation difficulty of NEET JTC algorithm due to the high dimensionality of state and the high nonlinearity of observation model in star-convex RHM model, two separate vectors are used to model the target state, and the probability update of target class is realized by particle filter based on closed likelihood function derivation. The simulation results show that the NEET JTC algorithm can accurately classify targets with similar size but different shapes, and improve the target state estimation results when compared with the extended target JTC algorithm based on elliptical shape. The results also show that the proposed algorithm can significantly improve the target state estimation results without significantly increasing the running time when compared with the extended target tracking algorithm based on star-convex RHM.]]></description>
<pubDate>2022/7/23 12:31:02</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[王丽萍,占荣辉]]></author>
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<item>
<title><![CDATA[A NIC-based Offloading Mechanism Supporting Reduction Operation on High-speed interconnection System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009010000001]]></link>
<description><![CDATA[Collective communication is widely used in the field of high-performance computing research and engineering. In large-scale scientific and engineering computing, collective communication overhead accounts for a large proportion, sometimes even reaching 80% of the total messaging overhead. It is the performance bottleneck of the high-performance computing system. This paper proposes a reduction operation method that combines hardware and software, by embedding reduction operation logic components on NIC, offloads the calculations originally performed by the CPU to the NIC, and implements the calculation of data during transmission, reducing the burden on the CPU and reducing the communication delay. A 16-node protocol operation experiment is realized through the FPGA platform, and the protocol operation in different node size is simulated based on the xNetSimPlus simulator. Experiments show that the method can effectively reduce the time of protocol operation in collective communication. The simulation results show that the NIC offloading mechanism proposed in this paper that supports reduction operation hardware offload can accelerate All-reduce operations by up to 2.53 times.]]></description>
<pubDate>2022/7/20 17:35:18</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[常俊胜,熊泽宇,徐金波]]></author>
</item>
<item>
<title><![CDATA[HPC 2020 Execution-failure Identification for Parallel Programs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011120000003]]></link>
<description><![CDATA[With the increasing complexity and scale of high performance computing systems, MTBF(mean time between failures) is getting shorter and shorter. Therefore, as the hardware and software failures increase, the probability of parallel program runtime failure increases. On the other hand, the possible bugs that exist in parallel programs can also lead to the runtime failure. Measures to deal with the above two types of runtime failure are totally different, users must pay attention to the type of runtime failures. In response to this issue, a parallel program execution failure identification system based on Slurm is designed and implemented. The system has all the supported features of Slurm, as well as the ability to monitor job status, resubmit and rerun jobs.  According to the results of the job execution, the system can distinguish the type of runtime failure. Experiments conducted by fault injection show that the system has high accuracy.]]></description>
<pubDate>2022/7/20 17:33:31</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[高玉林,刘轶,张国振]]></author>
</item>
<item>
<title><![CDATA[Dynamics Characteristics of Active Angle Deception Jamming Decoys]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009170000001]]></link>
<description><![CDATA[Aiming at dealing withthe active angle deception decoys that may appear in the process of high-altitude and high-speed target detectionof high altitude and high speed target detection, a comprehensive and theoretical analysis of the dynamics characteristics iwas presented. Firstly, the dynamics model equation of active decoy iwas derived.. Secondly,and the conservation of mechanical energy and moment of momentum of the decoy iswere analyzed. Theoretical analysis and experimental results indicate that active angle deception decoys show a significant difference comparing to true target in the aspect of dynamics characteristics. The decoys do not follow the elliptical orbit and the dynamical conversation law, which is the foundation of discrimination algorithms. Theoretical analysis and simulation experiments showed that the dynamic characteristics of the azimuth active decoy with fixed angle deception were completely consistent with the real target, and it was impossible to distinguish the true from the false in dynamics. In addition, other angle deception active false targets did not meet the elliptic orbit characteristics of high-altitude high-speed targets and the law of conservation of dynamics. Using this difference, false targets can be identified in the data processing layer.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[顾赵宇,饶彬,王国玉]]></author>
</item>
<item>
<title><![CDATA[DSets-DBSCAN radar signal sorting algorithm without parameter clustering]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011120000001]]></link>
<description><![CDATA[With the increasingly dense and complex electromagnetic signal environment, the radar signal sorting method faces severe challenges. The performance of many existing efficient sorting algorithms depends heavily on the parameters from external input, such as clustering number and clustering tolerance. In this paper, the parameterless clustering algorithm DSets-DBSCAN is applied to the radar signal sorting, and a parameterless radar signal pulse clustering algorithm is presented. The algorithm can automatically cluster without relying on any parameter settings. Firstly, the algorithm input is the pairwise similarity matrix processed by histogram equalization, which makes the Dominant Sets(Dsets) algorithm independent of any parameters. Then the input parameters of DBSCAN are given adaptively by using the obtained ultra-small cluster, and finally the cluster is extended by DBSCAN. The simulation results show that the proposed method is effective in sorting radar pulse descriptors without parameters. And the clustering accuracy of radar signals is more than 97.56% in the case of the false pulse ratio (false pulse/radar pulse) is no more than 80%.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈涛,李品,刘鲁涛,王璐璐]]></author>
</item>
<item>
<title><![CDATA[Method of satellite high-frequence attitude determination using compressive sampling]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011080000003]]></link>
<description><![CDATA[High-frequency attitude vibration is one of the major error sources that prevent satellites from achieving high attitude estimation precision. The frequency of vibration usually surpasses the sampling frequency of traditional attitude sensors. This paper proposes a novel high-frequency method for attitude determination using normal attitude sensors. The key idea is that the high-bandwidth attitude of the spacecraft is sparse in the frequency domain and can be recovered from normal-sampling-rate measurements.  In this method, an indirect Kalman filter is used to estimate attitude. The filters’ estimation results, three discrete series of attitude estimation with different time intervals, are merged to simulate a non-uniformly spaced sample set of the high-bandwidth attitude. Finally, the high-bandwidth attitude is reconstructed from the merged data using compressive sampling. Simulation results indicate that the proposed attitude determination is accurate, robust to noise, and capable of measuring high-frequency attitudes in a wide bandwidth range.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安玮,Hu Xiangyu,,,,]]></author>
</item>
<item>
<title><![CDATA[A spatial distribution model for behind-armor debris formed by the perforation of explosively formed projectile through the target]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011100000001]]></link>
<description><![CDATA[The deep space impact load is of great significance to the detection of the internal material composition and structural characteristics of small celestial bodies. So a spatial distribution model for BAD (behind-armor debris) formed by the perforation of variable cross-section EFP (explosively formed projectile) through the target is established. The variable cross-section characteristic of the EFP is considered and the sources of BAD (from target or EFP) are distinguished in the model. The thickness of the target is from 30 mm to 70 mm, the impact velocity of EFP is from 1650 m/s to 1860 m/s. The relationships between the velocity (mass, kinetic energy, quantity) and spatial position of every debris in the BAD cloud could be predicted quantitatively. The results indicate that the relative velocity increases by a linear function with the increase of the relative spatial position, the relative mass and the relative number increase by a power function with the increase of the relative spatial position.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔浩,郭锐,侯云辉,骆强,邢柏阳,徐伟华,杨赵兵,张东江,朱桂利]]></author>
</item>
<item>
<title><![CDATA[Multi constraint optimal intelligent gliding guidance via reinforcement learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010130000001]]></link>
<description><![CDATA[In order to improve the autonomy of gliding guidance for complex flight missions, this paper proposes a multi-constrained intelligent gliding guidance strategy based on optimal guidance and reinforcement learning (RL). Three-dimensional optimal guidance is introduced to meet the terminal latitude, longitude, altitude and flight-path-angle constraints. A velocity control strategy through lateral sinusoidal maneuver is proposed, and an analytical terminal velocity prediction method considering maneuvering flight is studied. Aiming at the problem that the maneuvering amplitude in velocity control cannot be determined offline, an intelligent parameter adjustment method based on RL is studied. This method designs a state space via terminal velocity and an action space with maneuvering amplitude. In addition, it constructs a reward function that integrates terminal velocity error and gliding guidance tasks, and uses Q-Learning to achieve the online intelligent adjustment of maneuvering amplitude. The simulation results show that the intelligent gliding guidance method can meet various terminal constraints with high accuracy, and can improve the autonomous decision-making ability under complex tasks effectively.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[包为民,李小平,赵长见,朱建文]]></author>
</item>
<item>
<title><![CDATA[High-Efficiency IQ Convolutional Network Structure for Radio Frequency Fingerprint Identification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011160000001]]></link>
<description><![CDATA[RF fingerprints can be used to identify specific transmitters. Existing convolutional neural networks are used to process time-sequence In-phase and Quadrature-phase (IQ) signals simply as images. There are problems with low recognition  accuracy and large calculations. This article focuses on the application of RF fingerprints recognition, an efficient IQ convolutional network structure is proposed. The network first extracted IQ-related features and time domain features step by step, then obtained the average value of each channel features through adaptive average pooling, and finally used only one fully connected layer for classification. The experimental results show that the network has a greater improvement of recognition accuracy under a variety of channel conditions than the traditional convolutional neural network, and the amount of calculation is smaller.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[安军社,崔凯,崔天舒,黄永辉,沈明,张晔,赵文杰]]></author>
</item>
<item>
<title><![CDATA[DSets-DBSCAN radar signal sorting algorithm without parameter clustering]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011120000001]]></link>
<description><![CDATA[With the increasingly dense and complex electromagnetic signal environment, the radar signal sorting method faces severe challenges. The performance of many existing efficient sorting algorithms depends heavily on the parameters from external input, such as clustering number and clustering tolerance. In this paper, the parameterless clustering algorithm DSets-DBSCAN is applied to the radar signal sorting, and a parameterless radar signal pulse clustering algorithm is presented. The algorithm can automatically cluster without relying on any parameter settings. Firstly, the algorithm input is the pairwise similarity matrix processed by histogram equalization, which makes the Dominant Sets(Dsets) algorithm independent of any parameters. Then the input parameters of DBSCAN are given adaptively by using the obtained ultra-small cluster, and finally the cluster is extended by DBSCAN. The simulation results show that the proposed method is effective in sorting radar pulse descriptors without parameters. And the clustering accuracy of radar signals is more than 97.56% in the case of the false pulse ratio (false pulse/radar pulse) is no more than 80%.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈涛,李品,刘鲁涛,王璐璐]]></author>
</item>
<item>
<title><![CDATA[Method of satellite high-frequence attitude determination using compressive sampling]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011080000003]]></link>
<description><![CDATA[High-frequency attitude vibration is one of the major error sources that prevent satellites from achieving high attitude estimation precision. The frequency of vibration usually surpasses the sampling frequency of traditional attitude sensors. This paper proposes a novel high-frequency method for attitude determination using normal attitude sensors. The key idea is that the high-bandwidth attitude of the spacecraft is sparse in the frequency domain and can be recovered from normal-sampling-rate measurements.  In this method, an indirect Kalman filter is used to estimate attitude. The filters’ estimation results, three discrete series of attitude estimation with different time intervals, are merged to simulate a non-uniformly spaced sample set of the high-bandwidth attitude. Finally, the high-bandwidth attitude is reconstructed from the merged data using compressive sampling. Simulation results indicate that the proposed attitude determination is accurate, robust to noise, and capable of measuring high-frequency attitudes in a wide bandwidth range.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安玮,Hu Xiangyu,,,,]]></author>
</item>
<item>
<title><![CDATA[A spatial distribution model for behind-armor debris formed by the perforation of explosively formed projectile through the target]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011100000001]]></link>
<description><![CDATA[The deep space impact load is of great significance to the detection of the internal material composition and structural characteristics of small celestial bodies. So a spatial distribution model for BAD (behind-armor debris) formed by the perforation of variable cross-section EFP (explosively formed projectile) through the target is established. The variable cross-section characteristic of the EFP is considered and the sources of BAD (from target or EFP) are distinguished in the model. The thickness of the target is from 30 mm to 70 mm, the impact velocity of EFP is from 1650 m/s to 1860 m/s. The relationships between the velocity (mass, kinetic energy, quantity) and spatial position of every debris in the BAD cloud could be predicted quantitatively. The results indicate that the relative velocity increases by a linear function with the increase of the relative spatial position, the relative mass and the relative number increase by a power function with the increase of the relative spatial position.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔浩,郭锐,侯云辉,骆强,邢柏阳,徐伟华,杨赵兵,张东江,朱桂利]]></author>
</item>
<item>
<title><![CDATA[Dynamics Characteristics of Active Angle Deception Jamming Decoys]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009170000001]]></link>
<description><![CDATA[Aiming at dealing withthe active angle deception decoys that may appear in the process of high-altitude and high-speed target detectionof high altitude and high speed target detection, a comprehensive and theoretical analysis of the dynamics characteristics iwas presented. Firstly, the dynamics model equation of active decoy iwas derived.. Secondly,and the conservation of mechanical energy and moment of momentum of the decoy iswere analyzed. Theoretical analysis and experimental results indicate that active angle deception decoys show a significant difference comparing to true target in the aspect of dynamics characteristics. The decoys do not follow the elliptical orbit and the dynamical conversation law, which is the foundation of discrimination algorithms. Theoretical analysis and simulation experiments showed that the dynamic characteristics of the azimuth active decoy with fixed angle deception were completely consistent with the real target, and it was impossible to distinguish the true from the false in dynamics. In addition, other angle deception active false targets did not meet the elliptic orbit characteristics of high-altitude high-speed targets and the law of conservation of dynamics. Using this difference, false targets can be identified in the data processing layer.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[顾赵宇,饶彬,王国玉]]></author>
</item>
<item>
<title><![CDATA[Analysis on application of aero engine in supersonic ejector system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010270000001]]></link>
<description><![CDATA[The pressure and temperature of air flow can be increased by aero engine, so the application of aero engine in supersonic ejector system is possible. The effects of air source on ejector performance and the effects of bleeding on aero engine performance were analyzed. And 3 types of aero engine layout in supersonic ejector system were presented. According to the requirements of a supersonic ejector system, the performance parameters of all 3 types of aero engine layout were calculated. The calculation results indicate that when the upstream pressure is 0.044×105Pa and 0.0293×105Pa, aero engine can used in super ejector system by selecting reasonable layout and working parameters.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[顾蕴松,任泽斌,史煜,徐大川,阳玲]]></author>
</item>
<item>
<title><![CDATA[Truth Discovery from Multi-Source Text Data Based on Deep Neural Networt]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011240000001]]></link>
<description><![CDATA[In order to solve the problem that the traditional truth discovery algorithm cannot be applied to text data directly, a truth discovery algorithm for text data based on deep neural network was proposed. For the features of multifactorial property of text answers, the diversity of word usages, and the sparsity of the text data, the "source-answer" vector was used as the network input, and the truth vector was recognized as the network output. The relationship between answers from each source could be unsupervised learned according to general hypothesis of truth discovery, and finally the truth vector was obtained by neural network. The experiment results show that the proposed algorithm is suitable for text data truth discovery, and it is better than the retrieval methods and traditional truth discovery algorithm.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[曹建军,常宸,蒋国权,陶嘉庆,翁年凤]]></author>
</item>
<item>
<title><![CDATA[Long-term Coherent Integration method for low-altitude small targets of LFMCW radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011060000001]]></link>
<description><![CDATA[Aimed at the problem of weak radar echo of small UAV(Unmaned Aerial Vehicle) targets and difficult target detection. Long-term coherent integration method under the LFMCW(linear frequency modulation continuous wave) radar was studied. By deriving the expression of LFMCW radar echo, an Radon-Fouier Transform implementation method based on Chirp-Z transformof time-domain beat signal was proposed. The computational complexity of this method was evaluated and compared with the method implemented in frequency domain.  Simulation and measured data verified the effectiveness of this algorithm for the coherent integration of weak targets under LFMCW radar.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[郭立民,,,]]></author>
</item>
<item>
<title><![CDATA[Multi constraint optimal intelligent gliding guidance via reinforcement learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010130000001]]></link>
<description><![CDATA[In order to improve the autonomy of gliding guidance for complex flight missions, this paper proposes a multi-constrained intelligent gliding guidance strategy based on optimal guidance and reinforcement learning (RL). Three-dimensional optimal guidance is introduced to meet the terminal latitude, longitude, altitude and flight-path-angle constraints. A velocity control strategy through lateral sinusoidal maneuver is proposed, and an analytical terminal velocity prediction method considering maneuvering flight is studied. Aiming at the problem that the maneuvering amplitude in velocity control cannot be determined offline, an intelligent parameter adjustment method based on RL is studied. This method designs a state space via terminal velocity and an action space with maneuvering amplitude. In addition, it constructs a reward function that integrates terminal velocity error and gliding guidance tasks, and uses Q-Learning to achieve the online intelligent adjustment of maneuvering amplitude. The simulation results show that the intelligent gliding guidance method can meet various terminal constraints with high accuracy, and can improve the autonomous decision-making ability under complex tasks effectively.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[包为民,李小平,赵长见,朱建文]]></author>
</item>
<item>
<title><![CDATA[Multi constraint optimal intelligent gliding guidance via reinforcement learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010130000001]]></link>
<description><![CDATA[In order to improve the autonomy of gliding guidance for complex flight missions, this paper proposes a multi-constrained intelligent gliding guidance strategy based on optimal guidance and reinforcement learning (RL). Three-dimensional optimal guidance is introduced to meet the terminal latitude, longitude, altitude and flight-path-angle constraints. A velocity control strategy through lateral sinusoidal maneuver is proposed, and an analytical terminal velocity prediction method considering maneuvering flight is studied. Aiming at the problem that the maneuvering amplitude in velocity control cannot be determined offline, an intelligent parameter adjustment method based on RL is studied. This method designs a state space via terminal velocity and an action space with maneuvering amplitude. In addition, it constructs a reward function that integrates terminal velocity error and gliding guidance tasks, and uses Q-Learning to achieve the online intelligent adjustment of maneuvering amplitude. The simulation results show that the intelligent gliding guidance method can meet various terminal constraints with high accuracy, and can improve the autonomous decision-making ability under complex tasks effectively.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[包为民,李小平,赵长见,朱建文]]></author>
</item>
<item>
<title><![CDATA[High-Efficiency IQ Convolutional Network Structure for Radio Frequency Fingerprint Identification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011160000001]]></link>
<description><![CDATA[RF fingerprints can be used to identify specific transmitters. Existing convolutional neural networks are used to process time-sequence In-phase and Quadrature-phase (IQ) signals simply as images. There are problems with low recognition  accuracy and large calculations. This article focuses on the application of RF fingerprints recognition, an efficient IQ convolutional network structure is proposed. The network first extracted IQ-related features and time domain features step by step, then obtained the average value of each channel features through adaptive average pooling, and finally used only one fully connected layer for classification. The experimental results show that the network has a greater improvement of recognition accuracy under a variety of channel conditions than the traditional convolutional neural network, and the amount of calculation is smaller.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[安军社,崔凯,崔天舒,黄永辉,沈明,张晔,赵文杰]]></author>
</item>
<item>
<title><![CDATA[High-Efficiency IQ Convolutional Network Structure for Radio Frequency Fingerprint Identification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011160000001]]></link>
<description><![CDATA[RF fingerprints can be used to identify specific transmitters. Existing convolutional neural networks are used to process time-sequence In-phase and Quadrature-phase (IQ) signals simply as images. There are problems with low recognition  accuracy and large calculations. This article focuses on the application of RF fingerprints recognition, an efficient IQ convolutional network structure is proposed. The network first extracted IQ-related features and time domain features step by step, then obtained the average value of each channel features through adaptive average pooling, and finally used only one fully connected layer for classification. The experimental results show that the network has a greater improvement of recognition accuracy under a variety of channel conditions than the traditional convolutional neural network, and the amount of calculation is smaller.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[安军社,崔凯,崔天舒,黄永辉,沈明,张晔,赵文杰]]></author>
</item>
<item>
<title><![CDATA[DSets-DBSCAN radar signal sorting algorithm without parameter clustering]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011120000001]]></link>
<description><![CDATA[With the increasingly dense and complex electromagnetic signal environment, the radar signal sorting method faces severe challenges. The performance of many existing efficient sorting algorithms depends heavily on the parameters from external input, such as clustering number and clustering tolerance. In this paper, the parameterless clustering algorithm DSets-DBSCAN is applied to the radar signal sorting, and a parameterless radar signal pulse clustering algorithm is presented. The algorithm can automatically cluster without relying on any parameter settings. Firstly, the algorithm input is the pairwise similarity matrix processed by histogram equalization, which makes the Dominant Sets(Dsets) algorithm independent of any parameters. Then the input parameters of DBSCAN are given adaptively by using the obtained ultra-small cluster, and finally the cluster is extended by DBSCAN. The simulation results show that the proposed method is effective in sorting radar pulse descriptors without parameters. And the clustering accuracy of radar signals is more than 97.56% in the case of the false pulse ratio (false pulse/radar pulse) is no more than 80%.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈涛,李品,刘鲁涛,王璐璐]]></author>
</item>
<item>
<title><![CDATA[Method of satellite high-frequence attitude determination using compressive sampling]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011080000003]]></link>
<description><![CDATA[High-frequency attitude vibration is one of the major error sources that prevent satellites from achieving high attitude estimation precision. The frequency of vibration usually surpasses the sampling frequency of traditional attitude sensors. This paper proposes a novel high-frequency method for attitude determination using normal attitude sensors. The key idea is that the high-bandwidth attitude of the spacecraft is sparse in the frequency domain and can be recovered from normal-sampling-rate measurements.  In this method, an indirect Kalman filter is used to estimate attitude. The filters’ estimation results, three discrete series of attitude estimation with different time intervals, are merged to simulate a non-uniformly spaced sample set of the high-bandwidth attitude. Finally, the high-bandwidth attitude is reconstructed from the merged data using compressive sampling. Simulation results indicate that the proposed attitude determination is accurate, robust to noise, and capable of measuring high-frequency attitudes in a wide bandwidth range.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安玮,Hu Xiangyu,,,,]]></author>
</item>
<item>
<title><![CDATA[A spatial distribution model for behind-armor debris formed by the perforation of explosively formed projectile through the target]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011100000001]]></link>
<description><![CDATA[The deep space impact load is of great significance to the detection of the internal material composition and structural characteristics of small celestial bodies. So a spatial distribution model for BAD (behind-armor debris) formed by the perforation of variable cross-section EFP (explosively formed projectile) through the target is established. The variable cross-section characteristic of the EFP is considered and the sources of BAD (from target or EFP) are distinguished in the model. The thickness of the target is from 30 mm to 70 mm, the impact velocity of EFP is from 1650 m/s to 1860 m/s. The relationships between the velocity (mass, kinetic energy, quantity) and spatial position of every debris in the BAD cloud could be predicted quantitatively. The results indicate that the relative velocity increases by a linear function with the increase of the relative spatial position, the relative mass and the relative number increase by a power function with the increase of the relative spatial position.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔浩,郭锐,侯云辉,骆强,邢柏阳,徐伟华,杨赵兵,张东江,朱桂利]]></author>
</item>
<item>
<title><![CDATA[Dynamics Characteristics of Active Angle Deception Jamming Decoys]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009170000001]]></link>
<description><![CDATA[Aiming at dealing withthe active angle deception decoys that may appear in the process of high-altitude and high-speed target detectionof high altitude and high speed target detection, a comprehensive and theoretical analysis of the dynamics characteristics iwas presented. Firstly, the dynamics model equation of active decoy iwas derived.. Secondly,and the conservation of mechanical energy and moment of momentum of the decoy iswere analyzed. Theoretical analysis and experimental results indicate that active angle deception decoys show a significant difference comparing to true target in the aspect of dynamics characteristics. The decoys do not follow the elliptical orbit and the dynamical conversation law, which is the foundation of discrimination algorithms. Theoretical analysis and simulation experiments showed that the dynamic characteristics of the azimuth active decoy with fixed angle deception were completely consistent with the real target, and it was impossible to distinguish the true from the false in dynamics. In addition, other angle deception active false targets did not meet the elliptic orbit characteristics of high-altitude high-speed targets and the law of conservation of dynamics. Using this difference, false targets can be identified in the data processing layer.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[顾赵宇,饶彬,王国玉]]></author>
</item>
<item>
<title><![CDATA[Energy efficiency analysis of the relay-assisted CR-NOMA system using SWIPT]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011240000002]]></link>
<description><![CDATA[In view of the shortcomings of limited terminal battery capacity and low energy efficiency in the existing research on Cognitive Radio Non-Orthogonal Multiple Access (CR-NOMA) networks, a relay is used to assist users in transmission, and a method of simultaneous transmission of wireless information and energy is introduced. Under the constraints of user service quality and minimum energy capture, the sub-user transmission energy efficiency expression is derived. The non-convex objective function is transformed into three convex single-objective problems of optimizing relay transmission power, relay power allocation and receiver power allocation by fractional programming method. Using function monotonicity, golden section algorithm, Lagrangian dual algorithm and multi-objective joint optimization algorithm for optimization, the global optimal solution is obtained to maximize the transmission energy efficiency of the secondary user system. The complexity of the adopted algorithm is analyzed .The simulation results show that compared with the traditional Orthogonal Multiple Access (OMA) scheme, while improving the system spectrum utilization, the sub-user transmission energy efficiency has been improved by 47%.]]></description>
<pubDate>2022/7/20 10:36:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[蔺莹,苗丰满,薛建彬,张海军,张永刚]]></author>
</item>
<item>
<title><![CDATA[AHP-Arena comprehensive evaluation method for the efficiency of the allocation of UAV flight training resources]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105040000001]]></link>
<description><![CDATA[In order to reduce the subjective one-sided influence of empowerment process of the traditional hierarchical analysis method (AHP, Analytic Hierarchy Process), a comprehensive AHP and Arena simulation modeling technology was proposed to evaluate the efficiency of the allocation of UAV training resources. Based on flight training process analysis, the factors influencing the efficiency of training resource allocation and efficiency evaluation index were determined, a hierarchical comprehensive evaluation system was established, and the comprehensive evaluation steps of AHP-Arena were summarized.  Arena modeling software was used to realize the dynamic simulation system of the training process and verify the validity, the single-variable numerical simulation method and the mean variance decision-making method were used to complete the objective empowerment of the influencing factors, and the comprehensive evaluation coefficient was obtained by linear weighting comprehensive method, so as to implement resource allocation efficiency evaluation and selection of the optimal program.The practical application shows the effectiveness of the method. Meanwhile, this method can be extended to other similar training processes, and can also provide references for other multi-factor multi-indicator evaluation decision-making processes.]]></description>
<pubDate>2022/7/20 10:36:46</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[王建楠,张尧]]></author>
</item>
<item>
<title><![CDATA[AHP-Arena comprehensive evaluation method for the efficiency of the allocation of UAV flight training resources]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105040000001]]></link>
<description><![CDATA[In order to reduce the subjective one-sided influence of empowerment process of the traditional hierarchical analysis method (AHP, Analytic Hierarchy Process), a comprehensive AHP and Arena simulation modeling technology was proposed to evaluate the efficiency of the allocation of UAV training resources. Based on flight training process analysis, the factors influencing the efficiency of training resource allocation and efficiency evaluation index were determined, a hierarchical comprehensive evaluation system was established, and the comprehensive evaluation steps of AHP-Arena were summarized.  Arena modeling software was used to realize the dynamic simulation system of the training process and verify the validity, the single-variable numerical simulation method and the mean variance decision-making method were used to complete the objective empowerment of the influencing factors, and the comprehensive evaluation coefficient was obtained by linear weighting comprehensive method, so as to implement resource allocation efficiency evaluation and selection of the optimal program.The practical application shows the effectiveness of the method. Meanwhile, this method can be extended to other similar training processes, and can also provide references for other multi-factor multi-indicator evaluation decision-making processes.]]></description>
<pubDate>2022/7/20 10:36:46</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[王建楠,张尧]]></author>
</item>
<item>
<title><![CDATA[DWA path planning algorithm based on multi-objective particle swarm optimization in complex environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111020000003]]></link>
<description><![CDATA[When the robot is running in a complex environment with densely distributed obstacles, the DWA algorithm is prone to obstacle avoidance failure or unreasonable planning. In this regard, an improved DWA planning algorithm based on Multi-Objective Particle Swarm Optimization (MOPSO) is proposed. Based on the establishment of multi obstacle environment coverage model, a method is put forward for judging obstacle-dense areas in complex environments. And the original DWA algorithm is improved by optimizing the sub-evaluation functions. On these basis, the adaptive change of DWA weight coefficients can be transformed into a multi-objective optimization problem, which can be solved by the improved MOPSO algorithm. According to the requirements of path planning, the corresponding multi-objective optimization model can be established, moreover the safety distance and speed can be set as the optimization goals. A series of simulations based on Matlab are carried out, and the results show that this method enables the robot to effectively pass through the dense area of obstacles while taking account of the safety and speed of operation, and has better path planning effect.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[常路,单梁,李薪颖,屈艺,张永]]></author>
</item>
<item>
<title><![CDATA[Roll control study of a flying wing based on trailing-edge jet at a wide speed range]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110220000001]]></link>
<description><![CDATA[The numerical simulation method is used to carry out a systematic study on the roll control of the flying wing using the trailing-edge CC(circulation control) jet at a wide speed range (Ma=0.145-0.7), compared with the configuration controlled by classical control surfaces. The research focuses the electromagnetic stealth characteristics, the roll control characteristics and their flow physics, and the impacts of the bleed air. The results show that as the Mach number increases, the roll control capability of the CC jet decreases due to the weakening of entrainment and blocking effects. However, the CC jet enhances the stealth performance at specific azimuth ranges remarkably. Moreover, it requires less bleed air, induces less thrust loss, and has a high control efficiency factor (aerodynamic moment coefficient produced per unit of additional drag coefficient). In conclusion, the trailing-edge CC jet is a highly promising roll control device for a flying wing.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭正,侯中喜,贾高伟,邵帅,阴鹏,张来平]]></author>
</item>
<item>
<title><![CDATA[Real-time evaluation of the progress of a social work using open-source big data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109090000003]]></link>
<description><![CDATA[Few quantitative models can be found amenable to the quantitative evaluation of social work, which motivates the work presented in this article. Moreover, a few related existing works suffer from no suitable indicator system and high expenses of time and money. To overcome these limitations, a real-time quantitative evaluation model using the Internet open-source big data was developed, a target indicator system was established, the rapid computation methods of each criterion were proposed, and a prototypical software system was designed and implemented. Case studies on selected social work were conducted, and the work performance of the 14 cities belonging to a certain province in China was evaluated. The results achieved were largely consistent with the subjective feelings of many respondents and relevant official assessment, which validated the efficiency and rationality of the model proposed.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[欧文孝,潘岩,王寅森,殷风景,张鑫]]></author>
</item>
<item>
<title><![CDATA[Optimal Control Method for Swarm Systems Formation Tracking Problem with LQR Performance Index]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111020000002]]></link>
<description><![CDATA[For the formation tracking problem for swarm systems,an optimal control method with LQR performance index is put forward.Firstly,establish the mathematical description of the formation tracking problem and design a formation tracking control protocol.Next,necessary and sufficient conditions for swarm systems with formation tracking are obtained and the stability of the system is analysed using common Lyapunov approach.Then topology conditions of the control protocol which can minimize LQR performance index are obtained and the formation tracking algorithm is designed .Finally, a numerical simulation is provided to illustrate the effectiveness of the control method.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈宏伟,王琳,张庆杰]]></author>
</item>
<item>
<title><![CDATA[DWA path planning algorithm based on multi-objective particle swarm optimization in complex environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111020000003]]></link>
<description><![CDATA[When the robot is running in a complex environment with densely distributed obstacles, the DWA algorithm is prone to obstacle avoidance failure or unreasonable planning. In this regard, an improved DWA planning algorithm based on Multi-Objective Particle Swarm Optimization (MOPSO) is proposed. Based on the establishment of multi obstacle environment coverage model, a method is put forward for judging obstacle-dense areas in complex environments. And the original DWA algorithm is improved by optimizing the sub-evaluation functions. On these basis, the adaptive change of DWA weight coefficients can be transformed into a multi-objective optimization problem, which can be solved by the improved MOPSO algorithm. According to the requirements of path planning, the corresponding multi-objective optimization model can be established, moreover the safety distance and speed can be set as the optimization goals. A series of simulations based on Matlab are carried out, and the results show that this method enables the robot to effectively pass through the dense area of obstacles while taking account of the safety and speed of operation, and has better path planning effect.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[常路,单梁,李薪颖,屈艺,张永]]></author>
</item>
<item>
<title><![CDATA[Vibration Reduction Analysis and Experiment of Multi-Rotor Drone]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201060000004]]></link>
<description><![CDATA[Aiming at the problem of excessive vibration of the multi-rotor drone, which causes instability of flight state, the vibration reduction analysis work is carried out based on CAE simulation technology and experimental methods. Through frequency analysis, the reason of excessive vibration is determined to be resonance，and the mode shape corresponding to the resonance frequencies are    the first-order waving, first-order swing and second-order swing mode shapes. An optimization design method for optimizing the cross-sectional shape is proposed. Without adding extra weight, the corresponding frequency points of the first-order waving mode, the first-order swing mode, and the second-order swing mode have been increased by 37.23%, 22.47 and 18.43%, respectively. The vibration reduction analysis and optimization design method proposed in the article can provide references for design work of drones.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔辉如,和英鹏,李道奎,马维力,申柳雷]]></author>
</item>
<item>
<title><![CDATA[Influence of lunar soil parameters on the lunar landing airbag cushioning performance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202250000003]]></link>
<description><![CDATA[To study the influence of lunar soil parameters on the airbag buffer performance, a lunar landing airbag was designed according to the landing conditions of Chang'e-3 probe, and then an airbag dynamic model considering the characteristics of lunar soil was established based on the crushable foam model. The airbag cushioning process under different lunar soils was analyzed, and it is found that the softer the lunar soil, the smaller the payload impact acceleration, but the airbag will sink into the lunar soil, which is not conducive to venting and affects its cushioning effect. Therefore, three indicators of airbag peak pressure, payload maximum acceleration, and payload maximum drop height were used to evaluate the airbag cushioning performance comprehensively, and the influence law of lunar soil parameters was quantitatively studied. The results show that the lunar soil density and shear modulus, as well as the yield parameters a0 and a1, have a significant influence on the cushioning performance, with a positive effect on the first two indicators and a negative effect on the latter one. Further research reveals that the relationship between each of the four lunar soil parameters and the three cushioning performance indicators is an exponential function.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李道奎,周仕明,周旋]]></author>
</item>
<item>
<title><![CDATA[Roll control study of a flying wing based on trailing-edge jet at a wide speed range]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110220000001]]></link>
<description><![CDATA[The numerical simulation method is used to carry out a systematic study on the roll control of the flying wing using the trailing-edge CC(circulation control) jet at a wide speed range (Ma=0.145-0.7), compared with the configuration controlled by classical control surfaces. The research focuses the electromagnetic stealth characteristics, the roll control characteristics and their flow physics, and the impacts of the bleed air. The results show that as the Mach number increases, the roll control capability of the CC jet decreases due to the weakening of entrainment and blocking effects. However, the CC jet enhances the stealth performance at specific azimuth ranges remarkably. Moreover, it requires less bleed air, induces less thrust loss, and has a high control efficiency factor (aerodynamic moment coefficient produced per unit of additional drag coefficient). In conclusion, the trailing-edge CC jet is a highly promising roll control device for a flying wing.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭正,侯中喜,贾高伟,邵帅,阴鹏,张来平]]></author>
</item>
<item>
<title><![CDATA[Real-time evaluation of the progress of a social work using open-source big data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109090000003]]></link>
<description><![CDATA[Few quantitative models can be found amenable to the quantitative evaluation of social work, which motivates the work presented in this article. Moreover, a few related existing works suffer from no suitable indicator system and high expenses of time and money. To overcome these limitations, a real-time quantitative evaluation model using the Internet open-source big data was developed, a target indicator system was established, the rapid computation methods of each criterion were proposed, and a prototypical software system was designed and implemented. Case studies on selected social work were conducted, and the work performance of the 14 cities belonging to a certain province in China was evaluated. The results achieved were largely consistent with the subjective feelings of many respondents and relevant official assessment, which validated the efficiency and rationality of the model proposed.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[欧文孝,潘岩,王寅森,殷风景,张鑫]]></author>
</item>
<item>
<title><![CDATA[Staring attitude control for deep space targets based on an uncalibrated video satellite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112220000001]]></link>
<description><![CDATA[A small video satellite can continuously observe deep space targets, which has a broad application prospect. A conventional staring attitude control method requires the information about the location of the target and the intrinsic and extrinsic parameters of the camera. In some cases, however, the accurate location of the observed target is unknown, and the camera parameters are affected by the in-orbit environment, making it hard to calibrate. We design an adaptive attitude controller, achieving staring at the target in the presence of the unknown target’s position and camera parameters. First, the estimated parameters are extracted to be linearized. Second, a potential function is introduced to meet the demand for the rank of the parameter matrix. At last, a self-updating principle of parameters is adopted to estimate the parameters on line, and accordingly the adaptive control method is proposed. Based on the Lyapunov theory and Barbalat’s lemma, the target image converging to the desired position in the image plane is proved. The simulation results reveal that the adaptive controller can affectively achieve staring observation for deep space targets with the uncertainties of the target position and the camera parameters.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[范才智,宋超,王猛猛]]></author>
</item>
<item>
<title><![CDATA[Model Predictive Based Disturbance Rejection and Obstacle Avoidance Guidance for Multi Rotor Unmanned Aerial Vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111010000002]]></link>
<description><![CDATA[The autonomous obstacle avoidance of Unmanned Aerial Vehicle (UAV) is the basis of completing complex tasks, and the obstacle avoidance performance directly affects the efficiency of UAV performing tasks. Aiming at the obstacle avoidance problem of UAV with external disturbance, a design method of anti-disturbance and obstacle avoidance guidance law based on model prediction is proposed. The disturbance observer is designed to estimate the external disturbance in the system dynamics, and the auxiliary guidance law is designed based on Lyapunov function method to establish the stability constraints. Combining the first two with model predictive control(MPC), the relationship between UAV and obstacles is considered in the MPC optimization solution, and the horizontal linear velocity and yaw angular velocity commands are solved according to the designed guidance law to realize the obstacle avoidance of UAV. Finally, the numerical simulation and physical flight verification of the proposed obstacle avoidance guidance law show the effectiveness of the proposed method.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈谋,兰庆湘,雍可南]]></author>
</item>
<item>
<title><![CDATA[Effect of structural parameters of regenerative cooling channels on hydrocarbon fuel flow distribution]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106160000001]]></link>
<description><![CDATA[Based on the regenerative cooling technology of liquid rocket engine, the flow distribution characteristics of Z-type parallel channels were studied by numerical simulation method. The effects of channel number, channel section shape and entrance confluence structure on the flow distribution characteristics were analyzed. The results show that the non-uniformity coefficient of flow distribution decreases from 2.59% to 0.5% with the increase of the number of channels in the regenerative cooling system. Increasing the number of channels under the same flow area can effectively ensure the uniformity of flow distribution. The channel section shape has little influence on the non-uniformity coefficient of flow distribution, which is mainly reflected in the flow velocity distribution and heat transfer area in the channel, and the heat transfer effect of the trapezoidal configuration is better than that of the rectangular configuration. The entrance confluence structure is beneficial to the uniform of flow distribution. The research has a certain reference significance for the structural design of regenerative cooling channel.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[丁 杰,刘伟强,尹 亮]]></author>
</item>
<item>
<title><![CDATA[Vibration Reduction Analysis and Experiment of Multi-Rotor Drone]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201060000004]]></link>
<description><![CDATA[Aiming at the problem of excessive vibration of the multi-rotor drone, which causes instability of flight state, the vibration reduction analysis work is carried out based on CAE simulation technology and experimental methods. Through frequency analysis, the reason of excessive vibration is determined to be resonance，and the mode shape corresponding to the resonance frequencies are    the first-order waving, first-order swing and second-order swing mode shapes. An optimization design method for optimizing the cross-sectional shape is proposed. Without adding extra weight, the corresponding frequency points of the first-order waving mode, the first-order swing mode, and the second-order swing mode have been increased by 37.23%, 22.47 and 18.43%, respectively. The vibration reduction analysis and optimization design method proposed in the article can provide references for design work of drones.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔辉如,和英鹏,李道奎,马维力,申柳雷]]></author>
</item>
<item>
<title><![CDATA[Influence of lunar soil parameters on the lunar landing airbag cushioning performance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202250000003]]></link>
<description><![CDATA[To study the influence of lunar soil parameters on the airbag buffer performance, a lunar landing airbag was designed according to the landing conditions of Chang'e-3 probe, and then an airbag dynamic model considering the characteristics of lunar soil was established based on the crushable foam model. The airbag cushioning process under different lunar soils was analyzed, and it is found that the softer the lunar soil, the smaller the payload impact acceleration, but the airbag will sink into the lunar soil, which is not conducive to venting and affects its cushioning effect. Therefore, three indicators of airbag peak pressure, payload maximum acceleration, and payload maximum drop height were used to evaluate the airbag cushioning performance comprehensively, and the influence law of lunar soil parameters was quantitatively studied. The results show that the lunar soil density and shear modulus, as well as the yield parameters a0 and a1, have a significant influence on the cushioning performance, with a positive effect on the first two indicators and a negative effect on the latter one. Further research reveals that the relationship between each of the four lunar soil parameters and the three cushioning performance indicators is an exponential function.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李道奎,周仕明,周旋]]></author>
</item>
<item>
<title><![CDATA[Influence of lunar soil parameters on the lunar landing airbag cushioning performance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202250000003]]></link>
<description><![CDATA[To study the influence of lunar soil parameters on the airbag buffer performance, a lunar landing airbag was designed according to the landing conditions of Chang'e-3 probe, and then an airbag dynamic model considering the characteristics of lunar soil was established based on the crushable foam model. The airbag cushioning process under different lunar soils was analyzed, and it is found that the softer the lunar soil, the smaller the payload impact acceleration, but the airbag will sink into the lunar soil, which is not conducive to venting and affects its cushioning effect. Therefore, three indicators of airbag peak pressure, payload maximum acceleration, and payload maximum drop height were used to evaluate the airbag cushioning performance comprehensively, and the influence law of lunar soil parameters was quantitatively studied. The results show that the lunar soil density and shear modulus, as well as the yield parameters a0 and a1, have a significant influence on the cushioning performance, with a positive effect on the first two indicators and a negative effect on the latter one. Further research reveals that the relationship between each of the four lunar soil parameters and the three cushioning performance indicators is an exponential function.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李道奎,周仕明,周旋]]></author>
</item>
<item>
<title><![CDATA[Vibration Reduction Analysis and Experiment of Multi-Rotor Drone]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201060000004]]></link>
<description><![CDATA[Aiming at the problem of excessive vibration of the multi-rotor drone, which causes instability of flight state, the vibration reduction analysis work is carried out based on CAE simulation technology and experimental methods. Through frequency analysis, the reason of excessive vibration is determined to be resonance，and the mode shape corresponding to the resonance frequencies are    the first-order waving, first-order swing and second-order swing mode shapes. An optimization design method for optimizing the cross-sectional shape is proposed. Without adding extra weight, the corresponding frequency points of the first-order waving mode, the first-order swing mode, and the second-order swing mode have been increased by 37.23%, 22.47 and 18.43%, respectively. The vibration reduction analysis and optimization design method proposed in the article can provide references for design work of drones.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔辉如,和英鹏,李道奎,马维力,申柳雷]]></author>
</item>
<item>
<title><![CDATA[Roll control study of a flying wing based on trailing-edge jet at a wide speed range]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110220000001]]></link>
<description><![CDATA[The numerical simulation method is used to carry out a systematic study on the roll control of the flying wing using the trailing-edge CC(circulation control) jet at a wide speed range (Ma=0.145-0.7), compared with the configuration controlled by classical control surfaces. The research focuses the electromagnetic stealth characteristics, the roll control characteristics and their flow physics, and the impacts of the bleed air. The results show that as the Mach number increases, the roll control capability of the CC jet decreases due to the weakening of entrainment and blocking effects. However, the CC jet enhances the stealth performance at specific azimuth ranges remarkably. Moreover, it requires less bleed air, induces less thrust loss, and has a high control efficiency factor (aerodynamic moment coefficient produced per unit of additional drag coefficient). In conclusion, the trailing-edge CC jet is a highly promising roll control device for a flying wing.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭正,侯中喜,贾高伟,邵帅,阴鹏,张来平]]></author>
</item>
<item>
<title><![CDATA[AHP-Arena comprehensive evaluation method for the efficiency of the allocation of UAV flight training resources]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105040000001]]></link>
<description><![CDATA[In order to reduce the subjective one-sided influence of empowerment process of the traditional hierarchical analysis method (AHP, Analytic Hierarchy Process), a comprehensive AHP and Arena simulation modeling technology was proposed to evaluate the efficiency of the allocation of UAV training resources. Based on flight training process analysis, the factors influencing the efficiency of training resource allocation and efficiency evaluation index were determined, a hierarchical comprehensive evaluation system was established, and the comprehensive evaluation steps of AHP-Arena were summarized.  Arena modeling software was used to realize the dynamic simulation system of the training process and verify the validity, the single-variable numerical simulation method and the mean variance decision-making method were used to complete the objective empowerment of the influencing factors, and the comprehensive evaluation coefficient was obtained by linear weighting comprehensive method, so as to implement resource allocation efficiency evaluation and selection of the optimal program.The practical application shows the effectiveness of the method. Meanwhile, this method can be extended to other similar training processes, and can also provide references for other multi-factor multi-indicator evaluation decision-making processes.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[王建楠,张尧]]></author>
</item>
<item>
<title><![CDATA[Real-time evaluation of the progress of a social work using open-source big data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109090000003]]></link>
<description><![CDATA[Few quantitative models can be found amenable to the quantitative evaluation of social work, which motivates the work presented in this article. Moreover, a few related existing works suffer from no suitable indicator system and high expenses of time and money. To overcome these limitations, a real-time quantitative evaluation model using the Internet open-source big data was developed, a target indicator system was established, the rapid computation methods of each criterion were proposed, and a prototypical software system was designed and implemented. Case studies on selected social work were conducted, and the work performance of the 14 cities belonging to a certain province in China was evaluated. The results achieved were largely consistent with the subjective feelings of many respondents and relevant official assessment, which validated the efficiency and rationality of the model proposed.]]></description>
<pubDate>2022/7/20 10:36:35</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[欧文孝,潘岩,王寅森,殷风景,张鑫]]></author>
</item>
<item>
<title><![CDATA[UAV swarm cooperative search based on moth pheromone courtship mechanism]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111270000001]]></link>
<description><![CDATA[In order to improve the efficiency of the UAV (unmanned aerial vehicle) swarm in cooperative search for moving targets, a UAV swarm cooperative search method was proposed based on the moth pheromone courtship mechanism.  According to the courtship behavior of moth in choosing flight direction by pheromone, a wind direction model in pheromone map and a moth pheromone courtship model were established. Considering the constraint of collision avoidance between UAV swarm, a map from moth pheromone courtship mechanism to UAV swarm distributed cooperative search was proposed, and the specific implementation process was given. Simulation results show the effectiveness and stability of the proposed method in solving the cooperative search problem of single moving target, and the outdoor flight experimental results verified the feasibility of the proposed method in practice.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[邓亦敏,段海滨,刘云昊,魏晨]]></author>
</item>
<item>
<title><![CDATA[Solution to continuous time Markov chain model for unmanned aerial vehicle swarm operation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112220000002]]></link>
<description><![CDATA[In order to solve the problem of low computing speed in the process of state transition in the analytical modeling of UAV (unmanned aerial vehicle) swarm operation, a fourth-order Runge-Kutta method based on row compressed storage was proposed. The UAV swarm operation process was divided into three stages according to the UAV swarm operation style, and continuous time Markov chain model was established for the state transition process of UAV swarm operation in stages. In the meantime, taking the reliability of UAV swarm to complete combat mission as the solving index, the fourth-order Runge-Kutta method was used to solve the Markov model, and the method based on row compressed storage was used to optimize the solving rate owing to the sparsity feature of the rate transfer matrix.  Simulation results show that the established continuous time Markov chain model has better effectiveness and feasibility than other models. At the same time, compared with other algorithms, the proposed algorithm has higher computing speed and better reliability requirements to meet the accuracy of results, which further shows the superiority of it.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[黄树彩,,,]]></author>
</item>
<item>
<title><![CDATA[DWA path planning algorithm based on multi-objective particle swarm optimization in complex environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111020000003]]></link>
<description><![CDATA[When the robot is running in a complex environment with densely distributed obstacles, the DWA algorithm is prone to obstacle avoidance failure or unreasonable planning. In this regard, an improved DWA planning algorithm based on Multi-Objective Particle Swarm Optimization (MOPSO) is proposed. Based on the establishment of multi obstacle environment coverage model, a method is put forward for judging obstacle-dense areas in complex environments. And the original DWA algorithm is improved by optimizing the sub-evaluation functions. On these basis, the adaptive change of DWA weight coefficients can be transformed into a multi-objective optimization problem, which can be solved by the improved MOPSO algorithm. According to the requirements of path planning, the corresponding multi-objective optimization model can be established, moreover the safety distance and speed can be set as the optimization goals. A series of simulations based on Matlab are carried out, and the results show that this method enables the robot to effectively pass through the dense area of obstacles while taking account of the safety and speed of operation, and has better path planning effect.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[常路,单梁,李薪颖,屈艺,张永]]></author>
</item>
<item>
<title><![CDATA[Occlusion and confusion targets recognition method for UAV under small sample conditions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111050000002]]></link>
<description><![CDATA[Aiming at the problem of occlusion and confusion targets recognition for unmanned air vehicle (UAV) under small sample conditions, a target recognition model integrating self-attention mechanism and few-shot learning is proposed. On the basis of using the idea of meta learning to obtain the ability of few-shot learning, the model introduces the self-attention mechanism to learn the context dependence between the internal parts of the target, so as to enhance the target representation ability and solve the problem of insufficient effective features in the case of occlusion and confusion. In order to verify the effect of the model, the occlusion and confusion target datasets are constructed by further processing the reference dataset and UAV aerial photography data, and different occlusion degrees and background confusion rates are set. Through the verification on different datasets and compared with the deep learning model, the proposed model has higher learning efficiency and recognition accuracy.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[李宏男,牛轶峰,吴立珍]]></author>
</item>
<item>
<title><![CDATA[Occlusion and confusion targets recognition method for UAV under small sample conditions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111050000002]]></link>
<description><![CDATA[Aiming at the problem of occlusion and confusion targets recognition for unmanned air vehicle (UAV) under small sample conditions, a target recognition model integrating self-attention mechanism and few-shot learning is proposed. On the basis of using the idea of meta learning to obtain the ability of few-shot learning, the model introduces the self-attention mechanism to learn the context dependence between the internal parts of the target, so as to enhance the target representation ability and solve the problem of insufficient effective features in the case of occlusion and confusion. In order to verify the effect of the model, the occlusion and confusion target datasets are constructed by further processing the reference dataset and UAV aerial photography data, and different occlusion degrees and background confusion rates are set. Through the verification on different datasets and compared with the deep learning model, the proposed model has higher learning efficiency and recognition accuracy.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[李宏男,牛轶峰,吴立珍]]></author>
</item>
<item>
<title><![CDATA[Review on motion planning methods for unmanned aerial vehicleuav cooperative maneuvering in cluttered environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111230000001]]></link>
<description><![CDATA[As the mission space height of multiple unmanned aerial vehicles (UAVs) cooperating gradually decreases to the cluttered near-ground environment in order to achieve concealed penetration on a more confrontational battlefield, it is necessary to combine cooperative technology with maneuver flight technology to study the UAV cooperative maneuver flight motion planning technology, to ensure flight safety of UAVs while completing cooperative missions. This paper introduces the basic principle, representative methods, and state-of-the-art research of the sub-module related research within the general framework of cooperative maneuvering flight planning from single UAV maneuvering flight to multi-UAV cooperative planning, including real-time navigation map construction, discrete-space path planning, continuous-space trajectory planning, hybrid planning, and multi-courses/trajectories cooperative planning. The next research directions are proposed based on the major technologies of the planning framework.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[贾圣德,李杰,刘天晴,牛轶峰]]></author>
</item>
<item>
<title><![CDATA[Solution to continuous time Markov chain model for unmanned aerial vehicle swarm operation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112220000002]]></link>
<description><![CDATA[In order to solve the problem of low computing speed in the process of state transition in the analytical modeling of UAV (unmanned aerial vehicle) swarm operation, a fourth-order Runge-Kutta method based on row compressed storage was proposed. The UAV swarm operation process was divided into three stages according to the UAV swarm operation style, and continuous time Markov chain model was established for the state transition process of UAV swarm operation in stages. In the meantime, taking the reliability of UAV swarm to complete combat mission as the solving index, the fourth-order Runge-Kutta method was used to solve the Markov model, and the method based on row compressed storage was used to optimize the solving rate owing to the sparsity feature of the rate transfer matrix.  Simulation results show that the established continuous time Markov chain model has better effectiveness and feasibility than other models. At the same time, compared with other algorithms, the proposed algorithm has higher computing speed and better reliability requirements to meet the accuracy of results, which further shows the superiority of it.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[黄树彩,,,]]></author>
</item>
<item>
<title><![CDATA[UAV swarm cooperative search based on moth pheromone courtship mechanism]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111270000001]]></link>
<description><![CDATA[In order to improve the efficiency of the UAV (unmanned aerial vehicle) swarm in cooperative search for moving targets, a UAV swarm cooperative search method was proposed based on the moth pheromone courtship mechanism.  According to the courtship behavior of moth in choosing flight direction by pheromone, a wind direction model in pheromone map and a moth pheromone courtship model were established. Considering the constraint of collision avoidance between UAV swarm, a map from moth pheromone courtship mechanism to UAV swarm distributed cooperative search was proposed, and the specific implementation process was given. Simulation results show the effectiveness and stability of the proposed method in solving the cooperative search problem of single moving target, and the outdoor flight experimental results verified the feasibility of the proposed method in practice.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[邓亦敏,段海滨,刘云昊,魏晨]]></author>
</item>
<item>
<title><![CDATA[Occlusion and confusion targets recognition method for UAV under small sample conditions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111050000002]]></link>
<description><![CDATA[Aiming at the problem of occlusion and confusion targets recognition for unmanned air vehicle (UAV) under small sample conditions, a target recognition model integrating self-attention mechanism and few-shot learning is proposed. On the basis of using the idea of meta learning to obtain the ability of few-shot learning, the model introduces the self-attention mechanism to learn the context dependence between the internal parts of the target, so as to enhance the target representation ability and solve the problem of insufficient effective features in the case of occlusion and confusion. In order to verify the effect of the model, the occlusion and confusion target datasets are constructed by further processing the reference dataset and UAV aerial photography data, and different occlusion degrees and background confusion rates are set. Through the verification on different datasets and compared with the deep learning model, the proposed model has higher learning efficiency and recognition accuracy.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[李宏男,牛轶峰,吴立珍]]></author>
</item>
<item>
<title><![CDATA[UAV swarm cooperative search based on moth pheromone courtship mechanism]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111270000001]]></link>
<description><![CDATA[In order to improve the efficiency of the UAV (unmanned aerial vehicle) swarm in cooperative search for moving targets, a UAV swarm cooperative search method was proposed based on the moth pheromone courtship mechanism.  According to the courtship behavior of moth in choosing flight direction by pheromone, a wind direction model in pheromone map and a moth pheromone courtship model were established. Considering the constraint of collision avoidance between UAV swarm, a map from moth pheromone courtship mechanism to UAV swarm distributed cooperative search was proposed, and the specific implementation process was given. Simulation results show the effectiveness and stability of the proposed method in solving the cooperative search problem of single moving target, and the outdoor flight experimental results verified the feasibility of the proposed method in practice.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[邓亦敏,段海滨,刘云昊,魏晨]]></author>
</item>
<item>
<title><![CDATA[Solution to continuous time Markov chain model for unmanned aerial vehicle swarm operation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112220000002]]></link>
<description><![CDATA[In order to solve the problem of low computing speed in the process of state transition in the analytical modeling of UAV (unmanned aerial vehicle) swarm operation, a fourth-order Runge-Kutta method based on row compressed storage was proposed. The UAV swarm operation process was divided into three stages according to the UAV swarm operation style, and continuous time Markov chain model was established for the state transition process of UAV swarm operation in stages. In the meantime, taking the reliability of UAV swarm to complete combat mission as the solving index, the fourth-order Runge-Kutta method was used to solve the Markov model, and the method based on row compressed storage was used to optimize the solving rate owing to the sparsity feature of the rate transfer matrix.  Simulation results show that the established continuous time Markov chain model has better effectiveness and feasibility than other models. At the same time, compared with other algorithms, the proposed algorithm has higher computing speed and better reliability requirements to meet the accuracy of results, which further shows the superiority of it.]]></description>
<pubDate>2022/7/20 10:36:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[黄树彩,,,]]></author>
</item>
<item>
<title><![CDATA[Staring attitude control for deep space targets based on an uncalibrated video satellite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112220000001]]></link>
<description><![CDATA[A small video satellite can continuously observe deep space targets, which has a broad application prospect. A conventional staring attitude control method requires the information about the location of the target and the intrinsic and extrinsic parameters of the camera. In some cases, however, the accurate location of the observed target is unknown, and the camera parameters are affected by the in-orbit environment, making it hard to calibrate. We design an adaptive attitude controller, achieving staring at the target in the presence of the unknown target’s position and camera parameters. First, the estimated parameters are extracted to be linearized. Second, a potential function is introduced to meet the demand for the rank of the parameter matrix. At last, a self-updating principle of parameters is adopted to estimate the parameters on line, and accordingly the adaptive control method is proposed. Based on the Lyapunov theory and Barbalat’s lemma, the target image converging to the desired position in the image plane is proved. The simulation results reveal that the adaptive controller can affectively achieve staring observation for deep space targets with the uncertainties of the target position and the camera parameters.]]></description>
<pubDate>2022/7/19 15:33:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[范才智,宋超,王猛猛]]></author>
</item>
<item>
<title><![CDATA[Effect of structural parameters of regenerative cooling channels on hydrocarbon fuel flow distribution]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106160000001]]></link>
<description><![CDATA[Based on the regenerative cooling technology of liquid rocket engine, the flow distribution characteristics of Z-type parallel channels were studied by numerical simulation method. The effects of channel number, channel section shape and entrance confluence structure on the flow distribution characteristics were analyzed. The results show that the non-uniformity coefficient of flow distribution decreases from 2.59% to 0.5% with the increase of the number of channels in the regenerative cooling system. Increasing the number of channels under the same flow area can effectively ensure the uniformity of flow distribution. The channel section shape has little influence on the non-uniformity coefficient of flow distribution, which is mainly reflected in the flow velocity distribution and heat transfer area in the channel, and the heat transfer effect of the trapezoidal configuration is better than that of the rectangular configuration. The entrance confluence structure is beneficial to the uniform of flow distribution. The research has a certain reference significance for the structural design of regenerative cooling channel.]]></description>
<pubDate>2022/7/19 15:33:15</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[丁 杰,刘伟强,尹 亮]]></author>
</item>
<item>
<title><![CDATA[Analysis on application of aero engine in supersonic ejector system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010270000001]]></link>
<description><![CDATA[The pressure and temperature of air flow can be increased by aero engine, so the application of aero engine in supersonic ejector system is possible. The effects of air source on ejector performance and the effects of bleeding on aero engine performance were analyzed. And 3 types of aero engine layout in supersonic ejector system were presented. According to the requirements of a supersonic ejector system, the performance parameters of all 3 types of aero engine layout were calculated. The calculation results indicate that when the upstream pressure is 0.044×105Pa and 0.0293×105Pa, aero engine can used in super ejector system by selecting reasonable layout and working parameters.]]></description>
<pubDate>2022/7/19 15:33:09</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[顾蕴松,任泽斌,史煜,徐大川,阳玲]]></author>
</item>
<item>
<title><![CDATA[Truth Discovery from Multi-Source Text Data Based on Deep Neural Networt]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011240000001]]></link>
<description><![CDATA[In order to solve the problem that the traditional truth discovery algorithm cannot be applied to text data directly, a truth discovery algorithm for text data based on deep neural network was proposed. For the features of multifactorial property of text answers, the diversity of word usages, and the sparsity of the text data, the "source-answer" vector was used as the network input, and the truth vector was recognized as the network output. The relationship between answers from each source could be unsupervised learned according to general hypothesis of truth discovery, and finally the truth vector was obtained by neural network. The experiment results show that the proposed algorithm is suitable for text data truth discovery, and it is better than the retrieval methods and traditional truth discovery algorithm.]]></description>
<pubDate>2022/7/19 15:33:09</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[曹建军,常宸,蒋国权,陶嘉庆,翁年凤]]></author>
</item>
<item>
<title><![CDATA[Long-term Coherent Integration method for low-altitude small targets of LFMCW radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011060000001]]></link>
<description><![CDATA[Aimed at the problem of weak radar echo of small UAV(Unmaned Aerial Vehicle) targets and difficult target detection. Long-term coherent integration method under the LFMCW(linear frequency modulation continuous wave) radar was studied. By deriving the expression of LFMCW radar echo, an Radon-Fouier Transform implementation method based on Chirp-Z transformof time-domain beat signal was proposed. The computational complexity of this method was evaluated and compared with the method implemented in frequency domain.  Simulation and measured data verified the effectiveness of this algorithm for the coherent integration of weak targets under LFMCW radar.]]></description>
<pubDate>2022/7/19 15:33:09</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[郭立民,,,]]></author>
</item>
<item>
<title><![CDATA[Energy efficiency analysis of the relay-assisted CR-NOMA system using SWIPT]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011240000002]]></link>
<description><![CDATA[In view of the shortcomings of limited terminal battery capacity and low energy efficiency in the existing research on Cognitive Radio Non-Orthogonal Multiple Access (CR-NOMA) networks, a relay is used to assist users in transmission, and a method of simultaneous transmission of wireless information and energy is introduced. Under the constraints of user service quality and minimum energy capture, the sub-user transmission energy efficiency expression is derived. The non-convex objective function is transformed into three convex single-objective problems of optimizing relay transmission power, relay power allocation and receiver power allocation by fractional programming method. Using function monotonicity, golden section algorithm, Lagrangian dual algorithm and multi-objective joint optimization algorithm for optimization, the global optimal solution is obtained to maximize the transmission energy efficiency of the secondary user system. The complexity of the adopted algorithm is analyzed .The simulation results show that compared with the traditional Orthogonal Multiple Access (OMA) scheme, while improving the system spectrum utilization, the sub-user transmission energy efficiency has been improved by 47%.]]></description>
<pubDate>2022/7/19 15:33:09</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[蔺莹,苗丰满,薛建彬,张海军,张永刚]]></author>
</item>
<item>
<title><![CDATA[Model Predictive Based Disturbance Rejection and Obstacle Avoidance Guidance for Multi Rotor Unmanned Aerial Vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111010000002]]></link>
<description><![CDATA[The autonomous obstacle avoidance of Unmanned Aerial Vehicle (UAV) is the basis of completing complex tasks, and the obstacle avoidance performance directly affects the efficiency of UAV performing tasks. Aiming at the obstacle avoidance problem of UAV with external disturbance, a design method of anti-disturbance and obstacle avoidance guidance law based on model prediction is proposed. The disturbance observer is designed to estimate the external disturbance in the system dynamics, and the auxiliary guidance law is designed based on Lyapunov function method to establish the stability constraints. Combining the first two with model predictive control(MPC), the relationship between UAV and obstacles is considered in the MPC optimization solution, and the horizontal linear velocity and yaw angular velocity commands are solved according to the designed guidance law to realize the obstacle avoidance of UAV. Finally, the numerical simulation and physical flight verification of the proposed obstacle avoidance guidance law show the effectiveness of the proposed method.]]></description>
<pubDate>2022/7/19 15:33:08</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈谋,兰庆湘,雍可南]]></author>
</item>
<item>
<title><![CDATA[Optimal Control Method for Swarm Systems Formation Tracking Problem with LQR Performance Index]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111020000002]]></link>
<description><![CDATA[For the formation tracking problem for swarm systems,an optimal control method with LQR performance index is put forward.Firstly,establish the mathematical description of the formation tracking problem and design a formation tracking control protocol.Next,necessary and sufficient conditions for swarm systems with formation tracking are obtained and the stability of the system is analysed using common Lyapunov approach.Then topology conditions of the control protocol which can minimize LQR performance index are obtained and the formation tracking algorithm is designed .Finally, a numerical simulation is provided to illustrate the effectiveness of the control method.]]></description>
<pubDate>2022/7/19 15:33:08</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈宏伟,王琳,张庆杰]]></author>
</item>
<item>
<title><![CDATA[Review on motion planning methods for unmanned aerial vehicleuav cooperative maneuvering in cluttered environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111230000001]]></link>
<description><![CDATA[As the mission space height of multiple unmanned aerial vehicles (UAVs) cooperating gradually decreases to the cluttered near-ground environment in order to achieve concealed penetration on a more confrontational battlefield, it is necessary to combine cooperative technology with maneuver flight technology to study the UAV cooperative maneuver flight motion planning technology, to ensure flight safety of UAVs while completing cooperative missions. This paper introduces the basic principle, representative methods, and state-of-the-art research of the sub-module related research within the general framework of cooperative maneuvering flight planning from single UAV maneuvering flight to multi-UAV cooperative planning, including real-time navigation map construction, discrete-space path planning, continuous-space trajectory planning, hybrid planning, and multi-courses/trajectories cooperative planning. The next research directions are proposed based on the major technologies of the planning framework.]]></description>
<pubDate>2022/7/19 15:33:08</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[贾圣德,李杰,刘天晴,牛轶峰]]></author>
</item>
<item>
<title><![CDATA[Effect of structural parameters of regenerative cooling channels on hydrocarbon fuel flow distribution]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106160000001]]></link>
<description><![CDATA[Based on the regenerative cooling technology of liquid rocket engine, the flow distribution characteristics of Z-type parallel channels were studied by numerical simulation method. The effects of channel number, channel section shape and entrance confluence structure on the flow distribution characteristics were analyzed. The results show that the non-uniformity coefficient of flow distribution decreases from 2.59% to 0.5% with the increase of the number of channels in the regenerative cooling system. Increasing the number of channels under the same flow area can effectively ensure the uniformity of flow distribution. The channel section shape has little influence on the non-uniformity coefficient of flow distribution, which is mainly reflected in the flow velocity distribution and heat transfer area in the channel, and the heat transfer effect of the trapezoidal configuration is better than that of the rectangular configuration. The entrance confluence structure is beneficial to the uniform of flow distribution. The research has a certain reference significance for the structural design of regenerative cooling channel.]]></description>
<pubDate>2022/7/18 15:18:17</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[丁 杰,刘伟强,尹 亮]]></author>
</item>
<item>
<title><![CDATA[Analysis on application of aero engine in supersonic ejector system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010270000001]]></link>
<description><![CDATA[The pressure and temperature of air flow can be increased by aero engine, so the application of aero engine in supersonic ejector system is possible. The effects of air source on ejector performance and the effects of bleeding on aero engine performance were analyzed. And 3 types of aero engine layout in supersonic ejector system were presented. According to the requirements of a supersonic ejector system, the performance parameters of all 3 types of aero engine layout were calculated. The calculation results indicate that when the upstream pressure is 0.044×105Pa and 0.0293×105Pa, aero engine can used in super ejector system by selecting reasonable layout and working parameters.]]></description>
<pubDate>2022/7/18 15:13:55</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[顾蕴松,任泽斌,史煜,徐大川,阳玲]]></author>
</item>
<item>
<title><![CDATA[Model Predictive Based Disturbance Rejection and Obstacle Avoidance Guidance for Multi Rotor Unmanned Aerial Vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111010000002]]></link>
<description><![CDATA[The autonomous obstacle avoidance of Unmanned Aerial Vehicle (UAV) is the basis of completing complex tasks, and the obstacle avoidance performance directly affects the efficiency of UAV performing tasks. Aiming at the obstacle avoidance problem of UAV with external disturbance, a design method of anti-disturbance and obstacle avoidance guidance law based on model prediction is proposed. The disturbance observer is designed to estimate the external disturbance in the system dynamics, and the auxiliary guidance law is designed based on Lyapunov function method to establish the stability constraints. Combining the first two with model predictive control(MPC), the relationship between UAV and obstacles is considered in the MPC optimization solution, and the horizontal linear velocity and yaw angular velocity commands are solved according to the designed guidance law to realize the obstacle avoidance of UAV. Finally, the numerical simulation and physical flight verification of the proposed obstacle avoidance guidance law show the effectiveness of the proposed method.]]></description>
<pubDate>2022/7/18 15:13:55</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈谋,兰庆湘,雍可南]]></author>
</item>
<item>
<title><![CDATA[Long-term Coherent Integration method for low-altitude small targets of LFMCW radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011060000001]]></link>
<description><![CDATA[Aimed at the problem of weak radar echo of small UAV(Unmaned Aerial Vehicle) targets and difficult target detection. Long-term coherent integration method under the LFMCW(linear frequency modulation continuous wave) radar was studied. By deriving the expression of LFMCW radar echo, an Radon-Fouier Transform implementation method based on Chirp-Z transformof time-domain beat signal was proposed. The computational complexity of this method was evaluated and compared with the method implemented in frequency domain.  Simulation and measured data verified the effectiveness of this algorithm for the coherent integration of weak targets under LFMCW radar.]]></description>
<pubDate>2022/7/18 15:13:55</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[郭立民,,,]]></author>
</item>
<item>
<title><![CDATA[Optimal Control Method for Swarm Systems Formation Tracking Problem with LQR Performance Index]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111020000002]]></link>
<description><![CDATA[For the formation tracking problem for swarm systems,an optimal control method with LQR performance index is put forward.Firstly,establish the mathematical description of the formation tracking problem and design a formation tracking control protocol.Next,necessary and sufficient conditions for swarm systems with formation tracking are obtained and the stability of the system is analysed using common Lyapunov approach.Then topology conditions of the control protocol which can minimize LQR performance index are obtained and the formation tracking algorithm is designed .Finally, a numerical simulation is provided to illustrate the effectiveness of the control method.]]></description>
<pubDate>2022/7/18 15:13:41</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈宏伟,王琳,张庆杰]]></author>
</item>
<item>
<title><![CDATA[Truth discovery for multi-source text data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011240000001]]></link>
<description><![CDATA[In order to solve the problem that the traditional truth discovery algorithm cannot be applied to text data directly, a truth discovery algorithm for text data based on deep neural network was proposed. For the features of multifactorial property of text answers, the diversity of word usages, and the sparsity of the text data, the "source-answer" vector was used as the network input, and the truth vector was recognized as the network output. The relationship between answers from each source could be unsupervised learned according to general hypothesis of truth discovery, and finally the truth vector was obtained by neural network. The experiment results show that the proposed algorithm is suitable for text data truth discovery, and it is better than the retrieval methods and traditional truth discovery algorithm.]]></description>
<pubDate>2022/7/18 15:13:41</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[曹建军,常宸,蒋国权,陶嘉庆,翁年凤]]></author>
</item>
<item>
<title><![CDATA[Energy efficiency analysis of the relay-assisted CR-NOMA system using SWIPT]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011240000002]]></link>
<description><![CDATA[In view of the shortcomings of limited terminal battery capacity and low energy efficiency in the existing research on Cognitive Radio Non-Orthogonal Multiple Access (CR-NOMA) networks, a relay is used to assist users in transmission, and a method of simultaneous transmission of wireless information and energy is introduced. Under the constraints of user service quality and minimum energy capture, the sub-user transmission energy efficiency expression is derived. The non-convex objective function is transformed into three convex single-objective problems of optimizing relay transmission power, relay power allocation and receiver power allocation by fractional programming method. Using function monotonicity, golden section algorithm, Lagrangian dual algorithm and multi-objective joint optimization algorithm for optimization, the global optimal solution is obtained to maximize the transmission energy efficiency of the secondary user system. The complexity of the adopted algorithm is analyzed .The simulation results show that compared with the traditional Orthogonal Multiple Access (OMA) scheme, while improving the system spectrum utilization, the sub-user transmission energy efficiency has been improved by 47%.]]></description>
<pubDate>2022/7/18 15:13:41</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[蔺莹,苗丰满,薛建彬,张海军,张永刚]]></author>
</item>
<item>
<title><![CDATA[Review on motion planning methods for unmanned aerial vehicleuav cooperative maneuvering in cluttered environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111230000001]]></link>
<description><![CDATA[As the mission space height of multiple unmanned aerial vehicles (UAVs) cooperating gradually decreases to the cluttered near-ground environment in order to achieve concealed penetration on a more confrontational battlefield, it is necessary to combine cooperative technology with maneuver flight technology to study the UAV cooperative maneuver flight motion planning technology, to ensure flight safety of UAVs while completing cooperative missions. This paper introduces the basic principle, representative methods, and state-of-the-art research of the sub-module related research within the general framework of cooperative maneuvering flight planning from single UAV maneuvering flight to multi-UAV cooperative planning, including real-time navigation map construction, discrete-space path planning, continuous-space trajectory planning, hybrid planning, and multi-courses/trajectories cooperative planning. The next research directions are proposed based on the major technologies of the planning framework.]]></description>
<pubDate>2022/7/18 15:09:26</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[贾圣德,李杰,刘天晴,牛轶峰]]></author>
</item>
<item>
<title><![CDATA[Truth Discovery from Multi-Source Text Data Based on Deep Neural Networt]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011240000001]]></link>
<description><![CDATA[In order to solve the problem that the traditional truth discovery algorithm cannot be applied to text data directly, a truth discovery algorithm for text data based on deep neural network was proposed. For the features of multifactorial property of text answers, the diversity of word usages, and the sparsity of the text data, the "source-answer" vector was used as the network input, and the truth vector was recognized as the network output. The relationship between answers from each source could be unsupervised learned according to general hypothesis of truth discovery, and finally the truth vector was obtained by neural network. The experiment results show that the proposed algorithm is suitable for text data truth discovery, and it is better than the retrieval methods and traditional truth discovery algorithm.]]></description>
<pubDate>2022/7/7 23:29:49</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[曹建军,常宸,蒋国权,陶嘉庆,翁年凤]]></author>
</item>
<item>
<title><![CDATA[Optimal Control Method for Swarm Systems Formation Tracking Problem with LQR Performance Index]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111020000002]]></link>
<description><![CDATA[For the formation tracking problem for swarm systems,an optimal control method with LQR performance index is put forward.Firstly,establish the mathematical description of the formation tracking problem and design a formation tracking control protocol.Next,necessary and sufficient conditions for swarm systems with formation tracking are obtained and the stability of the system is analysed using common Lyapunov approach.Then topology conditions of the control protocol which can minimize LQR performance index are obtained and the formation tracking algorithm is designed .Finally, a numerical simulation is provided to illustrate the effectiveness of the control method.]]></description>
<pubDate>2022/7/7 23:01:19</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈宏伟,王琳,张庆杰]]></author>
</item>
<item>
<title><![CDATA[Dynamics Characteristics of Active Angle Deception Jamming Decoys]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009170000001]]></link>
<description><![CDATA[Aiming at dealing withthe active angle deception decoys that may appear in the process of high-altitude and high-speed target detectionof high altitude and high speed target detection, a comprehensive and theoretical analysis of the dynamics characteristics iwas presented. Firstly, the dynamics model equation of active decoy iwas derived.. Secondly,and the conservation of mechanical energy and moment of momentum of the decoy iswere analyzed. Theoretical analysis and experimental results indicate that active angle deception decoys show a significant difference comparing to true target in the aspect of dynamics characteristics. The decoys do not follow the elliptical orbit and the dynamical conversation law, which is the foundation of discrimination algorithms. Theoretical analysis and simulation experiments showed that the dynamic characteristics of the azimuth active decoy with fixed angle deception were completely consistent with the real target, and it was impossible to distinguish the true from the false in dynamics. In addition, other angle deception active false targets did not meet the elliptic orbit characteristics of high-altitude high-speed targets and the law of conservation of dynamics. Using this difference, false targets can be identified in the data processing layer.]]></description>
<pubDate>2022/6/9 17:18:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[顾赵宇,饶彬,王国玉]]></author>
</item>
<item>
<title><![CDATA[Long-term Coherent Integration method for low-altitude small targets of LFMCW radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011060000001]]></link>
<description><![CDATA[Aimed at the problem of weak radar echo of small UAV(Unmaned Aerial Vehicle) targets and difficult target detection. Long-term coherent integration method under the LFMCW(linear frequency modulation continuous wave) radar was studied. By deriving the expression of LFMCW radar echo, an Radon-Fouier Transform implementation method based on Chirp-Z transformof time-domain beat signal was proposed. The computational complexity of this method was evaluated and compared with the method implemented in frequency domain.  Simulation and measured data verified the effectiveness of this algorithm for the coherent integration of weak targets under LFMCW radar.]]></description>
<pubDate>2022/6/9 17:17:55</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[郭立民,,,]]></author>
</item>
<item>
<title><![CDATA[A spatial distribution model for behind-armor debris formed by the perforation of explosively formed projectile through the target]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011100000001]]></link>
<description><![CDATA[The deep space impact load is of great significance to the detection of the internal material composition and structural characteristics of small celestial bodies. So a spatial distribution model for BAD (behind-armor debris) formed by the perforation of variable cross-section EFP (explosively formed projectile) through the target is established. The variable cross-section characteristic of the EFP is considered and the sources of BAD (from target or EFP) are distinguished in the model. The thickness of the target is from 30 mm to 70 mm, the impact velocity of EFP is from 1650 m/s to 1860 m/s. The relationships between the velocity (mass, kinetic energy, quantity) and spatial position of every debris in the BAD cloud could be predicted quantitatively. The results indicate that the relative velocity increases by a linear function with the increase of the relative spatial position, the relative mass and the relative number increase by a power function with the increase of the relative spatial position.]]></description>
<pubDate>2022/6/9 16:56:00</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔浩,郭锐,侯云辉,骆强,邢柏阳,徐伟华,杨赵兵,张东江,朱桂利]]></author>
</item>
<item>
<title><![CDATA[Analysis on application of aero engine in supersonic ejector system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010270000001]]></link>
<description><![CDATA[The pressure and temperature of air flow can be increased by aero engine, so the application of aero engine in supersonic ejector system is possible. The effects of air source on ejector performance and the effects of bleeding on aero engine performance were analyzed. And 3 types of aero engine layout in supersonic ejector system were presented. According to the requirements of a supersonic ejector system, the performance parameters of all 3 types of aero engine layout were calculated. The calculation results indicate that when the upstream pressure is 0.044×105Pa and 0.0293×105Pa, aero engine can used in super ejector system by selecting reasonable layout and working parameters.]]></description>
<pubDate>2022/6/9 16:55:29</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[顾蕴松,任泽斌,史煜,徐大川,阳玲]]></author>
</item>
<item>
<title><![CDATA[Method of satellite high-frequence attitude determination using compressive sampling]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011080000003]]></link>
<description><![CDATA[High-frequency attitude vibration is one of the major error sources that prevent satellites from achieving high attitude estimation precision. The frequency of vibration usually surpasses the sampling frequency of traditional attitude sensors. This paper proposes a novel high-frequency method for attitude determination using normal attitude sensors. The key idea is that the high-bandwidth attitude of the spacecraft is sparse in the frequency domain and can be recovered from normal-sampling-rate measurements.  In this method, an indirect Kalman filter is used to estimate attitude. The filters’ estimation results, three discrete series of attitude estimation with different time intervals, are merged to simulate a non-uniformly spaced sample set of the high-bandwidth attitude. Finally, the high-bandwidth attitude is reconstructed from the merged data using compressive sampling. Simulation results indicate that the proposed attitude determination is accurate, robust to noise, and capable of measuring high-frequency attitudes in a wide bandwidth range.]]></description>
<pubDate>2022/6/9 16:53:46</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安玮,Hu Xiangyu,,,,]]></author>
</item>
<item>
<title><![CDATA[AHP-Arena comprehensive evaluation method for the efficiency of the allocation of UAV flight training resources]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105040000001]]></link>
<description><![CDATA[In order to reduce the subjective one-sided influence of empowerment process of the traditional hierarchical analysis method (AHP, Analytic Hierarchy Process), a comprehensive AHP and Arena simulation modeling technology was proposed to evaluate the efficiency of the allocation of UAV training resources. Based on flight training process analysis, the factors influencing the efficiency of training resource allocation and efficiency evaluation index were determined, a hierarchical comprehensive evaluation system was established, and the comprehensive evaluation steps of AHP-Arena were summarized.  Arena modeling software was used to realize the dynamic simulation system of the training process and verify the validity, the single-variable numerical simulation method and the mean variance decision-making method were used to complete the objective empowerment of the influencing factors, and the comprehensive evaluation coefficient was obtained by linear weighting comprehensive method, so as to implement resource allocation efficiency evaluation and selection of the optimal program.The practical application shows the effectiveness of the method. Meanwhile, this method can be extended to other similar training processes, and can also provide references for other multi-factor multi-indicator evaluation decision-making processes.]]></description>
<pubDate>2022/6/9 16:53:14</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[王建楠,张尧]]></author>
</item>
<item>
<title><![CDATA[Roll control study of a flying wing based on trailing-edge jet at a wide speed range]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202110220000001]]></link>
<description><![CDATA[The numerical simulation method is used to carry out a systematic study on the roll control of the flying wing using the trailing-edge CC(circulation control) jet at a wide speed range (Ma=0.145-0.7), compared with the configuration controlled by classical control surfaces. The research focuses the electromagnetic stealth characteristics, the roll control characteristics and their flow physics, and the impacts of the bleed air. The results show that as the Mach number increases, the roll control capability of the CC jet decreases due to the weakening of entrainment and blocking effects. However, the CC jet enhances the stealth performance at specific azimuth ranges remarkably. Moreover, it requires less bleed air, induces less thrust loss, and has a high control efficiency factor (aerodynamic moment coefficient produced per unit of additional drag coefficient). In conclusion, the trailing-edge CC jet is a highly promising roll control device for a flying wing.]]></description>
<pubDate>2022/6/9 16:52:13</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭正,侯中喜,贾高伟,邵帅,阴鹏,张来平]]></author>
</item>
<item>
<title><![CDATA[DSets-DBSCAN radar signal sorting algorithm without parameter clustering]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011120000001]]></link>
<description><![CDATA[With the increasingly dense and complex electromagnetic signal environment, the radar signal sorting method faces severe challenges. The performance of many existing efficient sorting algorithms depends heavily on the parameters from external input, such as clustering number and clustering tolerance. In this paper, the parameterless clustering algorithm DSets-DBSCAN is applied to the radar signal sorting, and a parameterless radar signal pulse clustering algorithm is presented. The algorithm can automatically cluster without relying on any parameter settings. Firstly, the algorithm input is the pairwise similarity matrix processed by histogram equalization, which makes the Dominant Sets(Dsets) algorithm independent of any parameters. Then the input parameters of DBSCAN are given adaptively by using the obtained ultra-small cluster, and finally the cluster is extended by DBSCAN. The simulation results show that the proposed method is effective in sorting radar pulse descriptors without parameters. And the clustering accuracy of radar signals is more than 97.56% in the case of the false pulse ratio (false pulse/radar pulse) is no more than 80%.]]></description>
<pubDate>2022/6/9 8:45:25</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈涛,李品,刘鲁涛,王璐璐]]></author>
</item>
<item>
<title><![CDATA[Solution to continuous time Markov chain model for unmanned aerial vehicle swarm operation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112220000002]]></link>
<description><![CDATA[In order to solve the problem of low computing speed in the process of state transition in the analytical modeling of UAV (unmanned aerial vehicle) swarm operation, a fourth-order Runge-Kutta method based on row compressed storage was proposed. The UAV swarm operation process was divided into three stages according to the UAV swarm operation style, and continuous time Markov chain model was established for the state transition process of UAV swarm operation in stages. In the meantime, taking the reliability of UAV swarm to complete combat mission as the solving index, the fourth-order Runge-Kutta method was used to solve the Markov model, and the method based on row compressed storage was used to optimize the solving rate owing to the sparsity feature of the rate transfer matrix.  Simulation results show that the established continuous time Markov chain model has better effectiveness and feasibility than other models. At the same time, compared with other algorithms, the proposed algorithm has higher computing speed and better reliability requirements to meet the accuracy of results, which further shows the superiority of it.]]></description>
<pubDate>2022/6/7 17:57:33</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[黄树彩,,,]]></author>
</item>
<item>
<title><![CDATA[UAV swarm cooperative search based on moth pheromone courtship mechanism]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111270000001]]></link>
<description><![CDATA[In order to improve the efficiency of the UAV (unmanned aerial vehicle) swarm in cooperative search for moving targets, a UAV swarm cooperative search method was proposed based on the moth pheromone courtship mechanism.  According to the courtship behavior of moth in choosing flight direction by pheromone, a wind direction model in pheromone map and a moth pheromone courtship model were established. Considering the constraint of collision avoidance between UAV swarm, a map from moth pheromone courtship mechanism to UAV swarm distributed cooperative search was proposed, and the specific implementation process was given. Simulation results show the effectiveness and stability of the proposed method in solving the cooperative search problem of single moving target, and the outdoor flight experimental results verified the feasibility of the proposed method in practice.]]></description>
<pubDate>2022/6/6 11:16:14</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[邓亦敏,段海滨,刘云昊,魏晨]]></author>
</item>
<item>
<title><![CDATA[Decision tree algorithm for packet classification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011020000001]]></link>
<description><![CDATA[Packet classification is the fundamental function of network, and researchers have proposed many packet classification solutions in the past two decades. Among them, the decision tree algorithm for packet classification has received extensive attention and in-depth research due to its high throughput, suitable for multiple fields, and pipelining. The recent research on the decision tree algorithm for packet classification was introduced, the geometric meaning, common techniques and test benchmarks of the decision tree algorithm were described, and the decision tree algorithm from the two dimensions of node cutting technology and rule set grouping technology were systematically analyzed. The typical algorithms of the two types of common technologies for building decision tree were introduced respectively, the design ideas and characteristics of various algorithms were compared, and their applicable scenarios were given. The conclusion and discuss the future work of decision tree algorithms were stated out.]]></description>
<pubDate>2022/5/31 18:42:09</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[吕高锋,乔冠杰,谭靖,严锦立]]></author>
</item>
<item>
<title><![CDATA[Effect of structural parameters of regenerative cooling channels on hydrocarbon fuel flow distribution]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106160000001]]></link>
<description><![CDATA[Based on the regenerative cooling technology of liquid rocket engine, the flow distribution characteristics of Z-type parallel channels were studied by numerical simulation method. The effects of channel number, channel section shape and entrance confluence structure on the flow distribution characteristics were analyzed. The results show that the non-uniformity coefficient of flow distribution decreases from 2.59% to 0.5% with the increase of the number of channels in the regenerative cooling system. Increasing the number of channels under the same flow area can effectively ensure the uniformity of flow distribution. The channel section shape has little influence on the non-uniformity coefficient of flow distribution, which is mainly reflected in the flow velocity distribution and heat transfer area in the channel, and the heat transfer effect of the trapezoidal configuration is better than that of the rectangular configuration. The entrance confluence structure is beneficial to the uniform of flow distribution. The research has a certain reference significance for the structural design of regenerative cooling channel.]]></description>
<pubDate>2022/5/31 18:23:23</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[丁 杰,刘伟强,尹 亮]]></author>
</item>
<item>
<title><![CDATA[Estimation of submarine underwater corrosion electric field based on equivalent circuit and point current source]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009150000003]]></link>
<description><![CDATA[In order to quickly evaluate the underwater corrosion electric field in the damaged state of the submarine coating, the corrosion current equivalent circuit of submarine coating local damage was established based on the principle of electrochemical corrosion and the characteristics of submarine structure, , and the corrosion current intensity of submarine coating local damage was calculated. The corrosion electric field of submarine was modeled based on the point current source. The damaged part of submarine coating and exposed propeller were equivalent to point current source. The calculation formula of electric field of point current source in layered medium was used to estimate the corrosion stable electric field in the damaged state of the submarine coating. Compared with the simulation results of the commercial finite element software COMSOL for the corrosion electric field of a certain submarine , the results show that the submarine surface corrosion current and the electric field distribution curves of different paths obtained by this estimation method are basically consistent with the simulation results of COMSOL, the relative error of current calculation value does not exceed 6.5%,and the relative error of peak to peak value of each electric field component does not exceed 8%.]]></description>
<pubDate>2022/5/31 17:54:09</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[刘春阳,赵玉龙,周丹]]></author>
</item>
<item>
<title><![CDATA[Reliability assessment of flight vehicle stage separation under mixed uncertainties]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202012130000001]]></link>
<description><![CDATA[To quantity the comprehensive influence of both random and epistemic uncertainties during the process of flight vehicle stage separation, combined with the characteristics of hybrid model based on random and interval theory, a new reliability assessment method of separation between flight vehicle stages based on the hybrid model of random and interval theory was proposed. According to the requirements of the hypersonic vehicle separation mission, the separation kinetic simulation model was constructed. According to the geometric characteristic of the separation structure between the stages, a new rapid collision detection method was proposed. And the hybrid reliability assessment model of flight vehicle separation mission was constructed. The hybrid reliability assessment model was converted to unconstrained optimization problem of random reliability assessment. Considering of the characteristic of highly nonlinearity of system performance function due to complex external force and moment during the process of flight vehicle stage separation, the unconstrained optimization problem was efficiently solved by efficient global optimization and active learning Kriging method. It is shown that the influence of mixed uncertainty factors  on the flight vehicle separation process can be described exactly through this method and the interval of flight vehicle separation mission reliability can be given accurately, which can further support the detailed design of flight vehicle separation.]]></description>
<pubDate>2022/5/31 17:48:36</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[聂兆伟,秦梦,王浩,张海瑞]]></author>
</item>
<item>
<title><![CDATA[Analysis of Charging Effect on Spacecraft Surface under Solar Wind]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105200000002]]></link>
<description><![CDATA[The interaction between the spacecraft and the plasma in the solar wind will cause the spacecraft to be charged and cause the wake effect. At the same time, the electrostatic barrier formed by high-density photoelectrons and secondary electrons can recover low-energy electrons generated on the surface, so that the spacecraft can also be charged to a certain negative potential in the recent environment. The surface potential of the spacecraft and the electrostatic potential barrier cause a deviation in the particle density distribution in space, causing deviations in the measurement of plasma and electric field, which will affect the accuracy of the instrument measurement. Based on the spacecraft surface charging simulation software developed by the European Space Agency, this paper conducts a preliminary study on the surface charging of spacecraft under solar wind. This paper analyzed the space plasma potential distribution and the space particle density distribution after the spacecraft was charged in the solar wind environment, and discussed the influence of different materials of the spacecraft body on the space barrier and wake structure.]]></description>
<pubDate>2022/5/31 17:48:04</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郝建红,黄  赛,,赵  强]]></author>
</item>
<item>
<title><![CDATA[Analysis of the Dynamic Inductance Gradient of Electromagnetic Rail Launcher]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107030000001]]></link>
<description><![CDATA[The inductance gradient is the key parameter in the electromagnetic rail launcher, which reflects the ability of the device to output electromagnetic force. In traditional analysis, the inductance gradient obtained by electromagnetic field finite element simulation is often used to calculate both the energy storage inductance of the device and armature thrust, thus the error between system simulation and test results is large. The mathematical calculation model of armature inductance gradient under the conditions of uniform and non-uniform magnetic field distribution between guide rails is deduced. The velocity frequency is introduced to simulate the velocity skin effect. The time-harmonic simulation analysis is carried out on the 2D and the 3D electromagnetic field model. The inductance coefficient and the inductance gradient obtained from the simulation are used to calculate the dynamic inductance and the dynamic armature force in the simulation system. The comparison of simulation and experiment shows that both the current and the velocity error are less than 2%, which proves the correctness and accuracy of dynamic inductance gradient analysis and parameter extraction method.]]></description>
<pubDate>2022/5/31 17:47:31</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[李鑫航,刘华,彭之然,翟小飞]]></author>
</item>
<item>
<title><![CDATA[Staring attitude control for deep space targets based on an uncalibrated video satellite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202112220000001]]></link>
<description><![CDATA[A small video satellite can continuously observe deep space targets, which has a broad application prospect. A conventional staring attitude control method requires the information about the location of the target and the intrinsic and extrinsic parameters of the camera. In some cases, however, the accurate location of the observed target is unknown, and the camera parameters are affected by the in-orbit environment, making it hard to calibrate. We design an adaptive attitude controller, achieving staring at the target in the presence of the unknown target’s position and camera parameters. First, the estimated parameters are extracted to be linearized. Second, a potential function is introduced to meet the demand for the rank of the parameter matrix. At last, a self-updating principle of parameters is adopted to estimate the parameters on line, and accordingly the adaptive control method is proposed. Based on the Lyapunov theory and Barbalat’s lemma, the target image converging to the desired position in the image plane is proved. The simulation results reveal that the adaptive controller can affectively achieve staring observation for deep space targets with the uncertainties of the target position and the camera parameters.]]></description>
<pubDate>2022/5/31 17:46:16</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[范才智,宋超,王猛猛]]></author>
</item>
<item>
<title><![CDATA[Active Learning based on Instability Sampling]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106040000001]]></link>
<description><![CDATA[Active learning is a primary way for reducing labeling cost, which iteratively selects the most informative examples for annotation and improves the model generalization performance with lowest labeling cost. Recent active learning methods select examples by only considering the predictions of the current model. However, these methods neglect the information of the previous trained models, which reflects the stability of the prediction sequence for each unlabeled example during the active learning stage. Examples with the lowest stability are generally difficult to be discriminated by the model, which are useful to improve the classification performance. In this paper, we propose a novel active learning method with instability sampling, which attempts to estimate the potential utility of the unlabeled examples based on the difference among predictions of the previous models. In the proposed method, we first measure the instability of each unlabeled example based on the distance measurement of the posterior probabilities predicted by the previous models. Then the examples with the largest instability are selected to be queried for model training. Extensive experiments are conducted on multiple datasets with diverse classification models. Experimental results validate the effectiveness of the proposed method when compared with conventional uncertainty-based active sampling methods.]]></description>
<pubDate>2022/5/31 17:45:51</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[何花,黄圣君,谢明昆]]></author>
</item>
<item>
<title><![CDATA[Crowdsourced Label Inference Using Double-confidence]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106080000003]]></link>
<description><![CDATA[Fast-growing crowdsourcing platforms have made it easy to obtain a large amount of labels. Since the workers have significant differences in the knowledge level and evaluation criteria, the quality of the collected labels varies a lot. Improving the quality of labels and learning models play key roles in crowdsourced label learning. Obviously, the quality of the learning model is directly affected by the integrated label quality. A novel double-confidence inference algorithm is proposed to solve the problem of crowdsourced label inference. The workers’ confidence is obtained via the data distribution characteristics and label information. Then the label is inferred by this confidence so as to improve the quality of the integrated label. The experimental results show that the proposed algorithm outperforms other ground truth inference algorithms only based on label information.]]></description>
<pubDate>2022/5/31 17:45:36</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[王文剑,张琳]]></author>
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<item>
<title><![CDATA[Multi-instance Multi-label Learning for Labels with Directed Acyclic Graph Structures in Protein Function Prediction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106220000003]]></link>
<description><![CDATA[In MIML (multi-instance multi-label learning) tasks, labels are often correlated with each other, and DAG (directed acyclic graph) is a common hierarchically structure which often occurs in the prediction of GO (gGene oOntology) biological functions of proteins. Considering the labels with directed acyclic graph structures in MIML, a novel algorithm named MIMLDAG  (multi-instance multi-label directed acyclic graph) was proposed. MIMLDAG trained a low-dimensional subspace of shared labels from the feature space of original datasets, minimized the rank loss by a SGD (stochastic gradient descent) method, and then incorporated the inner DAG hierarchical structure of labels for optimizing the output labels. MIMLDAG was applied to predict the protein functions in multiple datasets, and the results show that MIMLDAG possesses higher efficiency and predictive performance.]]></description>
<pubDate>2022/5/31 17:44:53</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[刁业敏,梅德进,唐诗迪,吴建盛,朱燕翔]]></author>
</item>
<item>
<title><![CDATA[Multi-Channel Graph Attention Network with Disentangling Capability for Social Recommendation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109130000002]]></link>
<description><![CDATA[In recent years, graph neural networks have proved to be very powerful in learning graph structure data since social networks and user rating information in the social recommendation dataset can be represented as user-user social graph and user-item interaction graph. Social recommendation methods based on graph neural networks have gradually become a research hotspot in recommendation field. Nowadays, social recommendation models based on graph neural network are facing with the following challenges. 1) How to effectively extract and integrate user-user social information and user-item interactive information. 2) How to distinguish the users" purchase motivations. Therefore, in this study, we propose a Multi-channel Graph ATtention network with Disentangling capability for Social Recommendation named MGAT-D for social recommendation. This model mainly includes three modules: deep clustering module, the aggregation module based on multi-channel graph attention network, and the rating prediction module. Among them, the deep clustering module is used to group users and items. The clustering results can then be used to split user-user social graph and user-item interaction graph into multiple subgraphs to capture user interest groups and users" interests in different types of items. The aggregation module learns the attention of different sub-graphs related to prediction results. The rating prediction module merges user embeddings and item embeddings into the multi-layer perceptron (MLP) to predict the ratings. Extensive experiments on multiple real-world datasets demonstrate that the proposed model MGAN-D is better than other social recommendation algorithms. Specifically, compared with the latest state-of-the-art model GraphRec (Graph Neural Networks for Social Recommendation), the decrease of RMSE (Root Mean Square Error) on the Ciao and Epinions datasets is 2.58% and 3.06%, and that of MAE (Mean Absolute Error) is 2.26% and 2.07%, respectively.]]></description>
<pubDate>2022/5/31 17:39:00</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[洪明利,贾彩燕,王靖]]></author>
</item>
<item>
<title><![CDATA[Real-time evaluation of the progress of a social work using open-source big data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109090000003]]></link>
<description><![CDATA[Few quantitative models can be found amenable to the quantitative evaluation of social work, which motivates the work presented in this article. Moreover, a few related existing works suffer from no suitable indicator system and high expenses of time and money. To overcome these limitations, a real-time quantitative evaluation model using the Internet open-source big data was developed, a target indicator system was established, the rapid computation methods of each criterion were proposed, and a prototypical software system was designed and implemented. Case studies on selected social work were conducted, and the work performance of the 14 cities belonging to a certain province in China was evaluated. The results achieved were largely consistent with the subjective feelings of many respondents and relevant official assessment, which validated the efficiency and rationality of the model proposed.]]></description>
<pubDate>2022/5/30 17:29:28</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[欧文孝,潘岩,王寅森,殷风景,张鑫]]></author>
</item>
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<title><![CDATA[Occlusion and confusion targets recognition method for UAV under small sample conditions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111050000002]]></link>
<description><![CDATA[Aiming at the problem of occlusion and confusion targets recognition for unmanned air vehicle (UAV) under small sample conditions, a target recognition model integrating self-attention mechanism and few-shot learning is proposed. On the basis of using the idea of meta learning to obtain the ability of few-shot learning, the model introduces the self-attention mechanism to learn the context dependence between the internal parts of the target, so as to enhance the target representation ability and solve the problem of insufficient effective features in the case of occlusion and confusion. In order to verify the effect of the model, the occlusion and confusion target datasets are constructed by further processing the reference dataset and UAV aerial photography data, and different occlusion degrees and background confusion rates are set. Through the verification on different datasets and compared with the deep learning model, the proposed model has higher learning efficiency and recognition accuracy.]]></description>
<pubDate>2022/5/30 13:15:50</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[李宏男,牛轶峰,吴立珍]]></author>
</item>
<item>
<title><![CDATA[High-Efficiency IQ Convolutional Network Structure for Radio Frequency Fingerprint Identification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011160000001]]></link>
<description><![CDATA[RF fingerprints can be used to identify specific transmitters. Existing convolutional neural networks are used to process time-sequence In-phase and Quadrature-phase (IQ) signals simply as images. There are problems with low recognition  accuracy and large calculations. This article focuses on the application of RF fingerprints recognition, an efficient IQ convolutional network structure is proposed. The network first extracted IQ-related features and time domain features step by step, then obtained the average value of each channel features through adaptive average pooling, and finally used only one fully connected layer for classification. The experimental results show that the network has a greater improvement of recognition accuracy under a variety of channel conditions than the traditional convolutional neural network, and the amount of calculation is smaller.]]></description>
<pubDate>2022/5/30 13:02:59</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[安军社,崔凯,崔天舒,黄永辉,沈明,张晔,赵文杰]]></author>
</item>
<item>
<title><![CDATA[Intelligent Gliding Guidance based on Reinforcement Learning and Optimal Control]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010130000001]]></link>
<description><![CDATA[In order to improve the autonomy of gliding guidance for complex flight missions, this paper proposes a multi-constrained intelligent gliding guidance strategy based on optimal guidance and reinforcement learning (RL). Three-dimensional optimal guidance is introduced to meet the terminal latitude, longitude, altitude and flight-path-angle constraints. A velocity control strategy through lateral sinusoidal maneuver is proposed, and an analytical terminal velocity prediction method considering maneuvering flight is studied. Aiming at the problem that the maneuvering amplitude in velocity control cannot be determined offline, an intelligent parameter adjustment method based on RL is studied. This method designs a state space via terminal velocity and an action space with maneuvering amplitude. In addition, it constructs a reward function that integrates terminal velocity error and gliding guidance tasks, and uses Q-Learning to achieve the online intelligent adjustment of maneuvering amplitude. The simulation results show that the intelligent gliding guidance method can meet various terminal constraints with high accuracy, and can improve the autonomous decision-making ability under complex tasks effectively.]]></description>
<pubDate>2022/5/30 12:44:42</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[包为民,李小平,赵长见,朱建文]]></author>
</item>
<item>
<title><![CDATA[Influence of lunar soil parameters on the lunar landing airbag cushioning performance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202202250000003]]></link>
<description><![CDATA[To study the influence of lunar soil parameters on the airbag buffer performance, a lunar landing airbag was designed according to the landing conditions of Chang'e-3 probe, and then an airbag dynamic model considering the characteristics of lunar soil was established based on the crushable foam model. The airbag cushioning process under different lunar soils was analyzed, and it is found that the softer the lunar soil, the smaller the payload impact acceleration, but the airbag will sink into the lunar soil, which is not conducive to venting and affects its cushioning effect. Therefore, three indicators of airbag peak pressure, payload maximum acceleration, and payload maximum drop height were used to evaluate the airbag cushioning performance comprehensively, and the influence law of lunar soil parameters was quantitatively studied. The results show that the lunar soil density and shear modulus, as well as the yield parameters a0 and a1, have a significant influence on the cushioning performance, with a positive effect on the first two indicators and a negative effect on the latter one. Further research reveals that the relationship between each of the four lunar soil parameters and the three cushioning performance indicators is an exponential function.]]></description>
<pubDate>2022/5/30 12:11:38</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李道奎,周仕明,周旋]]></author>
</item>
<item>
<title><![CDATA[DWA path planning algorithm based on multi-objective particle swarm optimization in complex environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111020000003]]></link>
<description><![CDATA[When the robot is running in a complex environment with densely distributed obstacles, the DWA algorithm is prone to obstacle avoidance failure or unreasonable planning. In this regard, an improved DWA planning algorithm based on Multi-Objective Particle Swarm Optimization (MOPSO) is proposed. Based on the establishment of multi obstacle environment coverage model, a method is put forward for judging obstacle-dense areas in complex environments. And the original DWA algorithm is improved by optimizing the sub-evaluation functions. On these basis, the adaptive change of DWA weight coefficients can be transformed into a multi-objective optimization problem, which can be solved by the improved MOPSO algorithm. According to the requirements of path planning, the corresponding multi-objective optimization model can be established, moreover the safety distance and speed can be set as the optimization goals. A series of simulations based on Matlab are carried out, and the results show that this method enables the robot to effectively pass through the dense area of obstacles while taking account of the safety and speed of operation, and has better path planning effect.]]></description>
<pubDate>2022/5/30 12:06:55</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[常路,单梁,李薪颖,屈艺,张永]]></author>
</item>
<item>
<title><![CDATA[Vibration Reduction Analysis and Experiment of Multi-Rotor Drone]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202201060000004]]></link>
<description><![CDATA[Aiming at the problem of excessive vibration of the multi-rotor drone, which causes instability of flight state, the vibration reduction analysis work is carried out based on CAE simulation technology and experimental methods. Through frequency analysis, the reason of excessive vibration is determined to be resonance，and the mode shape corresponding to the resonance frequencies are    the first-order waving, first-order swing and second-order swing mode shapes. An optimization design method for optimizing the cross-sectional shape is proposed. Without adding extra weight, the corresponding frequency points of the first-order waving mode, the first-order swing mode, and the second-order swing mode have been increased by 37.23%, 22.47 and 18.43%, respectively. The vibration reduction analysis and optimization design method proposed in the article can provide references for design work of drones.]]></description>
<pubDate>2022/5/26 8:17:00</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔辉如,和英鹏,李道奎,马维力,申柳雷]]></author>
</item>
<item>
<title><![CDATA[Image segmentation algorithm combining hierarchical clustering algorithm and graph-based segmentation algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009140000002]]></link>
<description><![CDATA[Graph based segmentation (GBS) is one of the classical image segmentation algorithms proposed by felzenszwalb and huttenlocher, but there is obvious under segmentation in the segmentation results. Therefore, based on the GBS algorithm, this paper introduces the hierarchical clustering (HC) algorithm, constructs a method to solve the under segmentation of GBS algorithm, and uses the way of multi-threaded parallel processing of data, which effectively improves the processing speed of the traditional hierarchical clustering algorithm. Firstly, the GBS algorithm is used to obtain the initial segmentation result of each pixel in the image in RGB color space, and then the pixel value in each type of region is extracted and hierarchical clustering is carried out to obtain the category label of pixel value in each type of region. According to the category label obtained by hierarchical clustering and the preset category range, the initial segmentation result of each pixel is modified. Finally, a new segmentation graph is generated according to the region merging criterion. Experiments show that compare with kmeans SLIC (simple linear iterative clustering) algorithm and GBS algorithm, this method solves the phenomenon of under segmentation, and produces a semantic segmentation graph with high segmentation accuracy.]]></description>
<pubDate>2022/4/7 18:47:35</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[程超,郭昕刚,王佳]]></author>
</item>
<item>
<title><![CDATA[Influence of Different Galvanic Corrosion Protection Methods of TA2-B10 Pipe on the Corrosion Characteristics of B10 Pipe]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102080000001]]></link>
<description><![CDATA[In order to study the influence of TA2-B10 alloy tube on the corrosion characteristics of B10 tube under different galvanic corrosion protection methods. At the Qingdao Xiaomaidao Sea Water Test Site, three sets of TA2-B10 pipelines with different galvanic corrosion protection methods are set up with direct connection, electrical insulation connection, and electrical insulation+coating connection. Then carry out 1m/s, 3m/s, 4m/s flowing seawater and immersion alternate corrosion tests in sequence. Cut the three sets of B10 pipe lines after the test. Through the pipeline inner surface potential distribution test, analyze the corrosion type of the B10 pipeline under different galvanic corrosion protection methods; use the potential polarization curve, electrochemical impedance spectroscopy and microscopic characterization to analyze the corrosion characteristics of the B10 at a distance of 250 mm from the flange joint under different galvanic corrosion protection methods. The results show that the directly connected TA2-B10 tube is in a galvanic corrosion state, the potential in the B10 terminal is positively shifted and the corrosion is accelerated, and the electrical insulation connection and the insulation+coating connection TA2-B10 tube are in a self-corrosive state, but the electrical insulation+coating connection has better insulation effect; the B10 sample under electrical insulation+coating connection protection has the smallest corrosion current density and the most negative self-corrosion potential; the impedance spectra of the three groups of B10 samples all show the characteristics of single capacitive impedance arc, the B10 sample of electrical insulation+coating under the protection of layer connection has greater transmission resistance and film layer resistance; electrical insulation+coating connection can effectively slow down the three corrosion tendencies of pitting, pointed and intergranular corrosion. The above results comprehensively show that the insulation+coating protection method has a better galvanic corrosion protection effect.]]></description>
<pubDate>2022/4/7 18:44:58</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[陈页骍,李竹影,林育锋,夏江敏]]></author>
</item>
<item>
<title><![CDATA[Analysis of canopy optimization design on the aerodynamic characteristics of cluster parachute system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104230000002]]></link>
<description><![CDATA[With the vigorous development of manned spaceflight, deep space exploration and other space missions, spacecraft recovery quality has been greatly improved, the traditional deceleration system with a single parachute as the core of increasing mass recovery load, the development of cluster parachute system is to achieve the high-efficiency deceleration of large-duty spacecraft and non-destructive landing requirements of the development direction. In this paper, the pneumatic characteristics of the cluster parachute system are simulated by numerical simulation method, and the pneumatic characteristics of various configuration lower cluster parachute system are studied in combination with the optimized design of the ring-sail parachute configuration. Through the simulation results of flow field analysis and data comparison, it is found that the window/gap design can not only maintain the drag characteristics of the cluster parachute system, but also ensure the stability of the cluster parachute system, and avoid the collision between the single parachute due to force. Using numerical simulation can not only improve the efficiency of parachute development and reduce the cost of research development, but also provide a strong guarantee for designers to master the working principle of cluster parachute system and promote the development of parachute design theory.]]></description>
<pubDate>2022/4/7 18:44:28</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[董海波,黄明星,隋蓉]]></author>
</item>
<item>
<title><![CDATA[Context-Aware Deep Weakly Supervised Image Hashing Learning Method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106070000002]]></link>
<description><![CDATA[Most existing deep semantic image hashing approaches are supervised learning, i.e., they always utilize image and label information to learn the binary hash codes. Although they have achieved promising performance, they rely on substantial labeled image data, which is very expensive and impractical in the real-world applications. However, social images are associated with rich user-provided tags, which could describe the semantic information of images to a certain extent. Inspired by this, we present a weakly supervised deep context-aware image hashing model by utilizing tags associated with images as the supervision information. It not only enhances image representations by exploiting fine-grained visual context information, but it also raises the discrimination of the learnt hash codes. More specifically, we first extract fine-grained image region features, and then enhance them by adaptively capturing their related context information. Subsequently, by reasonably aggregating the enhanced region representations, we could obtain the image representation with powerful expressiveness. Meanwhile, we introduce a discrimination loss to force the enhanced image representation to regenerate the corresponding tags. In this way, we could obtain discriminative image representations, and further boost the discriminative ability of the learnt hash codes. Moreover, we evaluate our method on two datasets and the extensive experiments show the effectiveness of our model as compared to several state-of-the-art methods.]]></description>
<pubDate>2022/4/7 18:43:01</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[刘萌,聂秀山,齐孟津,田传发,周迪]]></author>
</item>
<item>
<title><![CDATA[Algorithm for model decision tree with multi-kernel bayesian optimization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106080000004]]></link>
<description><![CDATA[In the construction of the model decision tree, there are many parameters and the parameter combination is complex. The use of grid search and other parameter tuning methods will consume a lot of time, which will affect the improvement of the model performance. A model decision tree with multi-kernel bayesian optimization was proposed. In order to deal with the characteristics of different classified data, three Gaussian processes were used for modeling optimization. The Bayesian optimization technique was used to select the best parameter combination. The experimental results show that the proposed algorithm is better than the traditional model decision tree method in parameter optimization, and can find the global optimal parameter value in the case of a few iterations. To a certain extent, it improves the classification performance of the algorithm and saves a lot of parameter adjustment time.]]></description>
<pubDate>2022/4/7 18:42:00</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[高虹雷,门昌骞,王文剑]]></author>
</item>
<item>
<title><![CDATA[Decision solving algorithm for multiple optimal solution combinatorial optimization problem]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106030000001]]></link>
<description><![CDATA[Multiple optimal solution combinatorial optimization is a special type of combinatorial optimization problem with all the optimal solutions need to be calculated for convenience of decision maker’s trading-off and selection. Oriented to the combinatorial optimization problem with fixed sum of goods and multiple optimal solutions, the problem formulation was given by two examples: the fixed sum real number subset problem and buying wings problem. A integer state and a real number state multi-optimal solution dynamic programming algorithm based on 0-1 decision recursive search were put forward on the foundation of analysis of some classical methods like enumeration. In order to cope with the problem of time complexity tending to the extreme O(mn) at some cases with large number of solutions for the proposed algorithms, improvement was proposed with two algorithms: same decision path fusion algorithm and 0-x decision basedalgorithm. The computation time of the improved algorithms is consistent with the proportional relation with O(nb+nm) on the whole in experiments, which indicates that these algorithms have good performance for this type of problem.]]></description>
<pubDate>2022/4/7 18:40:52</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[陈  璟,胡振震,罗俊仁,袁唯淋,邹明我]]></author>
</item>
<item>
<title><![CDATA[Graph Embedding Based Smooth-PCANet for Image Recognition]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106200000004]]></link>
<description><![CDATA[Principal component analysis network (PCANet) is a simple deep learning algorithm with excellent performance in the field of image recognition. However, when constructing the convolution kernel, PCANet only pays attention to the principal components of the image and ignores the position relationship between the neighboring pixels. In general, the neighboring pixels of the image have strong spatial correlation, so it is more conducive to extract effective features by using the graph to maintain the position information of the pixels. Therefore, we integrate graph embedding into PCANet and propose a new image recognition algorithm, Smooth-PCANet. In order to verify the effectiveness of the Smooth-PCANet algorithm, adequate experiments are performed on different data sets such as face, handwritten characters, and images. Compared with several image recognition algorithms based on deep learning, the experiments demonstrate that the Smooth-PCANet performs better than the PCANet, and avoids overfitting more effectively in small sample training.]]></description>
<pubDate>2022/4/7 18:39:30</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈飞玥,蒋珂,田甲略,朱玉莲]]></author>
</item>
<item>
<title><![CDATA[Multi-Channel Graph Attention Network with Disentangling Capability for Social Recommendation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109130000002]]></link>
<description><![CDATA[In recent years, graph neural networks have proved to be very powerful in learning graph structure data since social networks and user rating information in the social recommendation dataset can be represented as user-user social graph and user-item interaction graph. Social recommendation methods based on graph neural networks have gradually become a research hotspot in recommendation field. Nowadays, social recommendation models based on graph neural network are facing with the following challenges. 1) How to effectively extract and integrate user-user social information and user-item interactive information. 2) How to distinguish the users" purchase motivations. Therefore, in this study, we propose a Multi-channel Graph ATtention network with Disentangling capability for Social Recommendation named MGAT-D for social recommendation. This model mainly includes three modules: deep clustering module, the aggregation module based on multi-channel graph attention network, and the rating prediction module. Among them, the deep clustering module is used to group users and items. The clustering results can then be used to split user-user social graph and user-item interaction graph into multiple subgraphs to capture user interest groups and users" interests in different types of items. The aggregation module learns the attention of different sub-graphs related to prediction results. The rating prediction module merges user embeddings and item embeddings into the multi-layer perceptron (MLP) to predict the ratings. Extensive experiments on multiple real-world datasets demonstrate that the proposed model MGAN-D is better than other social recommendation algorithms. Specifically, compared with the latest state-of-the-art model GraphRec (Graph Neural Networks for Social Recommendation), the decrease of RMSE (Root Mean Square Error) on the Ciao and Epinions datasets is 2.58% and 3.06%, and that of MAE (Mean Absolute Error) is 2.26% and 2.07%, respectively.]]></description>
<pubDate>2022/4/7 18:37:10</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[洪明利,贾彩燕,王靖]]></author>
</item>
<item>
<title><![CDATA[Hesitant fuzzy rough set decision-making method for determining spare parts variety of new small-scale equipment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009290000001]]></link>
<description><![CDATA[In view of the problem that the "hesitancy" and "modularity" of the decision-making information are prominent in the process of determining the varieties of spare parts for newly developed equipment, and it is difficult to use the traditional method of determining the varieties of spare parts for decision-making, a method of determining spare parts variety based on hesitation fuzzy rough set is proposed. The risk preference coefficient is used to extend the incomplete hesitancy information, which lays a foundation for establishing the hesitancy information system for different risk preference considering the influence of score function and numerical continuation boundary, an improved inclusion degree formula is given and proved based on the definition of inclusion degree. The reduction condition and rule acquisition method of spare parts variety decision attribute based on improved inclusion calculation are given, which realizes the depth mining and effective utilization of hesitancy and decision information. The method of determining the spare parts variety of a newly developed equipment is verified. The results show that this method can deal with hesitancy and decision information effectively, and obtain a simplified and practical decision rule set of spare parts variety, the feasibility of the method is verified.]]></description>
<pubDate>2022/3/31 21:06:04</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[陈小卫,侯兴明,秦海峰,杨超,张琳琳]]></author>
</item>
<item>
<title><![CDATA[Target detection in SAR images based on joint generative adversarial network and detection network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202008250000001]]></link>
<description><![CDATA[Aiming at the problem of difficult and limited sample acquisition in SAR image target detection, a learning model of joint GAN (generative adversarial network) and detection network was proposed. The original training set is used to pre train the specially designed faster regional convolutional neural network. The deep convolutional GAN based on attention mechanism was employed to generate extensive synthetic samples, which were input into the trained specially designed faster region-based convolutional neural network for prediction. The corresponding annotation information of the new samples was determined by the prediction information and probability equivalent class label allocation strategy, and the annotated new samples were used to expand the original dataset with a certain proportion. The detection network was retrained with the expanded dataset. Simulation results show that the proposed framework can improve the detection efficiency and performance of the network effectively.]]></description>
<pubDate>2022/3/31 20:59:31</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[付强,韩子硕,王春平,赵斌]]></author>
</item>
<item>
<title><![CDATA[Effect of diesel engine performance with fuel injection advance angle under the condition of adjustable fuel injection law]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005110000001]]></link>
<description><![CDATA[n order to obtain the effect law and genesis mechanism of fuel injection advance angle on the performance of diesel engine under the adjustable fuel injection law conditions. On the basis of the realization of adjustable fuel injection law injection, the working process calculation model of diesel engine was established based on Fire software, and the main parameters of model were calibrated through experiments, then the performance of diesel engine with the fuel injection advance angle under saddle-shaped fuel injection law were analyzed by using the model. The results show that with the delay of pressurization time, the fuel injection law changes from rectangle to slope and then to saddle-shaped, which realizes the flexible and adjustable fuel injection law. Under the condition of saddle-shaped fuel injection law, there is an optimal fuel injection advance angle to optimize the power and economy of diesel engine. At the same time, with the increase of fuel injection advance angle, the in-cylinder pressure, in-cylinder temperature and heat release rate of diesel engine increase gradually, and the time of reaching their peak value all move forward, while the NOx emissions and soot emissions show an increasing and decreasing trend respectively.]]></description>
<pubDate>2022/3/31 20:47:38</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[王 银,杨 昆,赵建华,周 磊]]></author>
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<title><![CDATA[Cohesive element method for the research on the “dewetting” damage of propellant]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202105260000002]]></link>
<description><![CDATA[Cohesive element is an important means to investigate the “dewetting” damage of propellant. The high filling ratio geometric model of propellant was constructed by molecular dynamics method, and the mesoscopic finite element analysis model of propellant was constructed by combining periodic geometry and periodic boundary treatment method. The “dewetting” behavior of the interface between the particle and the matrix was simulated by using the cohesion element and Park-Paulino-Roesler(PPR) cohesive zone model. The mechanical response of propellant mesoscopic structure was analyzed under uniaxial tensile and pure shear tests, and the damage mechanism of “dewetting” of propellant was studied. According to different volume fraction ratio, loading rate and cohesive strength, the influence law of “dewetting” damage was analyzed. The research methods and conclusions can provide a useful reference for the formulation of a new generation of high-performance propellant.]]></description>
<pubDate>2022/3/31 20:20:25</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[崔辉如,,]]></author>
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<title><![CDATA[The Review of RCS Measurement and Imaging Methods of Stealth Aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109140000002]]></link>
<description><![CDATA[Stealth aircraft has gradually become a great power, and will continue to play an important role, making stealth technology become the key technology of aircraft design. RCS(radar cross section) measurement of stealth aircraft is a necessary step to design, manufacture and maintain stealth aircraft. This paper reviews the basic process of RCS measurement of stealth aircraft from three aspects: RCS test of scaled model, outdoor RCS test of full-scale aircraft and indoor near-field test of full-scale aircraft, summarizes the theoretical basis of RCS near-field measurement of stealth aircraft, and focuses on analyzing the near-field RCS measurement technology which with imaging diagnosis function.The development trend and key technologies of stealth aircraft RCS measurement were prospected, which is helpful to have a general understanding of RCS measurement of stealth aircraft and grasp the development direction of RCS measurement.]]></description>
<pubDate>2022/3/31 20:10:22</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[贾高伟,邵帅,王建峰,阴鹏]]></author>
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<title><![CDATA[A Method for Individual Activities Recognition Incorporating Spatial Preference and Semantics]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106150000002]]></link>
<description><![CDATA[The semantic recognition of individual activities helps in the realisation of functions such as user profiling, personalised recommendations, abnormal behaviour detection, city-wide group behaviour analysis and resource allocation optimisation. A recognition method for the semantics of individual activities based on sparse social media check-in data was proposed. The temporal periodicity and tendency features of activity behaviors were extracted from the check-in data, and a spatial preference quantification algorithm was utilized to extract the preferences of groups and individuals from the spatial relevance between individual and group activities. The natural language embedding model BERT was used to extract the semantics of POIs (point of interest). The temporal features, spatial preference features and text features of POIs’ names constitute the joint spatio-temporal features characterizing group and individual preferences, which were classified by the XGBoost (extreme gradient boosting) classifier to obtain the activity semantic recognition results. With the results of comparison experiments and ablation experiments on the Foursquare dataset, it was validated that the model proposed can effectively improve the accuracy of activity semantics recognition.]]></description>
<pubDate>2022/3/31 19:39:25</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[郭茂祖,,,]]></author>
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<title><![CDATA[3D Channel-wise Attention Network for Spatio-Temporal Traffic Raster Flow Prediction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106160000003]]></link>
<description><![CDATA[Urban traffic flow forecasting is of great significance for traffic management and public safety. However, the correlations of traffic raster flow change with time. There are global spatio-temporal correlations in the city, and the contributions of channel-wise features vary on each city region. To tackle these challenges and make more accurate prediction, a novel spatio-temporal neural network model, named 3D-CANet (three-dimensional channel-wise attention network), was designed. A 3D-InnerCA (three-dimensional inner-channel attention) unit was proposed to dynamically capture the global spatio-temporal correlations for different channel-wise features. Meanwhile, an InterCA (inter-channel attention) unit was designed to adaptively recalibrate the contributions of different channel-wise features on each region. The experimental results on three real-world traffic raster flow datasets demonstrate that the predictive performance of the 3D-CANet model was better than the others,which proved the validity of the model proposed.]]></description>
<pubDate>2022/3/31 19:34:13</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[刘军,童凯南,]]></author>
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<title><![CDATA[Asymptotic Cluster Analysis of Single-Leader Cucker-Smale Model with Local Interchange Function and Free Will]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202106010000001]]></link>
<description><![CDATA[In order to study the relationship between cluster formation and radius, the Cucker-Smale model with a hierarchical structure of a single leader and the leader speed invariable was considered. The influence of free will on cluster was discussed. The sufficient conditions that the radius has a lower bound (the lower bound was related to velocity difference, particle number, communication intensity, etc.) could be obtained by proving. When the radius was greater than the lower bound, cluster would be generated. The related conclusion was verified by Matlab numerical simulation.]]></description>
<pubDate>2022/3/31 18:49:14</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[赵子玉]]></author>
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<title><![CDATA[Adaptive collaborative fault tolerance for multi-agent formation system with hybrid actuator faults and multiple unknown control directions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202107300000001]]></link>
<description><![CDATA[This paper investigates the cooperative fault-tolerant for the nonlinear multi-agent system with hybrid actuator faults and multiple unknown control directions based on robust adaptive fuzzy sliding mode technology (RAFSMT). Firstly, the piecewise Nussbaum function is used to solve the multiple unknown control directions, and the robust adaptive fuzzy technology is used to solve the nonlinear uncertainty in the system. A first-order sliding mode differentiator is introduced, and it is combined with the adaptive backstepping technique to obtain the first-order derivative of the virtual control law. At the same time, a robust bounded method is used to improve the convergence speed and tracking accuracy of the designed adaptive cooperative controller. Then, based on the algebraic graph theory, the error model of the agent system is established, the distributed consensus cooperative fault-tolerant controller is designed, and the Lyapunov candidate function is constructed to prove that the proposed controller can make the system stable. Finally, the effectiveness of the proposed method is verified by the comparison of simulation examples, which provides theoretical support for engineering practice.]]></description>
<pubDate>2022/3/31 12:47:05</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[高山,薛惠锋,张普,左轩]]></author>
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<title><![CDATA[Effect of transmitting nonideal quadrature signal on FDA beamform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009150000001]]></link>
<description><![CDATA[To analyze the impact of transmitting nonideal quadrature signal on FDA (frequency diversity array) beamform, based on the signal model of FDA, the orthogonality issue of baseband signal was brought out, the beamform expression was deduced mathematically under the condition that FDA system transmitedtransmitting pseudo-nonideal orthogonal baseband signal, and the performance of matched reception processing was further analyzed. Based on the calculation amount of beamform transmission and matched reception of FDA system, the influencing factors were extracted, and a quantitative analysis of the relationship of the orthogonal characteristics of the baseband signals with the performance of the beamform and matched reception was constructed. Based on the numerical simulation of six kinds of typical random distribution biphasic coded baseband signals, the correctness of theoretical analysis was verified by experiments. Different random distributions show different baseband signal orthogonal characteristics, and their influence on the performance of FDA beamform transmission and matching reception varies with the orthogonal characteristics. From the perspective of orthogonality, the application potential of baseband signal based on Normal, Uniform and Logistic random distribution will be better.]]></description>
<pubDate>2022/3/24 9:28:40</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[付耀文,杨进,杨威]]></author>
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<title><![CDATA[Analysis, Optimization and Design of Soft Pneumatic Manipulator]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111030000001]]></link>
<description><![CDATA[The structural characteristics of the pneumatic control software driver have a significant impact on its motion and mechanical characteristics, and there is a large room for optimization and improvement. Aiming at the design optimization of the pneumatic control software actuator, bending angle and the supporting reaction force are taken as the evaluation objective and a structural analysis and optimization design method of the pneumatic control software actuator is proposed in this paper. First, a simulation model of the pneumatic control software driver is established based on the static balance theory, and characteristic parameters are picked up further. Parameterized research method is taken to analysis single-parameter sensitivity to get high sensitivity parameter. Then normalization and weighting strategy and Evol optimization algorithm are used to optimize the inclination angle and the support reaction force to obtain the optimal parameters. The support reaction force and inclination angle by 29% and 132% respectively, and the bending deformation capacity and load capacity of the pneumatic control software driver are improved.]]></description>
<pubDate>2022/3/2 10:46:40</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈小前,黄奕勇,刘卓群,张翔,赵勇]]></author>
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<title><![CDATA[Nonlinear thermal flutter of thermoplastic laminated panels in supersonic flow]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007310000001]]></link>
<description><![CDATA[The flutter behavior of thermoplastic composite structures in high-speed flow is a key problem in the design of reusable spacecraft. The classical Mindlin thick theory along with the Von-Karman larger deformation relationship are used for structural modeling and the piston theory is for aerodynamic modeling, respectively. Also, the thermal stress and the change of mechanical properties of the thermoplastic material caused by the temperature are considered. Then, the aeroelastic model of thermoplastic composite panel is established based on the principle of virtual work and the finite element method, which is respectively solved by V-g in frequency domain and the Newmark method in time domain. After the validity and convergence of the presented method is verified, the effects of temperature on the frequency-domain mode coupling, time-domain limit cycle oscillation and stress response of the composite panel are investigated.]]></description>
<pubDate>2022/2/23 10:11:04</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[高艺航,]]></author>
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<title><![CDATA[Dynamic Modeling and Simulation of the Anti-UAV Tethered-Net Capture System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202008040000003]]></link>
<description><![CDATA[Aiming at the unmanned aerial vehicle (UAV) ‘Black Fly’ problem, a program consists of platform flying, tethered-net arresting and parachute recycling is conducted. By comparing with the test data, the platform flight trajectory model and the tethered-net dynamic model are verified. The results show that the system dynamics modeling and simulation program proposed in this paper is feasible and has guiding significance for engineering system design.]]></description>
<pubDate>2022/2/13 13:34:38</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈青全,,,,]]></author>
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<title><![CDATA[Modeling and simulation analysis of ultra high pressure common rail system for adjustable fuel injection rate]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202003170000002]]></link>
<description><![CDATA[Aiming at the problem of conventional high pressure common rail system in the injection process, such as the low fuel injection pressure and unable to flexibly change the fuel injection rate, an ultra high pressure common rail system for adjustable fuel injection rate based on domestic processing capacity and technology was proposed and designed. On the basis of introducing the working principle of this system, the simulation model of system was established via AMEsim software, the accuracy of this model was verified by experiment, the pressure characteristics and fuel injection control characteristics of the system were studied through the model, at the same time, the influence of the key structural parameters of the electric-controlled pressure amplifier on the system performance were analyzed. The results show that ultra high pressure common rail system for adjustable fuel injection rate can magnify fuel pressure to ultra high pressure state, and by changing the control signal working time of electric-controlled pressure amplifier and injector solenoid valve in system, the flexible and controllable fuel injection rate curve shape can be achieved. Compared with the control chamber volume and spool mass, the fuel outlet diameter and spool displacement have greater influence on the performance of this system, with the increase of fuel outlet diameter and spool displacement, the pressurization pressure and fuel injection rate peak value both increase, but the fuel leakage rate increases first and then decreases.]]></description>
<pubDate>2022/2/12 22:27:53</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[雷智斌,聂涛,杨 昆,赵建华,周 磊]]></author>
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<title><![CDATA[Application of the Method of Normal Forms to Projectile Nonlinear Motion Analysis]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009220000003]]></link>
<description><![CDATA[Nonlinearity especially from aerodynamic coefficients in high orders has a significant effect on projectile dynamics. However, its investigation has been hindered in the conventional analysis by the complexity in nonlinear motion equations and the lack of appropriate analysis tools. Therefore, the widely used method of normal forms is introduced for the analysis of projectile angular motion. Considering the second order damping and seventh order static moment terms, the normal form of the angular motion is derived and thus the universal analytical solution of the angle of attack is obtained, which is verified to show good agreement with the numerical integration results over a wide range of angle of attack and also demonstrated applicable to undamped case and cases with lower or higher order of static moment. In addition, the obtained relationship between initial conditions can give a conventional but simple determination of the region of attraction to the origin. Also, the amplitude equation combined with the equilibrium analysis provides a correct prediction for the existence and stability of limit cycle in angular motion.]]></description>
<pubDate>2022/2/12 22:25:43</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[常思江,李东阳,王中原,魏伟]]></author>
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<title><![CDATA[Research on Influencing Factors of Thyristor Expansion Speed in Pulse Condition]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009220000002]]></link>
<description><![CDATA[In order to study the influence of different factors on the current expansion speed of the thyristor during the turn-on process of the pulse condition, the equivalent circuit model of the pulse forming network based on the structural char-acteristics and working principle of the thyristor were established, and the simulation was carried out.   The results of numerical simulation show that if the forward blocking voltage increases from 3000V to 5000V, the spreading speed will increase by 24.6%. If the base width increases from 500μm to 900μm, the spreading speed will decrease by 31.7%. If the carrier lifetime increases from 1μs to 10μs, the spreading speed will increase by 56.9%. While the temper-ature increases from 300K to 330K, the spreading speed only increases by 0.3%. It can be seen that the temperature has little effect on the propagation speed. The research results are helpful to select appropriate parameters to ensure the ex-pansion speed required for opening, and have application value for improving the design of thyristor devices and im-proving the performance of thyristors.]]></description>
<pubDate>2022/2/12 22:24:33</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[戴宇峰,鲁军勇,武文轩,张冠祥,张晓]]></author>
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<title><![CDATA[Position and attitude estimation algorithm and error analysis of high-spin projectile based on dual high-speed cameras intersected]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202008120000001]]></link>
<description><![CDATA[In order to measure the various information of the high-rotation projectile at the muzzle, a new method for estimating the position and attitude of projectiles based on the intersection of dual high-speed cameras is proposed. The error modeling and analysis of the total angle of attack function are carried out. The analysis shows that the optical axes of the two cameras should be perpendicular to each other, and the measurement function of the camera with the optical axis far from the plane of attack should be selected to calculate the total angle of attack. At this time, the measurement error is the smallest. The conclusions of error analysis and the position and attitude estimation algorithm are verified by shooting range experiments. The experimental results show that the conclusions of error analysis are correct, and the position and attitude estimation algorithm proposed in this paper is not based on any assumptions and its accuracy is higher than that of the POSIT algorithm. The initial velocity measurement error does not exceed 0.6m/s, and the projectile centroid position measurement error does not exceed 0.3m. The measurement method is a non-contact measurement, which will not introduce other errors, and the measurement accuracy is high. The proposed measurement method is simple and easy to implement. More importantly, the measurement information is comprehensive. So it can provide reference basis for shooting range experiments and acceptance.]]></description>
<pubDate>2022/2/12 22:23:03</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[王良明,王垚,杨志伟,张喜峰]]></author>
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<title><![CDATA[On-line measurement of pressure wavespeed in hydraulic system with high precision]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202008040000004]]></link>
<description><![CDATA[The pressure wavespeed of pipe flow is the basic physical parameter to analyze and study the stability and dynamic quality of hydraulic system. The three-sensor measurement theory was deduced based on the wave equation of the transmission pipeline, the Foster equivalent shear coefficient model was introduced for high-precision estimation of various influence factors in the hydraulic line, and the Newton-Raphson iterative method was adopted to reduce the data processing error and accurately calculate the pressure wavespeed. An on-line test platform for measuring pressure wavespeed of hydraulic pipeline was built based on theoretical derivation, realizing accurate measurement and calculation of pressure wavespeed of hydraulic system under various working conditions by MATLAB software programming. The test results show that: (1) when the system is under the typical working pressure of 20 bar,50 bar,75 bar and 100 bar, the pressure wavespeed is about 1320 m/s, 1338 m/s, 1363 m/s, 1380 m/s, the measurement error is within ±1% in the wave speed interval with a confidence level of 95%; the pressure wavespeed of pipeline increases with the increase of the working pressure, and the function relationship between the two variables was given according to the test results; (2) the effect of pipe material on system flexibility should be considered in the precise calculation of pressure wavespeed. The results of test and analysis have important guiding significance and reference value for the on-line measurement and estimation of pressure wavespeed in hydraulic system.]]></description>
<pubDate>2022/2/12 22:12:37</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈宗斌,何 琳,梁云栋,徐荣武]]></author>
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<title><![CDATA[Tonal Noise Prediction of Subsonic Axial Fan with Stator and Rotor Interaction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009280000003]]></link>
<description><![CDATA[The tonal noise,radiated by interaction between stator and rotor,is the main noise of subsonic axial fan. A rapid method to predict fan tonal noise is significance to the parameter design in early stage of fan low radiation noise design. Therefore,on the basis of cascades response function and empirical rotor wakes model,a semi-analytic formula of fan sound power prediction is derived. The predicting formula is verified by comparing with the NASA experiment result and other predicting model’s result. Based on NASA experiment model ,the effect of rotor-stator spacing and stator blade parameters on tonal noise is analyzed further more. And the results show that increasing the rotor-stator spacing and lean design of stator blades can suppress tonal noise well.]]></description>
<pubDate>2022/2/12 22:11:54</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[胡鹏飞,靳栓宝,孙方旭,王东,魏应三,武星宇,祝昊]]></author>
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<title><![CDATA[Tree species classification of airborne LiDAR data based on 3D deep learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010250000002]]></link>
<description><![CDATA[Aiming at the problem that the traditional tree species classification method based on LiDAR data is difficult to directly and comprehensively use the 3D structure information of the point cloud, we proposes a tree species classification method of airborne LiDAR data based on 3D deep learning. This method directly abstracts high-dimensional features from 3D data without converting point clouds into voxels or two-dimensional images. Taking the airborne LiDAR data of white birch and larch trees in Saihanba National Forest Park as the research object. First, filter the data to remove noise and ground points; then extract the individual wood and make a data set based on the point cloud distance and improved watershed segmentation method. Finally, a neural network composed of weight-sharing multi-layer perceptrons, max pooling, fully connected layer and softmax is established, and the high-dimensional features of trees are automatically extracted using this network to realize tree species classification. The experimental results show that the overall classification accuracy rate is 86.7%, the kappa coefficient is 0.73, the optimal feature dimension is 1024D, and the most advantageous point density is 2048 points per tree. Compared with the method of projecting individual tree points to a two-dimensional view, this algorithm provides higher classification accuracy, and it can also effectively reduce the calculation cost and improve work efficiency.]]></description>
<pubDate>2022/2/12 22:10:34</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[陈一鸣,韩颜顺,韩梓威,刘茂华,刘正军]]></author>
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<title><![CDATA[LPI radar signal recognition based on multi-window  spectrogram analysis]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009070000001]]></link>
<description><![CDATA[In the current complex battlefield environment, low probability of intercept radar signal have been widely used due to their large time-bandwidth product, strong anti-jamming performance, high resolution and low interception. And it is difficult to identify the low probability of intercept radar signal by traditional radar reconnaissance methods. Based on the analysis of typical modulation of low probability of intercept radar, a radar signal classification and recognition method based on artificial intelligence was studied. Starting from the time-frequency characteristics of low probability of intercept radar signals,, a multi-window spectrogram analysis method was proposed. In this algorithm, Hermite function was used as the window function of spectrum analysis, and multiple window functions were also used for spectrum analysis. The effective signal with better aggregation is obtained, the noise interference is dispersed, and the time-frequency analysis characteristics of signal modulation characteristics are more obvious through this algorithm. On the basis of multi-window spectrogram, the idea of transfer learning was adopted, and ImageNet-VGG-f neural network was used to complete the task of signal classification and recognition. Experimental results show that the performance of the proposed algorithm is better than the traditional Choi-William distribution and Smooth and Pseudo Wigner-Ville Distribution methods at low signal-to-noise ratio.]]></description>
<pubDate>2022/2/12 22:10:04</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈林军,刘鲁涛]]></author>
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<item>
<title><![CDATA[Deception Jamming Optimization Strategy against Adaptive Filtering for Netted Radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005270000001]]></link>
<description><![CDATA[For the fact that adaptive filtering is used to estimate target state in the netted radar system when the target is maneuvering, a deception jamming optimization strategy is proposed in the context of netted radar with centralized fusion structure. First, the state and measurement model of the target tracked by the netted radar as well as adaptive filtering model of tracking maneuvering target are established. Then, based on this, deception jamming model is established, and the influence relationship of false target deception jamming against the adaptive filtering state estimation error covariance of the centralized netted radar fusion center is studied. Next, the trace of the error covariance matrix is used to quantify the effect of deception jamming and stand for the objective function of optimization. Finally, the Schur complement theory of matrix is used to change the constraints to a linear matrix inequality, and deception jamming optimization strategy is changed to solve the convex optimization problem for semidefinite programming. The simulation results verify the effectiveness of the proposed deception jamming optimization strategy.]]></description>
<pubDate>2022/2/12 22:09:22</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[黄天奇,田继伟,王布宏]]></author>
</item>
<item>
<title><![CDATA[Structure integrity analysis of the bonding interface of solid rocket motor in vertical storage based on axisymmetric cohesive element]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202103170000001]]></link>
<description><![CDATA[Axisymmetric cohesive element is an important method to conduct stress analysis of the bonding interface of solid rocket motor under vertical storage. The reference coordinate system is established on the deformed axisymmetric cohesive force element, and the transformation relationship for nodal displacement between the reference coordinate system and the global coordinate system is derived. The internal force vector and the stiffness matrix of the element were derived based on the elemental separation displacement. The separation test of the axisymmetric bonding plate was carried out to verify the accuracy and high efficiency of the axisymmetric cohesive element. The structural analysis of solid rocket motor in vertical storage under axial acceleration and wave load has been carried out successively, and the stress magnitude and distribution law at the bonding interface have been studied emphatically. Research method and conclusion can provide a useful reference for the structural analysis of bonding interface of solid rocket motor.]]></description>
<pubDate>2022/2/12 22:06:59</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[鲍福廷,崔辉如,王君祺]]></author>
</item>
<item>
<title><![CDATA[Effect of tip winglet on the leakage flow of  compressor cascade at high subsonic speed]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109290000001]]></link>
<description><![CDATA[Abstract: To explore the influence of different installation locations and different widths of tip winglets on the aerodynamic characteristics of transonic compressor cascades, the flow fields of seven diffused cascades were numerically studied at Ma=0.8. The results show that the suction surface tip winglets have negative effects in the flow field, which increase the complexity of the flow field. at different incidences. Under the same working conditions, the pressure surface tip winglets improve the leakage flow and reduce the flow loss. When the tip winglet changes from narrow to wider, the effect of the tip winglet in the flow field is more intuitive. The interference or improvement effect of the tip winglet is easier to be observed at positive angle of incidence. Under the condition of positive 6°, the most obvious effects of the two types of tip winglets can be obtained by comparing with the normal condition. The suction surface tip winglet with a width of is 2.0 times of the original width  causes 4.17% loss, while the pressure surface tip winglet whose width is 2.0 times of the original width is accompanied by an improvement effect of 10.1%..]]></description>
<pubDate>2022/2/12 22:04:21</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[钟兢军]]></author>
</item>
<item>
<title><![CDATA[Theoretical Solution of High-Order Shear Deformation Beam Theory for Bending Behavior of Cylindrical Tube on Elastic Foundation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109070000001]]></link>
<description><![CDATA[The transverse bending of cylindrical tubes embedded in Winkler elastic foundation was studied based on the higher-order shear deformation beam theory. A governing equation for bending of circular cylindrical tubes on elastic foundation or in a surrounding Winkler matrix was derived and accurate solutions were given for four typical boundary conditions. The obtained results show that the shear stress   automatically vanishes on the inner and outer surface of cylindrical tubes when an appropriate warping shape function instead of the shear correction coefficient is chosen. And it can provide analytical solutions with sufficient accuracy for the bending problems of cylindrical tubes with different length-diameter ratios and thickness-diameter ratios. When the stiffness coefficient approaches zero, the deflection curve of cylindrical tube embedded in Winkler elastic foundation approaches the deflection curve pf cylindrical tube placed in free space, which verifies the accuracy of the present method. Different from the Euler-Bernoulli beam theory,  the normal stress over the cross-section is no longer linear with the abscissa from the neutral surface in this method., and it is especially obvious when the  length-diameter ratio is small and the thickness-diameter ratio is large.The shear stress   decreases when the distance from the neutral surface becomes large, tending to zero at the top and bottom positions, and the maximum shear stress occurs at the neutral surface and close to the inner surface.]]></description>
<pubDate>2022/2/12 20:50:59</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李显方,马维力,申柳雷,宋殿义]]></author>
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<title><![CDATA[The critical initiation condition of cylindrical covered charge by double spherical fragments impact]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202008010000001]]></link>
<description><![CDATA[In order to investigate the shock initiation of missile warhead (cylindrical covered charge) by multiple fragments impact under actual combat conditions, based on the analysis of Jacobs-Roslund formula, the engineering calculation model of the impact critical initiation condition of cylindrical covered charge with single or double spherical fragments were established. The calculation model includes several parameters such as fragment diameter, impact angle, charge radius and shell thickness. The calculation model results are in good agreement with the simulation results and experimental results, the calculation model can provide a better prediction of the impact critical initiation condition of cylindrical covered charge with single or double spherical fragments.]]></description>
<pubDate>2022/2/9 17:34:47</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[顾文彬,郭淳,郭尚生,钱建平]]></author>
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<title><![CDATA[Performance optimization of infrared interference decoy based on trajectory correction technique]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202008170000001]]></link>
<description><![CDATA[Infrared interference decoy is an important way to improve the survival level of aircraft, and it plays an important role in air combat. In order to realize the low-cost transformation of weapon system, the trajectory correction technology is applied to the traditional infrared interference decoy, which can complete the flight companion mission for the aircraft. In order to solve the performance optimization problem caused by its high-dimensional nonlinear characteristics, an intelligent optimization algorithm based on DOE and RSM is proposed to change the traditional serial design method in the conceptual design stage. In the initial design stage, the basic projectile structure model and related design parameters are defined. Based on the DOE design, the design variables are mapped to the performance criteria to generate the stochastic Kriging response surface. At the same time, the neural network is trained to identify the unstable design. Finally, multi population genetic algorithm is used to determine the optimal projectile design. By changing its cost function, the Pareto frontier reflecting the performance tradeoff can be generated. Based on trajectory correction in the conceptual design stage, the simulation results show that the algorithm can obtain the optimal design configuration of the infrared interference decoy quickly and accurately, which provides a guarantee for the following accompanying flight mission.]]></description>
<pubDate>2022/2/9 17:34:26</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[邢炳楠]]></author>
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<title><![CDATA[Nano millimeter wave radar for bridge cable tension measurement]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009300000002]]></link>
<description><![CDATA[After the detailed analysis of the diffusion characters of bridge cables, the principle of vibrating frequency-based cable tension estimation, and the principle of interferometric deformation measuring radar, a nano 77GHz MMW (millimeter wave) radar is developed. A set of key parameters is achieved to control the maximum range, the deformation estimation precision, and the dynamic deformation measuring performance. Field experiments were conducted to compare the performances of the MMW radar with those of a 24GHz K band radar. The results show that the new radar is a compact, light-weighted, low-power consumption. The radar is of great value in cable tension measuring applications.]]></description>
<pubDate>2022/2/9 17:34:01</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[王建]]></author>
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<title><![CDATA[A Compensation Method of Parachute Deployment Load Based on Recurrent Neural Networks]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009100000001]]></link>
<description><![CDATA[Focusing on predicting the parachute deployment load in the process of inflation accurately, a compensation calculation method of parachute deployment load with recurrent neural networks (RNN) is proposed, including the model architecture and data processing. The predicted value calculated by inflation time method is brought into the RNN for the secondary calculation, so that the final result can be accurate with the airdrop experiment data. Feedforward networks(FNN), standard recurrent networks and long short-term memory(LSTM) networks are used to compare the model characteristic. The research verifies the applicability and accuracy of the prediction results and analyzes the effects of hyperparameters such as learning rate, input layer dimension and hidden layer dimension on the performance. The optimal training condition for reference to the compensation model is developed through the test. The results show that the utilization of RNN for parachute deployment load prediction is effective and provides a referential significance for the interdisciplinary research of machine learning and parachute industry.]]></description>
<pubDate>2022/2/9 17:32:44</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[戈嗣诚,姜添,李健]]></author>
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<title><![CDATA[Mesh parameterization in the reliability based design optimization for the life of turbine blade with film holes]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202008040000002]]></link>
<description><![CDATA[It is usually difficult to mesh a turbine blade with film holes due to its complicated geometry. Additionally, the large quantity of meshes makes it time-consuming to perform finite element analysis (FEA). The contradiction is, reliability-based design optimization (RBDO) requires a large number of FEA calls to simulate the variation of output. In order to meet the RBDO requirement for the life of turbine blade with film holes by automatic programmed control, local parameterization method is proposed based on the unstructured mesh, which significantly reduces the time costs of FEA. The turbine blade is separated into two regions: parameterized region and non-parameterized region. After meshes of non-parameterized region and control points of parameterized region are completed, only meshes of parameterized region are required to be reconstructed when the geometry of film holes is updated. Comparing with global deformation method based on structured mesh, the proposed method dramatically reduces the time costs of FEA, which highly improves the efficiency of RBDO.]]></description>
<pubDate>2022/2/9 17:32:10</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[贾贝熙,雷婧宇,吕震宙]]></author>
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<title><![CDATA[Elastic-plastic analysis for thermoplastic composite cantilever beams by bending moment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009260000001]]></link>
<description><![CDATA[In this paper, the analysis of elastic-plastic stress and deformation was carried out for thermoplastic composite cantilever beams subjected to bending. Based the Timoshenko beam theory and the Tsai-Hill yield criterion, a mathematical model for elastic-plastic analysis for cantilever beams by bending moment was established. In addition, the analytical solutions of stress and displacement were obtained. Then the solutions were verified in comparison with the ones available in the literature and finite element. Also, the effects of fiber orientation angle, bending moment, and aspect ratio on the elastic-plastic stress and displacement of the beam were examined in detail. The results can provide important references for the design and engineering applications of thermoplastic composites.]]></description>
<pubDate>2022/2/9 17:31:39</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[雷勇军,刘明伟]]></author>
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<title><![CDATA[Fully implicit LU-SGS algorithms applied to stiff problems in hypersonic thermochemical non-equilibrium flows]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202111040000002]]></link>
<description><![CDATA[In hypersonic thermochemical nonequilibrium flow calculations, a large difference between the numerical time step and the molecular vibration relaxation time or the chemical reaction time could bring serious numerical stiffness problems, which are exacerbated by grid refinement in strong interaction areas such as near-wall or corner. The initial maximum CFL number and convergence rate are thus limited under high Reynolds conditions. The original LU-SGS algorithm only considered the implicit treatment of the source term and convection term. The FLU-SGS and BLU-SGS algorithms were developed by deriving and implementing the diagonal approximation of the spectral radius of the viscous Jacobian matrix. The convergence speeds of the three algorithms were investigated in cases of high enthalpy two-dimensional cylinder flow and axisymmetric re-entry capsule flow. The results show that strong viscous interaction and large separation can be quickly established and 3~5 orders of increase of the maximum CFL number can be reached with FLU-SGS and BLU-SGS algorithms. The newly developed algorithms are efficient in accelerating convergence in the calculation of complex thermochemical non-equilibrium flows.]]></description>
<pubDate>2022/2/9 17:30:42</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杜洋,黄伟,蒋浩,柳军,王君媛]]></author>
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<title><![CDATA[Numerical Simulation of Structural Integrity Analysis of Finocyl Grainunder Ignition Loading]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202001170000001]]></link>
<description><![CDATA[In order to study the structural integrity analysis of finocyl grain for solid rocket motor under the ignition loading, the secondary development of commercial finite element software was used. The user subroutine was completed. The three-dimensional damage viscoelastic constitutive was considered. The numerical simulation was carried out by finite element method. The influence of temperature and ignition on the structural integrity analysis of finocyl grain was obtained. The results show that the deformation mode of inner surface of grain is different under the temperature loading and ignition loading. Secondly, on the condition of temperature loading or ignition loading, both the Von Mises stress and Von Mises strain in the fin-slot region of grain are higher than those in other parts. Finally, the method established in this paper can be applied to the security assessment of structural integrity analysis of solid rocket motor.]]></description>
<pubDate>2022/1/17 19:22:02</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[邓 哲,龚建良,龚婉军,金秉宁,张正泽]]></author>
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<title><![CDATA[Numerical Analysis for Aerodynamic characteristics of Electromagnetic Launch Hypervelocity Projectile]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007010000004]]></link>
<description><![CDATA[Electromagnetic launched hypervelocity projectile has the advantages of high speed, long range and great power. Which is regarded as the next generation of low-cost and multi mission guided ammunition. The aerodynamic characteristic of projectile is the primary work for the design.The numerical method was used to study the aerodynamic flow field characteristics of hypervelocity projectiles, especially in the reentry phase. The prediction accuracy of S-A and  SST turbulence modelwas verified by wind tunnel test data. The calculation results show that the prediction accuracy of the two turbulence models is higher than 2% in normal force prediction. In axial force prediction, the S-A turbulence model has a high prediction accuracy of 4.6%. When the projectile reenters at a large angle of attack, the transverse flow effect of projectile is more obvious. The shock wave makes the surface pressure of the projectile increase sharply on the windward side, while the large-scale streamwise vortex structure formed on the leeward side reduces the pressure, and the increase of the pressure on the windward side has a greater impact on the aerodynamic coefficient of projectile. The aerodynamic drag and lift coefficient at high angle of attack are obviously nonlinear, the drag coefficient is obviously increased, and the static stability margin is also sharply reduced, which makes the convergence characteristics of projectile worse, which is the main reason for the velocity attenuation during the reentry process of projectile.]]></description>
<pubDate>2022/1/17 19:20:01</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[冯军红,李开,李湘平,鲁军勇]]></author>
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<title><![CDATA[Generalized Finite Integral Transform Method for Dynamic Characteristic Analysis of Nonlocal Thin Plate]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007280000002]]></link>
<description><![CDATA[This paper aim to apply the generalized finite integral transform method to get the dynamic characteristic of a nonlocal thin plate based on the stress gradient nonlocal theory. The integral transform pairs are established by using the integral kernels which can satisfy the boundary conditions. Then, the higher-order partial differential equation of the nonlocal thin plate is transformed to a series of linear algebraic equation through the integral transform and the nature frequencies of the governing equations can be solved exactly. To confirm the validity of the simulated, the results are compared with the finite element method and the existing ones. The effects of the nonlocal parameter and the dimension of the plate on the nature frequency are studied. The present work of can provide a new way to solve the mathematical problem of the nonlocal plate problem.]]></description>
<pubDate>2022/1/17 19:19:44</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[姜人伟,李道奎,马维力,杨树涛,赵佳敏]]></author>
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<title><![CDATA[Failure-Oblivious routing strategy in airborne network for aeronautic swarm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202008070000002]]></link>
<description><![CDATA[Airborne network for aeronautic swarm is the information interaction bond between swarm members, and its routing strategy directly affects the reliability and real-time performance of information transmission, affecting the combat effectiveness of networked swarm. Considering that there are many uncertainties in airborne network for aeronautic swarm, in order to reduce the risk of route failure and avoid routing updates, a Failure-Oblivious routing strategy from the perspective of routing algorithm based on FRT graph embedding is proposed under software-defined network architecture. Theoretical derivation and simulation verification showed that this routing strategy can reduce the risk of route failure in airborne network for aeronautic swarm, guaranteeing that communication delay cost is under control.]]></description>
<pubDate>2022/1/17 19:19:23</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈坤,方宇,吕娜,潘颖,朱梦圆]]></author>
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<title><![CDATA[Game model for detecting cross-layer attacks in wireless ad hoc networks]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202010250000001]]></link>
<description><![CDATA[Compared with single-layer attacks, cross-layer attacks in wireless ad hoc networks can conceal attack behavior better, achieve better attack effects, or reduce the cost of attack. In order to detect cross-layer attacks in wireless ad hoc networks, a detection model based on game theory was proposed. As the attack will inevitably affect the parameters of each protocol layer, the corresponding strategy matrix and payoff matrix was built from the aspect of attack-defense game of protocol layer, and the mixed strategy Nash equilibrium solution was obtained by equilibrium analysis. The simulation experiments results show that the detection system adopted mixed strategy can achieve a better detection performance and save the energy consumption significantly, compared with the traditional detection system.]]></description>
<pubDate>2022/1/17 19:18:12</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[降 帅,刘星彤,王 剑]]></author>
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<title><![CDATA[Research on Room Temperature Terahertz Photodetector Based on New micro-nano materials Graphene ,Perovskite,etc.]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101110000002]]></link>
<description><![CDATA[Terahertz wave generally refers to the electromagnetic wave with frequency between 0.1-10THz. It has a series of unique properties and plays an important role in a variety of photoelectric systems. The high sensitivity terahertz detector operated at room temperature is the key to the application in this field and still needs to be solved. The terahertz detector based on the principle of thermoelectricity has a wide detection frequency range and can reach high sensitivity detection at room temperature. New micro-nano materials such as graphene and perovskite have high carrier mobility and excellent thermoelectric properties for terahertz detection. Through the use of graphene and perovskite and other new micro-nano materials to prepare high-performance terahertz photodetector operating at room temperature, the detection of the photoelectric response can be up to 271mA/W, the response time is less than 20ms.The results show that photothermoelectric detectors such as graphene and perovskite are expected to be a new generation of high performance detectors in terahertz frequency band.]]></description>
<pubDate>2022/1/17 19:17:51</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[李梦瑶,李依凡,唐新,姚建铨,张海建,张雅婷]]></author>
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<title><![CDATA[The metasurface antenna with cross-spectrum and low-observable performance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101270000003]]></link>
<description><![CDATA[Aiming at the new requirements of antenna for low-observable aircraft platform, a metasurface antenna with microwave/infrared cross-spectrum and low-observable performance was proposed and designed. To make the antenna own normal radiation properties and absorbing characteristics simultaneously, a novel idea that metasurface design thought integrated into the antenna design was proposed. In this way, radar cross section of the antenna can be reduced without additional loading of the absorbing metasurface, and only by using absorbing characteristics of the antenna structure. On this basis, to realize infrared low-observable of the antenna, an metasurface with microwave transparent characteristics and low emissivity characteristics in the infrared band was designed, and it was loaded above the antenna to reduce antenna emissivity. Experimental results show that the novel designed metasurface antenna operates from 2.72 to 2.82 GHz and the maximum gain reaches 6.72 dBi, which indicates the antenna possesses good radiation properties. The reflection magnitudes of the metasurface antenna are all less than –10dB from 2.70 to 2.80 GHz, which almost includes the antenna operation band. The minimum reflection magnitude is –12.49dB. The emissivity of the antenna is 0.212 by loading the metasurface, which is 0.334 (61.2%) lower than the antenna without metasurface. From the above results, it can be concluded that the novel designed antenna achieves microwave and infrared low-observable simultaneously while maintaining normal radiation properties. The novel metasurface antenna provides novel approach for antenna design of low-observable aircraft platforms.]]></description>
<pubDate>2022/1/17 19:17:26</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[郑月军,]]></author>
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<title><![CDATA[Research on fast Fourier transform-based scanning single-input-single-output array near-field imaging technology]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101310000002]]></link>
<description><![CDATA[In recent years, scanning single-input-single-output (SISO) array near-field imaging technology has attracted widespread attention in civilian fields such as security inspection and medical treatment. However, during the echo processing of traditional range migration algorithm, the multi-step approximation and interpolation operation cannot be avoided, and the adverse effect caused by signal propagation attenuation is ignored. Therefore, a fast Fourier transform (FFT)-based scanning SISO array near-field imaging technology was proposed, in which the amplitude attenuation factor in the echo model was preserved. Then the convolution operation on azimuth and altitude dimensions was performed according to the characteristics of the target echo equation. Finally, the target image could be obtained by applying FFT and coherent accumulation steps. Simulation analysis and experimental results show that the proposed method can not only improve the target image quality while ensuring the efficiency of image reconstruction, but also effectively reduce the impact of signal spatial propagation loss on the imaging quality.]]></description>
<pubDate>2022/1/17 19:15:29</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈旭,邓彬,王宏强,杨琪,曾旸]]></author>
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<title><![CDATA[Enhanced terahertz coded aperture imaging using convolutional neural networks]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102200000001]]></link>
<description><![CDATA[To address the problems of poor robustness and high computational complexity of some existing coded aperture imaging algorithms, an enhanced terahertz coded aperture imaging method based on convolutional neural networks is proposed in this paper. The method can implicit modeling of the imaging system by constructing an end-to-end neural network that exploits the network"s strong inversion ability and noise immunity for target reconstruction at low signal-to-noise ratios (SNRs). The simulation experiments show that the proposed method can achieve the reconstruction of targets with different sparseness at different SNRs. Moreover, the proposed method can achieve a higher resolution reconstruction of the target at low SNRs compared to the classical optimization iterative algorithm.]]></description>
<pubDate>2022/1/17 19:10:39</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[甘凤娇,罗成高]]></author>
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<title><![CDATA[Study of terahertz wave propagation characteristics in the plasma sheath of near space vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101070000001]]></link>
<description><![CDATA[Plasma sheath formed the during reentry of near space hypersonic vehicle will interferes the electromagnetic wave detection. In order to solve this problem, we built the model of the typical near space vehicle first, and simulates the flow field distribution under different flight conditions during the reentry process. Based on the flow field distribution, the plasma parameter distribution is modeled, and the transmission characteristics of terahertz wave in the plasma sheath are theoretically calculated by using the scattering matrix method. The results show that high frequency terahertz wave can penetrate plasma sheath effectively. In addition, terahertz active imaging experiments were carried out in the laboratory environment. The experimental results show that the plasma has little effect on the terahertz active imaging results. The simulation and experimental results preliminarily prove the potential of terahertz technology for hypersonic vehicle detection, which is of great significance for national defense.]]></description>
<pubDate>2022/1/10 18:02:24</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[陈锴,李吉宁,徐德刚,姚建铨,钟凯]]></author>
</item>
<item>
<title><![CDATA[Design and performance evaluation of a gravitational potential energy locking exoskeleton]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202104220000002]]></link>
<description><![CDATA[The existing passive exoskeletons have some defects, such as the lack of assistance effect. Based on the gait characteristics of human body, the principle of transforming gravitational potential energy during walking process into kinetic energy during lifting leg process was proposed, a passive lower extremity mechanical exoskeleton was designed by the combination of spring, crank slider mechanism, ratchet pawl mechanism and chain drive mechanism, and the performance of exoskeleton was evaluated by kinetic analysis and physiological cost index experiment. The results of kinetic analysis show that the total peak torque of hip joint is reduced by 23.43% and the total work of hip joint is reduced by 30.59% after wearing the exoskeleton, which preliminarily verifies the effectiveness of the exoskeleton. The results of experiment show no significant effect in short distance action conversion, but is reduced by 8.1% and 10.4% in long distance walking and uphill walking, respectively. Therefore, the assist performance of the passive exoskeleton has been verified, which provides an instance reference for research in related fields.]]></description>
<pubDate>2021/12/3 9:53:18</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[曹恩国,曹毅,高阳,胡伟峰,王刚]]></author>
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<item>
<title><![CDATA[A Multi-Agent Model of Epidemic Control Process for Large Cruise Ships]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202004240000002]]></link>
<description><![CDATA[The epidemic spread of large cruise ships is very fast. The research on the characteristics of epidemic spread is helpful to solve the problem of early control strategy of epidemic spread. Based on the theory of complex network and propagation dynamics, a social network is constructed, which conforms to the interaction characteristics of large cruise ships . The hierarchical structure of the communication network is defined, five rules of topology generation of the interaction network are analyzed, and the social networks construction method of the large cruise ships epidemic communication are given. Based on the Multi-Agent technology, the properties of the members of the interaction network nodes and the epidemic propagation characteristics are studied, the basic form of Agent member state-space is given, the physical characteristics of protection and treatment, management and control isolation, information interaction and other factors are integrated, the algorithm of agent state transfer and behavior interaction process are constructed, and the structure and interval characteristics of attenuation function are analyzed and demonstrated. Compared with the constant-distance model and the random-walk model, the simulation calculations of the epidemic transmission process of typical large cruise ships are carried out under 4 working conditions and 12 states respectively. The results show that the random-walk model is more suitable for the simulation of the early epidemic transmission process of large cruise ships and the analysis of epidemic prevention and control strategies with abundant information.]]></description>
<pubDate>2021/12/3 9:52:20</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[李营,罗雯军,任凯]]></author>
</item>
<item>
<title><![CDATA[Text Feature Extraction Based on Sparse Balanced Variational Autoencoder]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007070000004]]></link>
<description><![CDATA[In order to solve the problems of low feature differentiation of high-dimensional data in text feature extraction, poor self-learning performance of rule-based representation learning, and excessive pruning of Variational Autoencoder, a text feature extraction model based on sparse balanced Variational Autoencoder(SBVAE) was proposed. In order to eliminate noise interference and improve robustness of the text feature extraction model, a bidirectional noise reduction mechanism was designed for Variational Autoencoder in the input layer of the text feature extraction. A sparse balance method combined with simmulated annealing algorithm of weights of Kullback-Leibler (KL) terms was proposed to alleviate the effect of excessive pruning caused by KL divergence, and forced decoders to make full use of latent variables. The model improves discrimination of high-dimensional data features. Experiments are carried out in several aspects, including comparative analysis of text feature extraction model, sparse performance and influence of sparse balance on the lower bound of variation in hidden space. The results show that SBVAE model has good performance. The highest accuracy of SBVAE model of Fudan and Reuters datasets is 12.36% and 8.06% higher than that of PCA, respectively.]]></description>
<pubDate>2021/12/1 10:44:36</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[车蕾]]></author>
</item>
<item>
<title><![CDATA[Cross-modality Person Re-Identification Algorithm using  Symmetric Network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007220000001]]></link>
<description><![CDATA[Due to inter-modality difference caused by imaging principle，cross-modality person re-identification between visible light image and infrared light image is one of the difficult problems. For the difference between modalities, a cross-modality person re-identification algorithm which based on symmetric network was proposed. The network combined modal confusion based on probability distribution with adversarial learning, and generated modal-invariant features through symmetric network to achieve modal confusion. To deal with appearance differences and intra-modality differences, the network constructed a mixed-triplet loss using convolution features of different hidden layers which is to improve the characterization capability of the network. Numerous experimental results on the RegDB and SYSU-MM01 datasets demonstrate the effectiveness of the method.]]></description>
<pubDate>2021/12/1 10:26:21</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[屈磊,唐俊,王年,相旭,张艳]]></author>
</item>
<item>
<title><![CDATA[Voronoi diagram generation algorithm and application for large-scale interactive data space partition]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202008070000001]]></link>
<description><![CDATA[When the traditional Voronoi diagram divides a large number of point sets into Voronoi, there will be too many Voronoi cells, which makes it difficult to apply to many fields such as geographic information systems and biomedicine. In order to solve this problem, a Voronoi diagram based on adaptive density-based spatial clustering of applications with noise (DBSCAN) is proposed. The phenomenon of Voronoi unit merge was explained. The necessary and sufficient conditions for its occurrence were proved. The algorithm for generating the Voronoi diagram was proposed and simulated. In order to verify its effectiveness, the algorithm was applied to neutrophils under the microscope and fire point data on the surface of China. The results show that the algorithm can effectively solve the problem that Voronoi diagram is too meticulous when the point set size is large，which breaks through the traditional Voronoi diagram single point to single point division form. In addition，the algorithm broadens the application of Voronoi diagrams in the fields of graphic image processing，biomedicine，and geographic information systems.]]></description>
<pubDate>2021/12/1 10:24:47</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[熊鹏文]]></author>
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<item>
<title><![CDATA[Experimental study on the passive boundary layer control methods of Chemical-Oxygen-Iodine-Laser cavity]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007140000001]]></link>
<description><![CDATA[The experimental study on the passive boundary layer control methods of chemical oxygen iodine laser (COIL) cavity is implemented. The characteristics of flow in COIL channel is analyzed, such as three-dimensional effects, chemical reactio ns and internal heat release, low Reynolds number. The experimental facilities are presented. Three types of experiment rigs are designed. The upper and bottom wall of laser cavity is removable, so the boundary layer control effect with different experiment rig can be compared. The experiment results indicate that the thickness of boundary layer in laser cavity can be reduced by both slotted wall, mainstream ejected slot and perforated wall. The pressure distribution in cavity, especially in the latter of cavity, is improved. The boundary layer thickness can be reduced further by increasing the sucking rate in a proper range, meanwhile the cavity pressure is dropped and the COIL power is increased. The mainstream ejected slot is the most sensitive to sucking rate, while the perforated wall is the most insensitive to the sucking rate.]]></description>
<pubDate>2021/12/1 9:10:29</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[陈志强,顾蕴松,任泽斌,王海锋,徐大川]]></author>
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<title><![CDATA[Multi-voice activities detection method based on the terahertz radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101250000003]]></link>
<description><![CDATA[Speech signal detection technology based on terahertz radar has great application potential in the face of inaccessible sound source and complex noise environment, which can make up for the shortcomings of traditional voice signal detection technology represented by microphone. How to distinguish whether there is speech activity in radar echo is an important basis for speech signal enhancement and recognition. In order to overcome the problem that it is difficult to detect the sound activity correctly when there are multiple sound sources in the environment at the same time, a speech activity detection method based on threshold method for terahertz radar is proposed, which uses the range resolution of radar The advantages of this method are to overcome the influence of interference noise and obtain higher detection sensitivity by using terahertz frequency band. The experimental results show that the speech detection method based on terahertz radar can effectively detect speech activity compared with microphone mode when there are interfering sound sources on the transmission path.]]></description>
<pubDate>2021/11/29 13:14:49</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[邓彬,罗成高,王宏强,王元昊,杨琪]]></author>
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<item>
<title><![CDATA[Air space Configuration of Cooperative detection of Multiple Early Warning Aircrafts in Air Defense Operations of Key Targets]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007080000001]]></link>
<description><![CDATA[In order to solve the problem of early waring aircraft’s airspace configuration in key target air defense operations,a model of multiple early warning aircraft’s array selection and optimal configuration of aircraft number is constructed.Firstly,by analyzing the division of early warning lines for the key targets,the specific tasks of the early warning aircraft’s air defense operations are determined, and the quantitative model of array selection is constructed, and on the premise of ensuring its own safety and giving full play to the inherent detection power of early warning aircraft,a quantitative model of airspace configuration for parallel and tandem routes of multiple early warning aircraft is proposed. The results show that the model can compare and analyze the effects of key parameters on the cooperative detection of multiple early warning aircrafts in airspace configuration,deployment forces and route pattern selection,which will provide theoretical basis for mission planning of early warning aircraft’s combat troops.]]></description>
<pubDate>2021/11/29 13:14:10</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[程东升,蒋 伟,祁 炜,武文]]></author>
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<title><![CDATA[Investigation on the opposing jet in hypersonic flow using a fluid-thermal coupled method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005170000001]]></link>
<description><![CDATA[As one of active cooling method, opposing jet shows its advantages on the aerodynamic thermal reduction for hypersonic flight. To accurately predict the heat transfer properties of opposing jet, a fluid-thermal coupling strategy was adopted for a cone body with opposing jet. The related turbulent model and fluid-thermal coupled method were validated by comparison of the numerical and experimental results. Flow patterns were gained for different total pressure ratio of opposing jet, and its influence on the heat transfer between fluid and solid structure were discussed. Besides, the influences of attack angle and solid materials on structural heat reduction were also investigated. The numerical results indicate that the increase of total pressure ratio of opposing jet brings obviously further heating reduction, and accordingly the solid structure temperature present more uniform; calculation of the heating in 60s indicates the positive attack angle enlarges the temperature difference in the solid structure, and this induces the lower temperature air flowing to the leeward side furtherly, so the cooling for the leeward side of nosecone is enhanced; for alloy IN718 and C-103 two different materials, their discrepancy of heating could be neglected at the cooling recirculation region of nosecone and the area where the recompression shock influence obviously; compared with alloy IN718, the use of C-103 shows its advantage on thermal loads.]]></description>
<pubDate>2021/11/29 13:12:52</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘洪鹏,刘伟强,尹 亮]]></author>
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<item>
<title><![CDATA[Remote Sensing Image Matching Algorithm Based on Multi-scale PCA-HOG Dense Description]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007070000002]]></link>
<description><![CDATA[To solve the problem of non-linear gray level distortion and strong noise interference in remote sensing image matching, a remote sensing multi-modal image matching algorithm based on PCA-HOG dense description was proposed. This method uses Histogram of Oriented Gradients (HOG) dense description to extract the common features of geometric structure between images, which can effectively overcome the problem of nonlinear grayscale distortion of multi-modal images. Besides, this paper proposes a fast multi-scale Principal Components Analysis (PCA) algorithm, which can enhance the local gradient direction in HOG, so that it can accurately extract the structural features of the image under the condition of strong noise interference. In order to improve the calculation speed of the algorithm, this paper uses the integrated image method to reduce the computational complexity of the feature extraction process, and uses the fast Fourier transform to achieve a highly efficient matching search. The experiment uses a variety of remote sensing multi-modal images (including visible light images, SAR images, infrared images and Lidar images) to verify the matching algorithm in this paper. The results show that the proposed algorithm compared with existing algorithms has significantly improved the calculation speed and matching accuracy.]]></description>
<pubDate>2021/11/29 13:12:23</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[董晶,韩松来,罗世彬,王星,王钰婕]]></author>
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<title><![CDATA[Estimation of specular radar cross section for metal object with rough surfaces in the terahertz band]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101070000002]]></link>
<description><![CDATA[Research on the modulation of the surface roughness to the RCS (radar cross section) has vital importance to the RCS scaled measurement for rough metal targets in the terahertz (THz) band. RCSs of rough metal targets’ specular scattering with different surface roughness were studied. Based on the method of Kirchhoff Approximation, combining with the theory of coherent and incoherent scattering, the method for predicting the specular RCSs of rough metal targets was proposed under the condition of small surface roughness. The effectiveness of the estimation method was validated by simulation experiments. The proposed method could achieve the estimation of specular RCS for the metal target with small surface roughness, as well as specular RCS for the scaled model with rough surface.  This method will provide effective RCS value for the comparision with the measurement result, which will theoretically support the study of RCS scaled measurements for rough targets in the terahertz spectrum.]]></description>
<pubDate>2021/11/29 13:10:34</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[邓  彬,逄  爽,王宏强,杨  琪,曾  旸]]></author>
</item>
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<title><![CDATA[Enhanced terahertz coded aperture imaging using convolutional neural networks]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202102200000001]]></link>
<description><![CDATA[To address the problems of poor robustness and high computational complexity of some existing coded aperture imaging algorithms, an enhanced terahertz coded aperture imaging method based on convolutional neural networks is proposed in this paper. The method can implicit modeling of the imaging system by constructing an end-to-end neural network that exploits the network"s strong inversion ability and noise immunity for target reconstruction at low signal-to-noise ratios (SNRs). The simulation experiments show that the proposed method can achieve the reconstruction of targets with different sparseness at different SNRs. Moreover, the proposed method can achieve a higher resolution reconstruction of the target at low SNRs compared to the classical optimization iterative algorithm.]]></description>
<pubDate>2021/11/26 8:50:50</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[甘凤娇,罗成高]]></author>
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<title><![CDATA[Inter-satellite communication routing algorithm of smart-satellites-swarm using dynamic programming]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202011140000001]]></link>
<description><![CDATA[The network of Smart-Satellites-Swarm (SSS) was modelled in order to transfer the Inter-satellite Communication Routing Problem of Smart-satellites-swarm (ICRPS) into the least-delay path problem. Therefore, the Inter-satellite Communication Routing Algorithm of Smart-satellites-swarm (ICRAS) was developed to solve ICRPS by tackling a least-delay path problem. ICRAS used dynamic programming method to program the inter-satellite communication routing between two members of a SSS in multiple phases. The smart satellite which need transmit data adopted a static programming algorithm for inter-satellite communication routing to find its successor satellite during each programming phase. ICRAS was able to cope with the problem that data had to be delivered in pieces since the propagation capability of an inter-satellite link was restricted. A large quantity of simulation experiments were designed and conducted to examine and analyses the performances of ICRAS when different SSS utilized ICRAS to program inter-satellite communication routings.]]></description>
<pubDate>2021/11/25 13:23:30</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[李群,伦伟成,于芹章,张灿]]></author>
</item>
<item>
<title><![CDATA[Research on 220GHz transceiver front end for detection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101250000002]]></link>
<description><![CDATA[Based on the strong nonlinear characteristics of terahertz diode, a compact 220GHz transceiver front-end for continuous wave frequency modulation radar detection is developed by using multiple harmonic frequency doubling and mixing. In order to realize the transmitter with high power output, the power amplifier driver of 220GHz frequency multiplier adopts 4-way power synthesis method to realize 70GHz 300mW high-power  power amplifier module, and 70GHz high suppression 7th order cavity bandpass filter to suppress high-order harmonic signal. In order to achieve a high sensitivity receiver, the 220GHz harmonic mixer adopts hammer-head suppression structure and diode precise noise model to design the circuit structure, and the IF link adopts switch control to achieve dynamic gain control with dynamic range greater than 60dB. The 220GHz transceiver front-end achieves a maximum power output of more than 10mW in the range of 215-225GHz. The minimum noise figure of the receiver is less than 7dB, and the gain dynamic range is greater than 60dB (- 7dB-54dB).]]></description>
<pubDate>2021/11/25 13:13:23</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[邓贤进,何 月,黄 昆,刘 戈,苏伟,田遥岭]]></author>
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<item>
<title><![CDATA[Flexible spacecraft attitude maneuver planning based on variable amplitudes input shaping method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007050000001]]></link>
<description><![CDATA[In order to solve the attitude maneuver problem for flexible spacecraft with time-varying parameters, the variable amplitudes zero vibration derivative shaper with stronger robustness was developed based on the variable amplitudes zero vibration shaper. The robust attitude maneuver strategy was proposed, whose objective was to maneuver the spacecraft to the desired attitude state and cancel the residual vibration of the rotating flexible appendages at the same time. Simulations were conducted with a spacecraft with rotating solar wings which undergoes three-axis maneuvers. The results indicate that this strategy is robust to frequency variations, uncertainties of damping coefficient and other uncertain factors.]]></description>
<pubDate>2021/11/24 15:12:50</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[王杰,吴军,邹杰]]></author>
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<item>
<title><![CDATA[Compatibility multi-dimensional analysis method for geostationary satellite orbit systems]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202007170000001]]></link>
<description><![CDATA[Aiming at the compatibility analysis between GSO (geostationary satellite orbit) satellite systems, uplink and downlink interference scenarios were designed between single-beam and multi-beam GSO satellite systems, and GSO satellite systems interference was evaluated in multiple dimensions, such as satellite orbital position, system link availability, and interference system’s earth stations location. Recommendations were proposed on the nearest location of interference system’s earth stations at different orbital intervals, which met ITU (International Telecommunication Union) limit. The granularity of each dimension was refined. Different dimensions were compared horizontally, and interference variation characteristic curves and the influence level of each dimension were analyzed. When link availability was fixed, interference value changed slowly with orbital interval at > 2o; interference value changed rapidly with interval at ≤ 2o; especially interval at≤ 0.1o, interference value rose sharply. Taking network data of the CHNSAT-81.5 and INSAT-KA82.5E satellites registered by the ITU as examples, the interference-to-noise ratio and the carrier-to-interference ratio were compared with Visualyse, the result error was kept in the range of 0.7 dB with an effective evaluation performance.]]></description>
<pubDate>2021/11/24 15:12:01</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[董苏惠,高翔,韩锐,闫毅,姚秀娟]]></author>
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<title><![CDATA[Study of terahertz wave propagation characteristics in the plasma sheath of near space vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202101070000001]]></link>
<description><![CDATA[Plasma sheath formed the during reentry of near space hypersonic vehicle will interferes the electromagnetic wave detection. In order to solve this problem, we built the model of the typical near space vehicle first, and simulates the flow field distribution under different flight conditions during the reentry process. Based on the flow field distribution, the plasma parameter distribution is modeled, and the transmission characteristics of terahertz wave in the plasma sheath are theoretically calculated by using the scattering matrix method. The results show that high frequency terahertz wave can penetrate plasma sheath effectively. In addition, terahertz active imaging experiments were carried out in the laboratory environment. The experimental results show that the plasma has little effect on the terahertz active imaging results. The simulation and experimental results preliminarily prove the potential of terahertz technology for hypersonic vehicle detection, which is of great significance for national defense.]]></description>
<pubDate>2021/11/24 15:10:20</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[陈锴,李吉宁,徐德刚,姚建铨,钟凯]]></author>
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<title><![CDATA[Millimeter wave three-dimensional imaging algorithm with nonuniform planar array for nondestructive testing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202109050000002]]></link>
<description><![CDATA[Millimeter wave has great potential in the field of nondestructive testing due to its unique advantages of high resolution, high penetration and low photon energy. For the application of millimeter wave nondestructive testing, a three-dimensional imaging algorithm for nonuniform planar array was proposed by combining the idea of range migration algorithm and nonuniform fast Fourier transform. On the one hand, the proposed algorithm uses nonuniform fast Fourier transform to reconstruct the signal spectrum in wavenumber domain, which overcomes the limitation of nonuniform spatial sampling on traditional imaging algorithms based on Fourier transform. On the other hand, the proposed algorithm uses nonuniform fast Fourier transform to eliminate the complicated interpolation operation and improve the imaging efficiency. In order to verify the effectiveness of the proposed algorithm, back projection algorithm was used as a comparison, the simulation and experiment was carried out, respectively. Simulation and experimental results all show that the proposed algorithm can achieve high-efficiency imaging of dielectric targets with high imaging accuracy and fast speed.]]></description>
<pubDate>2021/11/24 11:36:34</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[邓彬,邓桂林,马昭阳,王宏强,杨琪,曾旸]]></author>
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<item>
<title><![CDATA[The evaluation method of the uncertainty of the temperature measurement for meteorological sounding rocket]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005070000001]]></link>
<description><![CDATA[Based on the temperature correction model of meteorological sounding rocket, through error analysis theory, the method of temperature correction and uncertainty evaluation is studied. According to the law of atmospheric density change during the falling process of rocketsonde, the mathematical model of temperature correction is established, and the formula of temperature correction is deduced. According to the error theory, eight error sources which affect the temperature correction are analyzed, and the expression of temperature correction error is given one by one. Taking one measured data as an example, using the above formula, the uncertainty of temperature inversion of sounding rocket is analyzed and calculated. The results show that the uncertainty of temperature is larger in 50-60km,and the maximum is 3.6K;40-50km is 0.3-0.9K;less than 40km, not more than 0.3K.The main factors that affect the uncertainty of temperature are: aerodynamic heating correction, lag effect correction, structural heat conduction correction, sensor to environmental heat radiation correction. It is not enough to use the reference atmosphere or the standard atmosphere for only single correction in data processing. Iterative correction is needed, and the maximum difference of iterative correction results of single correction results can reach 5.6K.]]></description>
<pubDate>2021/10/27 15:45:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[孙宇,,]]></author>
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<item>
<title><![CDATA[Theoretical analysis and experimental verification of nonlinear vibrational response of cracked blade]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202009210000002]]></link>
<description><![CDATA[Blade cracks pose a serious threat to aviation safety and lead to serious aviation accidents. In order to diagnose cracks at the early stage, the nonlinear vibration of cracked blades was investigated theoretically and experimentally. A nonlinear dynamic model was introduced to link the crack depth and the dynamic parameters. A quantitative expression of the coupling component power in the nonlinear vibration response was obtained. This response expression indicated that the harmonic element power was determined by the adjacent component power, component order, and the depth of the blade crack. Therefore, through the relative power of the vibrational components, a crack detection method is proposed. The results of the simulation and the testbed experiment showed that the cracked blades were effectively separated from the normal blades.]]></description>
<pubDate>2021/10/22 15:53:24</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[边子方,官凤娇,胡海峰,沈国际,杨拥民]]></author>
</item>
<item>
<title><![CDATA[Super resolution imaging using ultrasonic phased array based on time reversal]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202006100000002]]></link>
<description><![CDATA[The imaging methods in the field of ultrasonic phased array obey to the Rayleigh criterion and its resolution is limited by ultrasonic wavelength. The time reversal with multiple signal classification, termed TR-MUSIC, has been introduced to improve the resolution and achieve super resolution imaging. The ultrasonic array data from the test object can be captured via full matrix capture process. And then the data was post-processed by plane B scan as well as TR-MUSIC to obtain the two dimension and three dimension ultrasonic images. The test object was assessed according to the imaging results. A block of steel with six 1mm-diameter side drilled holes, which can be considered as point-like targets, has been machined as the test object. And the detection system of ultrasonic phased array has also been built. It is shown that TR-MUSIC can distinguish and locate these targets, but plane B scan fails. Therefore, the TR-MUSIC based on the theory of time reversal can increase the imaging resolution, and improve the quality of ultrasonic image.]]></description>
<pubDate>2021/10/22 15:49:31</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[樊程广,杨磊,余孙全,赵勇]]></author>
</item>
<item>
<title><![CDATA[Research on Data Availability Recovery Strategy in Information Knowledge Base]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201911190000001]]></link>
<description><![CDATA[The information knowledge base can improve production efficiency and reduce resource consumption in industrial production, but data failure occurs frequently. There are fewer erasure coding strategies for multi-node failure restruction, and the link relationship between participating nodes during the reconstruction of failed data is not fully considered, resulting in low restruction efficiency. Aiming at the data failure of the information knowledge base, a multi-node failure restruction method was proposed. According to the data processing capacity of the node, the new node with the highest data processing capacity was selected as the routing node; then according to the link bandwidth of the routing node, the candidate supply node and the remaining idle nodes, the supply node and the new node were determined, thereby constructing the data restruction network topology and improving the efficiency of restruct failed data. Experimental results show that this method has shorter restruction time and higher restruction success rate when compared with traditional erasure code restruction methods.]]></description>
<pubDate>2021/10/22 15:46:36</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[龚玉婷,孟宇龙,侍守创,徐鹏,朱群]]></author>
</item>
<item>
<title><![CDATA[Human-machine collaboration real-time remote situation intelligent perception system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005080000001]]></link>
<description><![CDATA[Aiming at the urgent need for human and remote unmanned devices to cooperate precisely and accurately, a remote situational awareness system of human-machine integration is proposed based on the robot operating system ROS, and experiments and analyses have been carried out. Based on visual positioning technology, with the integration of human-machine perception as the breakthrough point, through real-time 3D scene reconstruction technology and scene consistency fusion method, the environment and target information detected by unmanned equipment are 3D reconstructed. The result is consistent and fused with the human visual information and displayed by the augmented reality device to realize the coordinated positioning between the remote unmanned device and the augmented reality device worn by the person without GPS. The experimental results show that the system has better performance at close range. The accuracy of human-machine coordinated positioning is gradually reduced as the distance increases. The proposed system makes the unmanned device an extension of the human eye, realizes the ability to perceive obstacles, and crosses the line of sight without interfering with the normal movement of personnel. It can play an important role in future information operations.]]></description>
<pubDate>2021/10/22 15:44:13</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[樊铭瑞,李运,牛文龙,彭晓东,任敬义,谢文明,杨震]]></author>
</item>
<item>
<title><![CDATA[Design of Algorithm for Advanced Programmable Resistance Network Generation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005120000002]]></link>
<description><![CDATA[In order to improve the design efficiency of the high-precision programmable resistance network, the physical and mathematical models of the high-precision resistance network are established, and a high-precision programmable resistance network generation algorithm is proposed. The algorithm automatically generates a high-precision programmable resistor network based on the combination of the MRN, CRN and ORN according to the given range and accuracy. Taking the requirement of measuring range 90~250Ω and accuracy 5mΩ as an example, the algorithm was simulated and verified on the MATLAB platform, and the simulation results verified the feasibility of the algorithm. The results show that the generated programmable resistor network meets the requirements of target range and accuracy, and the algorithm solution time is only 18.128s. Compared with manual design, this algorithm greatly improves design efficiency.]]></description>
<pubDate>2021/10/22 15:42:42</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[金传喜,,,]]></author>
</item>
<item>
<title><![CDATA[Test of mechanical properties of C/SiC composites at elevated temperature in air]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202004200000001]]></link>
<description><![CDATA[To study the mechanical properties of C/SiC composites at elevated temperature air, the compression, bending and tensile properties of C/SiC composites were tested and the microstructure of fractures at different temperatures was analyzed by SEM. The research shows that: When the test temperature vary from room temperature to 1000 ℃, the compressive strength, flexural strength and tensile strength of C/SiC composites decreases respectively from 246.7 MPa to 78 MPa, 480 MPa to 277 MPa and 247 MPa to 152 MPa as the test temperature increases. Even the performance of the compressive strength, flexural strength and tensile strength of C/SiC composites is reduced by 68%, 42% and 38% respectively. As the temperature increases, high temperature oxidation leads to interface degradation and carbon fiber structural damage, which not only aggravates the degree of fiber breakage and damages the material matrix, but also changes the state of fiber-matrix bonding, causing the fiber toughening mechanism to gradually disappear and eventually lead to composite properties decay.]]></description>
<pubDate>2021/10/22 15:39:47</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[陈伟华,李冠姝,马静,王丽燕,王志江,张晗翌]]></author>
</item>
<item>
<title><![CDATA[Research and experimental evaluation of helium inflation calculation methods on the ground of high altitude balloon]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005120000001]]></link>
<description><![CDATA[Near space is currently a hot spot for countries to explore, as one of the platforms that can carry out scientific experiments in this area, high altitude balloon has attracted more and more researchers' attention. The amount of helium used in a balloon is an important issue, it directly affects balloon’s ascent velocity and altitude, and then affects the reliability and stability of the platform. Therefore, it is necessary to research the accurate calculation method of helium. Vertical dynamic model of balloons was established and the theoretical values of initial ascent velocity were calculated. It can be used to compare with the actual initial ascent velocity and provide a basis for evaluating helium inflation calculation methods. Three helium inflation calculation methods of high altitude balloon were summarized, and according to the flight experiments, the accuracy and error range of the three methods were analyzed and compared. The buoyancy compensation law was put forward, and three methods have been evaluated. According to the study of this paper, the existing helium inflation calculation methods can be modified effectively, and then it can provide guidance for future flight experiments.]]></description>
<pubDate>2021/10/22 15:39:07</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杜千仟,王帆,杨燕初,曾丹丹,张航悦]]></author>
</item>
<item>
<title><![CDATA[Experimental Study on Combustion Characteristics of Multi-elements Splash Platelet Injector]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005060000002]]></link>
<description><![CDATA[The combustion characteristics of single-element and multi-elements splash platelet injectors were studied experimental, the effects of different mixing ratios and different structural parameters on combustion chamber pressure and combustion efficiency were obtained, and the heat load of injector faceplate under different working conditions were investigated. The test results show that the mixing ratio has little effect on the pressure in the combustion chamber of the multi-elements injector, but has greater effect on combustion efficiency. For single-element injectors, the combustion efficiency increases with the increase of the mixing ratio, SP1 injector has the highest combustion efficiency, and the heat load of the injector faceplate is also the largest, and the injector faceplate of each injectors have different degrees of deformation or failure. This result is of great significance for correctly guiding the design of the platelet injector and screening the structure of the injector.]]></description>
<pubDate>2021/10/22 15:37:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘伟强,尹 亮]]></author>
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<title><![CDATA[A Review of dynamic characterization research of high power IGBTs and their combinations under multiple time scales]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005200000001]]></link>
<description><![CDATA[Modern large capacity power electronic instruments are hybrid systems with multiple time scales. The core power electronic devices also present complex multiple time scale characteristics. In recent years, with the deepening of the research on power electronic hybrid systems, research on multiple time scale modeling of high-power power electronic devices also gradually arisen. In this paper, based on demand of multiple time scale dynamic characterization of power electronic devices and their combination, the recent research progress and achievements on the widely used full-control power electronic devices—IGBTs, are analyzed systematically. These including the multiple time scales electro-thermal modeling of high power IGBTs and their combinations, quantitative failure evaluation methods based on the multiple time scales model and the assisted multi-rate simulation method. Furthermore, applications of the models are introduced in power electronic instruments design. In conclusion, this paper presents the dynamic characterization method of high power IGBTs and their combinations under multiple time scales from four aspects of modelling method, reliability evaluation, simulation method and application design. These can bring theoretical and technical support of power electronic devices to precise design of power electronic hybrid system.]]></description>
<pubDate>2021/9/26 16:26:11</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[贾英杰,李鑫,刘宾礼,罗毅飞,马伟明,肖飞]]></author>
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<title><![CDATA[Vibration Characteristics of Flexoelectric Timoshenko Nano-beam in Viscoelastic Medium]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202006220000001]]></link>
<description><![CDATA[Based on the Hamiltonian principle and taking nonlocal effect, piezoelectric effect and flexoelectric effect into consideration, the vibration governing equation and corresponding boundary conditions of the Timoshenko nano-beam in the viscoelastic medium are established, and the method of solving the governing equation of flexoelectric nano-beam with simply supported boundary conditions is given. The effects of nonlocal parameters, flexoelectric effect and viscoelastic medium on the vibration characteristics of the flexoelectric nano-beam are systematically studied. The results show that the transverse flexoelectric coefficient   can significantly increase the structural stiffness of the flexoelectric nano-beam, while the nonlocal parameters and the tangential flexoelectric coefficient   can reduce the structural stiffness of the system. In addition, the critical damping coefficient of the viscoelastic medium is obtained. The research results can provide a theoretical basis for the extension and application of flexoelectric nano-beam in energy harvester.]]></description>
<pubDate>2021/9/26 16:10:12</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[雷勇军,吴栋,张大鹏]]></author>
</item>
<item>
<title><![CDATA[Study of common view time comparison by new signal system of BeiDou-3]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202006220000002]]></link>
<description><![CDATA[In order to promote the application of BDS (BeiDou Navigation Satellite System), especially the BDS-3 to join the International Atomic Time (TAI) calculation , BDS-3 common view time comparison was implemented by using the pseudo code measured data of BDS-3 new signal between the National Time Service Center of Chinese Academy of Sciences (NTSC) and the Institute of Photonics and Electronics Academy of Sciences of the Czech Republic (TP). The results show that the signal of multipath noise and Signal-to-noise ratio of BDS-3 is less than that of BDS-2. And compared with previous studies, the noise of common view time comparison based on new BDS-3(B1C&B2a) signal is much better than that BDS-2(B1I&B3I) compatible signal, which is broadcasted by the BDS-3 satellite, and the results are similar to those of GPS and Galileo, the standard deviation of the result based on BDS-3 signal is increased by more than 40% compared with BDS-2 signal. The noise of BDS-3 single common view is smaller than that of BDS-2, and frequency stability of result is increased by more than 10% relative to BDS-2. The experiment can provide research foundation for the BDS-3 application in the TAI calculation.]]></description>
<pubDate>2021/9/26 10:27:25</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[董绍武,广伟,王威雄,袁海波,张继海,赵书红]]></author>
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<title><![CDATA[Application of Vondrak-Cepek combined filtering in the fusion of BeiDou CV and TWSTFT]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202004170000001]]></link>
<description><![CDATA[In order to reduce the diurnal in TWSTFT (two-way satellite time and frequency transfer), based on the fact that there is no diurnal in BeiDou common view link, the Vondrak-Cepek combined filtering was applied to combine BeiDou common view and SATRE (satellite time and ranging equipment)  TWSTFT or SDR (software-defined radio) TWSTFT between NTSC (national time service center), Chinese Academy of Sciences, PTB (physikalisch-technische bundesanstalt) and NIM (national institute of metrology). Two indexes, time deviation and amplitude spectrum, were used to evaluate the gain factors in reducing the diurnal of the fusion results, and the agreement of the two types of links was revealing by taking GPS PPP (precise point positioning) time comparison as reference. The results show that the diurnal of the fusion results is greatly improved after Vondrak-Cepek combined filtering, and the absolute value of the differences between the fusion solutions and GPS PPP solutions is kept within the calibration uncertainty of time link.  For the baseline of NTSC-PTB, the gain factors of 1-day time deviation(TDEV) of fusion results versus SATRE TWSTFT and SDR TWSTFT are 1.85 and 1.81, respectively. For the baseline of NTSC-NIM, the gain factors are 1.69 for SATRE TWSTFT and 1.59 for SDR TWSTFT. The short-term stability of fusion results is significantly improved.]]></description>
<pubDate>2021/9/23 20:35:14</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[董绍武,高  喆,郭  栋,王  翔,王威雄,武文俊]]></author>
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<item>
<title><![CDATA[Ensemble Learning for State Recognition of Payload From Telemetry Data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202004290000001]]></link>
<description><![CDATA[State recognition of payload depends on telemetry data. Further more, with this recognition, accessing to space mission performance fast becomes possible. In order to deal with various problems, such as high dimensionality, diversity, huge volume, unbalanced categories and failure to intuitively make sense about states of payload, in addition considering interpretability in space mission, this paper proposes a general method for fast identification of payload based on information gain and integrated learning method. Sample statistics and information gain is used to select features and reduce the dimension of the telemetry, meanwhile, the integrated learning algorithm is used to complete adaptive recognition and classification about payload states. The proposed method combines the advantages of the parameter classification information evaluation criteria of the information gain and strong modeling, high accuracy and strong anti-noise ability under unbalanced category samples. Also, the model has to be explanatory and is able to find the key parameters. The method was verified by experiments using actual mission data, which was tested using the payload telemetry data on operational scientific satellite mission. Following that, an state-of-art result, which overall recognition accuracy is higher than 90 percent and a few samples can also be identified, covered mission requirement in all and was proved the effectiveness and practicability.]]></description>
<pubDate>2021/9/17 15:22:56</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[董振兴,郭国航,胡钛,李虎,杨甲森]]></author>
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<item>
<title><![CDATA[Study on the evaluation method of the uncertainty of the temperature measurement for meteorological sounding rocket]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202005070000001]]></link>
<description><![CDATA[Based on the temperature correction model of meteorological sounding rocket, through error analysis theory, the method of temperature correction and uncertainty evaluation is studied. According to the law of atmospheric density change during the falling process of rocketsonde, the mathematical model of temperature correction is established, and the formula of temperature correction is deduced. According to the error theory, eight error sources which affect the temperature correction are analyzed, and the expression of temperature correction error is given one by one. Taking one measured data as an example, using the above formula, the uncertainty of temperature inversion of sounding rocket is analyzed and calculated. The results show that the uncertainty of temperature is larger in 50-60km,and the maximum is 3.6K;40-50km is 0.3-0.9K;less than 40km, not more than 0.3K.The main factors that affect the uncertainty of temperature are: aerodynamic heating correction, lag effect correction, structural heat conduction correction, sensor to environmental heat radiation correction. It is not enough to use the reference atmosphere or the standard atmosphere for only single correction in data processing. Iterative correction is needed, and the maximum difference of iterative correction results of single correction results can reach 5.6K.]]></description>
<pubDate>2021/9/17 15:22:41</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[孙宇,,]]></author>
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<item>
<title><![CDATA[Lightweight Optimization of Skinned Purlin Structure in Launch Vehicle Based on Sequential Basis Function]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201908210000001]]></link>
<description><![CDATA[Taking the lightweight optimization of skinned purlin structure in large-scale launch vehicle as the
research background, the post-buckling lightweight optimization of large-diameter and large-loaded skinned purlin
structure is carried out. In order to achieve ultimate bearing capacity of the structure, the post-buckling behavior of
skinned purlin structure is analyzed based on the parametric model established by python code. Considering that
discrete topology and continuous size variables are involved in the lightweight optimization of skinned purlin
structure, sequence approximate optimization method based on the surrogate model and combinatorial optimization
algorithm is proposed. What’s more, approximate optimal solution is used to accelerate algorithm convergence,
which can obtain the final design scheme of skinned purlin structure. The results of engineering examples show that
the sequence approximate optimization method propose in this paper make the weight loss effect of skinned purlin
structure obvious, and verifies the effectiveness of the method.]]></description>
<pubDate>2021/1/12 8:49:42</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[雷勇军,欧阳兴,王斌,王志祥,张大鹏]]></author>
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<title><![CDATA[Stress Concentration Effect Analysis of New Aviation Aluminum Alloy Corrosion Pit with Complex Morphology]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201907260000001]]></link>
<description><![CDATA[Based on simulation accelerared pitting corrosion test results of 7B04 aluminum alloy specimen,combinated with the pitting corrosion mechanisation and microstructure of aluminum alloy and stochastic process essence of pitting corrosion,two typical damage models with complex morphology which were composed of many micro- ellipsoid corrosion pits was erected through finit element method,two models were respectively named wedging model and encircling model.The stress concentration effect which was embodied by stress concentration factor and stress nephogram was caculated and analysed through ANSYS software and linear elastic fracture mechanics,it is deduced that stress concentration effect of wedging model and encircling model were very different from the resuslts of simplified ellipsoid corrosion pits model. Firstly,the stress concentration factor value of wedging model and encircling model is almost same,and becomes bigger because of interference and influence and superposition of each sigle micro- ellipsoid corrosion pits. Secondly, obvious area/location of stress concentration effect of wedging model and encircling model almost locates at the intersection region between each micro-ellipsoidal corrosion pit, the intersection regions almost are on the side of the macro corrosion pits. Thirdly,the size range of wedging model and encircling model stress concentration effect are equivalent with microscopic grain size and small crack size of aluminum alloy.]]></description>
<pubDate>2021/1/11 15:53:15</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[陈川,江帆,李心舒,刘旭,刘治国]]></author>
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<title><![CDATA[Multi-object tracking(MOT) algorithm  for mobile single camera]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201911050000001]]></link>
<description><![CDATA[Aiming at the moving objects in the video sequences collected by the mobile single camera, an online multi-object automatic tracker is focused on research, which is based on the relative motion information and data association strategies. The recovery of the object trajectory is achieved by the relative motion model between the objects, and the object trajectory fragmentation is reduced. The assignment between detection of the current frame and the past trajectories is improved based on the event matching algorithm, which reduces number of identity conversions during tracking. Experimental results show that the improved algorithm is more accurate than the original algorithm in tracking and positioning the object in the sequences, reducing the number of trajectory fragmentation and identity conversion, and our tracker performs state-of-the-art on the TUD-Campus sequence.]]></description>
<pubDate>2020/12/2 10:50:13</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈慧敏,关少杰,李兴玮,吕林珏]]></author>
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<title><![CDATA[A Simplified Deep Learning Model for epilepsy electroencephalogram]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201909240000001]]></link>
<description><![CDATA[The epilepsy electroencephalogram (EEG) recognition is of great value in the diagnosis and treatment of epilepsy, a neurological disease. A simplified deep learning model studies the problem of recognition based on the strong randomness and rapid dynamic change of EEG signals. The proposed model utilizes one-dimensional convolutional neural network, which simplifies the convolutional layers and pooling layers to improve the efficiency. Based on the overall Keras framework, the RMSProp algorithm is used for the model in the training process, and the algorithm estimates the loss through a predefined objective function. The model design incorporates a batch normalization layer and a global mean pooling layer. The EEG recognition is researched from two aspects based on the proposed model: (1) With empirical mode decomposition, the first three orders, the first five orders, the first seven orders, and the first eight orders of intrinsic mode functions are selected for comparative analysis on the simplified model. (2) Because of deep learning characteristics, the proposed model can directly recognize the original EEG signals without the feature extraction. (3) After extracting 7 types of features，it adds three different methods to compare the accuracy. The experimental results show that: (1) the recognition rate of the first three orders of intrinsic mode function reaches 92.1% for the five different types of EEG signals, which is higher than that of other features. The first eight orders’ recognition rate is lower than the original signal, which indicates that data preprocessing will lead to the noise. (2) The proposed simplified deep learning model can effectively deal with the epileptic EEG recognition problem with higher efficiency and better performance.]]></description>
<pubDate>2020/12/2 10:50:01</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈胜,,,魏建好,]]></author>
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<title><![CDATA[Influence of drive control on dynamic characteristics of solar array drive systems]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201908230000001]]></link>
<description><![CDATA[An analysis method for the dynamic characteristics of the solar array drive system (SADS) was modified by considering the effect of drive control. This method was verified via simulation and experiment and used to analyze the influence of drive control parameters such as drive speed and current-loop control gains on the dynamic characteristics of SADS. The results show that the solar array drive assembly (SADA) can still be equivalent to a "torsional spring -viscous damping" boundary condition of the solar array. The drive control has little effect on equivalent damping of SADA, but only weakens the equivalent stiffness of SADA. The torsion-mode natural frequency of SADS is positively correlated with the control gain and negatively correlated with the drive speed. When the drive speed increases, the drive control becomes one of the important factors affecting the dynamic characteristics of SADS.]]></description>
<pubDate>2020/12/2 10:49:48</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭欣,雷勇军,朱仕尧]]></author>
</item>
<item>
<title><![CDATA[Research on Ocean surface Current Retrieval by Along-track Interferometric SAR Based on Genetic Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201907270000001]]></link>
<description><![CDATA[The research on ocean surface current sounding by Along-track Interferometric SAR is an important role in realizing the globalization and refinement of current information. In order to improve the iteration convergence speed and parameter retrieval accuracy of ocean surface current, we transformed the correction coefficient design problem into scale factor selection problem under constraints of the phase difference between the simulated interference phase and the measured phase difference, and radar, and platform parameter, according to the parameter characteristics of the correction coefficient to construct the constraint relation of the fitness function. We design the technical method calculating the correction coefficient by Genetic Algorithm, which is embedded in the iterative retrieval algorithm to construct a new retrieval method. The results of spaceborne SAR data simulation show that the RMSE of current direction is better than 5.0°,and the RMSE of current velocity is better than 0.05m/s, and the retrieval current and real current is a high compliance. The improved ocean surface current retrieval algorithm effectively reduces the iteration numbers and improves retrieval efficiency. The research is of great significance to improve the effectiveness and accuracy of ocean surface current sounding by Along-track Interferometric SAR.]]></description>
<pubDate>2020/12/2 10:49:20</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[陆文,王蕊,严卫,赵现斌]]></author>
</item>
<item>
<title><![CDATA[A reliability analysis approach based on Kriging and advanced first order second moment method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201906150000001]]></link>
<description><![CDATA[For the problem of structural reliability analysis, a method of solving failure probability based on the Kriging and advanced first order second moment (AFOSM) is proposed. The traditional Advance first order second moment calculation requires the gradient information of the structural limit state function, it is difficult especially when it deals with the implicit limit state function problem involving the finite element model. The proposed approach combines Kriging method and AFOSM iteration effectively and fully. Kriging method provides the gradient information of limit state function with Kriging method, so as to overcome the difficulty of the derivation solution and improve the analysis efficiency of AFOSM. Finally, numerical and engineering examples verify the efficiency and feasibility of the proposed method.]]></description>
<pubDate>2020/12/2 10:49:06</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[顾健,孔冲冲,袁修开]]></author>
</item>
<item>
<title><![CDATA[Thermo-electro-mechanical vibration analysis of piezoelectric nanobeams embedded in viscoelastic medium based on nonlocal elasticity theory]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201906030000001]]></link>
<description><![CDATA[Based on the nonlocal elasticity theory and Hamilton's principle, the model for thermo-electro-mechanical vibration analysis is developed for a piezoelectric nanobeam embedded in viscoelastic medium. Governing equations of motion and boundary conditions for vibration analysis are derived where thermo-electro-mechanical loadings, viscoelastic foundation, nonlocal effect and piezoelectric effect are considered simultaneously. The transfer function method is employed to obtain the natural frequencies in closed form for the nanobeam with various boundary conditions. A detailed parametric study is also carried out for the effects of nonlocal parameter, boundary conditions and viscoelastic foundation on the vibration of nanobeams. The study demonstrates the efficiency and robustness of the developed model for vibration analysis of a complicated multi-physics system comprising nonlocal piezoelectric nanobeams, viscoelastic foundation and thermo-electro-mechanical loadings.]]></description>
<pubDate>2020/12/2 10:48:47</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[雷勇军,]]></author>
</item>
<item>
<title><![CDATA[Holonic-C2 Organization Decision-Making Allocation and Evolution Method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201906010000001]]></link>
<description><![CDATA[In order to effectively play the decision-making advantage of C2 organization"s centralized decision-making and collaborative decision-making, the decision-making assignment problem of Holonic-C2 organization with dynamic ability of decision-making authority is studied. In view of the shortcomings of the subjectiveness of expert fixed weights in group decision making, we propose an expert group selection method based on the combination of expert authority and opinion consistency. This method improves the objective rationality of multi-attribute decision making. In view of the dynamic evolution of decision-making allocation, we propose a decision-making evolution mechanism based on multi-stage decision making. The change of attributes in the front and back stages is considered in this method, and the decision mode transition mode in the adjacent stage is given. The simulation results show that the proposed method can give the ranking of the relatively objective decision-making modes and the multi-stage evolutionary route, which proves the feasibility and effectiveness of the method.]]></description>
<pubDate>2020/12/2 10:48:32</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[焦志强,万路军,王 勋,张杰勇]]></author>
</item>
<item>
<title><![CDATA[Attitude determination of CubeSat based on gyro/double star sensors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201905290000001]]></link>
<description><![CDATA[To solve the problem that the measurement precision of the rotation angle about line-of-sight vector of single star sensor is relatively low, a method of utilizing measurement from MEMS gyro and two simultaneously operating star sensors to obtain accurate attitude knowledge of CubeSat was proposed. Based on the idea of averaging two quaternions, two attitude determination schemes called centralized filter and decentralized filter were drawn up by using MEKF. The simulation results indicate that attitude determination performance is improved effectively by the presented method and it has higher precision and quicker convergence, under the circumstance of utilizing low-cost and low-accuracy attitude sensors and traditional attitude filtering algorithm. It provides a feasible reference for low-cost and high-precision attitude determination of CubeSat, and has certain engineering application value.]]></description>
<pubDate>2020/12/2 10:48:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[廖文和,陆正亮,马海宁,张翔]]></author>
</item>
<item>
<title><![CDATA[Triple-frequency kinematic-to-kinematic ambiguity resolution with BDS/INS tightly-coupled integration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201905150000002]]></link>
<description><![CDATA[Aiming at the problem that when pseudorange observation noise is high, the ambiguity calculation of TCAR method is unreliable in the condition of kinematic-to-kinematic, a triple-frequency kinematic-to-kinematic ambiguity resolution with BDS/INS tightly-coupled integration is proposed. Replacing the double-difference pseudorange observations in GF and GB patterns with the double-difference geometry distances estimated by the tightly-coupled integration system,  which obviously decreased the noise level of the pseudorange double-difference observations and improved the success rate of triple-frequency ambiguity calculation. Simulation results show that , the high-precision position output of BDS/INS tightly-coupled integration improved the accuracy of pseudorange observations by 60%. In short-baseline condition, when the pseudorange observation noise is 2m, the success rate of triple-frequency integer ambiguity calculation by GF-TCAR is 0.73% while 31.25% by GB-TCAR. However, the integer ambiguity calculation success rate by the new TCAR method is beyond 99% . And this new solution can achieve centimeter-level kinematic-to-kinematic relative positioning.]]></description>
<pubDate>2020/12/2 10:47:35</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[高玉洁,庞春雷,张良,赵修斌,朱楚江]]></author>
</item>
<item>
<title><![CDATA[LS-SVM for Solving Reflection Model of Submarine’s Internal and External Magnetic Field]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201905120000001]]></link>
<description><![CDATA[For the promotion of submarine’s magnetic silencing ability, it is necessary to monitor the submarine’s permanent magnetic field immediately, and a reflection method of submarine’s internal and external magnetic field based on LS-SVM(Least Squares Support Vector Machine) is proposed. Combined with internal and external reflection method and LS-SVM theory, an inside-out reflection model of submarine’s magnetic field is established by optimizing the model parameter with CV (Cross Validation). With the variation in the vertical component of the submarine’s external permanent magnetic field as an object of analysis, the extrapolation answers of simulation and hull experiment agree well with the standard value. Compared to the RBFNN (Radius Basis Function Neural Network), proposed method has better generalization ability and extrapolation accuracy apparently, fit more in engineering facts, and can provide useful guidance in the research for closed-loop degaussing technology.]]></description>
<pubDate>2020/12/2 10:47:23</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[何保委,刘胜道,赵文春,周国华]]></author>
</item>
<item>
<title><![CDATA[GNSS Ionospheric Tomography with the Unequal Pixel Size Considering the Geomagnetic Effect]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904230000002]]></link>
<description><![CDATA[In previous studies, traditional GNSS (Global Navigation Satellite System) ionospheric tomographic methods neglect the influence of geomagnetic field on the ionospheric variations. In this contribution, a new GNSS tomographic algorithm with the unequal pixel size in the height is proposed to image the ionosphere in the geomagnetic coordinate, which takes the influence of electron density variation at different ionospheric heights and the geomagnetic field into account. Also, a new iterative relaxation factor is established in the proposed GNSS tomographic algorithm to improve the accuracy of the ionospheric electron densities. The performance of GNSS ionospheric tomographic method with unequal pixel size considering geomagnetic effects is evaluated using the IRI-2007 (International Reference Ionosphere 2007) model, GNSS measured data, and ionosonde data. For simulation studies, IRI-2007 is used as references. For GNSS data, the ionosonde data are used as references. The peak ionospheric electron density error, the average absolute percentage error of electron density profile results and the root mean square error are estimated by different GNSS tomographic algorithms. The validity of the tomographic algorithm with the unequal pixel sizes considering the geomagnetic effects is verified.]]></description>
<pubDate>2020/12/2 10:47:07</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[霍星亮,刘昊杰,刘琦]]></author>
</item>
<item>
<title><![CDATA[Experimental and numerical study on propeller induced vibration of underwater hull]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904180000002]]></link>
<description><![CDATA[To consider real excitation characteristics of propeller,measurement experiment of stern fluctuating pressure and underwater hull vibration response induced by propeller in stern wake field was conducted in circulating water channel．The experiment results show that the fluctuating pressure has the maximum amplitude at blade-passing frequency(BPF),increases with propeller load and decreases with distance to propeller；four-blade-propeller has larger amplitude at high wake region after rudders while five-blade-propeller at low wake region between rudders；vibration response amplitude at most of the monitor points increases with propeller load,but there are cases that have less amplitude at BPF and no increase with propeller load；five-blade-propeller induced lateral vibration increases while axis vibration decreases compared with four-blade-propeller；vibration response amplitude at specific peak frequency presents the 1st order bending mode,whose frequency range relatively agrees with numerical result of finite element method．CFD,finite element and modal superposition method were combined to establish a numerical method to evaluate propeller induced vibration response of underwater hull．The comparison between numerical and experiment results illustrates that the numerical results provide a good agreement with experiment results and are closer to reality than harmonic response analysis method which uses unit harmonic excitation．]]></description>
<pubDate>2020/12/2 10:46:53</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[徐野]]></author>
</item>
<item>
<title><![CDATA[Algorithm of triangle star identification based on radial feature]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904180000001]]></link>
<description><![CDATA[Triangle star identification has strong reliability and operability, and is still widely used at present. But triangle star identification needs to traverse the navigation star, which is computationally intensive and low in identification efficiency. The radial feature quantity of the star point is constructed by the geometric distribution of the star point. And the star point is initially identified, the navigation star corresponding to the star point is limited to several navigation stars by initial recognition. On the basis of initial identification, the triangle segmentation identification algorithm is used to identify the initial recognition result again, which will improve the pertinence and efficiency of star map identification. The experimental results show that when the new algorithm is used to identify the stars, the accuracy and rapidity of star identification are improved.]]></description>
<pubDate>2020/12/2 10:46:39</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[常振军,刘先一,张志利,周召发]]></author>
</item>
<item>
<title><![CDATA[Improved FAHP-neural network health evaluation method for electromagnetic launch system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904160000003]]></link>
<description><![CDATA[It is of great significance to accurately and quantitatively evaluate the health status of electromagnetic emission system before launch. Firstly, this paper focuses on the large deviation of health value in evaluating the serial structure of electromagnetic emission system when applying the FAHP method, and which fails to meet the requirement of nonlinear variable weight of the system, and an improved health assessment method is proposed. The improved method can be calculated by constructing a nonlinear function that can satisfy the serial structure health assessment when calculating the health index of the same-level elements. The neural network model is introduced to solve the nonlinear variable weight requirement of system health evaluation. An improved health evaluation model based on the PFN pulse network system of an electromagnetic launch system is established and evaluation experiments are carried out. The results show that the proposed evaluation method has high assessment accuracy, and the results are in line with the actual health status of the system under various health conditions. Compared with the traditional FAHP method, the proposed improved method has greatly improved the accuracy of evaluation, and there will be no error and leakage, which verified the feasibility and practicability of the method.]]></description>
<pubDate>2020/12/2 10:46:28</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[鲁军勇,曾德林,郑宇锋]]></author>
</item>
<item>
<title><![CDATA[Radar Emitter Recognition method Based on the Deep learning of Time-frequency feature]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904160000002]]></link>
<description><![CDATA[Aiming at the problem of insufficient expansion ability and low recognition rate in radar emitter recognition, an intelligent recognition algorithm based on the deep learning of time-frequency feature is proposed. Firstly, the shallow two-dimensional time-frequency features with high recognition and stability are quickly extracted by down sampling of short-time Fourier transform (DS-STFT), and the noise reduction and other pre-processing are completed by using the sparseness of the local frequency-domain signal. Then, a convolutional neural network (CNN) for deep feature learning and recognition is designed, and the scale of the network is expanded by different scale convolution kernels to enhance the feature representation ability. Finally, the network is trained and tuned by using eight kinds of emitter signals under high SNR conditions, and the effectiveness of the algorithm and network is verified by low SNR sample. The experimental results show that the system achieves overall recognition rate of 98.31% at SNR of -8dB, which has strong robustness.]]></description>
<pubDate>2020/12/2 10:46:15</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李东瑾]]></author>
</item>
<item>
<title><![CDATA[Sensitive feature extraction method based on referenced manifold spatial fusion learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904040000001]]></link>
<description><![CDATA[Aiming at the problem of low recognition rate of heterogeneous patterns caused by the characteristics of small sample size, strong impact, short response period and wide resonance frequency bandwidth of telemetry vibration signals, a method for sensitive feature extraction and anomaly detection of telemetry vibration signal based on referenced manifold spatial fusion learning is proposed. Firstly, the multi-scale analysis method is used to decompose the signals orthogonally into each in the scale band; the multi-scale feature is extracted to construct the high-dimensional feature set. Then, the same normal signal sample is combined with the same type of abnormal sample to establish the exclusive reference model unit, and the linear manifold learning is used to obtain the multi-scale manifold feature difference of each reference model unit to enhance the sensitivity of anomalous features. The projection matrix of each reference model unit is used to enhance the original feature set and obtain the low- dimensional multi-scale sensitive manifold feature. Finally, the input to the classifier is used to realize the state recognition of the unknown sample. The measured signal processing results verify the effectiveness of the algorithm.]]></description>
<pubDate>2020/12/2 10:45:32</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李冬,刘学,孙翱]]></author>
</item>
<item>
<title><![CDATA[Review of multi-modal image matching assisted inertial navigation positioning technology for unmanned aerial vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201912270000002]]></link>
<description><![CDATA[High-precision positioning and navigation in GPS denied environments is a key technology for aircraft achieving autonomous scout, cruise, and strike. Vision navigation has the advantages of passive-type, low cost, and accumulated errors avoidable, etc. the fusion of vision and inertial navigation can give full play to their advantages and achieve the purpose of high-precision positioning. In this paper, we firstly summarize the development of aircraft positioning technology based on multi-modal image matching assisted inertial navigation. Then we elaborated this technology from five aspects: the vision-internal calibration, multi-modal image matching, attitude algorithm, data fusion, and back-end optimization. Finally, we propose four possible future directions, such as two types of passive positioning combined navigation systems based on deep learning, multi-modal image matching and inertial navigation. The four possible future directions provide a reference for realizing multi-modal image matching assisted inertial navigation aircraft positioning technology.]]></description>
<pubDate>2020/12/2 10:44:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[胡茂青,,]]></author>
</item>
<item>
<title><![CDATA[Manned Lunar Mission Planning based on Once LEO and Twice LLO Rendezvous and Dockings]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201908190000001]]></link>
<description><![CDATA[Aiming at the complex problem of matching flight windows and orbits connection due to the multiple flight stages, long duration and complicated constraints of the manned lunar mission based on once low earth orbit (LEO) and twice low lunar orbit (LLO) rendezvous and dockings (RVDs), a design strategy of connecting the full-mission nominal flight windows and orbits with the combining layered decomposition and the forward and reverse design approach are proposed. This paper introduces the characteristics and application prospect of the manned lunar mission based on once LEO and twice LLO RVDs, and supposes the basic mission requirements and engineering constraints. The effectiveness of the proposed method is verified by simulation. The nominal flight orbital elements and windows of the manned lunar mission based on once LEO and twice LLO RVDs can be responded rapidly.]]></description>
<pubDate>2020/12/2 10:44:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[贺波勇]]></author>
</item>
<item>
<title><![CDATA[Fault Tolerance in HPC Scientific Workflow Application]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201909210000001]]></link>
<description><![CDATA[Scientific workflow technologies in HPC are extensively applied in scientific research and engineering simulation domain. Application such as numerical simulation in complex multi-physics problems and multi-stages data process need many soft wares to compose an automatic executable workflow to increase the efficiency. There are lots of exceptions such as resource failure, task configurations errors which may cause the workflow execution to be ceased, therefore robust and continuous execution is important for workflow application. In this paper we make a taxonomy of fault tolerance in workflow and review some fault tolerance techniques in typical workflow systems. We propose a decision-tree based event-condition-action fault tolerance model, and design a non-intrusive extendable framework which was implemented in our HPC scientific workflow system HSWAP. Runtime configurable error recovery strategies were also implemented in our fault tolerance software module. In order to validate our new model and framework, fault tolerance functions were tested in real engineering simulation project. Results show that fault tolerance plays an important role in increasing workflow execution efficiency.]]></description>
<pubDate>2020/12/2 10:42:48</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[段博文,李于锋,莫则尧,肖永浩,赵士操]]></author>
</item>
<item>
<title><![CDATA[Research on the design rationale of the shift parameter in the nonlinear component of NORX]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903260000003]]></link>
<description><![CDATA[NORX is one of fifteen candidates which were selected as the third round ones in the Competition for Authenticated Encryption: Security, Applicability, and Robustness (CAESAR), its only nonlinear component is made up of XOR, AND and shift operations. The design rationale of the shift parameter was studied from nonlinear approximation and rotational properties. On the one hand, it was proved that the approximation probability of the variable shift function is three-valued corresponded to the shift parameter. Moreover, the function could have the best nonlinear property when the shift parameter takes 1. On the other hand,  the rotational probability of the variable shift function could be shown, and it was proved that all of the maximal rotational probability are the same no matter what the nonzero shift parameter is. Taking the above results into consideration, it could have the best nonlinear approximation and rotational properties when the shift parameter takes 1 in the NORX. These results could be applied to analyze the security of NORX and give some guidance when designing the similar ciphers.]]></description>
<pubDate>2020/10/15 9:30:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[何俊,沈璇]]></author>
</item>
<item>
<title><![CDATA[A Recomputation and Correction Mechanism Design for Tagged Instructions of the RISC-V Core]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904110000001]]></link>
<description><![CDATA[The reliability of the computer system is significantly compromised by the hardware transient faults which are mainly caused by the cosmic radiation and other environmental factors. To mitigate this undesirable impact and guarantee the correctness of the running programs, this paper proposes a recomputation and correction mechanism for tagged instructions for an open source core named “Humming bird e203”, which is based on the RISC-V instruction set architecture. This mechanism adds extra flag bits for each instruction and thus enables flexible recomputation for any tagged instruction at low hardware cost. Besides, it can issue the tagged instruction again automatically if the result of the first recomputation is different from the original one. This majority voting scheme efficiently rectifies most data flow errors caused by transient hardware faults. The experimental results show that with our proposal and the interrupt handler，the average probability at which programs can complete correctly increases by 86.67% under the random transient fault insertion.]]></description>
<pubDate>2020/10/4 11:23:01</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[邓丁,]]></author>
</item>
<item>
<title><![CDATA[Fault-tolerant federated filtering algorithm based on vector assignment in integrated navigation system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201902250000002]]></link>
<description><![CDATA[Aiming at the problem that the navigation accuracy of integrated navigation system of aircraft decreases due to uncertain faults in high dynamic environment, a fault-tolerant federated filtering algorithm based on vector information assignment is proposed. The fault detection function in vector form is designed to determine the fault degree of each observation, which overcomes the disadvantage of isolating all the observations of the fault subsystem at the same time. According to whether the observations are abnormal, the variable measurement noise matrix and information distribution vector coefficient are reconstructed to distribute the information among the state variables of the sub-filter. While isolating the abnormal observation of the fault subsystem, the correct observation information is utilized to the maximum extent. The simulation results show that the algorithm can give full play to the advantages of each navigation subsystem, greatly improve the utilization rate of navigation subsystem information, and has high accuracy and fault tolerance.]]></description>
<pubDate>2020/9/2 11:11:31</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[何广军,康旭超]]></author>
</item>
<item>
<title><![CDATA[Prediction of creep performance for multiple launch rocket canister under long-term storage]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903050000002]]></link>
<description><![CDATA[In order to investigate the creep performance of multi-barrel rocket weapon launch canister under long-term storage, uniaxial tensile creep test was carried out on composite laminate and the creep constitutive model parameters of single layer in the main directions were obtained. Finite element method and the user-defined material subroutine are used to establish long-term storage numerical analysis model of launch canister. Creep deformation of the bottom launch canister after 15 years storage was predicted. Taking the stored launch canister as initial state, the dynamic simulation model of rocket-tube coupling was built, and the influence of creep on rocket launching process was further investigated. The simulation results show that the change of the parallelism of the director and the flatness of the bottom surface of launch canister caused by creep are smaller than the specified values of technical indicators. The maximum residual deformation of director bundle is saddle-shaped in three-dimensional space, and the deformations of the middle position directors for upper and lower rows are largest, while that of the middle position directors for left and right columns are smallest. Creep deformation of the director reduces the clearance between rocket and director, increases the dynamic contact collision force and decreases the off-track velocity of rocket.]]></description>
<pubDate>2020/9/2 11:11:26</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[秦予铮,孙同生,王琪,于存贵]]></author>
</item>
<item>
<title><![CDATA[Research on Interference Suppression  Generative Adversarial Nets]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903070000001]]></link>
<description><![CDATA[In order to improve the communication quality of the extremely-low-frequency(ELF) communication further, based on the traditional improved generalized sidelobe cancellation, a new interference suppression algorithm in the field of ELF communication called generative sidelobe cancellation algorithm is proposed. And generative adversarial nets as one of the hot research topics in artificial intelligence is introduced into generalized sidelobe cancellation, the network structure and relevant hyperparameters of the generative model are designed and optimized, addressing the problem of the residual desired signal existing into the original algorithm effectively, providing more relevant reference information about the interference components in the main channel for the next-stage filtering algorithm of sidelobe cancellation channel, thereby enhancing the estimation accuracy of the interference components in the main channel. In order to validate the effectiveness of the optimized generative model and the suppression ability of the proposed algorithm on different types of interferences, an experimental platform is set up under the laboratory environment and multiple sets of controlled experiments are designed. The experimental results show that the optimized generative model has better generative ability, better robustness and relatively lower computational complexity. Comparing with the traditional improved algorithm, the proposed algorithm improves the signal-to-interference-plus-noise ratio within the signal bandwidth further.]]></description>
<pubDate>2020/9/2 11:11:21</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李春腾,,]]></author>
</item>
<item>
<title><![CDATA[The Cu-based Diamond-like Carbon Film with the High Adhesion Prepared by Pulsed Laser Deposition]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903070000002]]></link>
<description><![CDATA[Improvement for the adhesive property of the DLC film on the protected substrate has obvious value in the actual application, and the reason for the validity of the Cu-based multi-layer DLC film designed in our former research was analyzed in the view of the micro-theory. Then, in order to optimize the structure of the multi-layer film and improve its performance in the practical application, the influences of the thickness ratio between the DLC layer vs. SiC layer in the periodic layer on the adhesion property, nano-hardness and wear property was studied. The results of the nano-scratch and nano-indentation tests showed that the adhesive property and nano-hardness of the Cu-based multi-layer DLC film decreased and increased, respectively, when the thickness ratio increased. Critical load of the multi-layer DLC film on the Cu substrate could approach that of the single-layer DLC film with the thickness of 400nm on the Si substrate, when the thickness ratio was below 2.3. Meanwhile, the wear property of the Cu-based multi-layer DLC film approached that of the pure DLC film.]]></description>
<pubDate>2020/9/2 11:11:13</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[曹海源,程勇,黄国俊,陆益敏,米朝伟,王赛,奚琳]]></author>
</item>
<item>
<title><![CDATA[Design of a radial line continuous transverse stub (CTS) antenna for high-power microwave applications]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903120000001]]></link>
<description><![CDATA[In order to realize directly radiating of Ku-band high power microwave (HPM), a radial line continuous transverse stub antenna (RL-CTSA) is proposed in this paper. The antenna is fed by circularly polarized coaxial TE11 mode and radiated by a concentric continuous transverse stub (CTS) array after the wave propagation through a double-layered radial line waveguide. The interspace between adjacent stubs along radial direction is equal to one guide wavelength (λg), a shorting pin is located at the end of the upper radial line waveguide and the space between the pin’s surface and the innermost CTS radiator’s center is λg/2. As a result, the HPM-RL-CTSA works on standing wave. An antenna prototype with a height of 8 cm and an aperture radius of 30 cm operating at 14.25 GHz has been designed, which has a gain of 35.3 dB, reaching an aperture efficiency of 47%. The reflectance of this antenna is less than -25 dB and the radiation efficiency is more than 99.0%. The simulated results indicate that this antenna has a power handing capacity of more than 1 GW.]]></description>
<pubDate>2020/9/2 11:11:08</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[贺军涛,孙云飞,袁成卫,张强,张泽海]]></author>
</item>
<item>
<title><![CDATA[Integrated radar and communication signals  based on TDS-OFDM]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903180000001]]></link>
<description><![CDATA[In the integrated radar and communication system (IRCS) which using Orthogonal Frequency Division Multiplexing (OFDM) signals, cyclic prefix (CP) and pilots lead to the problem of high peak to side lobe (PSL) level in autocorrelation operation, which deteriorates the radar detection performance seriously. To solve this problem, a new RadCom signal based on time domain synchronization OFDM(TDS-OFDM) was proposed. TDS-OFDM adopts training sequence (TS) for guard interval, as well as synchronization and channel estimation, so that CP and pilots can be avoided. First, ambiguity function of TDS-OFDM RadCom signal was analyzed. And then, TS are optimized to suppress the range side lobe of TDS-OFDM signal and maintain the autocorrelation properties of TS simultaneously. Theoretical derivation and simulation results show that, TDS-OFDM signals are more suitable than CP-OFDM signals for IRCS.]]></description>
<pubDate>2020/9/2 11:11:03</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[左家骏]]></author>
</item>
<item>
<title><![CDATA[Analysis of electric field in seawater influenced by conductivity and shape of the object]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903190000003]]></link>
<description><![CDATA[Electric field measurements in seawater will affect the target electric field. In order to improve the accuracy of the electric field measurement, the influence factors of the object on distribution of the electric field in seawater are studied by the finite element method, and the distribution law of the distortion electric field is determined. The simulation results show that the magnitude of the distortion peak and the distortion area are affected by the conductivity and shape of the object. When the conductivity of the object is smaller or larger than that of the seawater, the effect on the electric field distribution is opposite. The larger the curvature of the object is, the larger the peak value of the distortion is, but the smaller the distortion area is.]]></description>
<pubDate>2020/9/2 11:10:59</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[嵇斗,王立祝,张建春]]></author>
</item>
<item>
<title><![CDATA[A Segmented Variable-step-size LMS Algorithm Based on Normal Distribution Curve]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903200000001]]></link>
<description><![CDATA[Traditional LMS adaptive filtering algorithm is always in a contradiction state because it has a fixed step size and resolves the relationship between steady-state error and convergence. To solve this problem, based on the analysis of the traditional fixed-step LMS adaptive filter algorithm, according to the step-size adjustment principle of the variable-step LMS adaptive filter algorithm algorithm, by constructing the nonlinear function of the step-size factor and the error signal, A Segmented variable step size LMS adaptive filtering algorithm based on the normal distribution curve is proposed, and the influence of the parameter value on the performance of the algorithm is analyzed. Aiming at the problem of difficult selection of reference signal in actual signal processing, a method of reference signal selection based on splitting array is proposed. The theoretical and sea trial data analysis results show that the convergence speed and steady-state error of the proposed algorithm are obviously better than the fixed-step LMS adaptive filtering algorithm and the variable step size LMS adaptive filtering algorithm (SVS-LMS) based on the Sigmoid function.]]></description>
<pubDate>2020/9/2 11:10:54</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[马凯,王平波,武彩]]></author>
</item>
<item>
<title><![CDATA[Intelligent routing strategy for software-defined satellite network based on Chebyshev neural network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903260000002]]></link>
<description><![CDATA[In the existing software-defined satellite network, the storage space of Ternary Content Addressable Memory occupied by the flow table is increasing, complex flow entry lookup and matching processes result in reduced route forwarding efficiency, which cannot meet the requirements of diverse application requirements. This paper proposes a neural network-based Software-defined satellite network intelligent routing framework. The controller acquires the transmission mode of the data flow by training the neural network, and replaces the flow table with the trained neural network. Based on this framework, an intelligent routing strategy based on chebyshev neural network is proposed. The switch predicts the forwarding path of data flow according to the service type of data flow to meet the QoS requirements of satellite network applications. The simulation results show that the proposed routing strategy significantly reduces the occupied storage space of Ternary Content Addressable Memory and improves the routing efficiency.]]></description>
<pubDate>2020/9/2 11:10:49</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[孙伟超]]></author>
</item>
<item>
<title><![CDATA[Directional-of-arrival estimation based on the sparse representation of array covariance matrix]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903280000001]]></link>
<description><![CDATA[In order to improve the efficiency of conventional directional-of-arrival (DOA) estimation methods based on the sparse representation of array covariance, an efficient DOA estimation method relying on the direct 2-D sparse reconstruction was proposed. In this method, the 2-D sparse reconstruction model was constructed using the array covariance matrix. By applying the eigenvalue decomposition, the noise power can be estimated and the influence of noise on DOA estimation can thus be reduced. When solving the 2-D sparse reconstruction problem, the 2-D smoothed L0 norm (2D-SL0) algorithm was used, which could deal with the 2-D data directly, free of matrix vectorization operation. Simulation results show that the efficiency of the proposed method could be improved significantly, and the performance of the proposed method is better than traditional methods under the conditions of low snapshot, low SNR and sparse array sensors, etc.]]></description>
<pubDate>2020/9/2 11:10:45</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[包长春,邱伟]]></author>
</item>
<item>
<title><![CDATA[Analysis of uniqueness and optimality of glide segment initial state for hypersonic glide vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904020000002]]></link>
<description><![CDATA[The trajectory characteristics of the near-space hypersonic glide vehicle are mainly affected by the initial state of glide segment and control law of the vehicle. The influence of glide segment initial state on trajectory characteristics of hypersonic glide vehicle are studied under the condition that the control law of vehicle is determined. According to the different forms of glide trajectory, under the condition of longitudinal equilibrium glide, the analytical formula of the vehicle state variable is derived theoretically, and the uniqueness of initial state of the equilibrium glide trajectory is analyzed in combination with the equilibrium glide condition. Under the condition of longitudinal skip glide, the evaluation indices of trajectory performance are constructed, and the initial state of glide segment with optimal trajectory performance is found by using the group intelligence algorithm. The uniqueness of the initial state of longitudinal equilibrium glide trajectory is proved by theoretical derivation, and the initial state corresponding to the optimal trajectory performance of longitudinal skip glide trajectory is obtained by using the particle swarm optimization algorithm. Using the method of single factor sensitivity analysis, the sensitivity analysis of the initial states of two forms of glide trajectory is carried out, and the initial velocity of initial state has the greatest influence on the trajectory characteristics. The analysis of the uniqueness and optimality of initial state can be used for reference in the trajectory design, trajectory tracking, trajectory prediction and trajectory optimization of hypersonic glide vehicle.]]></description>
<pubDate>2020/9/2 11:10:38</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[孟繁卿,田康生]]></author>
</item>
<item>
<title><![CDATA[Improvement of planar nearfield acoustic holography under the combined action of moving fluid medium and shear layer]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904110000002]]></link>
<description><![CDATA[Traditional planar nearfield acoustic holography places the hologram inside the jet. In order to reduce the adverse effect of window effect and wraparound error on reconstruction accuracy, it is generally required that the hologram size is more than twice that of the sound source, while larger microphone array placed inside the jet will interfere with the stability of the jet. To solve this problem, it is proposed to place the entire hologram outside the jet. According to the classical shear layer correction theory, the change of path and amplitude of sound wave propagating from sound source to hologram is analyzed. Then the modified sound field propagation formula is derived. Finally, the theoretical model of planar nearfield acoustic holography under the combined action of moving fluid medium with the Mach number below 0.3 and shear layer is established. Numerical simulations show that the improved planar nearfield acoustic holography leads to reconstructed acoustic fields of high resolution, with high localization accuracy of aerodynamic noise source and certain anti-interference ability.]]></description>
<pubDate>2020/9/2 11:10:33</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[蒋伟康,田章福,曾新吾,赵云,周鹤峰]]></author>
</item>
<item>
<title><![CDATA[Research on Temperature of Electromagnetic Launcher Based on Grey Model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904130000001]]></link>
<description><![CDATA[During the electromagnetic launch process, the temperature of the rail is affected by many factors and it is difficult to analyze some factors accurately. Based on this, the gray system is used to study the temperature of the electromagnetic launcher. In order to obtain the experimental data needed for the gray model, the electromagnetic launcher data collection system is built, and the current, the rail temperature, the launch speed and other data are collected. Due to the limitations of measuring instruments, this paper uses ANSYS finite-element simulation to correct the measured rail temperature data to obtain the inner surface temperature of the rail. Based on the classical Gray Modal (1,N) and Simpson formula, an improved gray model is proposed, and the rail temperature is studied by this method. The same energy level test is conducted to discuss the contribution of temperature rise of various factors at different locations. The conclusion provides a reference and basis for further research on the temperature of the rail.]]></description>
<pubDate>2020/9/2 11:10:28</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[程龙,李松乘,鲁军勇,吴羿廷]]></author>
</item>
<item>
<title><![CDATA[Energy absorption mechanism of filament wound composite sandwich cylinder under impact load]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904150000001]]></link>
<description><![CDATA[The numerical simulation analysis and experimental test verification are carried out for the energy absorbing element by using ABAQUS finite element software and hopkinson bar testing machine in order to investigate the damage modes and energy dissipation mechanism under high strain rate impact compression load. The analysis of the mechanical response characteristics and damage modes show that the energy absorbing element have typical elastic-plastic response characteristics under high rate impact compression loading. The compressive plastic damage come to occur and tensile breaking of hoop fibers is caused by the transverse expansion effect of buoyancy core. The results have shown that this type of energy absorbing element has excellent compression and energy absorption characteristics, and can realize the impact protection and buoyancy reserve requirements of the underwater structure platform.]]></description>
<pubDate>2020/9/2 11:10:23</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[梅志远,张焱冰,周晓松]]></author>
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<item>
<title><![CDATA[Robust Information Fusion Method in SINS/DVL/AST Underwater Integrated Navigation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904150000002]]></link>
<description><![CDATA[Strapdown inertial navigation system (SINS) has become the main navigation and positioning method for long voyage and long-endurance underwater navigation. In order to solve the problem that velocity information provided by doppler velocity log (DVL) and position information provided by acoustic single transponder (AST) are easily contaminated by non-Gaussian noise, this paper proposes a federated robust Kalman filter (FRKF) algorithm. In the proposed method, the mahalanobis distance (MD) algorithm is used to introduce a inflated factor to inflate the measurement noise covariance, which will improve the robustness of integrated navigation system. At the same time, the information distribution coefficient is adaptively tuned based on the performance of the sub-filter, which will guarantee the accuracy of integrated navigation system. The semi-physical simulation test for underwater integrated navigation is carried out by the FRKF and traditional FKF (TFKF) based on measured data of the river test. The experiment results demonstrate that the FRKF has good performance of underwater integrated navigation compared with the TFKF under the non-Gaussian condition and it can meet the requirements of fault tolerance and robustness for underwater integrated navigation system.]]></description>
<pubDate>2020/9/2 11:10:17</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[朱兵]]></author>
</item>
<item>
<title><![CDATA[Planar Array Pattern Synthesis of Wideband Real Time Delay Based on Particle Swarm Optimization Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201904150000003]]></link>
<description><![CDATA[For the problem of the pattern synthesis for planar array with large elements spacing, planar array pattern synthesis method of wideband real time delay based on particle swarm optimization algorithm is proposed. In this method, according to the characteristic that main lobe orientation is independent of the signal frequency and the grating lobes orientation changes with the change of the signal frequency under the condition of real time delay, the wideband real time delay is adopted to suppress the grating lobe of pattern. Then, the structure of array is optimized by particle swarm optimization algorithm, obtain the pattern with higher main-side-ratio. Finally, the effective is indicated by the simulation for 8×8 rectangular planar array. On the basis of it, the relationship between the grating lobe suppression performance and the signal bandwidth is simulation studied.]]></description>
<pubDate>2020/9/2 11:09:54</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[丛雯珊,杜鹏飞,罗雄,杨海达,余岚]]></author>
</item>
<item>
<title><![CDATA[A Two-level Heuristic Approach for the Production Routing Decisions of Equipment Maintenance Material]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201905080000001]]></link>
<description><![CDATA[Aiming at the shortage and backlog of equipment maintenance material, and the inefficiency of equipment distribution system in the current equipment supply system, integrated optimization of production, inventory and distribution operational links is a critical need. In order to reflect each decision link, the problem was formulated as a MILP with multivariable and multiple constraints. A two-level mathematical-programming-based heuristic was developed to solve it. In an actual example, the proposed model was validated; the algorithm and the CPLEX solver and a similar algorithm were compared and described in aspects of solution quality and computation time. Results show that the proposed model is feasible, and the algorithm exhibits extraordinary performance in solving different scales of equipment maintenance material supply problems.]]></description>
<pubDate>2020/9/2 11:09:48</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[丛　彬,何成铭,滕尚儒]]></author>
</item>
<item>
<title><![CDATA[The analysis and suppressing method on the operating range ambiguity of torpedo electromagnetic fuze]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201911130000001]]></link>
<description><![CDATA[Starting from the basic principle of the vertical configuration of the receiving and transmitting coils of torpedo electromagnetic fuze, the ambiguity of operating range caused by the double receiving coils located on the torpedo axis and deviating from the torpedo axis is analyzed respectively. For the first case, the modulo operation of the double receiving coils is proposed to eliminate ambiguity of operating distance; For the second case, a pairs of coils is appended to the symmetrical position and the output signal of the symmetrical position coil is averaged, then the modulo operation is taken to eliminate the ambiguity of operating range. The simulation results show that the method can effectively eliminate the ambiguity of the operating range and improve the operating range of the electromagnetic fuze.]]></description>
<pubDate>2020/9/2 11:09:40</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[谭思炜,唐波]]></author>
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<item>
<title><![CDATA[Model reduction of Maglev control systembased on Hankel norm approximation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903290000002]]></link>
<description><![CDATA[For magnetic suspension systems, it is very common to ignore the flexibility of the trajectory in the design of control algorithms. However, when the stiffness of the track is small, the control performance of this method is poor. The design of the control algorithm considering the track elasticity can theoretically ensure the good performance of the system, but it will increase the system complexity. In order to solve the above problems, the Hankel norm approximation method is used to reduce the order of the model based on the elastic track. The control algorithm is designed for rigid rail system model and reduced order model. Simulation results show that the performance of the reduced order model is good and feasible.]]></description>
<pubDate>2020/4/26 15:34:15</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[刘武斌,王泉]]></author>
</item>
<item>
<title><![CDATA[Model reduction of Maglev control systembased on Hankel norm approximation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201903290000002]]></link>
<description><![CDATA[For magnetic suspension systems, it is very common to ignore the flexibility of the trajectory in the design of control algorithms. However, when the stiffness of the track is small, the control performance of this method is poor. The design of the control algorithm considering the track elasticity can theoretically ensure the good performance of the system, but it will increase the system complexity. In order to solve the above problems, the Hankel norm approximation method is used to reduce the order of the model based on the elastic track. The control algorithm is designed for rigid rail system model and reduced order model. Simulation results show that the performance of the reduced order model is good and feasible.]]></description>
<pubDate>2020/4/26 15:32:34</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[刘武斌,王泉]]></author>
</item>
<item>
<title><![CDATA[Energy absorption mechanism of filament wound composite constrained spherical buoyancy core material under quasi-static compression loading]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201811130000001]]></link>
<description><![CDATA[The new energy absorption element has been put forward and the primary configuration has been designed to meet the asking for the energy absorption and the buoyancy reserve of sea structure plateform. The numerical model of element was built to simulate the damage formation, extension and evolvement law under quasi-static compression load. Comparative analysis of numerical simulation and experimental results demonstrate that the quasi-static compression process can be divived into three stages, including the initial elastic compression stage, the progressive damage stage and the structural damage stage. The key to the energy absorption design of the structure was the compatibility design of the poisson" s ratio between the composite surface and solid buoyant core. The smooth plastic compression damage and shear failure of the solid buoyant core come to occur due to the constraint stress of the composite surface with lower poisson"s ratio. The progressive tensile breaking of the composite surface was caused by transverse expansion deformation of the solid buoyant core. The results show that this new structure has good energy dissipation property and provide certain reserve buoyancy.]]></description>
<pubDate>2020/2/16 19:14:32</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[梅志远,张焱冰,周晓松]]></author>
</item>
<item>
<title><![CDATA[Development of Hot Gap Measurement System for the Ion Thruster Optics<sub>*</sub>]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201808220000002]]></link>
<description><![CDATA[In order to complete the high-precision measurement of the LIPS-300 ion thruster hot gap in the vacuum, high-temperature environment, a non-contact videometrics system using a telemicroscope is designed. Based on the captured image, the interactive partitioning edge detection method is used to obtain stable and clear edges of multiple circular cooperation logos, meanwhile magnification factor calibration, image distortion correction, horizontal plane correction and hot gap subpixel level deformation detection are performed with cooperation logos. Accuracy verification experiments show that the measurement accuracy of the system is better than 6μm under non-heating conditions, and the measurement accuracy is better than 12μm under heating conditions. The experimental results show that the greater the temperature difference between the screen and the accelerator grid, the larger the reduction of the grid hot gap, when the screen grid and the accelerator grid temperature difference is at most 150℃, the hot gap reduction reaches a maximum of 420μm. At the same time, due to the thermal deformation of the mounting ring, the thermal deformation of the grid decreases during thermal steady state, and the negative displacement occurs during the cooling period. The results of grid thermal deformation measurements are consistent with the trend of similar previous experiments, and the system meets the requirements of ion thruster hot gap measurement.]]></description>
<pubDate>2019/11/1 16:27:52</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[梁栋,,杨俊泰,袁杰红,]]></author>
</item>
<item>
<title><![CDATA[The new MWC wideband digital receiver design based on the polyphase structure]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201808150000001]]></link>
<description><![CDATA[While working on a high data rate, the existing discrete compressed sampling wideband digital receiver, which is based on modulated wideband converter (MWC) structure, can not be realized on Field－Programmable Gate Array (FPGA) easily. To solve this problem, a new MWC discrete compressed sampling wideband digital receiver structure based on the multiphase structure was proposed to intercept the wideband intermediate frequency signals. The new structure of receiver have three modules including series-parallel conversion, parallel multiplication and polyphase filter. Under the condition of using a same multiplication source, the data rate of the new receiver structure is much lower than the existing MWC structure, and the simulation results verified the correctness of the receiver. The proposed design establish the foundation of the MWC discrete compressed sampling digital receiver implementation on FPGA, which makes a more valuable practical engineering application .]]></description>
<pubDate>2019/9/25 10:36:18</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[蔡兴鹏,陈涛,]]></author>
</item>
<item>
<title><![CDATA[Air Combat Situation Assessment based on Improved Variational Autoencoder and Clustering Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201804190000003]]></link>
<description><![CDATA[Aiming at the problems of traditional assessment methods, such as the subjectivity of determining the weights, the weak ability of processing big data, and the lack of feature extraction ability, combining with deep unsupervised learning methods and the traditional advantage function, an improved air combat situation assessment method based on Variational Autoencoder (VAE) and clustering algorithm is proposed. First, according to the characteristic of continuity of situation changes, a situation classification method based on time period data is proposed, and the situation of both sides is divided into four categories based on the confrontation states. Then, on the basis of variational self-encoder (VAE), VAE-WRBM-MDN feature extraction model is proposed, which uses Mixed Density Network (MDN) to optimize VAE feature extraction capability as well as the similarity of generated data, and optimize initial weights of the network with Weighted uncertainty Restricted Boltzmann Machines (WRBM). Finally, the extracted features are input into two typical clustering algorithms(k-means++ and density peaks) for clustering, and then the situational function and actual battlefield conditions are used to modify the clustering results so as to remove singular points resulting from the situational changes, forming a correct situation classification criteria. In the experiment part, experiments of the optimal parameters adjustment, key feature extraction, clustering and correction were performed. The experimental results showed that the model classification accuracy rate reaches 95.69%, and the model runtime meets the application requirements. In addition, the assessment results of the example are consistent with the actual situation. Therefore, the proposed method is of practical value.]]></description>
<pubDate>2019/7/18 13:05:50</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[房育寰,杨任农,张彬超,张振兴,左家亮]]></author>
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<item>
<title><![CDATA[Multi-layer Wearable Diamond-like Carbon Film Prepared by Pulsed Laser Deposition on Soft Substrate]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201804190000004]]></link>
<description><![CDATA[In order to improve the wear resistance and corrosion resistance of the soft copper substrate, the protective multi-layer diamond-like carbon film on the copper substrate was prepared by pulsed laser deposition. The silicon carbide / diamond-like carbon cyclic layer was used to avoid the accumulation of internal stress in the diamond-like carbon layer and reduce the risk of rupture of the functional diamond-like carbon layer. The individual silicon carbide layer reduced the hardness difference between the soft copper substrate and the hard diamond-like carbon layer. The titanium layer made the copper substrate combined with the upper silicon carbide layer firmly. The measures showed that the protective multi-layer diamond-like carbon film adhered firmly on the copper substrate, and could be tested by heavy friction and adhesive adhesion as stipulated in the MIL-48497A and the temperature impact test by GJB150.5A-2009. At the same time, it could withstand the corrosion of weak alkali solution; the friction coefficient of the protective film was low and below 0.093, and the wear resistance was good for 2 hours. The multi-layer technics could be used as anti-wear film for mechanical tools in the corrosive environments after being improved for different substrates.]]></description>
<pubDate>2019/7/18 13:04:19</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[程勇,黄国俊,黎伟,陆益敏,米朝伟,田方涛,万强,韦尚方]]></author>
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<item>
<title><![CDATA[电磁发射超高速一体化弹丸研究]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201901200000001]]></link>
<description><![CDATA[Regarded as the launch object of electromagnetic (EM) energy weapon, hypervelocity integrated launch projectile (ILP) has a lot of scientific problems different from that launched from traditional artillery. This paper summarized the theoretical and experimental results of EM launch ILP at home and aboard in recent years, and analyzed the basic theory and key technologies faced to it. In addition, the solutions to these problems were put forward to provide some references to the subsequent research on EM launch ILP.]]></description>
<pubDate>2019/7/18 13:03:59</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李湘平,鲁军勇,马伟明]]></author>
</item>
<item>
<title><![CDATA[Design and Comparison Research of Graphene Electroacoustic Transducer]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201810030000001]]></link>
<description><![CDATA[Graphene material has made great achievement in electroacoustic application area. In order to optimize the performance of graphene electroacoustic transducer, this paper conducts research on the electroacoustic mechanism of graphene thermoacoustic sound device and graphene electrostatic sound device. Through theory modeling and analysis, the influence of structural parameters such as size, thickness and stress of graphene film on the frequency response characteristics of two kinds of electroacoustic transducers is obtained. At last, a batch of electroacoustic transducers with different structural parameters are designed and fabricated. The performance test and comparison analysis of these devices show that the thickness of graphene film has a significant influence on the sound pressure of the thermoacoustic transducer, that is, the thinner the film is, the larger the sound pressure of the electroacoustic transducer is. The electrostatic transducer is influenced by the radius, thickness and stress of graphene film, that is, the corresponding film with larger radius, thinner thickness and smaller stress of the electrostatic transducer would have a wider frequency bandwidth. This research applies support for the optimizing selection of graphene electroacoustic transducer, the optimizing design of structural parameters and the improvement of the device"s sound performance.]]></description>
<pubDate>2019/7/18 13:03:42</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[程先哲,刘冠军,邱静,杨鹏,张勇]]></author>
</item>
<item>
<title><![CDATA[Fault Simulation of Ducted RocketBased on System Configuration Switch Method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201809250000001]]></link>
<description><![CDATA[In order to comprehensively verify the fault detection algorithm in the ducted rocket rapidly, based on system configuration switch method, a simulation platform was build which can simulate various fault mode for ducted rocket. Based on the simulation platform, ducted rocket ignite fault model, pressure sensor fault model, device interface model and fault detection algorithm model which have a same interface and system configuration with the aircraft engine controller, etc. were build, comparing the fault detect result of mathe-matical model and engine control system under a same fault mode, the fault detection algorithm in the engine control system can be verified rapidly. Take the fault simulation of nozzleless booster ignition as an example, modeling, test and verification, the process of analysis are narrated, in addition, this method is also applicable to the fault simulation and verification of the shutdown of nozzleless booster, the open of air inlet cover, the ignition of gas generator, and fault tolerant control of gas flow, it is strong universality, and can greatly reduce the time cost on system development and verification, it has a strong applied value.]]></description>
<pubDate>2019/7/18 13:03:02</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[曾庆华,]]></author>
</item>
<item>
<title><![CDATA[Determination method of dominant acoustic radiation modes in coupling enclosure]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801290000001]]></link>
<description><![CDATA[At a certain frequency or in a band, one or several acoustic radiation modes which make a major contribution to the acoustic potential energy are defined as “Dominant acoustic radiation modes (DARMs) of coupling enclosure”. The determination of DARMs is of virtual important, it directly affects the effect of active structural acoustic control. However, among previous determination methods, either one-sidely emphasize the effect of radiation efficiency while ignoring the impact of modal amplitude, or require the knowledge of structural modes which was difficult to be extracted in engineering applications. To overcome these problems, comprehensively by the means of computation and testing, and fully considering both radiation efficiency and modal amplitude, a method based on “primary election-reservation-posteriori correction” was proposed to determine DARMs in coupling enclosure, and experimental research was performed to verify the effectivity and feasibility of the proposed method. The results show that the proposed method can accurately identify DARMs and does not require the knowledge of structural modes throughout the process, so this method can be used to guide the selection of control objective or reconstruct the acoustic potential energy of coupling enclosure.]]></description>
<pubDate>2019/4/24 13:02:47</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[苏常伟,]]></author>
</item>
<item>
<title><![CDATA[Remote Sensing Data User Request Merging Technology]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201802280000003]]></link>
<description><![CDATA[Remote sensing data, as national fundamental and strategic resources, plays important roles in economy, state security, environment protection, and ecology. Since, remote sensing data have been widely used in various industries.There is a large amount of data requests from different users, demanding a lot of valuable Earth observation resources(EOS) resources. On one hand, users’ data requests increase constantly, on the other hand, EOS resources are always limited. Our objective is to ease the contradiction between a large amount of users’ requests and limited EOS resources. The key idea is to merge identical or similar users’ requests in order to reduce the total number of requests. Then use requirement forecasting and requirement mining technology to improve requirement fusion efficiency.It is high likely that different users may share identical or similar data requests, since users may concerns about the same area of the earth over the same time range.]]></description>
<pubDate>2019/4/24 13:00:13</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[付 琨,徐崇彦,郑忠刚,周长飞]]></author>
</item>
<item>
<title><![CDATA[Time accuracy analysis of a primitive variable-based conservative form governing equations]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201802280000002]]></link>
<description><![CDATA[The governing equations using primitive properties of pressure, velocity and temperature as dependent variables but constructed in the conservative form can be applied for calculating solutions for steady state problems. When the method was recently used to simulate a canonical shock-tube problem, however, overshoot of temperature is observed after the shock. Moreover, the errors cannot be eliminated by using fine grid, high spacial order of accura-cy or any alternative inviscid fluxes schemes that are available, implying the numerical discrepancy may be caused by the method itself. Numerical analysis was conducted on the method using the one-dimensional Euler equations as the model equation system. It can be shown that the numerical error specifically arises from the discretized time terms. A dual-time-looping technique can be developed to address the issue. It uses conservative variables in physical-time derivatives while primitive variables for pseudo-time terms. An inner iteration procedure within two adjacent physical-time steps are driven until a steady state is reached. The resulting governing equation converges to the corresponding conservative form in time, and the time-accurate solution is recovered.]]></description>
<pubDate>2019/4/24 12:59:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[王光学,王靖宇,张怀宝]]></author>
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<item>
<title><![CDATA[Experimental study of failure mechanism on liquid cabin under warhead close explosion]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201802260000001]]></link>
<description><![CDATA[In order to study the failure mechanism of large warship broadside protective liquid-cabin, the scaled model of warhead and two kinds of liquid-cabin structure, including exposure model and airtight model, were designed based on the bearing characteristics of the liquid cabin, the combined damage experiment of high-velocity fragment and shock wave under warhead close explosion, including two kinds of posture, were preformed. According to the damage of liquid-cabin model after test, the failure mechanism of front plate and back plate of liquid-cabin under typical load was analyzed, the failure process and mode of liquid-cabin structure was summarized and analyzed. The result shows that high-velocity fragment is the main defensive object of protective liquid-cabin, the drag and cavitation of fragment are the main stage of liquid-cabin deformation and fracture, the shock wave and cavitation squeezing pressure caused by penetration of fragment cluster into liquid-cabin structure are the major load, which make structure deform and damage.]]></description>
<pubDate>2019/4/24 12:59:19</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[金键]]></author>
</item>
<item>
<title><![CDATA[A linear spectrum noise control method of electro-hydraulic steering gear based on dual pump source]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201802080000001]]></link>
<description><![CDATA[Electro-hydraulic steering gear system adopted variable frequency speed control strategy, has a characteristic of obvious linear spectrum noise, and it is difficulty to attenuate with the changing working condition. Combined with the principle of the electro hydraulic steering mechanism of double redundancy pump source, pressure ripple control strategy based on the auxiliary pump source confluence is proposed, and it only changes the control system. The theoretical analysis indicates that pressure ripple of odd harmonics can be attenuated when the two pump sources rotate at the same speed, and the initial phase difference at half cycle. Thus, the master slave synchronization control strategy is adopted, and the corresponding hardware is configured. With the method applying to actual steering gear system, the structure vibration on the pedestal can reduce 3-5 dB, and the first order line spectrum can attenuate 23dB.]]></description>
<pubDate>2019/4/24 12:58:59</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈宗斌,何琳,廖健]]></author>
</item>
<item>
<title><![CDATA[Fault isolation and parameter estimation of marine main power plant based on bicausal bond graphs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201802070000001]]></link>
<description><![CDATA[Aiming at inherent characteristics of complicated structure, multiple fault types and system uncertainty of marine main power plant, a quantitative algorithm for fault isolation and parameter estimation based on bicausal bond graph (BG) was developed. Based on sensor configuration scheme, the system bicausal BG model was built. By analyzing the model causal path, the system analytical redundancy relations (ARRs) were derived and the fault signature matrix was obtained. The linear fractional transformation (LFT) BG model was developed for fault simulation. Through coupling LFT and bicausal BG models, fault isolation and parameter estimation of marine main power plant were realized and the effectiveness was validated by Matlab/Simulink software. The results show that bicausalled BG helps to simplify ARRs deviation. Fault isolation and parameter estimation can be effectively realized and fault status can be tracked and predicted by analyzing the element constitutive equation of bicausalled BG..]]></description>
<pubDate>2019/4/24 12:57:54</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈于涛,程刚,黄林,朱国情]]></author>
</item>
<item>
<title><![CDATA[Fuzzy Control for Body-Fixed Hovering over Uncontrolled Tumbling Satellite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201802010000001]]></link>
<description><![CDATA[The problem of body-fixed hovering control of uncontrolled tumbling satellite is researched. A three-dimensional relative motion equation of arbitrary eccentricity is established in the target orbital coordinate system, the attitude motion characteristics of the uncontrolled tumbling satellite are analyzed. The hovering problem is decoupled into two-dimensional fuzzy control problem of three channels, and the Mamdani fuzzy controller is designed with the channel x as an example. Determine the corresponding fuzzy subset, membership function and fuzzy control rule table, using the area center method to solve the fuzzy. The correctness and good control performance of the designed fuzzy controller are verified by numerical simulation.]]></description>
<pubDate>2019/4/24 12:57:10</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李海阳,刘将辉]]></author>
</item>
<item>
<title><![CDATA[An On-board Data Preprocessing Method for Path Finder of Discovering the Sky at the Super-long wavelengths]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801310000001]]></link>
<description><![CDATA[Micro-Nano satellites are becoming more and more important in space exploration field. This work is focused on CE-4 lunar orbit duel micro satellites mission for super-long wave astronomy. Under the strict resource constraints, lunar orbit Micro-Nano satellites have very limited communication bandwidth. In order to maximize valuable scientific data, this paper presents a method of in-orbit signal preprocessing: the digital down conversion method is used to build the ultra-narrowband filter, which significantly reduces the data rate. The ultra-narrowband filtering scheme can perform comb filtering by increasing the down-conversion filter channels. The ultra-narrowband filter scheme simulations on the FPGA show that the key technical indicators such as flatness and linear phase meet the requirements, and the data rate reduces more than 10^3 times compared with original data rate.]]></description>
<pubDate>2019/4/24 12:56:01</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[蓝爱兰,武林,阎敬业,赵飞]]></author>
</item>
<item>
<title><![CDATA[Dynamic Weapon vs Target Assignment Based on Game of The Both Sides]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801280000001]]></link>
<description><![CDATA[Considering the high-dynamics, incomplete information and uncertainty of massive operations, on the basis of the analysis and induction of a methods to solve the problem of dynamic weapon target assignment, attempt structure a comprehensive mathematical of dynamic game based on both sides, apply phased solution based on Nash equilibrium algorithm and Pareto optimization. The results validate, that combining the mathematical model with the game theory method can deal with problem of dynamic weapon target assignment efficiently.]]></description>
<pubDate>2019/4/24 12:53:03</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[张先剑]]></author>
</item>
<item>
<title><![CDATA[Theoretical Study on Axial Residual Velocity of PELE Vertical Penetrating Thin Target]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801240000002]]></link>
<description><![CDATA[In order to obtain the theoretical model of the axial residual velocity of PELE under the condition of vertical penetration, the plane shock wave theory is used to analyze the mechanism of PELE vertical penetrating metal thin target. According to the penetration model of the flat head projectile, the energy loss during the penetration of PELE is divided into the following parts: the energy obtained by the annular plug block corresponding to the outer shell and the inner core, the increased internal energy of the outer casing and inner core, the shear energy dissipated in the outer casing, and the specific calculation method is also given. Based on the principle of energy conservation, the theoretical formula of axial residual velocity after PELE vertical penetrating thin metal targets can be deduced. To verify the rationality and accuracy of the theoretical model, the corresponding experiments are designed to verify the results. The results show that the calculated results coincides well with the experimental results under different conditions. Therefore, the theoretical model of axial residual velocity of PELE vertical penetrating thin target can provide guidance and reference for engineering application.]]></description>
<pubDate>2019/4/24 12:52:27</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[丁亮亮,樊自建,冉宪文,汤文辉,肖凡]]></author>
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<title><![CDATA[The Maintenance Model for T/R unit of Phased Array Radar’s Antenna under the restriction of reliability]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801240000001]]></link>
<description><![CDATA[In order to describe the maintenance activities for the phased array radar’s antenna system, this paper builds a time based maintenance model that “T/R unit can not be restored to as good as new” under the foundation of reliability.Firstly,the paper analyzes the antenna’s construction parameters under the T/R unit failure in series and determines the threshold value of failure T/R unit,then in view of the fact that“T/R unit can not be restored to as good as new” , a maintenance model that minimizes the average cost per unit time under the restriction of antenna’s operational availability is established by introducing failure rate increasing factor.Lastly, marginal efficiency analysis algorithm is applied to achieve the optimized maintenance cycle and service group. Several examples are given to verify that the model excludes the restriction of “T/R unit can not be restored to as good as new” , Which are more in accordance with the actual situation and will provide the theoretical foundation for preventive maintenance policy.]]></description>
<pubDate>2019/4/24 12:52:00</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[蒋 伟,,,]]></author>
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<title><![CDATA[Jamming method to imaging radar using intermittent sampling un-uniformly repeater]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801230000002]]></link>
<description><![CDATA[Interrupted-sampling repeater jamming(ISRJ) is an effective method to wideband imaging radar. According to basic principle of ISRJ, when the jamming with conventional uniformly repeater is applied to wideband imaging radar, a string of uniformly spaced artificial scatters are overlain on the high resolution range profile (HRRP). The characteristic of uniformly spaced for artificial scatters goes against with camouflage of jamming signal. In order to solve this problem, based on conventional ISRJ, a new jamming method using interrupted-sampling un-uniformly repeater, in which main purpose was broken the uniformly spaced of artificial scatters, is put forward in this paper, and effect of the new jamming method is also given. Finally, by means of simulation, it is found that the new jamming method can promote jamming effect to wideband imaging radar.]]></description>
<pubDate>2019/4/24 12:50:41</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[高磊,汪连栋,王伟,曾勇虎]]></author>
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<title><![CDATA[Speed Control Strategy for Servo Motor System based on Integral SMC]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801220000001]]></link>
<description><![CDATA[A speed control strategy based on integral sliding-mode was proposed to solve the problems such as poor control, large fluctuation and slow dynamic response of the output speed of Servo Motor System; The load torque observer was designed to resolve the load disturbance in the control process; The PMSM motor speed control model was established based on Simulink; The test system of motor was built to test and verify the steady-state performance and dynamic performance of the control system respectively. Experimental results show that the control strategy designed by this paper improves the robustness and rapidity of the system significantly and the chattering phenomenon of SMC control is inhibited.]]></description>
<pubDate>2019/4/24 12:49:07</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[黄皓,涂群章]]></author>
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<title><![CDATA[Effectiveness analysis of opposing jet thermal protection generating with solid fuel]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801160000002]]></link>
<description><![CDATA[In order to reduce the size of coolant supply system of opposing jet in hypersonic vehicles, the fuel gas generating with solid fuel was adopted as an opposing jet. The Reynolds-average Navier-Stokes(RANS) equations coupled with the Menter’s shear stress transport (SST) model is employed to solve the opposing jet flow field of hypersonic hemisphere model. And typical results have been validated with experiments performed in the literature. The influence of the high temperature fuel gas on the hemisphere model thermal protection characteristics was analyzed with different flying condition. Results show that the high temperature fuel gas weakens the heat flux reduction of opposing jet, but the peak heat flux exhibits a prominent reduction in contrast to that without injection. The cooling efficiency can be strengthened by increasing jet pressure. With reasonable jet pressure, the similar cooling efficiency can be obtained compared to that with normal coolant and it does not result in additional mass flux. Moreover, the three solid fuel and it’s combustion temperature are listed. For high Mach flying which is higher than 6, the solid fuel can provide required jet temperature for opposing jet thermal protection system.]]></description>
<pubDate>2019/4/24 12:48:45</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘伟强,沈斌贤,尹亮]]></author>
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<title><![CDATA[A method for extracting the texture features of point cloud based on LiDAR primitive discrete points]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801140000002]]></link>
<description><![CDATA[In order to eliminate the ambiguity in the land cover classification of LiDAR point cloud by using the image texture, the texture feature of point cloud based on the searching structure of KD tree and the gray level co-occurrence matrix (GLCM) has been proposed, which represents the distribution of attribute values of points and their surrounding neighborhood points. The influence of the parameters, such as search neighborhood, moving step and gray-level, on the texture features of point cloud has been analyzed. Using the support vector machine classification method, it was verified that the texture feature of point cloud can effectively assist the elevation and intensity to improve the results of the land cover classification. In addition, the results demonstrated that the land cover classification under the constraint of the texture features of point cloud has higher accuracy than that under the constraint of the raster-based image texture features, and the texture feature of point cloud performs outstandingly in distinguishing tiny land objects and separating the water and land. These excellent characteristics of the texture feature of point cloud could contribute significantly to the refined classification of coastal LiDAR data, the construction of high-precision DEM in coastal zone and the extraction of coastlines.]]></description>
<pubDate>2019/4/24 12:48:12</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[董箭,彭认灿,周唯]]></author>
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<title><![CDATA[Structure Design for The Wind’s Eye of Sabot Based on Genetic Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801120000004]]></link>
<description><![CDATA[Sabot is used as the connection and direction between the caliber projectile and launcher, and should be discarded fast being regarded as the parasitic mass after the chamber, in order to reduce the disturbance of sabot discard on projectile’s flight. Aming at the design requirements of easy separability and light mass for the sabot of integrated launch projectile, an optimization design model (ODM) was obtained by combining aerodynamic calculation model (ACM) by genetic algorithm (GA), in which ACM is establised based on the theory of shock and expansion wave trhough building the parameterized structure model for windward nest, to analyze the aerodynamic separation force of sabot in the process of discard. And the discard acceleration and sabot’s mass are used as the indicators to build performance function. Take the sabot design of Armor Piercing Fin Stabilized Discarding Sabot (APFSDS) of medium caliber as an example, and use the proposed ODM for the structure optimized design of the windward nest, and adopt the simulation model of sabot discard based on dynamic grid technique to verify the optimality. Simulation results show that the proposed ODM can obtain the optimal wind’s eye of, in view of the existing medium caliber APFSDS, the sabot structure can be further optimized to improve its rapidity.]]></description>
<pubDate>2019/4/24 12:47:09</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杜佩佩,冯军红,李湘平,鲁军勇]]></author>
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<title><![CDATA[Research on the Method of Capturing Task Allocation Based on Energy Balance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801120000001]]></link>
<description><![CDATA[With the deepening of the research on anti-encirclement strategy of underwater vehicles, the encirclement of underwater vehicles becomes more and more difficult. For this reason, a multi-layer annular ambush capture model is constructed and a task assignment method based on the capture task is designed, so that the underwater vehicle can make full use of its own characteristics to complete the task better. At the same time, considering that the energy consumption in the system will be uneven with the passage of time in the capture process, an energy balance method is proposed to balance the energy consumption of the system. Experiments show that the proposed task allocation method based on energy balance strategy of multi-layer annular capture model can effectively improve the success rate of capture and prolong the life of the system.]]></description>
<pubDate>2019/4/24 12:46:27</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[冯光升,吕骏,孟宇龙,徐东,张朦朦,张子迎]]></author>
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<title><![CDATA[Study on the Influence of Over-Under TBCC on the Performance of Hypersonic Aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801090000001]]></link>
<description><![CDATA[Two kinds of combined-cycle propulsions are studied to meet the requirement of a hypersonic vehicle that cruises at Mach number 6. One consists of turbine engine, ramjet and dual mode scramjet (T/RJ/DMSJ). The other consists of pre-cooled turbine engine, ramjet and dual mode scramjet (PCT/RJ/DMSJ). The ranges and the flying time of the hypersonic vehicle that uses T/RJ/DMSJ and PCT/RJ/DMSJ are obtained under thrust?weight?ratio of 0.8 and 1.0 with a given mission. The performances of two operating mode of PCT/RJ/DMSJ are compared. Results show that Mode 1 of PCT/RJ/DMSJ is better Mode 2 of PCT/RJ/DMSJ. The ranges and the flying time of the two combined-cycle propulsions are almost close. The range of PCT/RJ/DMSJ is 3.6% higher than T/RJ/DMSJ and the flying time of PCT/RJ/DMSJ is 3.8% more than T/RJ/DMSJ under thrust?weight?ratio of 0.8. When the thrust?weight?ratio is 1.0, the range and the flying time of PCT/RJ/DMSJ are 4.6% and 4.8% higher than T/RJ/DMSJ, respectively. Under the lower thrust?weight?ratio, the fuel consumption of the transonic flying phase is the large part during the acceleration and climbing process. The fuel consumption of the transonic flying phase will decrease as the increase of thrust?weight?ratio and then more fuel can be used in the hypersonic cruise and the cruise distance increases. The range will increase and the flying time will decrease as the increase of thrust?weight?ratio.]]></description>
<pubDate>2019/4/24 12:45:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[林鹏,马松,谭建国,王霄,左林玄]]></author>
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<title><![CDATA[Identification method of mechanism consistency for accelerated degradation testing based on likelihood ratio test]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801080000001]]></link>
<description><![CDATA[Accelerated degradation testing (ADT) has been widely used to investigate the reliability of long lifetime products. The test results at higher stress levels are extrapolated to the normal stress level in the ADT. For an accurate product reliability evaluation, the failure mechanism under accelerated stresses should be consistent with the mechanism under normal conditions. Based on the likelihood ratio test, an identification method and a flow chart are proposed in this paper. For describing the mechanism consistency and variation, two acceleration models are proposed and the mixed-effects model is introduced to depict the degradation process. According to the judgment between the consistency and variation of acceleration model parameters, the identification is completed. The simulation test and real test show that this method could identify the mechanism variation. Moreover, the stress boundary for consistent mechanism is found by the identification method.]]></description>
<pubDate>2019/4/24 12:45:19</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈循,鲁相,谭源源,汪亚顺]]></author>
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<title><![CDATA[Centralized payload control method for planetary rover exploration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801070000001]]></link>
<description><![CDATA[To satisfy requirement for autonomous scientific detection in resource constrained planetary rover exploration mission, a centralized payload control method is proposed. A novel highly integrated hardware architecture is constructed by integrating payload electronics units and traditional payload onboard data handling (OBDH) unit. Software adopts the control method based on the event table and work mode table to control the payload autonomously. Several health management measures are taken to make fault recovery and isolation according to pre-defined rules. The common control part weighs only 3kg, consumes 6W power. Software supports 9 work mode tables running at the same time. Instruction executing time accuracy is better than 40ms. The method has applied to China first mars exploration. Ground test results show that the method is simple, efficient and reliable, and suitable for payload control in planetary rover exploration missions with harsh resource constraints.]]></description>
<pubDate>2019/4/24 11:50:19</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[梁耀明,马苗,饶家宁,王连国,王蔚,朱岩]]></author>
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<title><![CDATA[The classification of missile launch envelopes based on Deep Belief Network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201712310000001]]></link>
<description><![CDATA[Aiming at the problems such as neglecting the dynamic changes existing in the conventional missile attacking envelop solution, a missile attack envelop classification model based on Deep Belief Network(DBN) is proposed. First, the missile attack envelop is divided into five parts according to the relationship between missile hits and target maneuvers. Then, by analyzing the situation parameters that affect the attack result of air-to-air missile, a missile attack prediction model is constructed. Next, in the experiments, reconstruction error and the test error rate are used to determine the network structure. Through extracting data layer by layer, analyze the features of parameters and discuss the approaching of fine-tuning data sampling. Finally, BP network and Support Vector Machine are selected for classification comparison experiments. The results show that DBN performs better than the other two algorithms in speed and prediction accuracy and the presented method is of great practical value.]]></description>
<pubDate>2019/4/24 11:46:43</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[杨任农,张振兴]]></author>
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<title><![CDATA[Effect of the back electromotive force on the accurate pointing of DFP spacecraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201712260000001]]></link>
<description><![CDATA[The back electromotive force of the non-contact actuator in a DFP spacecraft can cause the coupling between payload module (PM) and support module (SM), hence could be detrimental to the precise pointing of PM. To analyze its effect, a coupling dynamics model is established in this paper for the DFP spacecraft. In consideration of the cubic architecture DFP-interface, this dynamics model is developed by a combination of the Newton-Euler method with the Lagrange formulation. The output force of the non-contact actuator is derived, which is introduced into the dynamics model of the PM platform, then the coupling dynamics model with the back electromotive force is obtained. Considering the harmonic vibration caused by the static and dynamic unbalance of the flywheels as the disturbance torque, an on-orbit pointing model for the DFP spacecraft is established in Simulink. The simulation results illustrate that the larger value of the back electromotive force coefficient will cause larger effect on PM.]]></description>
<pubDate>2019/4/24 11:46:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[孔宪仁,李海勤,武晨,杨震国]]></author>
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<title><![CDATA[Research and application of three - section methods of load design for certain kinds of aircraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201712040000001]]></link>
<description><![CDATA[This paper presents a three-section method for the load design of tactical missile, which can solve effectively many shortcoming of traditional load design with the help of approximating the actual mass distribution and aerodynamic load distribution of the missile. For a simplified missile, we calculate the modal parameters and the section load by using the three-section method, the theoretical method and the mass-partition method. The results show, the three-section method and the theoretical method are consistent with the model parameters and the calculation principle, which can be considered as a method, so their modal parameters and the section load are identical. The load of the left and right section of the mass-partition method is inconsistent, which is very different, and it is not in accordance with the actual load condition. In a word, the three-section method can get a more real and reasonable section load distribution, and the engineering application is simple and reasonable and reliable. At the same time, it can reduce the design difficulty of missile load and structure.]]></description>
<pubDate>2019/4/24 11:45:26</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[商霖]]></author>
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<title><![CDATA[Numerical investigation of front variable area bypass injector with jet mixing enhancement]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201711080000001]]></link>
<description><![CDATA[In order to improve mixing performance of fan bypass and Core Driven Fan Stage (CDFS) bypass, a innovative configuration of Front Variable Area Bypass Injector (FVABI) with jet mixing enhancement is proposed in present paper. Numerical simulation is performed to investigate mass flow rate characteristic, flow mixing and total pressure loss of FVABI configuration with lobed mixer. Compared with baseline configuration, the predictions are discussed and several conclusions can be summarized. First, significant improvement in fan bypass mass flow rate is achieved by jet mixing enhanced configuration at high back pressure operating point. Second, not only is performance not degraded, but also total pressure loss is decreased at high back pressure operating point. At last, characteristic length of stream-wise vortex is the key of improving mixing performance, and optimization of lobed mixer is available to match further structural requirement of adjust configuration.]]></description>
<pubDate>2019/4/24 11:44:10</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[邓小刚,,,,张怀宝]]></author>
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<title><![CDATA[Collision Avoidance Strategy of the Three Fixed-wing UAVs Cooperative Formation Flight]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201803140000001]]></link>
<description><![CDATA[Aiming at the process of executing combat mission, the collision occurred between the UAVs and the UAV and the enemy plane, a collision avoidance control algorithm and a control strategy based on the artificial potential field are simultaneously   applied for a Multi-UAV collision avoidance control in this paper. The three UAVs constitute the triangular formation as the control object, the leader flight path as expected path, the followers track the leader to maintain the triangle formation flight. From the UAV formation encounter the obstacle to the UAV formation system avoid the avoidance, the UVA formation experienced three stages, including the merging the formation, splitting the formation and closing rank to the triangle formation, which is the convergence to the steady flight state, in the horizontal plane the leader and follower have the same forward speed and heading angle rate, in the vertical direction they keep the relative distance constant. The simulation results show that the proposed control the collision avoidance strategy can converge to the desired formation and the flight- stability state, and then provide a theoretical conference for engineering application.]]></description>
<pubDate>2019/3/15 11:31:23</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[张佳龙]]></author>
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<title><![CDATA[A searched-form robust Chinese remainder theorem based multibaseline phase unwrapping algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201801250000001]]></link>
<description><![CDATA[The performance of the multibaseline PU is directly related to noise level. As we know, the presence of phase noise makes the classical Chinese remainder theorem (CRT) method not robust enough and inapplicable in practical cases. In this letter, a method based on a searched-form robust Chinese remainder theorem (SRCRT) is presented, the common factor has been carried out to build the new system of simultaneous congruences. Theoretical analysis and experimental results prove the effectiveness of SRCRT method and demonstrate that selecting reasonable common factor could improve the noise robustness of the SRCRT method.]]></description>
<pubDate>2019/3/15 11:31:13</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[蒋志彪]]></author>
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<title><![CDATA[Aerodynamic parameter model of hypersonic gliding missile for adaptive tracking]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201802040000001]]></link>
<description><![CDATA[Aiming at the modeling problem of hypersonic gliding missile tracking, a method of aerodynamic parameter model based on the law of guidance variables is studied. First of all, the aerodynamic parameters are analyzed and the shortcomings of the traditional modeling method are pointed out. With the assumption that the guidance variables obey the first-order delay process, the aerodynamic parameter model is derived by using the linearized aerodynamic coefficients. The variants of the model under different flight conditions are analyzed, which prove that the model is adaptive to the target maneuver. Then, the values of unknown parameters in the model are discussed respectively, so as to realize the matching between the model and the target’s flight state online. Simulation results show that the performance of the proposed model is obviously better than the traditional model when the target is maneuvering. Simultaneously, the simulation under different filter parameters further confirms the validity of the model.]]></description>
<pubDate>2019/3/15 11:31:03</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[付婷婷,兰旭辉,习秋实,熊家军,张凯]]></author>
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<title><![CDATA[Overlapping community detection algorithm by label propagation based on PageRank and node clustering coefficients]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201802220000001]]></link>
<description><![CDATA[A community detection algorithm based on label propagation can detect overlapping community structures of complex networks. In this paper, an overlapping community detection algorithm (Community Overlap PRopagation Algorithm based on PageRank and Clustering Coefficient, COPRAPC) is proposed. The algorithm uses PageRank algorithm to rank the influence of nodes, which can stabilize the community finding results. The parameter of node clustering coefficient is a node-related parameter, which can be used to modify the parameters of the algorithm and limit the maximum number of labels each node, The change can improve the quality of community mining. Experiments on artificial networks and real-world networks show that the algorithm can effectively detect overlapping communities, and the algorithm has acceptable time efficiency and algorithm complexity.]]></description>
<pubDate>2019/3/15 11:30:51</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[樊建平,李红辉,刘峰,马健]]></author>
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<title><![CDATA[Foreground Estimation in Video Surveillance by Blind Source Extraction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201810160000002]]></link>
<description><![CDATA[In video surveillance, one scene image/frame can be modelled as a superimposition, or linear mixture, of foreground visual contents and background contents. In the real world, however, the background and foreground are correlated to each other. Therefore, the foreground extraction cannot be well solved by principle component analysis (PCA) and independent component analysis (ICA) algorithms. In this paper, the foreground extraction is modelled as a blind source extraction (BSE) problem. The mean square cross prediction error (MSCPE), one solution of BSE, is generalized to extract desired source signal which is correlated with other source signals. Then MSCPE BSE method is applied to background subtraction schemes using the basic model and eigenbackgrounds method. Experimental results on artificial video shows the feasibility of MSCPE, and the real-world video experiments demonstrate its effectiveness.]]></description>
<pubDate>2019/3/12 10:02:26</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[孙振江,王群,薛瑞]]></author>
</item>
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<title><![CDATA[Optimal sensor placement for aeroservoelastic analysis of high-aspect-ratio flexible aircraf]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201709150000002]]></link>
<description><![CDATA[An advanced criterion of optimal sensor placement is proposed for aeroservoelastic analysis of high-aspect-ratio flexible aircraft based on classical sensor placement index. On the one hand, the trace of observability Gramian matrix is proven to be the vibration energy, and the dimension of the ellipsoid is introduced as the geometric mean of eigenvalues, a high efficient simplify method is given as a computational approach. On the other hand different modes and sensors placement influences to the system are evaluated though the properties of  norm in connection with system impulse response, a balance between the low and high frequency modes is achieved to guarantee the dominant of low order vibration and avoid overflow. At last, considering the bending moment of the body, the bend and torsion of the wings, this paper evaluates the different sensor placement indexes. The result shows that, sensor placement can be set accurately and effectively, while different modes can also be fully weighted and reflected by the proposed criterion. This method can be used as an optimal tool to set the sensor placement through the whole flight track and has a great value in engineering application.]]></description>
<pubDate>2019/1/17 15:43:44</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨惠,杨伟奇]]></author>
</item>
<item>
<title><![CDATA[Optimal sensor placement for aeroservoelastic analysis of high-aspect-ratio flexible aircraf]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201709150000002]]></link>
<description><![CDATA[An advanced criterion of optimal sensor placement is proposed for aeroservoelastic analysis of high-aspect-ratio flexible aircraft based on classical sensor placement index. On the one hand, the trace of observability Gramian matrix is proven to be the vibration energy, and the dimension of the ellipsoid is introduced as the geometric mean of eigenvalues, a high efficient simplify method is given as a computational approach. On the other hand different modes and sensors placement influences to the system are evaluated though the properties of  norm in connection with system impulse response, a balance between the low and high frequency modes is achieved to guarantee the dominant of low order vibration and avoid overflow. At last, considering the bending moment of the body, the bend and torsion of the wings, this paper evaluates the different sensor placement indexes. The result shows that, sensor placement can be set accurately and effectively, while different modes can also be fully weighted and reflected by the proposed criterion. This method can be used as an optimal tool to set the sensor placement through the whole flight track and has a great value in engineering application.]]></description>
<pubDate>2019/1/17 15:39:37</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨惠,杨伟奇]]></author>
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<item>
<title><![CDATA[Image Super Resolution Convolutional Neural Network Acceleration Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201712150000001]]></link>
<description><![CDATA[Deep learning technology has made significant achievements in the field of image super-resolution, and which has demonstrated superior performance to the traditional methods either in speed and restoration quality. However, a large number of model parameters and high computational costs still hinder the practical application. In order to realize the real-time and embedded operation of the model, a lightweight convolutional neural network structure is proposed. By using a smaller filter size and introducing depth separable convolution, a large number of model parameters can be subtracted and the nonlinear capability can be improved. Secondly, sub-pixel convolution is introduced at the end of the network, then the mapping is learned directly from the original low-resolution image (without interpolation) to the high-resolution one, which can reduced the cost k<sub>2</sub> (k for the magnification factor) times. The experimental results on Set5 show that the model proposed in this paper is more than 25.8 times faster than the classical Super-Resolution convolution neural network algorithm and can run in real time on a common GPU. And the proposed method improves the PSNR with value of 0.17dB with the 30% parameters of SRCNN.]]></description>
<pubDate>2019/1/9 17:04:59</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[胡清平,刘超,张晓晖]]></author>
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<title><![CDATA[Plug and play resolution on 1553B data bus]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201710300000003]]></link>
<description><![CDATA[Based on traditional 1553B data bus protocol, a new protocol with Plug and Play(PnP) features is designed by adding Remote Terminal（RT） Electronic Data Sheet(EDS) and procedure of transferring EDS. According to this protocol, the PnP resolution of 1553B Bus Controller(BC) is designed, including constructing bus list algorithm while RTs plug in，management data structure, and dynamic operation and control bus list method. The constructing bus list algorithm uses RT EDS to analysis、calculate and transform an old bus list to a new one，to satisfy RTs’ communication requirements. Management data structure is used for analysis and store bus list information during initialization phase，to increase efficiency of operation control and data exchanging. Dynamic operation and control bus list method adopts main bus list with plug in messages method. The timeliness and use cases of the resolution are evaluated. The results show that its time of bus cycle and time of RT plug into the system can be accepted. The resolution can remain stable of communication process, and provide flexibility for PnP needs. In CCSDS SOIS architecture, 1553B data bus is one of subnetworks on the bottom layer. With PnP features, it can be extended to support constructing PnP system higher layer services and functions.]]></description>
<pubDate>2019/1/9 17:03:57</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安军社,吕良庆]]></author>
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<title><![CDATA[In situ fatigue crack closure determination using nonlinear acoustic testing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201706010000001]]></link>
<description><![CDATA[A mathematical model which reveals the relation between the vibro-acoustic modulation index and the crack contact area is developed. Basing on the analysis of crack faces response to the resultant of applied load and plasticity induced crack closure stress, a procedure of on-line approximating the opening and closure stress is proposed. To study the performance of this measuring method experimentally, on-line vibro-acoustic modulation tests were carried out on a central cracked aluminum alloy fatigue sample. The experimental estimations match well with other researches. Analysis of the experimental results suggests that the vibro-acoustic modulation technology is not only capable of measuring the fatigue crack opening and closure stresses but also capable of analyzing the crack closure behavior, even for physically short cracks.]]></description>
<pubDate>2018/6/19 10:35:22</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陶利民]]></author>
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<title><![CDATA[Comparison of Ionospheric Characteristic Parameters Retrieved from FY-3C and COSMIC Radio Occultation During 2014 to 2016]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201803250000003]]></link>
<description><![CDATA[The ionospheric Electron Density Profiles (EDPs) obtained during 2014 to 2016 from two GNSS Radio occultation (RO) missions, the Feng-Yun 3C (FY3C) mission and the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission, are used in this paper. The two ionospheric characteristic parameters, i.e., the peak density NmF2 and the peak height hmF2, derived from the EDPs provided by the two missions are compared under the collocation criterion with the time window of 7.5min and the space window of 2.5°. The results show that the peak parameters derived from the two RO missions are highly correlated, with the yearly average correlation coefficient of NmF2 and hmF2 being 0.87 and 0.75, respectively. The biases of the peak parameters derived from the two RO missions are very small, with the absolute and the relative bias of NmF2 and hmF2 being less than ±0.25×〖10〗^5 el/〖cm〗^3 and ±15.0% , and ±7.00km and ±1.80% , respectively. In addition, the strip-shaped spatial distributions of the two ionospheric characteristic parameters from both of the two RO missions show that the values of NmF2 and hmF2 are larger over the equator and low latitudes than over other regions and that the values of NmF2 and hmF2 declined significantly in 2016 compared with 2014 and 2015.]]></description>
<pubDate>2018/6/13 15:46:34</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[罗佳,王涵,徐晓华]]></author>
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<title><![CDATA[Loss Functions of Low-light Level Image Enhancement Neural Networks under Extreme Low-light Illumination]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201706200000003]]></link>
<description><![CDATA[LLL (Low-light level) / infrared image color fusion is an important development direction of night vision technology at home and abroad. Under extreme low light level conditions (environment illumination less than              ), the LLL image has the characteristics of low signal-to-noise ratio and low contrast, so that the target is difficult to identify and seriously affect the quality of the finally formed color fusion image. In this paper, we design a convolutional autoencoder deep neural network for image enhancement. In view of the fact that the traditional mean square error loss function does not meet the human visual perception characteristics, combined with the existing full reference image quality evaluation index, we study several loss functions including perceptual loss, and propose a novel, differentiable loss function. The experimental results show that the loss function proposed in this paper can improve the detail information of the image while improving the signal-to-noise ratio and contrast of the low-light level image when the network structure does not change.]]></description>
<pubDate>2018/6/13 15:44:16</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[胡清平,刘超,张晓晖]]></author>
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<title><![CDATA[Relative Pose Measurement of Satellite and Rocket Based on Vasion]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201705310000004]]></link>
<description><![CDATA[This paper presents a method of measuring the relative pose of Satellite-rocket separation based on vasion. In the camera parameters are known, the camera installed on the carrier rocket, and more than six cooperation signs are fixed on the satellite.Using cameras take pictures of the cooperation signs in real time.Based on the basic principle of monocular vision pose estimation. The relative pose relationship between satellite and rocket is solved by combining EPnP with Orthogonal Iteration. The simulation experiment and the semi - physical simulation experiment prove the feasibility and accuracy of the method. The measurement error is calculated according to the error calculation method proposed in this paper.The error of measurement results show that, within the scope of 6 m, the relative position measurement error is less than 1 ㎝, within the scope of the 21 °, relative position measurement error is less than 3 °.]]></description>
<pubDate>2018/6/13 15:43:53</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈浩,丁少闻,王洁,张小虎]]></author>
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<title><![CDATA[Influence of Average Torque Equilibrium Attitude of the Space Station based on Air Torque]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201706220000001]]></link>
<description><![CDATA[Average Torque Equilibrium Attitude (ATEA) of the Space station is the foundation of Space station attitude maneuver path planning and control strategy. The models of attitude movement are established in order to study on the influence factors of Average Torque Equilibrium Attitude (ATEA) of the Space station. Influence of the Air torque on the ATEA of the space station is analyzed. The models of dynamic and control of the Space station are established. Typical PD controller is used. Groups of 24 ATEA are separately obtained under two conditions. The results show that Air Torque exhibits a significant influence on ATEA. In order to keep the ATEA of the Space station, periodicity of control Torque need to be provided. Air Torque induced Momentum unloading and accumulating effects of the Space station can’t be neglected.]]></description>
<pubDate>2018/6/13 10:06:22</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李海阳,刘将辉,张亚坤]]></author>
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<title><![CDATA[Inspection of small diameter bending pipes using magnetostrictive torsional guided wave]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201611270000001]]></link>
<description><![CDATA[Aim to the problem of inspection of small diameter bending pipes using torsional guided wave, finite element method and experiments were used to investigate the problem. ANSYS was used to simulate the propagation of torsional guided wave in bending pipe. A magnetostrictive torsional guided wave transducer was designed to inspect small diameter pipes. The exciting and receiving theoretical model of the transducer was built. The experimental signals were explained using the theoretical model. The research results show that mode conversion happens at the elbow of the pipe and part of the T(0,1) mode converts to F(1,1) mode. The orientation of the F(1,1) mode perpendicular to the direction of extrados-intrados. The double end reflection phenomenon in inspection signal is caused by mode conversion. With the increase of frequency, ratios between end echoes’ amplitudes decrease. The longitudinal magnetostrictive forces excited by the transducer bring about small longitudinal guided wave in the signals. The conclusions will provide theoretical guide to the inspection of small diameter bend pipes using magnetostrictive torsional guided wave.]]></description>
<pubDate>2018/1/12 10:34:33</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈 乐,邓文力,耿海泉,王悦民,叶伟]]></author>
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<title><![CDATA[Restrain the circulate current for parallel operation of drivers for PMBLDCM]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201612010000001]]></link>
<description><![CDATA[With the widespread use of Permanent Magnet Brushless DC Motor, high-power, high-capacity drive technology is one of its research direction. The parallel operation of drivers can effectively expand the drive system’s capacity, but the way is easy to introduce circulate current, in order to restrain the circulate current, the system including separate DC power supply for two paralleled inverters that feed the PMBLDC was analyzed and the character of the system’s circulate current was inferred, and the control structure based on circulate current feedback was put forward. The control structure only need to control one inverter. Simulation result represent the control structure can make two DC supplies that have different amplitude feed the load, and suppress the circulate current, which achieve a separate power supply brushless DC motor with drivers in parallel.]]></description>
<pubDate>2018/1/12 10:33:48</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[暴宇,黄胜军,吴峻]]></author>
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<title><![CDATA[Gliding guidance with environmental parameter online identification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201611280000002]]></link>
<description><![CDATA[A numerical predictor corrector guidance with environmental parameter online identification is proposed for boost glide missile. Comprehensive environment parameter is introduced in gliding phase concerning both atmospheric density and aerodynamic parameter influence. Extend Kalman filter is used to identify the comprehensive parameter online. Based on identification results, gradual fading-memory recursion least square method is used to build identification model of environment parameter. And the model is gradually revised based on the updated identification. Longitudinal and lateral guidance laws are designed. Drop point is estimated based on the identification model to limit the influence of environmental disturbance. The guidance simulations are carried with atmosphere density and aerodynamic disturbance. The results demonstrate the identification model can predict environment parameter accurately and the guidance method has enough robustness to environmental disturbance.]]></description>
<pubDate>2018/1/12 10:33:27</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[江振宇]]></author>
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<title><![CDATA[Nonsingular Sliding Mode Finite-time Guidance with Missile Dynamic]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201610140000001]]></link>
<description><![CDATA[In order to realize intercept angle constraint and finite-time convergence when a missile intercepts a maneuvering target, a guidance model is proposed based on the first-order missile dynamics, regarding the target acceleration as unknown bounded external disturbance, and applying dynamic surface of nonlinear backstepping theory to design a nonsingular sliding mode guidance law with missile dynamic. Based on the Lyapunov stability theory, it is proved that the states of guidance system asymptotically converge to zero. Simulations on intercepting targets with constant maneuvering of low attitude and high velocity are made. Simulation results indicate that guidance law can reduce influence caused by the missile dynamic effectively, and the miss distance and intercept angle error are small, by contrasted with the optimal guidance law with missile dynamic and intercept angle constraint, the guidance law has higher guidance accuracy.]]></description>
<pubDate>2018/1/12 10:32:58</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[王超伦,薛林,闫晓勇]]></author>
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<title><![CDATA[Buffer Allocation Algorithm for SpaceWire Network  Hotspot Communication]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201610190000002]]></link>
<description><![CDATA[According to the working characteristics of SpaceWire network in hotspot communication mode, this paper studies the buffer allocation algorithm. Firstly, the definition of uniform communication mode and hotspot communication mode is given. Secondly, the calculation method of full-load probability and the average delay of nodes in the network are deduced, and the key communication nodes in the network are calculated. Then, the SpaceWire communication model is established by using the Opnet network simulation platform, and the key performance indexes of the different communication modes are simulated before and after adopting the buffer optimization strategy. The results show that, in the hotspot communication mode, the buffer allocation algorithm reduces the average delay of the network system under the same total resource. The performance of the SpaceWire network is optimized.]]></description>
<pubDate>2018/1/12 10:28:59</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[安军社,龚泉铭,姜秀杰,闫梦婷]]></author>
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<title><![CDATA[Measurement of disturbance torque of seeker servo mechanism and optimization of precision assembly process based on electrical measurement]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201708290000001]]></link>
<description><![CDATA[In order to reduce the disturbance torque during the assembly of the seeker’s servomechanism, a drive torque measurement system of servo-mechanism is built on the basis of electrical measurement. The upper software and lower software of measurement system is respectively developed using Labview and Dliphi, In the process of precise assembly and adjustment, the drive torque is measured in real time and the assembly parameters are adjusted so as to reduce the disturbance torque. The characteristics of the mass unbalance torque and the moving cable torque in the driving torque are experimentally verified, and the balancing and routing methods are determined. The relationship between the preload of the bearing and the friction torque of the servo mechanism is experimentally verified. It is of great significance to solve the problem of automatic running process to reduce the fluctuation amplitude of the friction torque. The method of measuring the rotation error of the rotating shaft is determined, which is used for determining optimum preload of bearing. Based on the drive torque measurement system, the traditional assembly process of servo mechanism is optimized, and the qualitative method based on the experience of technician"s experience is optimized as a quantitative method.]]></description>
<pubDate>2017/9/26 15:42:49</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[曹玉君,尚建忠,吴伟,于乃辉]]></author>
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<title><![CDATA[Scattered pilots aided channel estimation based on compressed sensing in OQAM/OFDM system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604290000002]]></link>
<description><![CDATA[Under the multi-path channel condition, the preamble-based channel estimation methods have very large pilots overhead in offset quadrature amplitude modulation/orthogonal frequency division multiplexing (OQAM/OFDM). A scattered pilots aided channel estimation method based on compressed sensing (CS) for OQAM/OFDM system is proposed utilizing the sparsity of wireless channel. The principle of OQAM/OFDM channel estimation method based on CS is established and a scattered pilots pattern, which deploys pilots symbols on few subcarriers randomly, is also designed. The proposed method can reduce the pilots overhead significantly and realize the highly accurate channel estimation. The simulation results validate the efficacy and superior performance of the proposed method in both slow and fast time-varying wireless channel.]]></description>
<pubDate>2017/9/14 11:38:02</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈西宏,刘晓鹏,童宁宁,谢泽东,张  凯]]></author>
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<title><![CDATA[High accuracy fractional delay filter design based on Remez algorithm with boundary fitting]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605040000002]]></link>
<description><![CDATA[In order to improve ranging accuracy between satellites and increase available bandwidth of systems in the simulation and tests, a boundary fitting Remez algorithm for high accuracy fractional delay filter was proposed. The proposed algorithm used the polynomial approximation achieved in Farrow structure, to fit the impulse response boundary coefficients of the filter designed by Remez algorithm, and achieve fractional delay filters through the polyphase decomposition. The proposed algorithm made the impulse response boundary continuous when high-order filters was used, while reduced the group delay error and improved accuracy. The simulation results show that the proposed algorithm improves fractional delay filters accuracy a little, doubles the available bandwidth and reduces the number of multipliers need to be used.]]></description>
<pubDate>2017/9/14 11:37:58</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈鼎,,,,]]></author>
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<title><![CDATA[A Survey of Alert-Correlation Based Network Threat Detection Techniques]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605110000001]]></link>
<description><![CDATA[The rapid development of Internet also causes more and more network threats. How to detect the network threats in a real-time and accurate manner becomes one of the key technique issues. The alert-correlation-based network threat detection technique is becoming the research hotspot, which couples with the widely used security products and fully exploits the relation between abnormal events to reconstruct the attack scenario. Starting from the features of network threats and security environment, the requirements and classification of network threat detection are introduced. Then we illustrate the basic concepts and system model of alert-correlation-based network threat detection technique are in detail. We focus on the key module of the model, alert correlation method, stating the fundamentals and features of different kinds of typical algorithm in detail, including causal-relation-based method, case-based method, similarity-based method and data-mining-based method. Furthermore, three kinds of representative detection system architectures are discussed with practical instances, namely centralized architecture, hierarchical architecture and distributed architecture. Finally, based on the analysis of recent research work, the future work is discussed and outlined.]]></description>
<pubDate>2017/9/14 11:37:54</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[程力,马行空,王意洁]]></author>
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<title><![CDATA[Particle Filtered Matching Pursuit for Compressive Sensing of Blind Sparsity Signal]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605110000003]]></link>
<description><![CDATA[In this paper, a particle filtered matching pursuit for compressive sensing of blind sparsity signal polluted by Non-Gaussion noise is proposed. While conventional detectors(e.g. least-squares estimates) are known to be sensitive to the Non-Gaussion nature of noise. The proposed algorithm which combines the Huber cost(loss) function with an l1-norm does not need the sparse prior while it eliminates the interference of measuring noise by particle filter estimation. Meanwhile, sparsity adaptive matching pursuit is used to sift the effective support set to inverse the original states. The results of simulation indicate that the proposed algorithm outperforms the existing greedy iterative inversions in the same condition, especially in the Non-Gaussion noise situation.]]></description>
<pubDate>2017/9/14 11:37:50</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[胡猛,梁俊,刘玉磊,肖楠,杨萌]]></author>
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<title><![CDATA[Scattering for L(0,1) mode guided wave at the elbow in small diameter tube]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605160000001]]></link>
<description><![CDATA[The experimental and finite element simulation methods were used to investigate the mode conversion and reflection and transmission phenomenon at the elbow in small diameter tubes. Excitation signals of different frequency were used to inspect tubes involve elbows of different bending radius. The results show that mode conversion phenomenon occurs at the elbow and the L(0,1) guided wave converts to F(1,1) guided wave. The orientation of F(1,1) is identical to the extrados-intrados direction of the elbow. With in increase of the inspection frequency and bending radius, the reflected F(1,1) mode decreases monotonically while the transmitted F(1,1) mode changes non-monotonically, the reflected L(0,1) mode decreases while the transmitted L(0,1) mode increases. When the inspection frequency and bending radius increase to some extent, the change of inspection frequency or bending radius has little influence to the reflected F(1,1) mode, reflected L(0,1) mode and transmitted L(0,1) mode. The experimental results agree with the simulation results well which validates the truth of the simulation results. The conclusions will provide theoretical guide to the inspection of small diameter tubes involve elbows.]]></description>
<pubDate>2017/9/14 11:37:46</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈 乐,邓文力,耿海泉,王悦民]]></author>
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<title><![CDATA[A Platform Jitter Measurement Using Linear Accelerometer Method for High-resolution Optical Satellite Images Reconstruction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605160000002]]></link>
<description><![CDATA[Under the condition of satellite platform''s jitter, the push-broom high resolution optical imaging often produces distortion, which affects the accuracy of the image positioning and information extraction. According to the critical compensation issue for distorted images, this paper proposes a steady-state imaging model with the linear accelerometer directly measuring platform jitter to achieve reconstruction of HR distorted images. This paper validates the effectiveness by using distorted panchromatic image of a high resolution satellite affected by platform jitter. The analysis results show that the linear accelerometer can effectively detect and measure the platform jitter, the designed on-ground reconstruction model of jitter image can effectively improve distorted imaging of push-broom optical image caused by platform jitter, and the jitter image’s distortion phenomenon is obviously eliminated.]]></description>
<pubDate>2017/9/14 11:37:34</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[金淑英,潘俊,,王艳,张彪]]></author>
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<title><![CDATA[Maximum Likelihood Calibration for MEMS Triaxial Accelerometer]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605190000004]]></link>
<description><![CDATA[Development of Micro-electromechanical System (MEMS) technology has lead to low cost sensors being widely used in both military and commercial fields. Accelerometer is one of the fundamental measurement units of inertial navigation system (INS). It is difficult to meet the precision requirement for low-cost sensors due to the manufacturing process and all kinds of sensor errors. Calibration for accelerometer is essential before being used. This paper establishes the sensor errors model by taking comprehensive consideration of zero bias, scale errors non-orthogonal errors, installation errors and measurement noise of the accelerometer, based on which the calibration problem of accelerometer is transformed into maximum likelihood estimation (MLE) problem of calibration parameters. The self-calibration algorithm based on maximum likelihood Estimation is tested by both numerical simulation and real data experiment. The result shows the MLE algorithm has a high precision of parameters estimation which can calibrate the errors caused by factors mentioned above effectively.]]></description>
<pubDate>2017/9/14 11:37:25</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[贺静波,刘忠,陆欣,张宏欣]]></author>
</item>
<item>
<title><![CDATA[Creep behavior and life predication for anti-detaching spring]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605190000006]]></link>
<description><![CDATA[According to the loading mode and failure mechanism of a certain anti-detaching spring, a testing device for creep of anti-detaching spring was designed and manufactured. The creep accelerated aging test was done, and the effect of the temperature and loading on the creep behavior of anti-detaching spring was investigated with image measuring technology. Furthermore, the creep kinetic equation of anti-detaching spring subjected to loading and temperature based on Arrhenius equation was derived to predict the service life of the anti-detaching spring. The results show that the displacement of the spring due to creep is a monotonic non-decreasing function of time. Increasing the temperature or initial preload will increase its creep displacement. The method and conclusion may be helpful in creep anti-detaching spring design and life prediction.]]></description>
<pubDate>2017/9/14 11:37:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[孔繁杰]]></author>
</item>
<item>
<title><![CDATA[Dynamic analysis of nonlocal nanobeams resting on viscoelastic foundation subjected to a magnetic field]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605240000001]]></link>
<description><![CDATA[Based on nonlocal Euler-Bernoulli beam theory, the dynamic characteristics analysis model was built for nanobeams resting on viscoelastic foundation and subjected to a magnetic field. The Kelvin viscoelastic foundation model and the Lorentz magnetic force were introduced to derive the governing equations of the system. The new general analytical expressions for the complex natural frequencies of the nanobeams were obtained for Kelvin-Voigt model and some typical special cases were also discussed. Then the governing equations of motion were solved by using the transfer function method to obtain the natural frequencies and corresponding mode shapes in closed form for the nanobeams with arbitrary boundary conditions. Considering a single-walled carbon nanotube as a numerical example, the first three natural frequencies for various boundary conditions were obtained, and a detailed parametric study was conducted to examine the effect of nonlocal parameter, the strength of the magnetic field, aspect ratio, damping parameter and boundary conditions on the vibration characteristics of nanobeams. The results demonstrate the efficiency of the proposed model for dynamic characteristics analysis of the nanobeams resting on viscoelastic foundation under a magnetic field.]]></description>
<pubDate>2017/9/14 11:37:15</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[雷勇军,申志彬,张大鹏]]></author>
</item>
<item>
<title><![CDATA[A Modified Tracking Differentiator Design for Missile in Hardware-in-loop Simulation System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605250000001]]></link>
<description><![CDATA[In order to inhibit the influence of the output signals of three-axis simulator exhibits the phase delays and noise on the performance of missile’s hardware-in-loop simulation system, a modified tracking differentiator which is used to filter and phase advanced is analyzed and designed. Based on the principle of traditional tracking differentiator, the basic structure of tracking the output signals of three-axis simulator is designed, the phenomenon of the output signals present vibration is analyzed that is owing to the differential signal which is via the tracking differentiator trembles when the input signal exist noise. On this basis, a design method that the differential signal cascades another tracking differentiator is proposed to filter the signal pollution and output signals noise. Finally, as the examples of one missile’s hardware-in-loop simulation system which is the output signals of three-axis simulator exhibits the phase delays and noise, the performance of the system is verified by compared with that of the lead correction method. Simulation results show that the attitude angular velocity can be extracted by the modified phase advancer efficiently, and the modified phase advancer possesses excellent filter and phase advanced performance, which prove the correctness and validity of the modified phase advancer in the hardware-in-loop simulation system for missile.]]></description>
<pubDate>2017/9/14 11:37:07</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[白宏阳,明超,孙瑞胜,祝刚]]></author>
</item>
<item>
<title><![CDATA[Processing the Sliding Spotlight Bistatic SAR Based on Direct-Path Signal Compensation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201605260000001]]></link>
<description><![CDATA[In fixed-receiver bistatic synthetic aperture radar (SAR), the spaceborne SAR was used as the illuminator. Taking account into the high signal-to-noise ratio (SNR) advantage, the direct-path signal is used as reference signal for range match filtering. Then the range compression can be realized with time and frequency synchronization process. However, after range compression, the range history of point target consists of three square-root terms which is hardly to use the Principle of Stationary Phase (POSP). Based on azimuth preprocessing, direct-path signal compensation and nonlinear Chirp Scaling imaging algorithm, a new focusing algorithm is presented in this paper. Simulation results of point targets are presented to validate the feasibility and efficiency of the proposed method. Finally, this algorithm was also validated by the measured data of the HITCHHIKER system.]]></description>
<pubDate>2017/9/14 11:37:02</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[常文革,黎向阳,闫飞飞,张启雷]]></author>
</item>
<item>
<title><![CDATA[BeiDou multi-service satellite system and application——discussion on BeiDou S band navigation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201706060000001]]></link>
<description><![CDATA[Radio frequency is a non-renewable resource, and frequency sharing has become the consensus of the International Telecommunication Union (ITU). Multi-service integration has been the development trend of the world radio satellite system. S band 2483.5MHz~2500MHz has been determined into the sharing band of satellite multi-service including Radio Determinations Satellite Service(RDSS), Radio Navigation Satellite Service and Mobile Satellite Service(MSS) by ITU, and is expected to provide four function: satellite navigation, route tracking, emergency rescue and information relay. In this paper, it introduces the development of S band space based system, the frequency characteristics of navigation communication, the prospect of S band multi-service, the future application and social and economic benefits of the S band navigation in China.]]></description>
<pubDate>2017/9/14 11:36:57</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[谭述森]]></author>
</item>
<item>
<title><![CDATA[Comparison between GPS-derived PWV and Rainfall During 2013 to 2016 over Hong Kong]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201703130000001]]></link>
<description><![CDATA[The atmospheric precipitable water vapor (PWV) is derived from GPS observations of 5 stations over Hong Kong during four years from 2013 to 2016 and the accuracy of PWV(GPS) is assessed with PWV(ECMWF). The PWV(GPS) is then compared with rainfall based on harmonic analysis. The results show that taking PWV(ECMWF) monthly means as references, the RMS of PWV(GPS) monthly means is between 1.02 mm and 3.07 mm and the bias is between -2.14mm and 2.52mm. Both PWV and rainfall have similar periodic characteristics. The peaks of PWV occur in July with amplitudes varying between 14.65 mm and 16.79 mm. The peaks of rainfall also occur in July and the amplitudes are between 147.64 mm and 211.01 mm. The annual increase rate of PWV is positive at each GPS station, indicating that PWV over Hong Kong has an increasing trend during the past 4 years.While the annual increase rate of actual rainfall is negative except in HKOH station, which means a decreasing trend during the 4 years.]]></description>
<pubDate>2017/9/14 11:36:43</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[刘宏康,罗佳,徐晓华]]></author>
</item>
<item>
<title><![CDATA[BDS Positioning Accuracy Improvement based on Pseudolites]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604280000002]]></link>
<description><![CDATA[Compass satellites concentrating near the equator, which resulting in a low positioning accuracy within the Homeland in north-south direction. And because the visible satellites are positive elevation, the vertical positioning accuracy is also low. To solve the above problems, a method to improve BDS positioning accuracy is proposed, which is using pseudolites to improve the user observation geometry. Simulation results show that the DOP in north-south and vertical direction can be reduced effectively by lying pseudolites in the north area of users, thus the positioning accuracy can be effectively improved.]]></description>
<pubDate>2017/9/14 11:36:35</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李昊,欧钢,徐博]]></author>
</item>
<item>
<title><![CDATA[Research of Constant Envelope Modulation / Multiplexing Technologies for Modern BeiDou Global Navigation Signals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201607080000002]]></link>
<description><![CDATA[For the purpose of structural enhancement and backwards compatibility, BeiDou Navigation System has proposed several new constant envelope modulations recently, including QMBOC and ADualQPSK modulations, the new MBOC modulation and constant envelope multiplexing technologies applied for B1 band; TD-AltBOC and ACE-BOC modulations, the constant-envelope modulation that multiplexes four binary spreading codes as two QPSK signals at two different carrier frequencies applied for B2 band; DualQPSK modulation, the constant-envelope modulation that multiplexes four binary spreading codes as two QPSK signals at one carrier frequency applied for B3 band; GCE-BOC modulation, the constant-envelope modulation that multiplexes arbitrary signals at two different carrier frequencies. In this paper, all the new modulations are analyzed, including several aspects such as application backgrounds, modulation principles and multiplexing efficiencies. On the basis of this, a unified analytical expression of constant envelope modulation / multiplexing is summarized based on GCE-BOC modulation, which will provide an important reference for the comprehensive understanding of the signal design of the Beidou global navigation satellite system and the development of new type of constant envelope modulation / multiplexing technology on this basis.]]></description>
<pubDate>2017/9/14 11:36:31</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄新明,欧钢,宿晨庚,周鸿伟,朱祥维]]></author>
</item>
<item>
<title><![CDATA[Differential Positioning Algorithm for Mobile Base Station Based on BeiDou Navigation System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201706050000002]]></link>
<description><![CDATA[Aiming at the problem that fixed measurement environments cannot establish a fixed base station and carry out precise positioning, a mobile station differential positioning algorithm based on BeiDou navigation system is proposed which means achieving high-precise differential positioning while the base station and the rover both moving. Based on the carrier phase measurement, under the condition of dynamic short baseline, the datum are inter-station and inter-satellite double-difference processed, eliminating receiver clocks and other common errors. Based on the linear combination of multi-frequency measurement, the observation of the super-wide lane, the wide lane, the middle lane and the narrow lane is obtained, the window-moving average filter is carried out and the ambiguities are fixed by the stepwise ambiguity method, that is, along the order from the super-wide lane to the narrow lane to solve the ambiguity. In order to verify the effectiveness of the algorithm, a verification experiment of the external geometric parameter detector based on the BeiDou navigation system is designed to realize the static relative positioning accuracy of millimeter and the RTK relative positioning accuracy of centimeter.]]></description>
<pubDate>2017/9/14 11:36:23</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[王一军,杨杰,余明杨]]></author>
</item>
<item>
<title><![CDATA[Applying SVM to Fault Channel Detection in VectorTracking Loop]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604250000001]]></link>
<description><![CDATA[Vector tracking loop is one of the advanced technology of the satellite navigation receiver. The algorithm employs a central kalman filter to complete the tracking and navigation, and then calculate the loop parameter using the navigation solutions. Making full use of the shared information of the different channels can better the performance of the anti-interference and bridge the instantaneous blocked signals. However, the disadvantage is that the fault channel could influence other channels and cause the receiver fail to provide navigation information. This paper proposed a channel fault detection algorithm, which employs a trained SVM to classify the channel. The simulation results show that this method can accurately detect faulty channels, improve the performance and robustness of the vector tracking loop.]]></description>
<pubDate>2017/9/14 11:36:15</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[薄煜明,陈帅,邓贵军,蒋长辉,屈新芬]]></author>
</item>
<item>
<title><![CDATA[Carrier Tracking in Presence of Ionosphere Scintillation Using Online Wavelet De-noising]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201606270000003]]></link>
<description><![CDATA[Since carrier tracking in presence of ionospheric scintillation is non-stationary, nonlinear and non-Gaussian, the conventional discriminator or Kalman filter-based methods used to enhance the robustness of tracking loops are less effective. This paper proposes a carrier tracking algorithm for scintillation mitigation based on online wavelet de-noising, which can character the non-stationary scintillation signal much better. By designing a sliding window-based online wavelet de-noising filer after the integration of I and Q channels, the non-Gaussian noise caused by scintillation can be filtered effectively. As a result, the effect of ionospheric scintillation on loop discriminator is mitigated, and the accuracy and robustness of the tracking loop is improved. Experimental results prove the validity of the analysis and the proposed carrier tracking algorithm.]]></description>
<pubDate>2017/9/14 11:35:55</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈华明,黄仰博,孙广富,孙鹏跃,唐小妹]]></author>
</item>
<item>
<title><![CDATA[Research on key experimental requirements of a Bragg diffraction-based cold atom interferometry gravimeter]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201601220000003]]></link>
<description><![CDATA[In this paper, we present a new type of cold atom interferometry gravimeter based on Bragg diffraction, which is able to increase the gravity measurement sensitivity and stability of common Raman atom gravimeters significantly. By comparing with Raman transition, the principles and advantages of Bragg diffraction-based atom gravimeters have been introduced. The theoretical model for a time-domain Bragg atom gravimeter with atomic incident direction parallel to the wavevector of Bragg lasers has been constructed. Some key experimental requirements for an nth-order Bragg diffraction-based atom gravimeter have been deduced, including the temperature of atom sources, the diameter, curvature radius, frequency, intensity, and timing sequence of Bragg pulses, etc. The analysis results were verified by the existing experimental data in discussion. The theoretical model and conclusions presented in this paper provide a meaningful reference for the understanding and construction of a Bragg diffraction-based cold atom gravimeter.]]></description>
<pubDate>2017/9/14 11:35:51</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[胡青青,杨俊]]></author>
</item>
<item>
<title><![CDATA[Intuitionistic Fuzzy Matter-element and Its Application in Multi-attribute Group Decision-making with Unknown Weight]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201603210000001]]></link>
<description><![CDATA[:Intuitionistic fuzzy theory makes contributions to the development of the multi-attribute group decision-making. This paper offered intuitionistic fuzzy matter-element model with intuitionistic fuzzy decision information based on the traditional matter-element theory. It presented relative similarity to replace the traditional correlation function and then integrally described intuitionistic fuzzy matter-element multi-attribute decision-making method and its steps. This paper used an example to show the effectivity of this method and especially it analyzed the multi-attribute group decision-making problem with unknown weight based on projection method and intuitionistic fuzzy entropy to prove the practicability of this method.]]></description>
<pubDate>2017/9/14 11:35:46</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[张洋铭]]></author>
</item>
<item>
<title><![CDATA[ROBDD Algorithm for Analyzing the Reliability of Phased-Mission System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604060000004]]></link>
<description><![CDATA[The reliability analysis approach of phased-mission system(PMS) based on Markov process encounters the state explosion problem for large systems. In this paper, the PMS reliability model using hierarchical method is proposed to avoid the state-explosion problem. The hierarchical method use a low-level continuous time Markov chain(CTMC) to describe components’ dynamical behavior and the upper-level binary decision diagrams(BDD) to describe system behavior. The isomorphic nodes consolidation strategy and the redundant nodes removal strategy are given to construct reduced hierarchical model. The above nodes compressing strategies can improve the efficiency of model generation and storage. A recursive computing algorithm solving the hierarchical model based on the PMS components ordering is designed, and its computational complexity is linear with the number of nodes in model. Finally, by a case study, the number of nodes in original model is compared with it using nodes compressing strategies, also the mission reliability in the hierarchical model is compared with it in the Markov model. Results show the correctness and effectiveness of the reduced hierarchical model.]]></description>
<pubDate>2017/9/14 11:35:37</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[郭立卿,邢云燕,闫华,张立]]></author>
</item>
<item>
<title><![CDATA[Midcourse trajectory cluster generation based on neighboring optimal control theory]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604220000001]]></link>
<description><![CDATA[Aiming at the high velocity and unpredictable trajectory characteristics of the hypersonic targets in near space, the optimal midcourse trajectory design and trajectory cluster generation methods are proposed for the effective coverage of the target’s predicted impact area. Firstly, by analyzing the challenges that the hypersonic targets have formed to the existing air defense systems, the necessity of the trajectory cluster design and generation in midcourse phase is illustrated. Secondly, the optimal midcourse trajectory design is treated as the problem of searching for optimal solutions under numerous constrains, and the nominal optimal trajectory is generated with the optimal control theory. Thirdly, based on the neighboring optimal control (NOC) theory, the neighboring optimal trajectory cluster generation algorithm is developed to meet the adjusted terminal constraints. Finally, the simulation results testify the effectiveness of the proposed method.]]></description>
<pubDate>2017/9/14 11:35:31</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[雷虎民,邵雷,翟岱亮,张大元,周觐]]></author>
</item>
<item>
<title><![CDATA[Research on the method of multipath prediction based on backward ray tracing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604270000003]]></link>
<description><![CDATA[Multipath is the key factor which affects communication, navigation system performance. It not only affects the signal power, but also causes time delay, frequency shift and polarization parameters changing, resulting in a decrease in the communication and navigation system. To solve this problem, the fast reverse ray tracing algorithm based on virtual source tree, partition, backward detection, is proposed to predict multipath signal loss and delay distribution accurately. Besides, the urban scenes are taken as examples to show the algorithm of signal multipath transmission, and the diffraction algorithm is studied to improve the accuracy of the prediction. Finally, taking the signal propagation through simplified street models for example, the consistency of reflection path and power distribution can be proved by comparing the MATLAB program based on the algorithm which is mentioned in this paper and the simulation from using Wireless Insite software, in which way, the validity of the algroithm is also verified.]]></description>
<pubDate>2017/9/14 11:35:15</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[于学伟①]]></author>
</item>
<item>
<title><![CDATA[Disturbance estimation and compensation of free space optical communication coarse tracking system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604270000004]]></link>
<description><![CDATA[Affected by the influence of the attitude variation and vibration of the satellite platform in the process of tracking and pointing, free space optical communication terminal will therefore reduce the tracking precision of the system. In order to improve the system''s ability to for the purpose of resisting disturbance, this paper, on the basis of coarse tracking system,  put forward cascade linear active disturbance rejection controller . The coarse tracking system for DC brushless torque motor driving two-dimensional turntable as the actuator, through the coarse tracking controller to control it. Firstly, Analysis of the system disturbance is required, for which we apply the tracking differentiator (TD) to extract. Secondly, with azimuth axis of the two-dimensional turntable as the object, the cascade linear active disturbance rejection controller was applied to position loop and speed loop for the sack of active disturbance compensation through linear extended state observer (LESO), therefore, double isolation of internal and external loop disturbance could be achieved, and the tracking precision shall be improved. Finally, the experimental analysis, and comparison with the PID controller are also included in this paper. The research results show that there is a 50% decrease of standard deviation referred to the tracking error，when inputting 2 Hz，5 Hz and 8Hz sinusoidal signals with the same disturbance signal simulation. At the same time, this paper verified the observer’s disturbance compensation effect in the circumstance of linear expansion.A high tracking accuracy is still ensured when ADRC controller is not sensitive to the frequency variation of inputted sinusoidal signal with changing frequency.]]></description>
<pubDate>2017/9/14 11:35:04</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[崔宁,王岩,于志亮]]></author>
</item>
<item>
<title><![CDATA[Fault Detection and Diagnosis of Launch Vehicle’s Servo Mechanism Based on Extended Multiple Model Adaptive Estimation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201706190000001]]></link>
<description><![CDATA[Aim at servo mechanism fault of launch vehicle, A fault detection and diagnosis（FDD） based on extended multiple model adaptive estiamtion was proposed. Firstly, Attitude dynamic model of launch vehicle considering servo mechanism fault was established. Secondly, the fault Angle was used as the state variable to obtain the augmented state space model. Then, the nonlinear estimation of state vector and fault parameters was carried out using Extended Kalman Filter, and based on the sensor measurement data, the probability of the occurrence of faults was calculated by the hypothesis testing algorithm, Finally, the fault detection and diagnosis procedure based on extended multiple model adaptive estimation is presented. The advantage of this FDD algorithm is that FDD of one servo mechanism can be realized by only one Extended Kalman Filter, so the amount of filters applied to FDD of servo mechanisms can be reduced sharply. Simulation results shows that , not only health monitoring of the servo mechanism can be carried out by the algorithm without fault, but also under single servo mechanism fault, the algorithm can timely and exactly detect which core servo mechanism’s fault happened, and the angle of nozzle under servo mechanism fault can be estimated accurately.]]></description>
<pubDate>2017/9/14 11:34:51</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈宇,程堂明,李家文,唐国金]]></author>
</item>
<item>
<title><![CDATA[UAV Relative Navigation Method Research Based on Multi-sensor Information Fusion]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201706200000001]]></link>
<description><![CDATA[In order to improve the operational effectiveness and operational indicators of the unmanned aerial vehicle (UAV), enhance the accuracy and reliability of the UAV relative navigation system, a novel relative navigation method is proposed in this paper. Under the background of relative navigation system, the cubature information filter is researched based on the cubature Kalman filter and information filter. Moreover, an INS/GPS/VisNav relative navigation filter is designed by making use of the multi-sensor information fusion theory and distributed information fusion structure to fuse the information from INS, VisNav and GPS, and then the relative position, velocity and attitude are obtained. By making use of this algorithm, the accuracy, reliability and stability of the reliability navigation system are all improved. In addition, the accuracy decrease and numerical instability which often occur to traditional filter is avoided by cubature information filter. Some simulations are conducted in this paper. The simulation results indicate the method could improve the accuracy and reliability of the UAV relative navigation system, and the algorithm proposed in the paper is verified.]]></description>
<pubDate>2017/9/14 11:34:41</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[金红新,王小刚,杨涛,姚旺,周国峰]]></author>
</item>
<item>
<title><![CDATA[Parallel correlation algorithm based on vector dot product]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201702150000001]]></link>
<description><![CDATA[The correlator is the core module of serial search acquisition and channel tracking in a navigation receiver. Computing resource requirements are high for real-time correlation of several tens of channels in software receiver, but most of the software receiver algorithms are sequential algorithms based on a single core processor. For solving the real-time problem of the software correlator, a parallel receiving model of spread spectrum signal based on vector dot product is proposed. By parallel computing correlation value of each channel with a large number of ALU in GPU, the calculation speed of the signal correlation is improved. The simulation results show that, with the Vector Dot Product parallel correlation algorithms based on GPU, 25 channels with 150 correlators consume 967us in all for 1ms signal of 25MHz sampling rate. Compared with the implementation on CPU based on MKL, the method speeds up to 61.4 times, then real-time correlation of the broadband spread spectrum signals in software can be realized.]]></description>
<pubDate>2017/9/14 11:29:18</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[白洋,牟卫华,倪少杰,欧钢,孙广富]]></author>
</item>
<item>
<title><![CDATA[Uncorrelated Differential Robust Estimation of Allan Variance Based on Huber Weight Function]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201702240000001]]></link>
<description><![CDATA[The estimation of atomic clock’s frequency stability will significantly deviate from its true value if anomalies occur. This paper proposes an uncorrelated differential robust estimation method based on Huber weight function. Firstly, difference estimation model of Allan variance is established, and computation complexity of noise identification and whiten introduced by correlative difference is analyzed based on statistical property of difference clock sequence. In order to solve this problem, a construction model of uncorrelated difference sequence is established to avoid complex noise identification and whiten computation effectively. Based on this, correlative difference robust estimation method of Allan variance is derived, followed by a counteracted technique of error accumulation introduced by robust estimation. Finally, the integrated robust estimation solution is given, and its effectiveness is verified by experiment. The results show that the method has significance robust ability for phase outliers and phase jumps, and the relative deviation introduced by anomalies can be reduced from almost 200% to less than 5%.]]></description>
<pubDate>2017/9/14 11:29:03</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[龚航,李井源,刘增军,孙广富,朱祥维]]></author>
</item>
<item>
<title><![CDATA[Performance Analysis of Global Navigation Satellite System Anti-jamming Optimal Receivers and Correlation Receivers]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201702240000002]]></link>
<description><![CDATA[Interfere suppression is one of the hotspot on Global Navigation Satellite System (GNSS). It is the focus how the performance of interfere suppression and signal reception can be simultaneously improved in anti-jamming receivers. The sole antenna GNSS anti-jamming optimal receivers are lucubrated on basis of the maximal signal-to-interference-noise ratio (MSINR) norm in partial-band interferences circumvent. Theirs frequency responses, SINR losses and match output functions are analyzed in detail. The sole antenna GNSS anti-jamming correlation receivers, which are used to reduce the hardware realization difficulty, are also studied in partial-band interferences circumvent. Theirs frequency responses, SINR losses and correlation output functions are present. It is showed that the SINR losses of anti-jamming optimal receivers and correlation receivers will increase with the bandwidth and power increase of interferences. The SINR losses will decrease with the bandwidth increase of noise and the frequency difference increase between interferences and signals. Moreover, it is showed that the match and correlation output main lobes will be depressed and the side lobes will be raised by jammers. As a result, the acquisition, track and multipath mitigation performance of anti-jamming receivers will be affected. The analysis results will provide the design basis for the GNSS anti-jamming receivers.]]></description>
<pubDate>2017/9/14 11:28:45</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈华明,李峥嵘,王飞雪]]></author>
</item>
<item>
<title><![CDATA[Optimization of Accelerated Burn-in Time with Reliability and Cost Constraints]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509080000003]]></link>
<description><![CDATA[In order to improve the field reliability of products and reduce the total cost of burn-in procedure and warranty, an optimization method of accelerated burn-in time for products with infant mortalities is developed based on the utility function with reliability and cost constrains in this paper. Considering the uncertainties with respect to the lifetime distribution parameters of the product, prior distributions of these parameters are derived by using the bootstrap method, then the joint utility function combining field reliability with cost is constructed through simulation technique. Choosing the maximum of joint utility as objective, the optimal accelerated burn-in time model is established, and the optimal burn-in duration is derived. The application of the above method is illustrated explicitly by a numerical example, in which a product with log-normal distribution is burned-in under elevated temperature condition, and parameters’ sensitivity analysis is also conducted. The results show that not only the burn-in duration can be shortened by applying the proposed method, but requirements for cost and reliability can be met simultaneously at utmost.]]></description>
<pubDate>2017/5/2 15:34:22</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[程龙,黄秀平,周经伦]]></author>
</item>
<item>
<title><![CDATA[Horizontal body position control method of a trotting hydraulic driving quadruped robot]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509140000003]]></link>
<description><![CDATA[In order to control the horizontal body position of a trotting hydraulic quadruped robot, an approximated dynamical model is built based on motion decomposition along the support line, which simplifies the body and the stance legs to a seven-link mechanism and a linear inverted pendulum. And a landing position control algorithm is proposed based on the approximated dynamical model in this paper. Then, for the velocity limitations of the hydraulic cylinders pushing and pulling, an optimization algorithm is designed based on the redundant joints in the legs, which is able to decrease the demands for the joint angular velocities. Furthermore, in comparison to the conventional pseudo-inverse optimization algorithm, the proposed algorithm can avoid the singular state of the legs more effectively. The simulation and experiment results show that the desired horizontal body position trajectories can be tracked accurately by using the proposed algorithms, even the joint angular velocities being limited.]]></description>
<pubDate>2017/5/2 15:34:13</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[郎琳,马宏绪,王剑,韦庆,许佳奇,张献鹏]]></author>
</item>
<item>
<title><![CDATA[Technology of error compensation in navigation systems based on nonlinear Kalman filtering]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511090000003]]></link>
<description><![CDATA[As for nonlinear/non-Gaussian information processing problems in navigation systems, a kind of adaptive integrated navigation system was established based on modified nonlinear Kalman filtering by utilizing self-organization algorithms, neural networks and genetic algorithms. First, applying self-organization algorithms with redundant trends, Volterra neural networks and genetic algorithms, error models of integrated navigation systems are built based on Kalman filtering. Then, predicted values of navigation errors are obtained using the established error models. Second, comparing the predicted values with the estimated values by Kalman filtering, the difference between them, functioning as an index of divergence of Kalman filtering, is formulated. Finally, the modification of nonlinear Kalman filtering is made and a novel technology of navigation error compensation is thus developed based on adaptive control methods. Applying traditional and modified Kalman filtering respectively, the semi-physical simulation study based on the navigation systems KIND-34 and Com-paNav-2 was carried out. The analyzed results indicated that the accuracy of error estimation and compensation in nav-igation systems was improved using modified nonlinear Kalman filtering with self-organization algorithms, neural net-works and genetic algorithm, and thus the ability of self-adaption and fault tolerance was enhanced in integrated navigation systems.]]></description>
<pubDate>2017/3/29 11:00:02</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[A.V.普拉列达尔斯基,,,,]]></author>
</item>
<item>
<title><![CDATA[Service model and performance analysis of TOC based on complex queuing system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201610180000002]]></link>
<description><![CDATA[Ternary optical computer's request processing lacked reasonable, systematic standard and system for performance evaluation. Therefore, a four-stage service model was built based on complex queuing systems including M/M/1, M/M/n, MX/M/1 and M/MB/1. Meanwhile, strategy and algorithm of instant-scheduling and end-scheduling were proposed in detail. Then computation of receiving time, preprocessing time, operating time and transmitting time of operation requests were discussed based on different queuing systems, and the final response time could be obtained. Finally, two strategy models are verified by simulation experiments, and the results show that end-scheduling strategy is superior to instant-scheduling strategy.]]></description>
<pubDate>2017/3/9 17:23:58</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[王先超,]]></author>
</item>
<item>
<title><![CDATA[Impact analysis and experimental research on friction torque of seeker servo mechanism under changing temperature]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201507150000003]]></link>
<description><![CDATA[A friction torque analysis model of seeker servo mechanism including thermal coupling deformation was established. The influence of changing environment temperature on geometry parameters and friction torque of angular contact bearing was mainly studied. Taking mirror-type seeker as an example, its friction torque was calculated and analyzed using the proposed calculation model. The results show that grease viscosity is the main cause of sharp rise of friction torque as the temperature dropping and the friction torque caused by coupling thermal deformation is not the main component. An experimental system for friction torque measurement was established based on electrical method and a rapid temperature experiment chamber was used to simulate environment temperature. The theoretical calculation results and experiment results were compared and analyzed.]]></description>
<pubDate>2017/2/27 10:50:48</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[曹玉君,陈治富,李欣,尚建忠,于乃辉]]></author>
</item>
<item>
<title><![CDATA[Locating Method of Moving Periodic Sound Source With Double-Array]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201512210000002]]></link>
<description><![CDATA[Aiming at the intensive calculation and difficulty in test with common methods of moving sound source locating, a locating method based on array signal processing was proposed. Locating ability of single and double five-element cross array were analyzed. Based on the high performance of direction estimating with single array, location of moving sound source was achieved by azimuth of double arrays crossing according to beamforming. Locating experiment was carried on while using engine noise of self-propelled vehicle as simulated source. Then the length selection of short correlation and compensation of moving path were studied. Experiment shows that the method is effective to moving sound source locating with high precision, maximum relative error stays below level of 5%.]]></description>
<pubDate>2017/1/9 16:29:14</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[熊超,张炳文,郑坚]]></author>
</item>
<item>
<title><![CDATA[Sequential approximate optimization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509040000002]]></link>
<description><![CDATA[As more and more high precise time-consuming model is revealed into optimization procedure, general intelligence optimization algorithm cannot get a desirable result in feasible computing cost. The developing sequential approximate optimization approach overcomes this drawback by introducing the approximate model in the optimization procedure, and adds infill points sequentially to search the promising areas. This advantage makes it more and more practical technique for time-consuming engineering optimization. This paper gives an overview of the sequential approximate optimization algorithm and its core techniques, which can expend the application of the algorithm. Finally, some relevant improved methods and new developmental trends concerning SAO were presented.]]></description>
<pubDate>2017/1/9 16:28:58</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[胡凡,王东辉,武泽平,]]></author>
</item>
<item>
<title><![CDATA[Sensitivity analysis of the torque axis considering the times of load action with Multiple Failure Modes]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201510110000001]]></link>
<description><![CDATA[Several potential failure modes may occur when mechanical components fail, and they have several correlation in some way, for that the condition of load action many times have an impact on the reliability of mechanical components, thus it was necessary to take all the failure modes and load action many times into account when study the mechanical reliability sensitivity analysis. Combined the order statistic theory to study the influence of load action time on the reliability and sensitivity calculation, applying the probabilistic perturbation method and the Edgeworth series technique, a reliability calculation model of mechanical components with multiple failure modes and load action many times modes had developed using the stress-strength interference mode. The calculating formulas of reliability sensitivity with respect to the mean and variance of random variables were derived with the gradient method, according to the result of the torque axis reliability sensitivity analysis, the curves of reliabilities and sensitivities were obtained, and the production can be very useful if it extended to correlated area of machine sensitivity design.]]></description>
<pubDate>2016/9/23 15:55:19</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[贾长治,刘喆,陶凤和]]></author>
</item>
<item>
<title><![CDATA[Rigid-flexible Coupling Dynamics Simulation of Anti-backlash Gear Transmission System Considering Shaft Distance Errors]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201506010000002]]></link>
<description><![CDATA[It is widely recognized that the shaft distance errors have vital effect on the accuracy and performance of anti-backlash gear transmission system. However，the essential mechanism and property is still undiscovered. Based on the contact constrained dynamics model of anti-backlash gear transmission system，the rigid-flexible coupling dynamics model of anti-backlash gear transmission system based on ADAM/ Flex was established. Then，the rigid-flexible coupling dynamics simulation was carried out to study the vibration and frequency characteristics of the anti-backlash gear transmission system with different shaft distance errors. It is discovered that the spring torque，contact force and the friction torque will increase with the decrease of shaft distance，which will hamper the normal motion of the active gear and decrease the magnitude of rotation speed of the fixed shaft ; the main frequency of the main shaft will decrease with the increase of shaft distance，and the decrease will be sharper when the shaft distance is a little more larger than standard centre distance. These discoveries will be helpful in the design and assembly of anti-backlash system.]]></description>
<pubDate>2016/9/23 15:54:07</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[罗自荣,,,]]></author>
</item>
<item>
<title><![CDATA[Research on coarse-fine composite technology for scanning in inter-satellite laser communication]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505140000001]]></link>
<description><![CDATA[The system of inter-satellite optical communication includes acquisition, pointing and tracking technology, the acquisition is the premise and guarantee for normal work. The principle of acquisition, key technology and engineering implementation under scanning stare mode are research in detail. A method for combination of the coarse fine pointing of spiral sine is presented. Numerical simulation results for the scanning process prove that, compared with traditional single coarse scanning, the coarse fine scanning is smaller leak scanning method, the study provides a method for scanning acquisition process of optical communication.]]></description>
<pubDate>2016/9/23 15:53:03</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[曹开锐,陈兴林,耿光晓,于志亮]]></author>
</item>
<item>
<title><![CDATA[Impact of Signal Bandwidth on CCRW Code Tracking Accuracy]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201508180000001]]></link>
<description><![CDATA[Code Correlation Reference Waveform has been the research hotspot for its flexibility for complex electromagnetic environment and outstanding multipath mitigation performance in GNSS receivers．The analysis of code tracking accuracy for CCRW from the literature is mainly on the assumption for the infinite channel bandwidth, and simulation how the gate width parameters affect the code tracking accuracy. The analytical expression of code tracking accuracy is derived in the paper. The analysis shows that unlimited channel bandwidth can be increased to reduce the width of the gate wave code tracking accuracy, but there is an optimal value of the gate width in the band-limited condition. The research results can be used to guide CCRW algorithm design for GNSS receivers．]]></description>
<pubDate>2016/9/23 15:51:28</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[刘瀛翔,倪少杰,欧钢,庞晶]]></author>
</item>
<item>
<title><![CDATA[Incremental neural network and clustering algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509280000003]]></link>
<description><![CDATA[Neural network model is powerful in problem modelling. But the traditional back propagating algorithm can only execute batch supervised learning, and its time expense is very high. According to these problems, we put forward a novel incremental neural network model and corresponding clustering algorithm. This model is supported by biological evidences, and it is built on the foundation of novel neuron’s activation function and synapse adjusting function. On this base, we put forward an adaptive incremental clustering algorithm, in which mechanisms such as “winner-take-all” are introduced. As a result, “catastrophic forgetting” problem can be successfully solved in the incremental clustering process. Experiments results on classic datasets show that this algorithm’s performance is comparable with traditional clustering models such as K-means. Especially, its time and space expenses on incremental tasks are much lower than traditional clustering models.]]></description>
<pubDate>2016/9/23 15:46:53</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[刘培磊,唐晋韬,王挺,谢松县]]></author>
</item>
<item>
<title><![CDATA[Observability analysis for misalignments of inertial sensors in inertial platform self-calibration]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505180000001]]></link>
<description><![CDATA[The observability of inertial sensor misalignments in inertial platform self-calibration problem was analyzed, highlighting the effects of the system model and platform coordinate frame on observability. Based on different system dynamic models and measurement vectors, four system models were built up. The observability of inertial sensors misalignments in different models with different definition of platform coordinate frame was investigated. The theory conclusions and simulation results showed that: the system is observable only in two conditions: 1) the system measurement models was built up with platform angles and accelerometer triad outputs, the system dynamic model was built up with platform angles and the platform coordinate frame should be defined with the benchmark hexahedron of platform; 2) the system measurement models was built up only with accelerometers triad outputs, the system dynamic models was built up with platform attitude or misalignment models and the platform coordinate frame should be defined with the accelerometer sensor axes.]]></description>
<pubDate>2016/9/23 15:40:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[蔡洪,丁智坚,]]></author>
</item>
<item>
<title><![CDATA[SAR position method based on high precision scene matching]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505270000002]]></link>
<description><![CDATA[Aimed to improve the location precision of SAR platform, a location method based on scene matching is proposed in this paper. According to that the platform is on the centerline of SAR image at the imaging central time, some points on the centerline are equably  engaged as control points in the proposal method , whose spatial position can be obtained by highly precision matching with optical reference image. Then equation of the projection line on the local horizon of centerline can be estimated with the points.  Finally we can calculate the projection point position of the SAR platform on the projection line, as well as the spatial position of the platform. Considering the difference between boresight and squint imaging mode, rough rectifying methods are respectively proposed according to the two modes to improve the matching precision. The impact of different errors on location precision is also analyzed in this paper and the precision estimation formulas are derived. Both simulation and real data test results show accuracy, high precision and practical value for engineering of the proposal method.]]></description>
<pubDate>2016/9/23 15:39:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈圣义,雷志辉,李晓雪,刘晓春,滕锡超]]></author>
</item>
<item>
<title><![CDATA[Aerodynamic interference investigation of supersonic cluster munition dispensed by sequential]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505040000001]]></link>
<description><![CDATA[In order to analyze the multi-body flow characteristics and the aerodynamic interference characteristics for the sub-munitions in different bays under sequential separation. Based on the governing equations of fluid dynamics and rigid body motion equations of 6DOF, the three dimensional unsteady flow field of the cluster munition under two types of sequential separation and single separation style was simulated with the use of the dynamic mesh method. The variation of flow characteristics and the aerodynamic interference characteristics of the sub-munitions in different separation styles was showed and the interaction process of separation between the sub-munitions was revealed as the results. Numerical simulation results show that the flow characteristics get complicated and the aerodynamic separation characteristics of the rear sub-munition become lower than before because of the shock wave interaction between the sub-munitons under the type of sequential separation. The security of the separation between the sub-munitions was affected during short sequential separation.]]></description>
<pubDate>2016/9/23 15:38:05</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[江坤,陶如意,王浩,王金龙,王政伟]]></author>
</item>
<item>
<title><![CDATA[Adaptive tracking guidance in the injection phase for hypersonic glide vehicles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505130000001]]></link>
<description><![CDATA[According to the trajectory tracking problem of hypersonic glide vehicle under great deviation conditions, a new adaptive tracking guidance method in the injection phase has been put forward based on the adaptively revised weighting matrix. The main control mode and standard trajectory characteristics were analyzed; the simplify longitudinal motion equations were linearized near the standard trajectory; further, an improved adaptive tracking guidance method was designed by introducing the error term in linear quadratic performance index. The simulation results of CAV-H indicate that this method could achieve a great performance in adaptive tracking guidance in the injection phase, and has a good robustness to the initial and process deviation.]]></description>
<pubDate>2016/9/23 15:36:57</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[何睿智]]></author>
</item>
<item>
<title><![CDATA[Integrated guidance and control of a hypersonic vehicle based on fuzzy disturbance observer]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505260000002]]></link>
<description><![CDATA[A three-dimensional integrated guidance and control(IGC) approach based on fuzzy disturbance observer(FDO) is proposed to take advantage of the coupling between the centroid motion and the attitude motion and of the uncertainty of the vehicle in dive phase. An IGC model that can be applied to bank-to-turn control strategy is proposed according to the dynamic equations of the vehicle and the line-of-sight(LOS) relative motion between the vehicle and the target. The uncertainty in the model is compensated, and then an IGC approach is developed by using the block dynamic surface backstepping control method. The states of the closed-loop system are proved to be uniformly ultimate bounded by adopting proper Lyapnove function. Simulations show that the IGC method is robust to the uncertanty and satisfies the required performance.]]></description>
<pubDate>2016/9/23 15:33:09</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[赵暾]]></author>
</item>
<item>
<title><![CDATA[Motion modeling, Mechanism Analysis and Trajectory Optimization for Dynamic Soaring]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505290000001]]></link>
<description><![CDATA[Albatrosses use a flight manoeuvre called dynamic soaring to gain energy from horizontal wind gradient so as to travel for a very long journey and period almost without making stopovers or flapping their wings. Dynamic soaring is considered a promising technique which can be widely applied to UAVs for extending mission capabilities. In this paper，the equation of motion (EOM) of a small UAV in the gradient wind field is derived and simplified in the air-path frame of axes based on the flight dynamics. The energy-gain mechanism during dynamic soaring is analyzed using the simplified EOM according to the theorem of kinetic energy and mechanical energy variation with respect to the noninertial frame of reference respectively. The Differential Flatness Method is employed to solve the loiter pattern and travel pattern trajectories for the objective function of minimum average change rate of control inputs. The analysis indicates the upwind climb and downwind dive is the basic energy-gain ways of dynamic soaring. The optimal results show that the control inputs are smoothed，even become staged constant inputs and the actual control will be simpler. In the optimization of loiter pattern，when the wind gradient is treated as a decision variable，the optimization process finds the optimal wind gradient in the range of [0，0. 5s-1] for the objective function. While in the optimization of travel pattern the value of the objective function is monotonically decreasing in the same range.]]></description>
<pubDate>2016/9/23 15:31:28</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘多能]]></author>
</item>
<item>
<title><![CDATA[Effect of Mars Rarefied Atmospheric Dynamic Error During Aerobraking]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505020000001]]></link>
<description><![CDATA[For the problem of Mars rarefied atmospheric dynamic errors that cause by seasonal variation and diurnal change during Mars areobraking, the orbital dynamic equation including aerodynamic force is established. Through the research of aerodynamic parameter calculation method applied to rarefied flow, the effect of dynamic errors on aerodynamic force and aerobrake result is analysed. Considering the application in Mars exploration, the characteristics of aerodynamic and orbit during Mars aerobraking are simulated under condition of atmospheric dynamic errors exist. To assure the safety of spacecraft and the aerobraking duration, the corridor of aerobraking and the requirement of navigation are proposed. The result can be a reference for the aerobraking implementation of future Chinese Mars exploration.]]></description>
<pubDate>2016/9/23 15:30:29</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[方宝东,吴美平,张伟]]></author>
</item>
<item>
<title><![CDATA[Helper Thread Pre-fetching Model Based on Learning Gradients of Control Parameters]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511160000004]]></link>
<description><![CDATA[The applications with irregular accessing memory would incur serious Cache miss in the run-time. Helper thread is an effective technology to improve the performance of multicore systems. Helper thread pre-fetches data from memory to the Cache which is the closest one to CPU. If the overhead of accessing memory for a given application is much greater than that of computation, it would make helper thread lag behind the main thread. Hereby, we propose an improved helper thread pre-fetching model by adding control parameters. Furthermore, gradient descent algorithm is one of the most popular machine learning algorithms, which is adopted here to determine the optimal control parameters. The amount of the memory access tasks are controlled by the control parameters effectively, which makes helper thread be finished before main thread. The experiment results show that the speedup of system performance is achieved by 1.2 times to 1.5 times.]]></description>
<pubDate>2016/9/23 15:27:57</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[宁静,裴颂文,张俊格]]></author>
</item>
<item>
<title><![CDATA[CacheFI: A Microarchitectural Fault Injection Tool for On-chip Caches]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511300000001]]></link>
<description><![CDATA[Compared with the logic, SRAM is more influenced by process variations and aging. Architectural solutions of on-chip cache fault tolerance are considered as an effective means for high persistent failure probabilities. However, there are little fault injection tools for on-chip caches. Consequently, current proposed microarchitectural mechanisms are short of comprehensive validation. Therefore, CacheFI is proposed. It is a fault injection tool based on the full-system simulator Simics. It employs the fault generation and injection separation mechanism design. Fault generation consists of stochastic distribution control, failure patterns and explosive timing. Fault injection is focused on the requirement of repeatability and modularity. According to the experiments based on Simics and 15 benchmarks from SPEC CPU2000, it evaluates typical microarchitectural fault mechanisms, such as Buddy, MAEP etc., by injecting cache faults with CacheFI.]]></description>
<pubDate>2016/9/23 15:25:59</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[何若愚,黄智濒,马华东,周锋]]></author>
</item>
<item>
<title><![CDATA[VM memory resources reservation method in cloud computing system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511250000007]]></link>
<description><![CDATA[Abstract: In order to reduce the consumers’ costs of renting resources in cloud computing system, we present a random integer linear programming model and method for memory reservation base on cost constraints. Combined with the memory resource price of reservation plan and on-demand plan we design random cost function, which consists of costs and total amount of resources constraints, an algorithm applies for optimal of amount of memory reserved aiming at minimize expected value of the cost function. The experiments show that the cost of renting recourses by this method is less than the cost of renting recourses by reservation plan, on-demand plan and other methods.]]></description>
<pubDate>2016/9/23 15:24:45</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[阚运奇,刘宏伟,张展,左德承]]></author>
</item>
<item>
<title><![CDATA[A Multiple-Level Arbitration in Optical Network-on-Chip based on Resource Reservation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511250000005]]></link>
<description><![CDATA[we propose a multi-level arbitration based on resource reservation in optical network-on-chip. The fast and high efficiency arbitration scheme divides the network into multi-stages. With the design of multi priority queues in every node, arbiters provide differential transmissions for different kinds of flows. The arbiter also presents the transmit bund resource reservation scheme to fairly reserve time slots for all nodes, and therefore achieving the throughput of 100%. Propose and layout the fast arbitration channels (FACs) to degrade the arbitration period, reducing the packet transmitting delay. The simulation results show that, with the multi-level arbitration based resource reservation, all nodes are allocated with almost equal service under various patterns. This scheme improves throughput by 17% when comparing to FeatherWeight under the self-similar traffic pattern and decreases arbitration delay by 15% to 2-pass arbitration, incurring total power overhead of 5%.]]></description>
<pubDate>2016/9/23 15:23:15</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[翦杰,赖明澈,肖立权]]></author>
</item>
<item>
<title><![CDATA[Shared cache management scheme with location information and eviction probability in multi-core system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511190000002]]></link>
<description><![CDATA[Last level cache(LLC) plays an important role in multi-core systems. This paper aims to propose a shared LLC management scheme with fine granularity, low latency and simple hardware complexity. In this work, the performance goal is translated into eviction probabilities of each core. Then, a victim core which is near from the current core and has higher eviction probability is chosen to provide the victim cache block for replacement. In this way, LLC are dynamically partitioned among all cores at finer granularity of cache blocks. This proposal is more flexible than traditional way-partitioning scheme. In addition, the combination of location information and eviction probability improves the locality between cache resources and the corresponding cores, which can reduce the cache access latency. The proposed scheme requires only little additional hardware changes to traditional cache structure. Results on M5 simulator suggest that performance improvements from 6.8% to 22.7% can be achieved while compared with related works.]]></description>
<pubDate>2016/9/23 15:22:10</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李 琰,庞征斌,徐金波]]></author>
</item>
<item>
<title><![CDATA[Thread Affinity for Buffer Management Mechanism based on Multi-core Network Processing System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511110000002]]></link>
<description><![CDATA[The packet processing performance of the general multi-core is plagued by many factors, including high packet I/O cost, multi-core share memory competition, TLB entries failure rate, etc. A thread affinity for buffer management mechanism TABM based on multi-core network packet processing system for high-speed packet forwarding application is proposed and completed on network dedicated co-processing engine NPE. TABM mechanism adopts thread affinity scheduling strategy with no interrupt, it sends each packet data and descriptor which contains control and buffer address information to several successive shared buffers according to the corresponding thread ID, and organizes the packets and descriptors which processed in the same thread in the form of a chain. This paper tests the packet forwarding performance based on general multi-core and FPGA platform. The experimental data shows that TABM can obtain the packet forwarding performance speedup about 1.12x over the baseline architecture. It can effectively reduce the IO overhead.]]></description>
<pubDate>2016/9/23 15:19:43</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈一骄,戴幻尧,李世星,李韬,杨惠]]></author>
</item>
<item>
<title><![CDATA[Soft error analysis and evaluation of dual-layer 3D SRAM based on 65nm technology]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511110000001]]></link>
<description><![CDATA[We designs a novel 3D SRAM soft error analysis platform to study the soft error characteristic of 3D SRAM. This platform integrates many tools, in which Geant4, TCAD and Nanosim simulate the particle striking and circuit behavior, ROOT recodes and processes the intermediate data, Calibre extracts the layout information, and Perl and Shell scripts link the tasks and analyze the results. A 3D SRAM is designed by dividing a 2D SRAM according to word line. Then, the soft error characteristic of designed 3D SRAM and original 2D SRAM are analyzed via our designed platform. It is found that 3D SRAM and 2D SRAM have the same upset cross section, but the soft error of 3D SRAM is more severe than that of 2D SRAM, which makes it difficult to harden 3D SRAM by using ECC technology. At static test mode, the upset sensitive nodes only distribute in the memory array of both 3D SRAM and 2D SRAM. It indicates that the logic circuit can not induce soft error at static test mode.]]></description>
<pubDate>2016/9/23 15:18:16</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[邓 全,郭 维,李 鹏,张民选,赵振宇,周宏伟]]></author>
</item>
<item>
<title><![CDATA[The Research and Implementation of TSV Open Test Algorithm in 3D SRAM Based on BIST]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511160000002]]></link>
<description><![CDATA[In 3D-IC technology based 3D SRAM, the large number of TSVs implemented in circuits. The manufacturing process of TSV is not mature yet which makes TSVs becoming more prone to open defects, brings new challenges to the 3D SRAM test. The existing 2D BIST method has the ability to detect the faults in 3D SRAM. However, this method cannot tell whether it’s derived from TSV or SRAM itself. Although the specific circuit of TSV can find out where the faults are, it need extra specific circuit to implement which increases both the area overhead and its design complexity. In consideration of what discussed above, this paper proposes a new idea to detect the open defects of TSV based on a test algorithm. It is an effective method to detect the open defects of TSV in 3D SRAM without any additional testing circuit and extra overhead. The results show that there is no functional problem with the algorithm and realized the purpose of TSV open fault detection.]]></description>
<pubDate>2016/9/23 15:16:51</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[邓全,蒋剑锋,李鹏,曲连华,唐皓月,赵振宇]]></author>
</item>
<item>
<title><![CDATA[Optimization method of decoding circuits’ synthesis on unsatisfiable subformulas]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511170000001]]></link>
<description><![CDATA[Explaining the causes of unsatisfiability of the Boolean formulas has many real applications in various fields. The minimum unsatisfiable subformulas can provide most accurate explanation for the causes of infeasibility in many application fields such as the automatic circuits’ synthesis. Two best algorithms of extracting the minimum unsatisfiable subformulas, respectively called the branch-and-bound algorithm and greedy genetic algorithm, are integrated in the decoding circuits’ synthesis tool. Adopted the standard encoding circuits in communication fields as the benchmarks, the two algorithms are compared and analyzed. The experimental results show that the greedy genetic algorithm outperforms the branch-and-bound algorithm on runtime and removed clauses per second. The results also show that the unsatisfiable subformulas plays an important role in process of synthesizing automatically the decoding circuits.]]></description>
<pubDate>2016/9/23 15:11:39</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[黎铁军,马柯帆,肖立权,张建民]]></author>
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<title><![CDATA[Deep Convolutional Neural Network for Motion Compensated Frame Interpolation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604270000002]]></link>
<description><![CDATA[Existing approaches for motion compensated frame interpolation are commonly based on correspondence-based image warping technique, hence strictly rely on accurate dense correspondences between images i.e. optical flow field. However, due to the fact that optical flow computation itself is a typical ill-posed problem, the quality of the in-between frames generated by these approaches is hardly guaranteed in real-world scenarios. This paper explores the application of deep learning theory in the problem of motion compensated frame interpolation. A deep convolutional neural network (DCNN) built with Convolutional blocks and Deconvolutional blocks is proposed and then trained with temporal coherent image triplets which are collected from natural videos. The proposed DCNN is capable of processing input images with different resolutions and preserving fine-grained image details. Qualitative and quantitative experiments show that the trained DCNN obtains better interpolated images than traditional approach in two testing images sequences.]]></description>
<pubDate>2016/9/23 15:04:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[龙古灿,,]]></author>
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<title><![CDATA[Solar thermal propulsion system condenser parameters optimization research]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201512150000001]]></link>
<description><![CDATA[This paper uses advanced genetic algorithm, making an optimization analysis on the solar thermal propulsion system condenser parameters. This paper considers condenser sunlight collection efficiency and the mass of condenser as the objective function of the optimization, and establishes a mathematical model and simulation model of the condenser work. The simulation results show that advanced genetic algorithm can be effectively used in sunlight collection efficiency and the quality of condenser optimization analysis.]]></description>
<pubDate>2016/9/23 14:58:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[黄敏超]]></author>
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<title><![CDATA[Counters Based Performance Analysis and Optimization of a Processor Core]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511250000006]]></link>
<description><![CDATA[With the ever-increasing design complexity in the processor microarchitecture, performance analysis becomes more and more important in the research and design of processors. Performance models are used widely in the performance analysis, which are more suitable for the design space exploration in the early stage. When being used in microarchitecture optimizations, the accuracy and speed of performance models are the limiting factors. In this paper, a performance analysis method based on counters is proposed. In this method, the RTL code of an processor core is used as a baseline, and a specialized performance monitor unit is added to collect the events needed by the microarchitecture analysis and optimization. Then the collected events are sent to a result analyzer, where the factors affecting the performance are obtained. Adopting the method, we analyze what affect the performance when running SPEC CPU2000 benchmarks on FPGA prototyping, and optimize the microarchitecture of processor core according to the analysis results. The performance of the optimized processor core is improved obviously.]]></description>
<pubDate>2016/9/23 10:54:26</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[黄立波,李文哲,隋兵才,孙彩霞,王俊辉,王蕾,王永文]]></author>
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<title><![CDATA[Unbiased Multipath Mitigation Technique for TMBOC signal]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201601190000002]]></link>
<description><![CDATA[Code Correlation Reference Wave technique (CCRW) is widely used in modern GNSS receivers for its better performance and lower complexity. The pilot channel of GPS L1C signal is modulated with TMBOC modulation. The discrimination curve of TMBOC modulated signal is with bias when received with code correlation reference wave technique. In order to eliminate the tracking bias, an unbiased multipath mitigation technique is proposed. The novel technique generates two categories of local waves for the BOC(1,1) and BOC(6,1) modulated component respectively, its ensuring the discrimination output is zero when there is no code phase bias. The technique obtains unbias tracking while having better accuracy with better utilization of BOC(6,1) signal component.]]></description>
<pubDate>2016/9/23 10:48:30</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[刘瀛翔,倪少杰,王飞雪,肖志斌]]></author>
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<title><![CDATA[Design of semi-physical simulation for micro/nano-satellite attitude determination and control]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201602250000002]]></link>
<description><![CDATA[Performance of Attitude Control System is an important indicator and can directly affects performance of satellite. As Attitude Control System requires special operating environment, it is hard to assess on the ground, which has brought a certain risk of satellite design. In this paper, a set of semi-physical simulation system for attitude determination and control of micro/nano-satellites is designed and implemented according to the characteristics of micro/nano-satellite. Digital model simulates satellite motion and orbit environment, sensor model generates measured data, actuator model generates control torque, sensor simulator realizes communication protocol and finally realizes whole system simulation. The system can be connected to the satellite control system loop to assess software and hardware of the attitude control system and verify the performance of the algorithm. The system has been applied and comprehensively assessed software and hardware of attitude control system in ground simulation of satellite TT-3, and has been proved reasonable and credible.]]></description>
<pubDate>2016/9/23 10:41:45</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[白玉铸,,,,]]></author>
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<title><![CDATA[Applications of High-Order Weighted Compact Nonlinear Scheme for Thermo-Chemical Nonequilibrium Flow]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604010000003]]></link>
<description><![CDATA[High-order scheme has advantages in the simulations of complex flow, for its good behavior of preserving high spatial resolution with lower cost than the second order methods. Weighted Compact Nonlinear Scheme (WCNS-E-5) is applied in the simulations of thermo-chemical nonequilibrium flow around a cylinder with the freestream velocity of about 5~5.7km/s. Correct flowfield properties are acquired, the pressure and heat flux on the surface agree well with the experimental data. WCNS-E-5 also exhibits better performance on the grid convergence of heat flux than the second order MUSCL scheme. The results show that the present attempt to combine high order scheme with the calculations of stiff chemically reacting flow is basically successful, and has established a good foundation for the further study.]]></description>
<pubDate>2016/9/21 16:38:25</pubDate>
<category><![CDATA[化学]]></category>
<author><![CDATA[葛明明,曾明,赵小宇]]></author>
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<title><![CDATA[The equivalent compensation theory of the earth disturbance gravity on the hit accuracy of the range rocket]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509180000002]]></link>
<description><![CDATA[In order to eliminate the effect of the disturbance gravity and improve the hit accuracy of ballistic missile, according to the characteristics on the movement of ballistic missile, we have established the equivalent theory based on control system theory. According to the characteristics of different compensation modes and compensation quantity, we provided embedded mode, fractional step mode and sectional mode and so on. It provides a general framework and theoretical basis for compensating the influence of disturbance gravity to the movement of ballistic missile.]]></description>
<pubDate>2016/7/20 17:04:42</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[马宝林]]></author>
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<title><![CDATA[Optimization Design for Impulse-Correction Projectile Based on Particle Swarm Optimization Method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505080000004]]></link>
<description><![CDATA[According to the discontinuous characteristics of impulse correction projectile, this paper presents a class of parameters optimization method for its control system. Considering the two requirements of the correction cost and precision of impulse thrusters, the minimum amount of numbers of impulse thrusters and the control miss-distance are taken as a double-objective function, and it is put forward to select the time interval between the two neighboring impulse forces as design variable in condition of wind disturbance. Then on basis of it, a kind of modified particle swarm optimization algorithm is developed to improve the convergence speed of this optimization process. The simulation result indicates that the presented optimization algorithm can obtain the optimal solution efficiently, which provides a reference approach to find the optimal impulse correction parameters and work modes under wind disturbance.]]></description>
<pubDate>2016/7/20 16:56:01</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈晋璋,洪侨,孙传杰,孙瑞胜]]></author>
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<title><![CDATA[Analysis and Research on Failure Data of Warship Electromechanical System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505130000002]]></link>
<description><![CDATA[The fault data of ship mechanical system are usually not well recorded during operation and maintenance activities, and are typically incomplete and inaccurate. For such imperfect data, fault trends are justified by graphical representation. Moreover, history fault data are analyzed using homogeneous Poisson process, non- homogeneous Passion process and geometric process, respectively. Numerical results show that the accuracy of geometric process is the best, and it is used to predict future fault intensity.]]></description>
<pubDate>2016/7/20 16:55:31</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈丹丹,李磊,刘艳彬,姚智刚]]></author>
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<title><![CDATA[Timing Synchronization Based on Early/late Loop with Multi-h Continuous Phase Modulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505070000001]]></link>
<description><![CDATA[Timing Synchronization with the early/late loop scheme based on sequence detection is proposed for multi-h continuous phase modulation. The timing error detector is implemented by the survival metrics of Viterbi algorithm. The so-called S-curve and estimation variance are used for optimizing the acquisition range and tracking performance, as well as eliminating false lock points of the loop. Using the pulse amplitude modulation (PAM) representation of multi-h CPM, the proposed timing error detector is simplified. Simulation results show that the estimation range is as large as ±0.5 symbol period, and estimation precision is close to the modified Cramer-Rao bound at medium and low SNR, and just well at high SNR. Bit error rate(BER) with simplified shcemes are derived. It is demonstrated that when the number of Viterbi metrics is reduced to 1/8 of maximum likelihood sequence detection, the performance loss is only less than 0.5 dB for M-ary, partial response and multi-h CPM.]]></description>
<pubDate>2016/7/20 16:54:11</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[谢顺钦,谢滔,杨春,张健,钟声]]></author>
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<title><![CDATA[Experimental Investigation on Fracture Toughness of Metal Foam]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505290000003]]></link>
<description><![CDATA[In practical applications, fracture properties and fracture toughness of porous metal foam for the bearing are very important. In this paper, based on ASTM standards, three-point bending of aluminum foam samples are used to determine I type fracture toughness. It is shown that the fracture of metal foam is brittle fracture. The deformation is localized to thinnest regions of the cell walls surrounding the crack tip. With further loading, the strain to fracture is reached in some cell walls and microcracks appear in the vicinity of the crack tip. With increasing load a main crack is initiated at the notch root or at the pre-crack by a coalescence of microcracks, and starts to propagate through the cell structure. The crack follows the weakest path through the structure and builds thereby secondary and crack bridges. The way of crack extension is I type fracture in all. According to the P-V curve characteristics, taking the force and displacement of maximum load point to calculate critical crack tip opening displacement, the average is 0.051mm.]]></description>
<pubDate>2016/7/20 16:53:25</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[彭向和,王新筑,周雄,朱炳杰]]></author>
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<title><![CDATA[Research on Health Simulation and Evaluation for Electric Servo System Based on Parameter Identification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201512020000004]]></link>
<description><![CDATA[Health simulation and evaluation are conducted for electric servo system based on state variable detection and system model. Common failures of electric servo system are summarized, mathematical models are built up for common health states; The characteristics of unhealthy state are obtained by fault injection to build knowledge base. The health factor is applied to evaluate the change trend of failed parameter; The feasibility of health factor algorithm is verified by simulation experiments.]]></description>
<pubDate>2016/7/20 16:52:53</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李学锋,曾庆华,周维正]]></author>
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<title><![CDATA[The influence analysis of ducted fan profile parameters on aerodynamic characteristics]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201506220000002]]></link>
<description><![CDATA[The influence of ducted fan profile parameters to aerodynamic characteristics was investigated in this paper. Firstly, it calculated the thrust produced by different part of ducted fan which was affected by diffuser angle based on the momentum theory and Bernoulli equation. At the same time, the three-dimensional incompressible viscous Navier-Stokes equations and SST k-omega turbulence model were used to simulate the complex flow of a 2-blade propeller, which was based on the sliding mesh method. To demonstrate the feasibility of the method, the result was compared with experimental data. Then, it analyzed the influence of the lip shape, diffuser angle and the height of ducted fan on aerodynamic characteristics and flow field, on the condition of hovering. The thrust coefficient produced by ducted fan with the elliptical lip was small, and its aerodynamic efficiency was very low. The power coefficient was the smallest when the diffuser angle was 8.2deg. The flow separation would emerge near the duct under the propeller disk, with the increase of diffuser angle. The sensitivity of thrust coefficient to the change ducted fan height was low. The power coefficient descended slightly with the increase of height.]]></description>
<pubDate>2016/7/20 16:52:30</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈清阳,郭正,李晓华,柳兆伟]]></author>
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<title><![CDATA[Preliminary Application of Reynolds Stress Model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509180000003]]></link>
<description><![CDATA[Focusing on the verification and validation of SSG/LRR-w reynolds stress model, four typical two dimensional cases from NASA turbulence resources website are chosen, including zero pressure gradient flat plate, bump-in-channel, airfoil near-wake and NACA0012 airfoil. Numerical results are in good agreement with that of CFL3D and experiment. For flow over NACA0012 airfoil, lift coefficients of reynolds stress model and SA model are compared. It is obvious that near the stall angle of attack, reynolds stress model has advantages over SA model. Based on these results, SSG/LRR- reynolds stress model is applied to the simulation of complex DLR-F6 wing-body configuration. Pressure coefficient in typical stations is comparable to that of experiment. Besides, small range of separation in the wing-body intersection is well captured.]]></description>
<pubDate>2016/7/20 16:43:38</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[董义道]]></author>
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<title><![CDATA[Characteristics of air layer fluctuations on flat bottom air cavity ship with groove]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201506180000002]]></link>
<description><![CDATA[In order to improve the design effectiveness of large flat bottom ship with groove, a calculation method with combination of RANS equations and VOF two-phase-flow model is proposed for a large flat bottom ship with groove. The dynamic development of air layer in the groove was found. Based on the analysis of air layer fluctuations with different flow velocity, the difference of air layer fluctuations characteristic between three-dimensional and two-dimensional is explained and the fluctuations similar-law of air layer is obtained. Numerical results show that air layer appear fluctuations in the groove and the wavelength of air layer increases with increasing of velocity; the wavelength is equal to 0.64 times of the square of velocity; Air layer presents phenomenon of coherent and reflection at the side walls of groove, so the wave height and thickness of local air layer were changed; Fluctuations of air layer is satisfy with Froude similar.]]></description>
<pubDate>2016/7/20 16:42:11</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[欧勇鹏,吴浩]]></author>
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<title><![CDATA[Numerical simulation on parachute's infinite mass inflation dynamics]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201511160000001]]></link>
<description><![CDATA[To analyze the supersonic opening performance parachute in Mars entry environment are studied. Based on the Multi-material Arbitrary Lagrange Euler (MMALE) method algorithm, the coupling models between compressible fluid and flexible structure of parachute are solved. The evolution of 3D shape of DGB parachute during supersonic inflation is simulated, and the structural dynamics behaviors of canopy fabric is predicted. The drag area and coefficients are compared with the wind tunnel data. The inflation performance of parachute and the influence of forebody are analyzed. Finally, the wake of unsteady fluid and distribution of shock wave around supersonic parachute are investigated. The results show: The DGB parachute is well inflated without seriously collapse. As the increase of Mach numbers, the drag coefficients gradually decrease, along with the increase of the inflation time, which bring into correspondence with the test results, and prove the validity of the method proposed in this paper.]]></description>
<pubDate>2016/7/20 16:41:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[高庆玉,高兴龙,唐乾刚,杨涛,张青斌]]></author>
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<title><![CDATA[Accelerated Rendering for Electromagnetic Environment under Single Device Restriction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504280000001]]></link>
<description><![CDATA[Rendering electromagnetic environment with a high efficiency based on single device supports more widely use. But the efficiency of parallel ray-casting for rendering electromagnetic environment is restricted by the device. Based on researching the restriction of device for parallel ray-casting, a pixel interpolation method focusing on the restriction is presented. To deal with the restriction the number of rays when casting is reduced, what means a part of pixels in the rendering image are generated by ray-casting and the rest pixels through interpolation. Pixel interpolation gets rendering efficiency at the cost of image quality, so when image update is pause the interpolated pixels will be regenerated to recover image quality. The experiments show that pixel interpolation obviously improves rendering efficiency when implementation on a low device. Comparing the rendering images of some volume data and the errors in these images, the electromagnetic environment data has the best rendering result, which proves that pixels interpolation is useable especially for rendering electromagnetic environment on a low device.]]></description>
<pubDate>2016/7/20 16:39:57</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[冯晓萌,吴玲达,杨超,于荣欢]]></author>
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<title><![CDATA[Attitude Control of Dynamic Scanning Imaging Satellite of Control Moment Gyros]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504270000003]]></link>
<description><![CDATA[According to the problem of attitude control of satellite dynamic scanning imaging, the dynamic model of the satellite attitude is built and the specific requirement of dynamic scanning imaging tasks for attitude control is analysed. Combined with the dynamic scanning imaging tasks, a typically attitude maneuver scheme is designed. After that, the required control moment of the process of dynamic scanning imaging is estimated. Then, a pitching maneuver control law based on the expected torque and real-time attitude of satellite is developed, and the steering law of five pyramid configuration gyros(FPCGs) is given. A numerical simulation was presented for designed control law based on a maneuver task. The simulation results proved that the proposed scheme can satisfy the requirement of attitude control of dynamic scanning imaging satellite.]]></description>
<pubDate>2016/7/20 16:39:40</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[赵波林]]></author>
</item>
<item>
<title><![CDATA[Numerical Research on the Effect of Tail Cavity on Underwater Vehicle Hydrodynamic Damping Force]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509120000001]]></link>
<description><![CDATA[Based on Reynolds averaged NS equations, combining with rotating reference frames and cavity multiphase flow simulation technique, the influence of tail cavity on underwater vehicle hydrodynamic damping force has been numerical calculated. Compared with experiment result, the validity and accuracy has been proofed. Numerical research indicates that the unbalance of vehicle tail part pressure distribution has been relieved by tail cavity, which causes the reduction of hydrodynamic damping force. As the cavity expands, the decreasing rate trends toward being slow. The tail cavity also changes the shape of attack angle and damping force curves. The research reveals the necessary consideration of the effect of tail cavity on hydrodynamic damping force during underwater design.]]></description>
<pubDate>2016/7/20 16:39:02</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[鲍文春,程少华,权晓波,王占莹,肖鲁,尤天庆]]></author>
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<title><![CDATA[Three-dimensional flat-plate boundary layers generated by two swept shock waves]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201510180000001]]></link>
<description><![CDATA[In order to seek a type of sidewall compression to weaken the interaction of swept shock waves and boundary layers, the three-dimensional boundary layer generated by the interaction of two swept shock waves and the flat-plate boundary layer is numerically studied. The mechanism of this three-dimensional boundary layer is analysised. Also, the three-dimensional boundary layer is quantatively compared with the one generated by one swept shock wave which has the same flow turning angle. The results show that, in the case of two swept shock waves, the first swept shock wave makes the boundary layer next to the sidewall thinner, so the interaction between the second shock wave and the boundary layer becomes weaker, resulting in the weaker interaction between two shock waves and the boundary layer than the one swept shock wave case. The total flow turning anlge of two swept shock waves is the same with one shock wave case, so the strength of the interaction swept shock is essentially the same. The three-dimensional boundary layer generated by the interaction swept shock is still conical, and the angle between the separation line and the inflow is essentially the same with the one swept shock case.]]></description>
<pubDate>2016/7/20 16:38:39</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[何刚,周进]]></author>
</item>
<item>
<title><![CDATA[Analysis and Improvement of Weights in WENO Schemes]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201601150000001]]></link>
<description><![CDATA[The WENO scheme is of great significance for the accurate calculation of complex flow fields, which has high precision and high resolution. In order to improve the computational performance of the WENO scheme, a new WENO scheme named WENO-E scheme is constructed, which decreases dissipation close to discontinuities. The new scheme is constructed by introducing indirect smooth indicator, based on the analysis of the algorithm of weighted factors in the classical WENO scheme which is named WENO-JS for proposed by Jiang and Shu. The theoretical analysis shows that the WENO-E scheme can reach the same convergence order of WENO-JS, with the same computational efficiency; but obtain smaller truncation errors at smooth parts of the solution, and higher resolution close to discontinuities, with the same grids. Subsequently, numerical experiments with the linear transport equation, the nonlinear Burgers equation and the one dimensional Euler system of equations are conducted; compared with the classical WENO scheme, the WENO-E scheme has achieved better numerical solutions.]]></description>
<pubDate>2016/7/20 16:38:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[柴得林,李雨润,孙中国,席光]]></author>
</item>
<item>
<title><![CDATA[Calibration and application of  γ-Re<sub>θ</sub> transition model based on high-order scheme WCNS]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201603010000001]]></link>
<description><![CDATA[On the platform of high-order numerical wind tunnel, the low speed flat plate data is adopted for the calibration of  γ-Re<sub>θ</sub> transition model based on high-order scheme WCNS. Based on the calibrated transition model, the flow over the low speed airfoil is studied. Comparisons between calculated results and experiment data indicate that the γ-Re<sub>θ</sub> transition model based on WCNS can predict the transition location of natural transition, bypass transition or separated transition very well and has low grid sensitivity. Moreover, it is indicated that while at moderate Reynolds number range where the length of the laminar flow region is comparable to that of the turbulent flow region, only the transition model can calculate the drag coefficient accurately.]]></description>
<pubDate>2016/7/20 16:38:07</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[邓小刚,董义道,王光学,王圣业]]></author>
</item>
<item>
<title><![CDATA[Scalar transport and diffusion study progress of supersonic mixing layer with high Reynolds number]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201510090000003]]></link>
<description><![CDATA[The mixing processes of fuel-rich gas and air in the combustor of combined cycle engine was viewed as the supersonic mixing layer which was featured by the high Reynolds number. Moreover, the transport and diffusion processes of scalars including temperature and concentration were important factors for controlling the gas-gas mixing and combustion process. Under high Reynolds number, the turbulence scale, the transport and diffusion of scalar, vortex shape and scalar interfacial area of the mixing flow field revealed more complex physical mechanisms. In this paper, the application background of the scalar mixing in the supersonic mixing layer on the combined cycle engine was introduced, and the study progress of the supersonic mixing layer and the scalar mixing process in the supersonic mixing layer both at home and abroad was summarized, then the methods for counteracting the shortcomings of the study on scalar transport and diffusion characteristics of supersonic mixing layer with high Reynolds number were proposed. Finally, some directions being worth studying deeply in the field were pointed out.]]></description>
<pubDate>2016/7/20 16:37:23</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[冯军红,沈赤兵,石少平]]></author>
</item>
<item>
<title><![CDATA[Application of fifth-order accurate HWCNS for low-speed complex flow field]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504300000001]]></link>
<description><![CDATA[Fifth-order accurate explicit HWCNS is used to solve Reynolds Averaged Navier-Stokes equations, by generating multi-block structured grids, grid convergence study of 30P-30N is performed, the effects of HWCNS and second-order accurate MUSCL on pressure distribution and velocity profiles at typical stations are studied without regard to transition using SA trubulence model, furthermore numerical and experimental results are compared and analysed. The trapezoidal wing is numerically simulated using HWCNS and SA turbulence model, by analysing aerodynamic characters and pressure distribution, the performance of application of HWCNS for low-speed complex cofiguration flows is discussed.]]></description>
<pubDate>2016/7/20 16:31:13</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[周云龙]]></author>
</item>
<item>
<title><![CDATA[Multi-objective Trajectory Optimization for Hypersonic Glide Vehicle Based on Boundary Intersection Method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504270000001]]></link>
<description><![CDATA[The trajectory designs for hypersonic glider vehicle subject to complex constraints are multi-objective trajectory optimization problem. A multi-objective trajectory optimization method combining the boundary intersection method and pseudospectral method is proposed in this paper. The multi-objective trajectory optimization problem (MTOP) is established based on the analysis of the feature of trajectory for hypersonic glider vehicle. The MTOP is translated into a set of general optimization subproblems by using the boundary intersection method and pseudospectral method. The subproblems are solved by nonlinear programming algorithm. In the method, the solution that has been solved is employed as the initial guess for the next subproblem. The maxima cross range and minimal peak heat problem is solved by the proposed method. The numerical results demonstrated that the proposed method can obtain the Pareto front of the optimal trajectory, which can provide the reference for the trajectory design for hypersonic glider vehicle.]]></description>
<pubDate>2016/7/20 16:19:33</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[葛健全,,,杨涛]]></author>
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<title><![CDATA[Facet-based Rapid electromagnetic modeling and SAR imaging for composite ship-sea scene]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504170000002]]></link>
<description><![CDATA[In the high frequency, sea surface or ship target usually possesses electrically-large size and very sophisticated structure, which imposes a huge computational burden for the electromagnetic modeling of the composite ship-sea scene. To simplify the calculation, based on the facet-model theory, the graphical electromagnetic computing method (GRECO) and the four path model, a hybrid method for the electromagnetic scattering computation of electrically-large composite ship-sea scene is presented. Under the precondition of guarantee calculation precision, the efficiency is improved obviously. The radar cross section (RCS) of time-varying sea surfaces and and ship target for different radar parameters are simulated and analyzed. The results show good agreement with the experimental data and accurate numerical results, which demonstrate the correctness of the method. Accordingly, application of the model to SAR imaging of marine scenes is finally developed. Simulation results demonstrate the effectiveness of the proposed method.]]></description>
<pubDate>2016/7/20 16:19:25</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李宁,聂丁,王欣,张民]]></author>
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<title><![CDATA[A guidance law based on correcting velocity direction continuously]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504150000001]]></link>
<description><![CDATA[Taking the limited control authority and guidance information of a gun-launched guided projectile into account, a novel three-dimensional terminal guidance law based on the combination of the correction of the velocity direction via impact point prediction and continuous distribution of acceleration command is proposed. The deviations between the impact point of the projectile and the target are predicted based on the series solutions of the nonlinear ballistic equations. According to the deviations, the paper addresses two methods to calculate the direction angles corrections of the current speed. Design the remaining flight time as the correction time. The acceleration correction formulas are established through sharing the direction angles corrections of the current speed into the whole remaining guided flight to reduce the possibility of command saturation. By predicting the impact point and distributing acceleration corrections continuously to shape the trajectory in real time. The simulation results show that the proposed guidance law is feasible and effective, and provides the performances of high precision and little requirements of control authority and great guidance and damage effects, which provides a reference for the application of the guided projectile.]]></description>
<pubDate>2016/7/20 16:18:49</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[王中原,徐秋坪]]></author>
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<title><![CDATA[Research on Active Control using Flexible Neural Network Sliding Mode Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504020000005]]></link>
<description><![CDATA[For the vibration control in complex excitation, the active control of double-layer vibration isolation system using magnetostrictive actuator of Jiles-atherton model is researched. Based on the traditional sliding mode control, a flexible neural network sliding mode control algorithm is proposed and the controller switching matrix is designed by the regularization method, then the updating formula of the neural network weights and flexible mapping parameter are also established. Furthermore the control strategy is used for the active vibration control in double- layer vibration isolation system. At the last the single frequency, multi frequency and random signal excitation are simulated and the results show that: the flexible neural network sliding mode controller has a strong robustness, which can make the active control significantly attenuate the disturbance in double- layer vibration isolation system.]]></description>
<pubDate>2016/7/20 16:18:40</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[楼京俊,杨理华,杨庆超,朱石坚]]></author>
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<title><![CDATA[A new method for transferring flow informationamong meshes basing on mesh deformation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504020000002]]></link>
<description><![CDATA[According to the data interpolation problems between the old and new grid in the mesh reconstruction, a flow field information transmission algorithm based on lattice format supported finite volume method was proposed. By using unstructured dynamic grid technology, the method made the old cells move to the new grid cells and solved control equation in time domain, then assigned the datum to the new grid cells, in order to realize information transfer between the two sets of the grid. The result shows that this method is not introduced interpolation error in the process of information transmission, the theory precision of the method is equal to the precision of information transmission, and the verification results show that the proposed method is significantly better than that of the second order interpolation method.]]></description>
<pubDate>2016/7/20 16:18:16</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[董海波,刘君,徐春光]]></author>
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<title><![CDATA[Experimental test system design for thermal wakes of submerged vehicle based on scale model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504020000001]]></link>
<description><![CDATA[According to similarity principles, set up an infrared imaging experimental test system based on scale model, designed several different work conditions in the condition of scale model based vehicle volume, submerged depth, movement, wake discharging, and etc so that it is possible to realize the static and dynamic thermal wake detection tests of scaled vehicle. The aim is to determine the detectability of submerged vehicle thermal wakes on one side, and find the influencing factors at thermal wakes detection and changing rules of the wakes to lay a foundation for future work.]]></description>
<pubDate>2016/7/20 16:18:10</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李吉成,杨卫平,俞忠,张志龙]]></author>
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<title><![CDATA[Repeater jamming against chirp rate polarity jittered SAR based on sub-Nyquist sampling]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504010000001]]></link>
<description><![CDATA[Aim to the limitation of conventional deceptive jamming in the chirp rate polarity jittered SAR (CRPJ-SAR), the sub-Nyquist sampling repeater jamming against CRPJ-SAR is investigated in the paper. The signal model of truncated sub-Nyquist sampling repeater jamming is built, and the features of the jamming in CRPJ-SAR are discussed based on the 2-D imaging output. Analytical formulas to calculate the locations and amplitude of false targets are given and the various jamming effect with different sampling intervals is also addressed. The correctness of theoretical analysis is validated further by simulation experiments.]]></description>
<pubDate>2016/7/20 16:18:04</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[代大海,]]></author>
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<title><![CDATA[Multi-layer Structural Architecture for Bio-inspired Self-healing Hardware]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503300000001]]></link>
<description><![CDATA[Inspired by the circulatory secretion and paracrin of hormone, aiming at solving the problems such as low efficiency, complexity and etc. during cellular communicating, a four-layer structural architecture for bio-inspired self-healing hardware is proposed based on Network on Chip (NoC) and neighborhood connections. A self-healing hardware realizing an FIR filter based on the architecture is brought in to explain the architecture in detail. The hardware shows flexible routing ability and potential good fault-tolerant ability. It indicates that the structural architecture provides a new approach to design a self-healing hardware with high reliability.]]></description>
<pubDate>2016/7/20 16:17:53</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[李岳,钱彦岭,王南天]]></author>
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<title><![CDATA[Analyses of Carry Phase Difference Detection for Satellite Navigation Receivers Anti-spoofing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503110000006]]></link>
<description><![CDATA[A spoofer has no way to simulate the space distribution characteristic of the authentic GNSS signals. In this paper, a detection technique based on carry phase difference is proposed. Knowing the baseline and attitude of the antenna array, the carry phase difference of a signal is only related with the angle of incidence. The precise positions of satellites can be determinate by the ephemeris, and the carry phase difference of the authentic signals can be known and an effective spoofing detection could be conducted. In this paper, all errors of the detection are analyzed, and the multiple hypotheses testing to the spoofing detection is built. In the end, through theoretical analyses and simulation tests, the spoofing detection method proposed in the paper is verified to be effective. The longer baseline of the array and smaller angle of incidence lead to a better spoofing detection performance of the method proposed in this paper.]]></description>
<pubDate>2016/7/20 16:17:28</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[王飞雪,徐博,雍玲]]></author>
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<title><![CDATA[Numerical Simulation of Hypersonic Double Cone Flowswith High-order Methods]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201604060000001]]></link>
<description><![CDATA[Hypersonic low enthalpy laminar flows over a 25/55deg double cone geometry were simulated using high-order weighted compact nonlinear schemes (WCNS), and their capabilities to accurately predict laminar shock wave-boundary layer interaction were examined. The simulations were performed with second order MUSCL, third and fifth-order WCNS as spatial discretization schemes. The second-order dual time-stepping approach was employed for time integration. Different flux functions were used for compare, such as hybrid Roe-Rusnov, AUSMPW  and Van Leer. We analyzed the effects of high-order methods on time and grid convergence, as well as the dissipation characteristics of flux functions. Finally, we found that high-order methods can get well resolved results on coarse grid, and eliminate the sensitivity of flux functions. However, high-order methods need longer computational time to reach convergence. The computed results show good agreement with experimental data, and the computational accuracy may be characterized as reasonable for most engineering purposes.]]></description>
<pubDate>2016/7/20 16:14:17</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[王光学]]></author>
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<title><![CDATA[Numerical simulation on VFE-2 rounded leading edge delta wing using WCNS]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201603010000002]]></link>
<description><![CDATA[Numerical simulation on VFE-2 rounded leading edge delta wing is carried out by using high-order scheme WCNS and γ-Re<sub>θ</sub> transition model. The key of this paper is to study the influence of transition on the vortex structure of delta wing. The comparisons between calculated results and experiment data indicate that the leading edge vortex begins at a certain distance of the wing apex and the transition has great influence on the onset of leading edge vortex. Using turbulence model without transition, the leading edge separation is delayed much, while with transition model the calculated results show a good agreement with experiment data. Moreover with transition model, numerical simulation on VFE-2 rounded leading edge delta wing at variation of the angle-of-attack is carried out. The calculated results which agree well with experiment data show that at a low angle-of-attack, there is no separation-induced leading-edge vortex, but with the increasing of angle-of-attack the leading edge separation begins close to trailing edge and moves upstream.]]></description>
<pubDate>2016/7/20 16:04:13</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[邓小刚,王东方,王光学,王圣业]]></author>
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<title><![CDATA[A study of anti-jamming algorithm in GNSS receiver utilizing subspace projection and beamforming]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503060000001]]></link>
<description><![CDATA[Space-time adaptive processing (STAP) using antenna array combines the benefits of spatial domain and time domain adaptive filters, which can effectively improve the ability of narrowband and broadband interferences suppression in the GNSS receiver. Considering that the GNSS signal is buried in the strong interference and thermal noise, a novel anti-jamming scheme which utilizes subspace projection and beamforming method is proposed in this paper. Firstly the data vector received by antenna array is projected onto the noise subspace which is orthogonal to interference subspace to achieve interference suppression. When the local code is synchronized with the reference antenna jammer-free data, beamforming is performed according to the minimum mean square error (MMSE) criterion. Simulation results show that the proposed method can steer the main beam to the direction of GNSS signal wave with effective interference suppression, and the output signal-to-noise ratio (SINR) can be significantly increased while the correlation peak curve and the carrier tracking performance are not corrupted.]]></description>
<pubDate>2016/5/17 10:56:45</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[关刚强,黄仰博,聂俊伟,王飞雪]]></author>
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<title><![CDATA[Research on Distortion Error Evaluation Indexes of Binary Offset Carrier Modulation Signals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503150000001]]></link>
<description><![CDATA[With the development of Global Navigation Satellite System (GNSS), Binary Offset Carrier (BOC) signal is widely adopted. Evaluation of distortion errors of BOC signals is of great importance to GNSS signal integrity evaluation and monitoring. In former researches of BOC signal distortion, there were no analytical methods and indexes to describe the distortion errors of BOC signals. In this paper, the analytical evaluation indexes for three signal distortion errors of BOC signals were first developed. Then the proposed evaluation indexes were used to evaluate the distortion errors of BOC(14,2) and MBOC(6,1,1/11) signals, which were the advised basis signals of BeiDou global navigation satellite system. The distortion error evaluation indexes proposed in the papar could be used to evaluate the distortion errors of modern GNSS signals, and are advisodary to modern signal design and integrity monitoring.]]></description>
<pubDate>2016/5/13 10:49:17</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄仰博,孙广富,姚丽红,余小游,张勇虎]]></author>
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<title><![CDATA[A dual-mode reconfigurable GPS/COMPASS RF front-end receiver in 0.18μm CMOS process]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201602070000001]]></link>
<description><![CDATA[A highly integrated, dual-mode reconfigurable GPS/COMPASS receiver radio frequency front-end is realized in 0.18μm CMOS process. This  receiver front-end adopts a low-IF architecture and can be configured to GPS L1-mode or COMPASS B1-mode. Main blocks like mixer and IF-filter are reconfigurable, which reduces chip area and power consumption. The front-end achieves better performance and exhibits a voltage gain of 103dB with 37.8mW power consumption from 1.8V voltage supply. The noise figures are less than 3.2 dB in both GPS and COMPASS bands. The silicon area of this chip is 2.263×2.098mm<sub>2</sub>.]]></description>
<pubDate>2016/5/13 10:49:07</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[江金光,刘江华,唐亚男,周细凤]]></author>
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<title><![CDATA[Design of Any-Order DDS Synthesizer for High-Dynamic GNSS Signal Doppler Simulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201601180000002]]></link>
<description><![CDATA[In order to accurately simulate the Doppler characteristics of high dynamic GNSS signals, we propose a method for designing any-order DDS synthesizer. An any-order DDS synthesizer structure is designed; By using theoretical analysis, we derive a formula for calculating the initial phase of every accumulators in DDS synthesizer, and develop a technique to determine the DDS word length. Finally, simulations are performed to validate the proposed method, which can accurately simulate the Doppler characteristics of GNSS signals. In addition, since the proposed method for designing DDS synthesizer has no order limitation, it can be widely used in different types of signal simulator.]]></description>
<pubDate>2016/5/13 10:49:00</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[戴卫华,乔纯捷,王跃科,周超]]></author>
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<title><![CDATA[An Unambiguous Multipath Mitigation Algorithm with Multi-Region Discriminator for High-Order BOC Signals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201512310000005]]></link>
<description><![CDATA[The traditional multipath mitigation algorithms for high-order binary offset carrier (BOC) signals have a narrow effective convergence region, which is a weakness for stably tracking. The paper proposes a multi-region discriminator for multipath mitigation of high-order BOC signals. The proposed algorithm applies the optimized QStrobe discriminator when code error is in the near zero region, which improves the multipath mitigation performance, and in the other regions the QBOC discriminator is applied which have an excellent convergence performance. The Kalman filter (KF) is utilized to estimate the tracking error with open-loop method for choosing discriminator. The simulations of BOC(15, 2.5) and BOC(14, 2) signals show that the multi-region discriminator algorithm can eliminate the tracking ambiguity. In addition, comparison with traditional QStrobe algorithm, 6dB attenuated multipath error envelope area is improved by 51% and 57% respectively.]]></description>
<pubDate>2016/5/13 10:48:48</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[欧钢,唐小妹,田丰]]></author>
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<title><![CDATA[Study of carrier phase double difference GNSS spoofing detection technique base on antenna-array direction change]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201512300000007]]></link>
<description><![CDATA[GNSS spoofing signals are generally transmitted from a single antenna, so, the arrival angle of each spoofing signal is uniform, and the phase disparity at two different elements of an antenna-array receiver contains the information of the arrival angle. Thereby, the phase disparity could be used for spoofing detection. Carrier phase double difference GNSS spoofing detection technique is an effective one of those methods based on phase measurement, but high false alarm probability problem is caused by angle ambiguity for double-element antenna-array. In order to solve the problem, a technique based on antenna-array direction change is presented. The carrier phase double differences are estimated in different antenna-array directions, and then the carrier phase double differences are used to discriminate the spoofing signals. In this way, the angle ambiguity could be eliminated, and the false alarm probability is reduced. Simulation results verify the effectiveness of the proposed spoofing detection technique.]]></description>
<pubDate>2016/5/13 10:48:42</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[耿正霖,李柏渝,李峥嵘,聂俊伟,王飞雪]]></author>
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<title><![CDATA[Accuracy Assessment of BDS Signal-in-Space Range Errors for 2013-2015]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201512310000001]]></link>
<description><![CDATA[Based on precise ephemeris provided by Wuhan University, BDS broadcast ephemeris errors are computed over the past three years from 2013 to 2015. The orbit errors, clock errors, and Signal-in-Space User Range Errors(SISREs) are presented and analyzed in different time periods for assessment. The results show that the radial accuracy of overall BDS satellites is less than 0.7m and normal accuracy of that is less than 1.4m. Additionally, no obviously long term trends are found in both radial and normal errors. In term of along-track errors, the accuracies of IGSO and MEO satellites are all less than 2.1m and the along-track accuracy of GEO is improved from 14m to 8m. The clock accuracies of GEO, IGSO and MEO are 6.3ns,4.7ns and 4.3ns,respectively,and the clock accuracies of all satellites are not more than 6ns. The SISREs of all satellites are generally less than 2m, and the SISREs of MEO satellites are relatively stable over the past 3 years. However, IGSO SISRES and GEO SISRES have some fluctuation in certain level.]]></description>
<pubDate>2016/5/13 10:48:34</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[刘万科]]></author>
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<title><![CDATA[Detection and repair of cycle slips for undifferenced BDS triple-frequency observations]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201512300000005]]></link>
<description><![CDATA[Cycle-slip detection and correction are important issues in high-precision Global Navigation Satellite System (GNSS) data processing. The presence of the new frequency introduces more observations and degrees of freedom in data combination, which is beneficial for cycle-slip detection and repair. We proposed a novel real time cycle-slip detection and repair method based on undifferenced triple-frequency observations. This method employs two groups of geometry-free and ionosphere-free combinations of code and carrier phase observables, and constructs the third linearly independent detector for cycle-slip by eliminating the ionospheric delay variation between two consecutive epochs. The performance of the proposed method is validated with BeiDou triple-frequency observations with 30-s sampling interval. Results show that this method can effectively detects and corrects the cycle slips on each frequency, even under high ionospheric activity condition.]]></description>
<pubDate>2016/5/13 10:48:27</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李柏渝,刘文祥,孙广富,王兴]]></author>
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<title><![CDATA[Adaptive Extended Kalman Filter Carrier Tracking Algorithm for BeiDou Signals under Ionosphere Scintillation Conditions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201512300000003]]></link>
<description><![CDATA[Ionospheric scintillation is a rapid change in the phase and amplitude of GNSS signals, resulting in degraded accuracy and robustness of signal tracking loops. Compared with the frequency lock loop and delay lock loop, phase lock loop is much weaker, and would lose lock much more continually in scintillation. This paper proposes a carrier tracking algorithm for BeiDou signals scintillation mitigation based on adaptive extended Kalman (EKF) filter. The integration of I and Q channels are used to estimate the phase lock indicator (PLI) values, which is the control parameter to adjust the measurement vector of EKF adaptively with different scintillation scenarios. Through the adaptive measurement vector, the accuracy and robustness of the proposed algorithm can be improved, and the probability of divergence can be decreased. Experimental results prove the validity of the analysis and the proposed carrier tracking algorithm.]]></description>
<pubDate>2016/5/13 10:48:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈华明,孙广富,孙鹏跃,唐小妹]]></author>
</item>
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<title><![CDATA[The Power-Weighted Combing Acquisition Algorithm with Data and Pilot Signals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504070000001]]></link>
<description><![CDATA[The modulation with different power of data and pilot channels will be used in the next generation Global Navigation Satellite Systems (GNSS). However, the traditional acquisition algorithms are mostly designed with equal-weighted coefficient of data and pilot channels. Unfortunately, when the power of data and pilot channels are not equal, the traditional algorithms are not suitable for optimizing the performance. The paper proposes a power-weighted combing acquisition algorithm, which uses the different weighted coefficients for data and pilot channels. And uses the Least-Square fitting method to optimize the coefficients. The detection and false-alarm probabilities are derived with characteristic function of decision variable. The simulations prove that the acquisition threshold of the algorithm is improved 0.4 dB, when the power ratio of data and pilot channels is 1:3, and the detection and false-alarm probabilities are 0.8 and 10-3, respectively.]]></description>
<pubDate>2016/3/29 9:26:00</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[欧钢,唐小妹,田丰]]></author>
</item>
<item>
<title><![CDATA[Human behavior recognition based on generative model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505290000002]]></link>
<description><![CDATA[A novel method based on generative model is proposed for human behavior recognition. The behavior is represented using a set of descriptors computed from key point trajectories, which include orientation- magnitude descriptor, trajectory shape descriptor, and appearance descriptor; In order to reduce feature dimensions, the  Agglomerative Information Bottleneck (AIB) approach is used for vocabulary compression; The semi-supervised learning method for behavior recognition based on generative model is proposed to solve the problem of small sample in recognition, which makes use of both the labeled and unlabeled samples. This method is compared with other state-of-the-art methods in both UCF Sports database and YouTube database. The results show that our method has higher recognition accuracy.]]></description>
<pubDate>2016/3/7 12:58:42</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[</Section>  <Section>      王军,夏利民,夏胜平]]></author>
</item>
<item>
<title><![CDATA[Modulation recognition of MQAM signals based onconstellation recovery]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505080000002]]></link>
<description><![CDATA[An algorithm for modulation recognition of MQAM signals based on constellation recovery is proposed. This algorithm firstly estimates the carrier frequency and signal to noise ratio from its spectrum, and subsequently the baud rate sampling is done according the symbol timing. Then non-decision-aided carrier frequency offset estimator is used to mitigate the effect of frequency offset and phase offset in constellation recovery. Finally, the modulation type is recognized by the average likelihood ratio test method. Simulation results demonstrate that the proposed algorithm have the better recognition performance, compared with the amplitude-based maximum likelihood algorithm.]]></description>
<pubDate>2016/3/7 11:55:37</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陆珊珊,王国玉,王伟]]></author>
</item>
<item>
<title><![CDATA[Generalized Extended State Observer Based Robust Flight Control]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201501250000001]]></link>
<description><![CDATA[The generalized extended state observer based robust flight control is investigated to address the parameter uncertainties, external disturbances and measurement noise. Firstly, the nonlinear longitudinal dynamics are transformed into linear-like structure state-space equations of state-dependent coefficients based on the state-dependent Riccati equation (SDRE) control method. And then, according to the generalized extended state observer based control, the disturbance compensation gain is designed to estimate and attenuate the external disturbances. Consequently, the control command is derived to track the desired angle of attack by solving the state-dependent coefficients and the algebraic Riccati equation on-line. Simulation results are illustrated compared with the other control methods. It is demonstrated that the proposed approach not only is robust with the parameter uncertainties and external disturbances, but also remains perfect tracking performance with the measurement noise.]]></description>
<pubDate>2016/3/7 9:57:27</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[江振宇,杨华波,张为华,张银辉]]></author>
</item>
<item>
<title><![CDATA[High Accurate State Propagation of Non-Cooperate Relative Orbit in Space]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503070000003]]></link>
<description><![CDATA[Based on relative orbit dynamics equations and second order Runge-Kutta method, a high accurate state propagation model of non-cooperative relative orbit motion is proposed. Taking the J2 perturbation into account and expanding the target orbit equations into second order Taylor series beside the reference orbit, the relative orbit dynamics equations is built. Then the second order Runge-Kutta method is used to propagate the relative orbit motion. With the use of second order Runge-Kutta method, the computing efficiency is improved while calculation accuracy is guaranteed. What’s more, the model can be widely used without any limiting condition because of numerical integral method is used. Two simulation scenarios, a low Earth orbit scenario and a high Earth orbit scenario, are designed to testify the generality and precision.]]></description>
<pubDate>2016/3/4 10:03:11</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[闫野,朱正龙]]></author>
</item>
<item>
<title><![CDATA[Mulit-skilled Labor Allocating Method Based on Improved Hungary Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505060000001]]></link>
<description><![CDATA[The optimal allocation of labor is of great significance to improve the efficiency of equipment manufacturing. For the shortage of traditional Hungary algorithm that can't solve the resource scheduling problem which contains parallel jobs, an improved Hungary algorithm is proposed in this paper. The improved algorithm converts the problem to a typical assignment problem by replacing parallel link jobs with virtual job. And then, optimizing it with classical Hungary algorithm and determining the realizability of the virtual job based on the results. Finally, the optimal scheme will be got through iterative searching. In addition, an example of mulit-skilled labor allocation system is introduced to verify the effectiveness of the proposed algorithm.]]></description>
<pubDate>2016/2/24 17:34:38</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[李廷鹏,李岳,钱彦岭]]></author>
</item>
<item>
<title><![CDATA[Gaussian-Sum Based 5th-Order Cubature Kalman Filter for Source Geolocation Using Dual GEO Satellites]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504160000002]]></link>
<description><![CDATA[This paper considers the problem of tracking a cruising ground source with known altitude and carrier frequency using two geostationary (GEO) satellites. The source motion parameters are identified from the source signal time difference of arrival (TDOA), frequency difference of arrival (FDOA) and Doppler shift estimated at the GEO satellites. To tackle the high nonlinearity inherent in the above tracking problem, a Gaussian-sum (GS) based 5th-order cubature Kalman filter (5CKF), referred to as GS-5CKF, is proposed. It consists of multiple parallel 5CKFs and they are initialized through partitioning the candidate source positions determined by the measured TDOA at the beginning of the tracking process with respect to the source latitude. Besides, a new nonlinearity measure is advocated, on the basis of which a splitting and merging procedure is developed to further enhance the performance of GS-5CKF while keeping its computational complexity fixed. Simulation results show that compared with the tracking algorithm using a single 5CKF as well as the GS-3CKF method developed in literature, the newly proposed GS-5CKF technique exhibits higher source geolocation accuracy.]]></description>
<pubDate>2016/2/24 17:34:24</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[郭福成,李曦,刘洋,杨乐,张敏]]></author>
</item>
<item>
<title><![CDATA[Calculation Method of Ship’s Shaft Rate Electric Field Equivalent Source Magnitude]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504160000001]]></link>
<description><![CDATA[In order to exploit horizontal time-harmonic electric dipoles to model shaft rate electric field of practical vessels, magnitude and location of equivalent source need to be determined. Aiming at vessels mounting impressed current cathode protection system, by analyzing underlying physical mechanism of shaft rate electric field, the fact that the equivalent source is superimposition of two directionally opposite horizontal time-harmonic electric dipoles is clarified. On the basis of former conclusion, a practical calculation method of equivalent source magnitude of shaft rate electric field was proposed, which says that the magnitude can be obtained by combining source magnitude of static electric dipole inverted from measured static electric field，with the ratio coefficient between the maximum value of shaft rate signal envelope and that of static electric field signal. Besides, location of equivalent source is identical to that of static electric dipole. Effectiveness of proposed method was validated by means of vessel model test in the laboratory.]]></description>
<pubDate>2016/2/24 17:34:09</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[程锐,龚沈光,姜润翔]]></author>
</item>
<item>
<title><![CDATA[A distributed algorithm based on partial evaluation to graph pattern matching]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503270000002]]></link>
<description><![CDATA[In order to execute graph pattern matching quickly in distributed large-scale graphs, an effective distributed algorithm based on partial evaluation which is named disGPM-PE is proposed. Firstly, partial matching is performed locally at each computer nodes in parallel. Secondly, a coordinator node assembles the partial matching results, evaluates and sends the matching conditions of boundary nodes to corresponding computer nodes. Thirdly, each computer nodes determines the matching conditions of the nodes connected to the boundary nodes. Finally, the maximum match is collected at the coordinator node. The experiment results show that disGPM-PE can avoid the impact of the dependent relations between data fragments on the execution time. Compared with the previous distributed graph pattern matching algorithms, disGPM-PE can reduce the execution time of graph pattern matching while do not increase the network traffic obviously.]]></description>
<pubDate>2016/2/24 17:33:45</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[高建良,王建新,王伟平,张丽霞]]></author>
</item>
<item>
<title><![CDATA[Comprehensive analysis method for vulnerability of complex systems]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503260000001]]></link>
<description><![CDATA[In order to identify vulnerable points in complex system roundly and assess its vulnerability scientifically, to improve the insufficiency of the pure topological methods, an analysis method integrated complex network theories and effectiveness assessment (CNEA) technologies was proposed, which considers both the topological and non-topological factors of vulnerability. Firstly, based on centricity measurements of complex network, a generalized indicators method was used for topological vulnerability analysis. At the same time, refering to the probability risk assessment theory, non-topological vulnerability was analyzed from susceptibility and brittleness. Then the final vulnerability results were integrated from the former two results. The demonstration results show that there is a intersecion set but also some differences between topological and non-topological analysis. These two asepects of vulnerability are correlative and complementary close, they both contribute to the screening of critical points and links in a complex system, and comprared to purely topological study, conclusions from integrated analysis were more comprehensive.]]></description>
<pubDate>2016/2/24 17:33:28</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[张旺勋]]></author>
</item>
<item>
<title><![CDATA[Experimental observation of non-reaction flow field based on cavity supersonic combustor on condition of side wall shock wave]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503210000002]]></link>
<description><![CDATA[Shock wave due to side wall is induced into cavity supersonic combustor. In order to study internal flow characteristics of the combustor, Nano-particle planer laser scattering (NPLS) system and particle image velocimetry (PIV) technology are employed to observe internal flow field based on full scale combustor model formed by glasses. Gray images and average velocity distributions of side view and top view are caught by experimental facilities. Observation results reveal that speed and density of fluid inside cavity is low in the region far away from the side wall. Mass and momentum exchange is enhanced in region near the side wall on condition of side wall shock wave with high speed and density. Boundary layer of combustor bottom wall becomes nonuniform due to side wall shock waves. Large scale low speed region is generated at the rear of cavity with obvious three dimensional characteristics.]]></description>
<pubDate>2016/2/24 17:33:13</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[梁剑寒,赵延辉]]></author>
</item>
<item>
<title><![CDATA[A Simplified Method for the Integration of Heterogeneous Database Application System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503180000001]]></link>
<description><![CDATA[The database application system (DBAS) is widely used in diverse domains, and plays an extremely important role. However, the continuous growth of enterprise, adjustment and change of inside and outside the organization, result in the occurrence of many heterogeneous DBAS. How to effectively integrate these heterogeneous systems has become a hot spot of integration field. The existing integrated methods are mainly aimed at the layer of database system. In view of the shortages of those methods, this paper mainly focuses on the integration method in the application layer. According to a new perspective of access control to DBAS, this paper separates the access control layer from the application layer. Then a new method called as "fusion" access control is put forward. Based on the method, this paper put forward a simplified integration method (SIM) of heterogeneous DBAS. Finally, an example shows how to apply the SIM method to achieve the integration of heterogeneous DBAS, and the advantages of the new method are verified by comparison analysis.]]></description>
<pubDate>2016/2/24 17:32:58</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈立南,,刘健]]></author>
</item>
<item>
<title><![CDATA[Maintenance Optimal Model for Phased Array Antenna with Regional Quantification]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503170000001]]></link>
<description><![CDATA[There exist several problems in the maintenance of phased array antenna, such as high maintenance costs, unsure maintenance chance, complicated model simulation and arithmetical operation. Considering these problems, this paper puts forth a maintenance optimal model on the basis of regional quantification. Firstly, a regional quantification model is given, and then the maintenance problems of phased array antenna are turned into the maintenance optimal of a K/N system, which consists of different regional array elements. Secondly, a maintenance optimal model for the antenna is built, which chooses minimum maintenance costs per unit time as the object and the operational availability as the subject. Finally, simulations and analysis of one instance are conducted to verify the validity of the proposed model. The results show that the proposed model could solve the maintenance problems of the asymmetrical array antenna well.]]></description>
<pubDate>2016/2/24 17:32:38</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[李陆军,王永攀,杨江平,张宇]]></author>
</item>
<item>
<title><![CDATA[Hop Timing Precise Estimation for Freqence-Hopping Signals Based on Improved OMP Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503130000002]]></link>
<description><![CDATA[Hop Timing is one of the most important parameters of FH signals, which is crux to receive the FH signals and estimate other parameters, such as hop duration, hopping frequencies and so on. The problem is that hop timing estimates derived from existing methods are coarse and unreliable, therefore, a novel method for estimating hop timing for FH signals precisely is proposed based on improved OMP algorithm. Firstly, the sparse representation model for hop timing estimation is established according to the principle of FH signals. Then, the improved OMP is used to solute the model and get hop timing finally. The theoretical analysis and simulation results verify the method is capable of obtaining precise hop timing, and is better than current methods.]]></description>
<pubDate>2016/2/24 17:31:42</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[沙志超]]></author>
</item>
<item>
<title><![CDATA[Optimization method of carrying maintenance material support project for Warship formation based on CML model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503120000002]]></link>
<description><![CDATA[Most of the studies published in this area focus on multi-constraints, where either qualitative or quantitative condition, is taken into consideration. Nevertheless, the mix-conditions have not been reported to the best of our knowledge from the literatures. The researches usually concern the single warship, but fewer to research about the warship formation. Therefore, go to a step further researches is still need. In view of this problem, the warship formation carrying spare parts at the mission preparation before sailing is taken as a research background, the warship formation support cost, warship storage space, warship carrying ability and maintenance per hour cost are adopted as mixed-constraints conditions, spare parts support probability is served as the objective function. Normal reverse distribution cloud model, marginal effect and Lagrange multiplier methods(CML model) are used to solve such warship formation spare parts allotment problem, A method is proposed for the determination and dynamical updating of system resource constraint factors, meanwhile, the selecting methods and calculating process of the model is optimized. At last, the reliability of the method which can provide the new try for the problem of warship formation spare parts allotment was proved by an actual case.]]></description>
<pubDate>2016/2/24 17:30:20</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[蔡芝明,金家善]]></author>
</item>
<item>
<title><![CDATA[Estimating Tropospheric Slant Delay of Two Way Troposphere Time Transfer]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503110000003]]></link>
<description><![CDATA[Troposphere slant delay is the main error sources in two way troposphere time transfer. But there isn’t an accurate model to estimate the tropospheric slant delay of this system. This article analyzed the Hopfield model and the CFA2.2 mapping function model of the satellite system. In order to be accepted by estimating tropospheric delay caused by tropospheric scatter, Hopfield model and mapping function were modified. Meteorologic data of three observation stations of 35 to 37N in 2010~2012 were selected to improve the applicability of the Hopfield model, The results suggest that precision is less than 35mm. Then, in order to calculate the tropospheric delay under different angle of incidence through modified model, three parts observation stations were distinguished by different length, meteorologic data of those stations in 2012 were used. The results suggest that max delay is 21.82m~35.45m in a single way time transfer. In two way time transfer, when the delay can counteract 90% or 95%, time delay is 7.3ns~11.7ns or 3.6ns~5.9ns.]]></description>
<pubDate>2016/2/24 17:30:02</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[陈西宏,,刘赞,,]]></author>
</item>
<item>
<title><![CDATA[A Time-domain Worst-case Noise algorithm for Power Delivery Network With Non-zero Current Transition Times]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503090000001]]></link>
<description><![CDATA[With increasing clock frequency and decreasing supply voltage, power integrity becomes a critical issue. The effect of the transition time of load currents is taken into account, and it thus allows a more realistic worst-case noise prediction. In addition, A dynamic programming algorithm is introduced on the time-domain impulse response of the power distribution system, and a modi?ed Knuth-Yao Quadrangle Inequality Speedup is developed which reduces the time complexity of the algorithm from O(n<sub>2</sub>m) to O(nmlogn).]]></description>
<pubDate>2016/2/24 17:29:35</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[邓全,蒋剑锋,孙浩,赵振宇]]></author>
</item>
<item>
<title><![CDATA[Phase center evaluation method in adaptive GNSS antenna]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503070000005]]></link>
<description><![CDATA[Beam forming processing of adaptive antenna introduces change of antenna phase center. In high precision GNSS applications, the change must be evaluated. Because of the adjustable reception pattern, the calibration of the phase center variations of adaptive antenna is more complex compared to the fixed-pattern antennas. In order to solve the problem, a evaluate method based on availability beam ratio of antenna array is proposed, the method achieves the target in three steps. Firstly, it starts by setting the availability beam threshold. Secondly, phase of antenna beams in availability beam areas are obtained when the direction of interference signal is a pseudorandom values drawn from the standard uniform distribution. Finally, the average phase center variations are calculated under least squares method. The method was validated by simulation under four typical four-elements-arrays. The analysis of simulated results indicates that the proposed methods can be used to evaluate the phase center characters of adaptive antenna conveniently. What’s more, In order to fulfill the performance of high precision for adaptive antenna array, a choice is to reduce the availability beam threshold. the research can be used as a guideline for choice of distributions of antenna elements in high precision GNSS.]]></description>
<pubDate>2016/2/24 17:27:37</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈华明,李立勋,庞晶,王飞雪]]></author>
</item>
<item>
<title><![CDATA[A Flexible Framework for Quality of Information Estimation in Wireless Sensor Network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504140000001]]></link>
<description><![CDATA[In order to establish an integrated system for quality of information estimation in wireless sensor network (WSN), a flexible framework is proposed in this paper to dynamically estimate information accuracy and information timeliness in different WSN applications. The framework aggregates all the sensor nodes’ information at the sink based on information fusion theory and timescale marking technique. Through approximating the fusion result to Ground Truth, the accuracy of measurement data and decision information is quantified by the numerical/nominal difference between the observed information and the fusion result, respectively. According to application deadline and delay sensitivity of information acquisition, timeliness is classified as three categories for characterization and representation, and quantified through the lightweight measurement of the information acquisition time. The estimation results along the time are dynamically updated by adopting a sliding window mechanism and an incremental calculation algorithm. The effectiveness of the framework is validated by simulations, including timeliness estimation in three target surveillance application scenarios, and accuracy estimation in two environmental monitoring application scenarios. Simulation results match with the reference criteria, which demonstrate that the framework can be flexibly tailored to estimate information accuracy and information timeliness in different WSN applications.]]></description>
<pubDate>2016/1/18 17:07:10</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[郭浩,潘仲明,周靖]]></author>
</item>
<item>
<title><![CDATA[Design and Amelioration to Prevent Surge in Sensors of the Middle-low Velocity Maglev Train]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201412050000002]]></link>
<description><![CDATA[The sensors gathering data of the suspension state of the electromagnet can be of real significance in the safety of the maglev train. Mechanism of surge under the local circumstance is analyzed; details of the surge experiment are confirmed. Feasibility of the existing design in preventing surge is explained at a point of current flow capacity view, and insufficiency of reliability under the local circumstance is pointed out. With a capacitance paralleling in front of the circuit, the surge is hindered, the impact to the latter components is reduced, and capability of the circuit to prevent surge is promoted.]]></description>
<pubDate>2016/1/6 11:45:38</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[曾晓荣,]]></author>
</item>
<item>
<title><![CDATA[Global optimization of solar sail gravity assist and solar photonic assist trajectory for interstellar mission]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201501190000002]]></link>
<description><![CDATA[With the goal of solar sail mission to near interstellar space (200AU) in 20 years, a global optimization problem of solar sail gravity assist and solar photonic assist trajectory for interstellar mission is studied. In this paper, a mathematical model for solar sail time-optimal trajectory is established. By taking constrains of solar sail gravity assist and solar photonic assist into the object function, the four-point boundary value problem of orbit optimization can be converted to multi-variable optimization problem of no constraint. With appropriate constrain proportions chosen, the problem is solved by using genetic algorithm and SQP method. Optimization result shows that plenty of time could be saved by adding Jupiter gravity assist, though solar sail gains a large velocity with solar photonic assist. The global optimization algorithm of solar sail gravity assist and solar photonic assist trajectory proposed by this paper, will provide a reference for the preliminary design of solar system escape orbit.]]></description>
<pubDate>2016/1/6 11:43:15</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李明涛,,,]]></author>
</item>
<item>
<title><![CDATA[Thermodynamic process of sphere cam engine applied in HEVs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503260000002]]></link>
<description><![CDATA[As a new kind of power source of extend range system applied in Hybrid Electrical Vehicles(HEVs), sphere cam engine is said to have high power density and compacted structure. Based on the introduction of working principle and structure of sphere cam engine, the variation of cylinder volume is studied. Furthermore, the combustion process of sphere cam engine is analyzed to establish the theory thermodynamic model of engine. Then the theory model is validated by simulation of thermodynamic process of engine using FLUENT. The oil spray process is simulated using the CFD model. Results show that the calculated pressure curve and temperature curve in cylinder are similar to the simulation results. The comparison results validate the theory model. However the vortex of sprayed oil may lead to the rich oil phenomena, which may decrease the combustion efficiency.]]></description>
<pubDate>2016/1/6 11:22:50</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[潘存云,徐海军,徐晓军,张雷]]></author>
</item>
<item>
<title><![CDATA[Estimate of the Radar Beam’s Azimuth Based on Particle Filter]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201506040000001]]></link>
<description><![CDATA[The estimate of the radar beam"s azimuth is the key technology of radar reconnaissance and accurate jamming for mechanical scan radar. Traditional estimate method has limited capacity when the scan rate of radar antenna varies with time. Thus a state space model for estimating beam azimuth is established, and the particle filter is introduced to estimate the state variables. Particle filter is a powerful method for state estimation in non-linear and non-Gauss case. The radar beam’s azimuth estimating algorithm based on particle filter has better performance, and can adapt to the case where the scan rate of radar antenna varies with time. The simulation results show the efficiency of the proposed algorithm.]]></description>
<pubDate>2016/1/6 11:22:49</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陆珊珊,王国玉,王伟]]></author>
</item>
<item>
<title><![CDATA[A method and apparatus for synthesis of gas hydrate by microwave heating in porous media]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503090000002]]></link>
<description><![CDATA[For the problem of uneven distribution of gas hydrate synthesized in porous media,a new method for obtaining samples of hydrates in porous media by microwave heating is proposed in this paper. Based on electromagnetic theory and influencing factors of heating uniformity, the adjustable multi-feeding microwave heating system is created,and relevant simulation and heating test are made to analyze the uniformity of the apparatus,which is of great significance for gas hydrate synthesis by this method. The simulation and test results show that the heating  uniformity is greatly affected by the variation of distance between the waveguides and specimen, which gets better with distance significantly. The consequence of numerical simulation is consistent with the result of experiment. The heating uniformity of the apparatus is less affected by heating time,and the apparatus can meet the requirement of synthesis of hydrates in uniformity,and its design may provide certain reference significance for design of testing devices with some  requirements in microwave heating uniformity.]]></description>
<pubDate>2016/1/6 11:22:47</pubDate>
<category><![CDATA[专题：高性能计算]]></category>
<author><![CDATA[罗永江,彭枧明,吴冬宇,张鑫鑫]]></author>
</item>
<item>
<title><![CDATA[The Design and Mechanism of the Fault Tolerance mechanism of Solid State Recorder]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503030000002]]></link>
<description><![CDATA[High-capacity solid state recorder (SSR) has become one standard composition in space borne data handling system. When the spacecraft flies above the domestic ground data receive stations, all the data in SSR would be read out and sent to earth as planed or following the ground orders. The data transmission system is the work platform of the SSR. The work modes and procedures are introduced and they are faced with various threats. The data reliability depends on many segments with different problems. This paper presents the SSR fault tolerance mechanism schedule to cover Single Event Upset (SEU) in semiconductor devices, the Flash retention effect, the transmission noise and so on. The SSR of the satellite is based on NAND Flash medium with a large-scale FPGA and a high-performance Loongson CPU. The SSR uses 4-pipeline writing and bus expansion techniques to achieve the throughput rate of almost 1Gbps theoretically and the capacity of 256Gb. Three EDAC techniques are adopted to protect the data bit streams. The Harmming Code is used to protect management information of SSR, the RS code is used to correct errors in Flash medium brought by the space radiation and interface interrupts, and the Low Density Parity Check Code (LDPC) encoding suggested by CCSDS is used to get a high channel gain between the satellite and the earth. All these techniques are introduced and analyzed. Furthermore, advanced research of one ARQ method based on the SSR platform with CCSDS File Delivery Protocol (CFDP) is also proposed in this paper to improve the reliability in file-level. All the techniques work together to cover the main procedures from different aspects.]]></description>
<pubDate>2016/1/6 11:22:42</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[安军社,李姗,宋琪,朱岩,邹业楠]]></author>
</item>
<item>
<title><![CDATA[Parameterized Multi-standard High-throughput Radix-4 Viterbi Decoder on FPGA]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201502250000001]]></link>
<description><![CDATA[To achieve the goal of high performance and flexibility, this paper presents a parameterized multi-standard adaptive radix-4 Viterbi decoder with low complexity on FPGA. This decoder adopts constraint lengths ranging from 3 to 9, code rates in the range 1/2-1/3 and arbitrary truncation lengths. The unsigned quantization, ACSU optimization and normalization strategies are used to improve system throughput. It achieves low bit error ratio in multiple standards such as GPRS, WiMax, LTE, CDMA and 3G. The throughput can reach to 541Mbps, apparently superior to related works.]]></description>
<pubDate>2016/1/6 11:22:40</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李荣春,聂晶,王文涛,]]></author>
</item>
<item>
<title><![CDATA[Review of interdependent networks]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201501300000002]]></link>
<description><![CDATA[In recent years, the network dependency and interdependent networks have become a research hotspot in the field of complex network. Interdependent networks show some different nature compared with isolated network because of the existence of dependency between nodes, such as failure propagation across networks, first order percolation transition. Research of interdependent networks has made many achievements. In this paper, the background theory of interdependent networks is briefly introduced, then the related progress are introduced from three aspects effect the nature of interdependent networks: characteristics of sub network, type of dependency edge, the combination of sub networks. Finally, the future development direction is prospected.]]></description>
<pubDate>2016/1/6 11:22:39</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[老松杨,]]></author>
</item>
<item>
<title><![CDATA[Evaluation Model of Equipment Time-varying Availability for Combat Units under Finite Repair Capacity]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201502060000002]]></link>
<description><![CDATA[Aim at the demand of spare parts changes dynamically as the mission phases does, considering the influence of the scrap probability owing to the finite carrying repair capacity of combat units, by the scrap factor, the evaluation model of time-varying operation availability for two echelon support system is developed, in which, the failure parts can be scrapped and there is no exterior supply. And then, simulation is realized based on ExtendSim software and the availability results is received, according to the results, the parameter fitting is carried into execution and the approximate analytical formula of scrap factor in the availability model is obtained. In a given example, the scrap factor can adapt different reliability and maintainability parameters, and the adaptability is validated. The evaluation model is a complementary for conventional models which is developed based on spare parts balance in support system and can help equipment personals to make appropriate spare parts programs.]]></description>
<pubDate>2016/1/6 11:22:36</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[徐 立]]></author>
</item>
<item>
<title><![CDATA[The structure of partial-DNA cyclic memory for embryonics cell]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201501290000001]]></link>
<description><![CDATA[In order to reducing embryonics system’s hardware overhead while ensure system reliability, a novel genome memory structure, partial-DNA cyclic memory, was presented, and only part of the system’s entire DNA was stored. The embryonics array’s functional differentiation and self-repair were achieved through the gene cyclic and non-cyclic shift in the cell and between cells, and the genes stored in memory were updated during the self-repair process. In this memory structure, the stored gene number can be set according to actual demand in design process, and was independent from the number of idle resources in embryonics array. Theoretical analysis and simulation results show that the new genome memory structure not only to achieve the embryonics array’s functional differentiation and self-repair, but also ensure system reliability while reducing hardware overhead, and has practical engineering value.]]></description>
<pubDate>2016/1/6 11:22:34</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[朱赛]]></author>
</item>
<item>
<title><![CDATA[Impact Analysis of CFAR Detection for Active decoy Using Interrupted-Sampling Repeater]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201501280000002]]></link>
<description><![CDATA[This paper analyzed the impact of interrupted-sampling repeater Jamming (ISRJ) on radar constant false alarm rate detection. The generation principle of false target using ISRJ is introduced at first. Then generation methods of false targets jamming are given. On base of it, the detection cost caused by the false alarm and false dismissal in a search period of radar is chosen as the criteria of detection performance. The detection costs of CA-CFAR, OS-CFAR, CMLD-CFAR detectors under three types of dense multiple false targets jamming environment are analyzed. Specially, we analyze the influence of ISRJ key factors on detection costs. The simulation result shows that detection costs will increase remarkably due to false targets exist and it is sensitive to the jammer power and duty ratios, but has little relationship to the repeating frequency. Among three detectors, the detection cost of radar CMLD-CFAR detectors is higher than that of radar adopting OS-CFAR and that of radar adopting CA-CFAR.]]></description>
<pubDate>2016/1/6 11:22:33</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[冯德军,,]]></author>
</item>
<item>
<title><![CDATA[Research on Key Technology of Transplantable Human Auricular Scaffold Based on 3D Printing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201501060000005]]></link>
<description><![CDATA[Auricular deformity is a commonly seen illness in clinic. Autologous tissue transplanting is the most frequently used treatment for this disease. This surgery is technique demanding, whereas the sculptured scaffold is incapable of highly imitating the complex structure of auricle, and complication may also occur because of the remove of costal cartilage. This paper proposed to replace the sculptured scaffold with an artificial silicon-made one. CT scan and reversed modeling were used to obtain the digital auricular model, and 3D printing technology was utilized to manufacture the mold of auricular scaffold, and medical silicon MED 4735 was used as the material of the scaffold. Animal experiments were then implemented to examine the biocompatibility of the scaffold. The scaffold made by these technologies highly imitated a normal auricle, with high accuracy, short manufacturing cycle, and no immune rejection, which provided basis for further clinical human experiments.]]></description>
<pubDate>2016/1/6 11:22:30</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[蒋涛,尚建忠,唐力,王卓]]></author>
</item>
<item>
<title><![CDATA[The Delay-Waiting Detection Method based on Local Maximum to Suppress Repeater Spoofing Interferences]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503080000006]]></link>
<description><![CDATA[A large side-lobes will be formed in the output of correlator after rejecting narrow-band interface. Use the traditional method based on the delay of the repeater jamming will be locked on the side-lobes. This paper presents a new method based on local maximum value. As a prerequisite, to ensure the side-lobes do not superpose the repeater jamming , to prevent capture module from locking side-lobes, and it also choose the earliest code-phase from those local maximum to remove repeater jamming. Compare with traditional method, the performance is same in the absence of narrow-band interface, but it is significant improve the performance in the narrow-band interface condition. The simulation results validate the theory analysis.]]></description>
<pubDate>2016/1/6 11:22:28</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[孙广富]]></author>
</item>
<item>
<title><![CDATA[Data collection for failure prediction toward exascale supercomputers]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504090000001]]></link>
<description><![CDATA[With the rapid development of supercomputers from petascale to exascale, the reliability of supercomputer faces enormous challenges, while the proactive fault-tolerance techniques based on failure prediction become one of the effective ways to improve the system's fault tolerance ability. Data collection is the basis of the failure prediction and impact the prediction accuracy, while the current failure prediction data collection method is incomplete with less data attributes and has huge overhead. Toward exascale supercomputer FPDC (Failure Prediction Data Collection Framework) is introduced to fully collect the data related to the state of compute nodes’ health. An adaptive multi-layer data aggregation method is presented for data aggregation with less overhead. Extensive experiments, by implementing FPDC on TH-1A，indicated that FPDC has the advantage of high efficiency and good scalability.]]></description>
<pubDate>2016/1/6 11:22:25</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[董文睿,胡维,蒋艳凰,刘光明]]></author>
</item>
<item>
<title><![CDATA[Enriched finite element analysis of stress intensity factors of bi-material V-notch]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201502020000004]]></link>
<description><![CDATA[A new method is proposed for the computation of the stress intensity factor in the V-notched bi-material structure. The V-notch asymptotic displacement field is derived through a approach based on the Williams’ series expansion and linear algebraic transforms in the method. By incorporating the displacement expressions to the common isoparametric element, the enriched and transition element displacement model are obtained, and then the enriched finite element equation is derived consequently. The enriched finite element models for a V-notched bi-material three-point bending beam and a orthogonal bonded materials interface end plane problem are constructed, and the stress intensity factors can be solved directly from the finite element equation. Comparisons between the results and published data computed with other algorithm indicate that the present method is correct and can be used to analyze the fracture property of the V-notched bi-material structure.]]></description>
<pubDate>2016/1/6 11:22:23</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[韩珺礼,雷勇军,蒙上阳,杨军辉]]></author>
</item>
<item>
<title><![CDATA[Quantitative identification of coating thickness and inner defects of the material by infrared testing technology]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201502060000001]]></link>
<description><![CDATA[Aiming at the problems of infrared quantitative detection of thermal barrier coating structures, the LM (Levenberg-Marquardt) recognition algorithm based on pulse phase was put forward. The transient thermalmodel of TBC structures by an axisymmetric cylindrical coordinates was established in view of the research problem. The surface temperature field of the research model was calculated by the finite volume method. And then the phase of the inspection surface was obtained through FFT. The impacts of parameters to be detected on the phase of the inspection surface were analyzed. Based on the phase for the input parameter, quantitative identification method of coating thickness and inner defects of the metal was researched by using LM recognition algorithm. The quantitative identification method based on phase detection was verified by using numerical experiment. The effectiveness of the quantitative identification method was evidenced  on the basis of the numerical experiment results.]]></description>
<pubDate>2016/1/6 11:22:21</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[陈林,范春利,石宏臣,杨立,赵小龙]]></author>
</item>
<item>
<title><![CDATA[Sequential Approximate Optimization Study and Application in Rocket Shape Rapid Design]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201502030000001]]></link>
<description><![CDATA[Sequential approximate optimization method has shortcomings in two respects as surrogate models establishing and infill strategy at present. Based on local density of sampling points, optimal kernel width of radial basis function (RBF) is obtained by means of total influence volume optimization. Potential feasible region infill strategy was proposed, and potential optimal strategy was applied together, both exploration and exploitation capacity of sequential approximate optimization algorithm were satisfied. Convergence criterion was seted up. Algorithm flow process was constructed. For Golinski reducer optimization problem, global optimal solution was solved after calculating original model 42 times. Shape optimization mathematical model was established for TH-II rocket (TianHang), global optimal shape was gained after 165 times original model calling using proposed method. TH-II rocket aerodynamic shape was proved reliable by flight testing.]]></description>
<pubDate>2016/1/6 11:22:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[胡凡,彭科,武泽平,张为华]]></author>
</item>
<item>
<title><![CDATA[Optimization Method Design and Analysis of Footprint for Multiple-pulse Missile]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201501230000001]]></link>
<description><![CDATA[In order to formulate tactical indicators and mission plan,the footprint for multiple-pulse missile was investigated. The footprint optimization problem can be transformed into an optimal control problem by introducing the cost function which is formulated as a weighted combination of down-range and cross-range. A multiple constraints and phases trajectory optimization model was established including double optimization design variables that composed by the angle of attack and slip angle,and solved by hp-adaptive pseudo-spectral method. Moreover, the effects of multiple-pulse motor parameters and terminal constraints on the footprint were emphatically analyzed. The simulation results show that efficiency of the proposed method in solving the footprint optimization design problem with multiple constraints and phases.The smaller pulse interval time,the greater thrust radio and the smaller mass radio of the pulse motor is corresponded to a bigger footprint,the impact angle affects footprint less compared with terminal velocity．]]></description>
<pubDate>2016/1/6 11:22:13</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[白宏阳,梁卓,明超,孙瑞胜]]></author>
</item>
<item>
<title><![CDATA[Study on the ring laser gyroscope bias compensation based on the compound signals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509300000001]]></link>
<description><![CDATA[As a complex system combined with optics, electronics and mechanics, the ring laser gyroscope (RLG) can measure the angle rate with high accuracy. In order to meet the requirement of longer-time and higher precision in inertial navigation system, the characteristics between the RLG drift error and different signals from various sensors are studied. Based on the traditional RLG drift error compensation model, compound signals from thermometers, photodiodes and piezoelectric ceramics attached on the dithered mechanism are introduced into the model. Moreover, by utilizing the support vector machine algorithm, the model is optimized by the correlation features between the mechanically dithered RLG (MDRLG) drift error and the compound signals. The experimental results show that the precision of the MDRLG drift error compensation model in this paper is higher than the traditional one.]]></description>
<pubDate>2016/1/6 11:22:02</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[李耿,龙兴武,张鹏飞]]></author>
</item>
<item>
<title><![CDATA[Failure analysis of composite T-joints under bending load]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503160000002]]></link>
<description><![CDATA[A finite element model of the composite T-joints under bending load has been established. The Tsai-Wu failure criterion and a cohesive zone model were used to simulate and analyze the failure mechanisms and carrying capacities of the composite T-joints under bending load. By static bending experiments four failure modes have been investigated during bending failure processes of the composite T-joints. The maximum bending load of the T-joint calculated by FEM methods was consistent well with experimental results.]]></description>
<pubDate>2016/1/6 11:22:00</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[文思维,吴海,肖加余,邢素丽,杨孚标,杨金水]]></author>
</item>
<item>
<title><![CDATA[Electromagnetic transmission characteristics of frequency selective surfaces with carbon fiber fabric/epoxy composite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201507280000001]]></link>
<description><![CDATA[Traditional FSSs were made of metals, such as cooper and aluminum. There were problems when the FSSs were used with composite structures, such as thermal mismatch and second bonding layers. To avoid these disadvantages, carbon fiber fabric/epoxy composite FSSs were put forward in this study. A four-legged slot array composite FSS was fabricated by cutting carbon fiber/epoxy composite panels. Free space method and finite integral method were carried out to evaluate the electromagnetic transmission characteristics of the composite FSS specimens, respectively. Results show that the composite FSS with four-legged slot array can realize the function of frequency selection and its minimum transmission loss can be decreased by increasing the electrical conductivities of the composite material, adjusting the thickness and increasing the aperture-to-cell ratio of it.]]></description>
<pubDate>2016/1/6 11:21:57</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[李长亮,,]]></author>
</item>
<item>
<title><![CDATA[The influence of boundary conditions on the quasi-static indentation damage of composite laminates]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509040000001]]></link>
<description><![CDATA[Carbon fiber/bismaleimide composite laminates are riveted to the metal frame when applied on aircrafts, hence the boundary condition of composite laminates is four edges clamped. Based on the real application, in this study, the differences of quasi-static indentation damage of composite laminates under four edges clamped and under simply supported were systemically compared from four aspects: delamination propagation, contact force, dent depth and damage width. The experimental results showed that all these four aspects were different when composite laminates were under different boundary conditions. Also the results provided experimental data for investigating quasi-static indentation damage of composite laminates based on real application.]]></description>
<pubDate>2016/1/6 11:13:10</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[唐俊,肖加余,邢素丽]]></author>
</item>
<item>
<title><![CDATA[Rapid fabrication and ablation resistance test of modified C/C composite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509070000001]]></link>
<description><![CDATA[The modified C/C composite was quickly prepared by liquid impregnation combined reactive melt infiltration technique, the microstructure was studied and the ablation behavior exposed under oxyacetylene flame and high-frequency plasma wind tunnel (HFWT) atmosphere was assessed. Results show that many high melting point refractory compounds such as HfC, ZrC, TaC were introduced into the modified C/C composite, the density and open porosity of which were 3.53g/cm3 and 4.71%, respectively. A compact oxide film generated upon the modified C/C composite after oxyacetylene flame ablated 360s, which was mainly consisted of HfO2, ZrO2 and Ta2O5. The linear ablation rate of modified C/C composite was 0.00518mm/s. The ablation resistance of modified C/C composite bulb model was assessed by HFWT, the stagnation temperature was 2293℃, the heat flux was 3.53MW/m2 and the test duration was 180s. After ablation, a dense oxide protective layer formed on the surface of the model, the shape and the dimension of the model were changed insignificant, the linear ablation rate was 0.00172mm/s after removed the oxide layer.]]></description>
<pubDate>2016/1/6 11:13:07</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[白宏德,白书欣,叶益聪,张虹,朱利安]]></author>
</item>
<item>
<title><![CDATA[The study on the thermo-physical property of the SiC<sub>p</sub>/Cu composite fabricated by hot pressing method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509070000005]]></link>
<description><![CDATA[The molybdenum coating was successfully deposited on the surface of silicon carbide by direct current magnetron sputtering method and the crystallized heat-treatment, its surface morphology and chemical composition were analyzed. Then the SiCp/Cu composite was prepared by vacuum hot-pressing sintering, and the effects of the interfacial layer thickness on the thermal conductivity were studied in detail. The results are as fellows, molybdenum coating can be successfully deposited on the surface of silicon carbide by direct current magnetron sputtering method, with the sputter time postponed the roughness and the thickness of the film was enhanced, furthermore the molybdenum on the surface was in amorphous state. After crystallized heat treatment, the molybdenum coating came to be densification crystalline state. The sputtering time affects the thickness of the Mo coating and the thermal conductivity of SiCp/Cu obviously, with the time postponed the thickness of the Mo coating increased, and the thermal conductivity shows the change trend of firstly increase and then decreased. The thermal conductivity of the SiCp/Cu composite fabricated by the 9h Mo coated SiC powders can reached 274.056W/(m·K) when the volume fraction of SiC is about 50%.]]></description>
<pubDate>2016/1/6 11:13:03</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[白书欣,李顺,刘猛,熊德赣,赵恂]]></author>
</item>
<item>
<title><![CDATA[Preparation and Properties of Quartz Fiber / Bisphenol-E Isocyanate Ester Composites]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509090000001]]></link>
<description><![CDATA[The viscosity and curing characteristics of bisphenol-E cyanate ester resin was studied through experiments to reveal the influence of catalyst on the curing mechanism of the cyanate ester resin. Quartz fiber/bisphenol-E cyanate ester composites were fabricated by RTM and VIMP processes to investigate its mechanical properties. The results show that the viscosity of the resin system is less 300mPa?s and its gel time is more than 10h at temperature range from room temperature to 90℃. The initial curing, curing and final curing temperature of the resin system is 186±5, 235±5 and 286±5 ℃, respectively. And the curing characteristic temperature decreases with the increasing content of the catalyst until the catalyst saturation, which is in the range from 200 to 300ppm. The curing temperature of the resin system can be decreased nearly 60 ℃ by the catalyst. That is very important for avoiding implosion and successfully fabrication of quartz fiber/ cyanate ester composites by liquid composite molding. The mechanical properties of VIMP manufactured sample is obviously higher than that of RTM fabricated sample.]]></description>
<pubDate>2016/1/6 11:13:00</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[李娟,魏凯耀,杨金水]]></author>
</item>
<item>
<title><![CDATA[Mechanical performance of integrated stitched sandwich composite materials]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509090000002]]></link>
<description><![CDATA[New type stitched structure of sandwich composite materials which can avoid the disadvantages of fiber cross caused by the traditional angled stitched was designed The integrated stitched sandwich composite materials was prepared by vacuum infusion molding process(VIMP). The flatwise compression test and three-point bending test was employed to study the effect of stitching structure, stitching mode and stitching yarn on compression properties and bending properties. The results show that the integrated stitched sandwich composite materials have excellent compression mechanical properties, and the flexure failure load increased by 94.4% compared to the vertical structure; compressive strength and bending load were improved significantly by penetrate stitched mode compared to the un-penetrate stitched mode; the compression properties and flexure properties of stitched sandwich composite materials have been improved with the increase of stitching yarn.]]></description>
<pubDate>2016/1/6 11:12:50</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[杜刚,鞠苏,魏凯耀,杨金水,曾竟成]]></author>
</item>
<item>
<title><![CDATA[Repairing performance of  carbon fiber/bismaleimides (C/BMI) composite materials]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509140000001]]></link>
<description><![CDATA[In order to get the best repairing effect of C/BMI composite materials. Carbon fiber/epoxy(C/EP) composite materials and epoxy film adhesive was used as the repair materials to repair C/BMI composites with the pre-drilled hole of Φ15 mm and Φ5 mm. Single-lap repair, double-lap repair and step-lap repair was adopted to repair the composite structures with pre-drilled hole. Discussed the effect of the patch numbers, patch lengths and patch stacking sequences on repairing performance. The failure model of the repaired plates was analyzed through the experimental method,and the patch-repairing parameters was optimized. The results show that the stress concentration and through-thickness tensile stress along the edges of the patch is the key reason to the fracture of the parent plate. The tensile strength of the double-lap repaired specimen can be recovered over to 90% of the strength of undrilled specimen. And the strength of the specimen repaired by the single-lap repair and step-lap repair also can recover over to 80% of the undrilled specimen. It is great important for composite quick repair technology.]]></description>
<pubDate>2016/1/6 11:05:39</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[文思维,肖加余,肖中璠,邢素丽,杨金水]]></author>
</item>
<item>
<title><![CDATA[Effects of organic functionalization on Glass Transition Temperature and Toughness of Carbon Nanotubes Reinforced Epoxy Resin Composites]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201509290000004]]></link>
<description><![CDATA[Carbon nanotubes (CNTs) were supposed to increase the glass transition temperature (T<sub>g</sub>) and toughness of polymers simultaneously, since they could hinder the motion of polymer chains and transfer stresses. The properties of the composites related with the interphase between the CNTs and the polymer matrix. T<sub>g</sub> and toughness of the epoxy resin composites reinforced by different functionlized carbon nanotubes (CNTs) were investigated. Results showed that T<sub>g</sub> of the composites with amino groups (-NH<sub>2</sub>) grafted CNTs was the highest, while that of the composites with carboxyl groups (-COOH) grafted CNTs were lower than T<sub>g</sub> of the neat epoxy resin. Toughness of the composites was doubled with the embedded CNTs, which implied that the embedding of CNTs into the epoxy resin should be an effective way to increase both the T<sub>g</sub> and toughness of the epoxy resin. The variations in the properties due to different interphase formed in the CNTs/epoxy composites.]]></description>
<pubDate>2016/1/6 11:04:58</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[江大志,蒋彩,鞠苏,林少锋,尚新龙,张鉴炜]]></author>
</item>
<item>
<title><![CDATA[Structural optimization of composite truss based on Isight Platform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201510080000002]]></link>
<description><![CDATA[Fiber-reinforced composites have been widely used in aerospace and aircraft structures because of their excellent mechanical properties and light weight. Glass fiber reinforced epoxy composite(GFRC) truss with square cross section under three-point bending exhibits nonlinear behavior according to finite element analysis. On the Isight platform, a multi-parameter optimization method is conducted to obtain five key geometric parameters of the optimal composite truss which meets the demand of structural stiffness, load bearing and light weight. Finally, nonlinear structural responses of the optimal composite truss are obtained.]]></description>
<pubDate>2016/1/6 11:04:36</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[黄春芳,江大志,鞠苏,肖加余,郑青]]></author>
</item>
<item>
<title><![CDATA[Bearings health monitoring under varying operation conditions using RVM and adaptive threshold model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201412100000001]]></link>
<description><![CDATA[Operation conditions usually change when rotating machinery works. The changing operational conditions, as well as machine fault, could make the mechanical vibration characteristics change and cause diagnosis errors. This paper presents a new method for the health monitoring of bearings under changing operational conditions. In this method, Relevance Vector Machines (RVMs) are used for regression of the relationships between the adaptive parameters of the threshold model and the statistical characteristics of vibration features. And the adaptive threshold model is constructed based on these relationships. This method is validated on bearings running at changing speeds. The monitoring results show that this method is effective as long as the rotational speed is higher than a relative small value.]]></description>
<pubDate>2016/1/4 9:09:11</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[胡  雷,]]></author>
</item>
<item>
<title><![CDATA[Schedule of rescue helicopter departure time considering airway intersection]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201501070000002]]></link>
<description><![CDATA[There is a growing tendency of using helicopters in disaster rescue, which is more crucial and difficult for scheduling the departure time of multiple helicopters. This paper sets up a mathematical programming model for multiple helicopters in multiple airports, aiming at minimizing the departure time of the last helicopter. Then designs a heuristic algorithm based on task priority to solve the model. This paper also puts forward a scheme to deal with the airway intersection, and comes up with an algorithm to solve the scheme. At last, we conduct a case study with 24 helicopters in 12 airports to validate the model and algorithms, basing on the 6.8 magnitude earthquake in Yunnan Ludian. The influence of airway intersection and the treatment measures are discussed. The results indicate the efficiency of the method to deal with the problem proposed in this paper.]]></description>
<pubDate>2015/11/29 15:00:38</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[陈超,,,,王一杉,]]></author>
</item>
<item>
<title><![CDATA[A carrier phase aided anti-jamming algorithm for GNSS antenna array]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505080000005]]></link>
<description><![CDATA[Interference and multipath are the two dominant factors that affect the performance of Global Navigation Satellite System (GNSS). This paper proposed a beam steering/null steering switchable algorithm for interference mitigation using adaptive antenna array. The beam steering is realized with the aid of the carrier phase of the output signal from each individual antenna, and the null steering and beam steering is switched by an optimal criteria. The simulation results show that, the proposed algorithm performs well at “cold” start when the receiver is initiated in strong interference conditions. It could enhance the GNSS signal by steering beams to the satellites under interference free or weak interference conditions. The proposed algorithm requires no array calibration and prior knowledge. It has less cost than traditional beamforming algorithms for implementation.]]></description>
<pubDate>2015/10/30 11:18:31</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈飞强,聂俊伟,苏映雪,王飞雪]]></author>
</item>
<item>
<title><![CDATA[Ionosphere Effects Simulation with High Precisionfor High Order BOC Modulated Signals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503090000005]]></link>
<description><![CDATA[The navigation signal simulator needs to simulate the signal delay and dispersion effects caused by the ionosphere. For the traditional BPSK signal, the simulation method is directly adjusting the relative relationship between the code phase and carrier phase for simulating the influence of the ionosphere. The method is based on the assumption of a single frequency for BPSK signal. BOC (Offset Carrier Binary) modulation signal is widely used in the new generation of satellite navigation signals, it has a wider bandwidth, single frequency assuming will cause a non negligible modeling error for the dispersion effects caused by the ionosphere. In this paper, a high accuracy simulation method of high order BOC signal based on the bilateral model is proposed, and the correctness of the algorithm is verified by simulation. The method can be applied to simulate the effect of the ionosphere dispersion for BOC signal in the navigation signal simulator.]]></description>
<pubDate>2015/10/30 11:17:58</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[庞晶,]]></author>
</item>
<item>
<title><![CDATA[Research of Hybrid Brake Method for EM UAV Launcher]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201412060000001]]></link>
<description><![CDATA[Electromagnetic launch (EML) for unmanned aerial vehicle (UAV) which utilizes linear motor to accelerate in short distance is already a new trend for launching fixed-wing UAV. To brake shuttle in shorter distance when aircraft taking off, it proposes and analyzes a hybrid brake method including solid stator eddy current brake, eddy current brake based on Halbach permanent arrays and rubber damping brake. When the speed of shuttle is above 10m/s, it is notable for the brake by means of solid stator eddy current brake. In addition, when the speed of shuttle is below 3m/s, the brake force induced by solid stator eddy current is decreased greatly. It can increase 30% brake force by Halbach permanent arrays eddy current brake. By model analysis and collision experiments, rubber damping brake can absorb kinetic energy to brake shuttle in short distance as the final stage braker.]]></description>
<pubDate>2015/8/25 15:20:53</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[邓志雄,吴 峻,杨 宇,赵宏涛]]></author>
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<title><![CDATA[Conceptual Design of Stratospheric Airship Based on PSO Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504130000004]]></link>
<description><![CDATA[Minimizing the total weight of a stratospheric airship reflects the design object of lowest total cost to a certain extent. To meet the power requirement of payload is the springboard and goal for the conceptual design of the airship. In this paper, the model of paving solar cells on curved surface and the model of energy-closed loop during day and night are introduced in the parametric modeling of the airship. The Particle Swarm Optimization (PSO) algorithm is used to optimize the parameters of outside size. The design object is to find a feasible airship, which is with minimum total mass and satisfies the constrains including three balances: the balance between the energy supply and the energy requirement, the balance between mass and buoyancy, and the balance between drag ant thrust. The sensitivity of the optimization results with different requirement of payload power and payload specific power is analyzed. The analysis results showed that (1) the total airship weight increases linearly with the payload power requirement; (2) the total airship weight decreases steeply with the payload specific power, but the change rate of the total weight also decreases, and the total weight tends to stable. At last, the results of energy system simulation indicate the validity of the conceptual design method, as well as the critical characteristics of the design results.]]></description>
<pubDate>2015/7/6 10:18:43</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘多能]]></author>
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<title><![CDATA[A Moving Mesh Strategy for Large Deformation of Near-Space Aircrafts]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504020000004]]></link>
<description><![CDATA[For the high-aspect-ratio near-space aircrafts, they would undergo very large deformation during flight, so it is a highly demand to develop a robust moving mesh method which is capable for large deformation of the boundary. This paper presents a strategy of moving mesh for large deformation. The strategy bases on the mapping interpolation method in which the displacement of node is regarded as the results of the boundaries. In this paper,  (1/d)^n is chosen as the interpolation factor. The influence on the mesh quality of the index n was studied, and some 2D/3D moving mesh cases were presented as well. The results suggest that this method is capable to hand the moving mesh cases in which the large deformation is involved.]]></description>
<pubDate>2015/7/6 8:26:14</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈立立,侯中喜,柳兆伟]]></author>
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<title><![CDATA[Structural analysis of large-scale flexible inflatable structures for stratospheric airships]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504130000006]]></link>
<description><![CDATA[As a large-scale flexible inflatable structure by a huge inner lifting gas volume of several hundred thousand cubic meter, the stratospheric airship’s structural characteristic plays an important role in its flight performance. According to the inflatable structure theory, a numerical model of inflatable membrane for stratospheric airships is developed and the nonlinear finite element procedure is integrated. Based on the validation of the computation model, the distribution of the deformations and stresses of the membrane are calculated with the variations of the pressure load and gondola load. The effects of structural configurations on the inflatable membrane structural safety are evaluated. The numerical results can be referenced for the structural design of the stratospheric airship.]]></description>
<pubDate>2015/7/6 8:15:23</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[侯中喜,麻震宇,杨希祥]]></author>
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<title><![CDATA[Midcourse Guidance of Interception using State Transition Matrix]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201505110000001]]></link>
<description><![CDATA[In this paper a method of midcourse guidance of exoatmospheric interception is developed. The mechanism is, treating the initial and modified trajectories as chief and deputy objects respectively, modeling the dynamics of the deputy relative to the chief by the relative motion theory and the initial corrections can be obtained through the final relative states. Firstly the universal relative motion model is provided. Secondly the state transition matrix of relative motion under the influence of J2 disturbance is derived by employing the geometry and the variation method. Lastly the midcourse guidance method using state transition matrix is proposed. Simulation example shows that the proposed method serves as an efficient support for midcourse guidance of interceptors in practice.]]></description>
<pubDate>2015/7/2 10:25:10</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[柴华,梁彦刚]]></author>
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<title><![CDATA[Flight mode analysis for stratospheric airships]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201412250000001]]></link>
<description><![CDATA[The flight mode of a stratospheric airship is investigated analytically. First, reference frames and motion variables of the airship are defined, and the nonlinear dynamics model is linearized based on the “small disturbance” theory. Second, an analytical method based on eigenvalue and eigenvector of the state equations is proposed for analysis of flight mode, and the parameters describing the mode characteristics are defined. Third, the flight modes of the stratospheric airship are investigated according to eigenvalues and eigenvectors of the characteristic matrix. The longitudinal motion can be divided into three modes: heave mode, surge mode and pendulum mode, whereas the lateral motion can be divided into another three modes: yaw mode, slideslip mode and roll oscillation mode.]]></description>
<pubDate>2015/6/23 9:03:37</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[邵汉斌,闫野,杨跃能]]></author>
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<title><![CDATA[Analysis of Influential Factors to Supercooling Phenomenon during Ascent Stage of Stratospheric Long Duration Balloons]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201412200000001]]></link>
<description><![CDATA[Supercooling phenomenon of stratospheric long duration balloons means that the temperature of helium gas inside is lower than that of atmosphere outside, this will cause loss of buoyancy and effect ascent process of the balloon as a result. Thermal model and vertical dynamic model of long duration balloons were established, influence regularity of some important factors on supercooling phenomenon is analyzed, including initial net buoyancy, radiation performance of the film, launch time and launch date. Simulation results show that temperature difference between helium gas and outside atmosphere enlarges remarkably along with the increase of initial net buoyancy, and temperature difference decrease when absorptivity for visible light and infrared radiation increases. Simulation results also show that influence of launch time and launch date on  supercooling phenomenon is much smaller, while flight time from ground to designed altitude has great difference when launch time is different. All those can provide theoretical reference for conceptual design and flight test]]></description>
<pubDate>2015/6/23 9:02:57</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[侯中喜,麻震宇,杨希祥]]></author>
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<title><![CDATA[Research on performance of a New-Type Power Transmission Mechanism in Twin-Rotor Piston Engine]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503250000001]]></link>
<description><![CDATA[This paper proposes a power transmission mechanism of twin-rotor engine based on wobble plate and cam. The structure is simple, completely symmetrical arranged, good balance, and the movement is controllable . For analysis on operating characteristics of it, basic kinematic model is established, and its trajectory and cam contour lines are obtained. Effects to volume variation of the main structural parameters, such as plate inclination angle and roller axis angle, are taken in to account. It is mainly concluded: the closer to 90° roller axis angle is, the larger volume variation is. Plate inclination angle and volume variation is directly proportional. For 4-blade pistons rotor, the maximum plate inclination angle is approximately 65°. In practice, the best roller axis angle is 90°, plate inclination angle should be large enough after taking the thickness of blade piston in to account.]]></description>
<pubDate>2015/6/1 8:43:48</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈虎,江磊,潘存云,徐海军,邹腾安]]></author>
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<title><![CDATA[A two-stage anti-jamming algorithm for GNSS antenna array]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503080000001]]></link>
<description><![CDATA[Interference and multipath are the two dominant factors that affect the performance of Global Navigation Satellite System (GNSS). This paper proposed a two-stage beamforming algorithm for interference mitigation using adaptive antenna array. In the first stage, the power inversion algorithm is applied to suppress the interference. Then, the Signal-to-noise-ratio (SNR) of GNSS signal is improved by dispreading processing, and the spatial signature vector is estimated. In the second stage the estimated spatial signature vector is used to weight and sum the output of the first stage. The proposed algorithm could null the interference and steer beams in the direction of GNSS signals simultaneously. The simulation results show that, the performance of the proposed algorithm is much better than that of power inversion (PI) algorithm, and is similar to that of Minimum Variance Distortionless Response (MVDR) algorithm. The proposed algorithm requires no array calibration and prior knowledge. It has less cost than MVDR algorithm for implementation.]]></description>
<pubDate>2015/5/21 14:42:20</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[雍玲]]></author>
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<title><![CDATA[Analysis and Design of Phasing Strategy for Near-Earth Short Rendezvous Mission]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201409100000001]]></link>
<description><![CDATA[Based on the two-day profile of Chinese rendezvous and docking mission, a 5-revolution short-rendezvous phasing strategy is proposed by reasonably cutting down the flight duration for orbit determination, computation of maneuver parameters, and non-visible course of flight. This phasing strategy is solved by using a four-impulse modified special-point maneuvers’ algorithm. The required precision of orbit determination to meet the control precision at the end of phasing is first obtained. Then, the optimal phase range and total velocity increment are analyzed. Further results show that the optimal phase range is affected by the target spacecraft’s orbital altitude, the chaser’s orbit insert precision and apogee height, and the final desired target point of rendezvous phasing. Finally, both the target spacecraft’s phasing strategy and the chaser’s launch chances are analyzed for the short rendezvous mission.]]></description>
<pubDate>2015/5/21 13:06:15</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨震,]]></author>
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<title><![CDATA[The deployment dynamic characteristics analysis of space web system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201409070000003]]></link>
<description><![CDATA[Space webs are new species of lightweight flexible space structure, which indicate great potential application value. This paper conducts an in-depth research on the issues of the dynamic characteristics of space web. Firstly, the dynamic model of space web is established, which considering different mechanical environment in space and on ground. Then, the reliability of the simulation model is validated by the ground test. At last, based on deployment parameters, which are deployment area, flight distance, etc, the deployment characteristic of flexible web, such as the web shape, stress distribution and energy, is simulated and analyzed, and the influence of the orbit height, capture direction and casting parameter to the deployment characteristic is also considered.]]></description>
<pubDate>2015/5/21 13:05:24</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘海涛]]></author>
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<title><![CDATA[Timing Receiver Toughen Technique in Complicated Jamming Environments]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201503270000001]]></link>
<description><![CDATA[GNSS timing receiver is widely applied in national economic base infrastructure, such as power grid, communication station and finance system. Usually, the present GNSS timing receivers did not have the ability of detect jamming and spoofing attacks, vulnerable to jamming and spoofing attack to get wrong timing information enven to cause great harm. The threat models and spoofing attack detection technology are summarized is this paper. Combined with the operating principle and characteristics of timing receiver, a general architecture of timing receiver reinforcement technology is presented. On this basis, two interference detection methods have been proposed. One is clock aided method, which taking the advantage of multi satellite clock difference redundancy and the local clock characteristics based on multi-source clock data fusion; the other is network aided method, which can be used for interference detection, evaluation even positioning with the help of data mining of signal parameters and calculation results through the entire network. The interference detection results can be used to integrity assessment and guide the GNSS timing receiver working mode, thus improving the satellite timing reliability and integrity in complicated interference environment.]]></description>
<pubDate>2015/5/21 13:01:50</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[龚航,刘文祥,王飞雪,伍贻威,朱祥维]]></author>
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<title><![CDATA[An optimization Method for Multi-core Last Level CacheBased on the Memory Access Modes]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201410220000002]]></link>
<description><![CDATA[Multi-core architectures have been broadly utilized in current processors. Meanwhile, the diversity of memory access modes in applications brings challenges to the last level cache in multi-core processors. An optimization method for LLC based on the access modes is proposed in this paper. This method includes three coordinated and progressive levels: 1) the configurable share/private cache partition, 2) the configurable bypass cache policy, and 3) the priority replace policy. Using this method, programmers can neatly alter the behavior of the LLC to effectively adapt the variety of memory access modes in applications. Experiment results show that the proposed method can observably decrease the miss rate of the LLC and increase the system performance of the processor.]]></description>
<pubDate>2015/1/22 17:11:25</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[刘胜,]]></author>
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<title><![CDATA[Kineto-static analysis on the Differential Velocity Drive Mechanism of the Dual-rotor Piston Engine]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201404110000002]]></link>
<description><![CDATA[Dual-rotor Piston Engine (DRPE) is a new type of differential rotary engine. Compared with traditional engines, DRPE has many advantages. The complex valve systems can be omitted. Its structure is more compact. Its power density is higher, and so forth. In the paper, we analyze the working characteristics of DRPE, and figure out the mechanical structure characteristics of the Differential Velocity Drive Mechanism (DVDM) of the DRPE. Define its kinetic parameters. Then establish the mathematical models for the kineto-static analysis of the DVDM by using vector mechanics methods. The mathematical models were calculated by Matlab. The mechanical characteristics of DRPE’s main components were obtained. In order to verify the rationality of the established mathematical models, multi-body dynamics simulations were done. The virtual prototype model of the DRPE-350 was established in the RecurDyn. The simulation results compared with the calculation results, the value changing rules are almost the same. The changing processes are all four cycles. Impact positions are basically the same. It shows that the established dynamic theory model conforms to the actual situation. It is reasonable and can be trusted. It can be used as the theoretical foundation for the follow-up improvements of the DRPE.]]></description>
<pubDate>2015/1/22 15:55:46</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈虎,潘存云,徐小军,邹腾安]]></author>
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<title><![CDATA[Research on the Star Spot Centroiding Method with Inertial Measurement Information]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201408160000001]]></link>
<description><![CDATA[As for the low centroid precision of blurry star spots acquired by the star sensor in vibration environment, the star spot centroiding model aided by inertial measurement information is proposed here and the centroiding algorithm is formed. The weighted center of the star spot is regarded as the centroid at the initial time of the exposure course by the algorithm, then the centroid track can be computed with the vibration information by the strap-down inertial sensor, and the star imaging area and its weighted center can be estimated with the star spot power distribution model, finally the exact centroid at the finish time can be got by using iterative operation to make the two weighted centers coincide with each other. The centroiding precision of the algorithm and the effect of relevant factors on it are analyzed using simulation data, and the numerical results indicate that the method can reach about 0.01-pixel centroid precision even at the vibration environment with a good applicability performance.]]></description>
<pubDate>2014/11/18 16:49:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[吕汉峰,王鼎杰,吴杰,张良]]></author>
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<title><![CDATA[Prediction of polar motion based on BP neural network model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201409290000003]]></link>
<description><![CDATA[A predictive model was set up to improve the prediction precision of polar motion of earth orientation parameters. The periodic characteristics of interpolated basic series was studied by fourier analysis, the feasibility of basic series resampling was verified, then the trend terms was derived from the interpolation basic series, and the multiple input single output BP neural network model was used to predict the residual series for different days into future, finally the predicted polar motion was achieved by combining the trend terms with residual series. Prediction results indicate that the appropriate selection of interpolation basic series can realize high precision prediction of polar motion. Moreover, the BP neural network can be applied to the prediction of polar motion of earth orientation parameters effectively.]]></description>
<pubDate>2014/11/17 16:55:11</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[廖瑛,余越,张志]]></author>
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<item>
<title><![CDATA[Research on Optimization towards hybrid and hierarchy storage architecture]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201406110000004]]></link>
<description><![CDATA[Today’s advancing modern science is generating and analyzing increasing scale of datasets and makes HPC storage system facing new challenges both on architecture and software approach. In order to exploit potential benefits of emerging hybrid and hierarchy storage architecture on Milky-2 system, a I/O middleware approach named APBB, is introduced to make full use of the solid state disk based in-system storage resources. APBB aggregates distributed in-system storage close to running tasks into single namespace during application runtime and manages it as cooperative persistent burst buffer tightly coupled with its host application. To take full advantage of cooperative burst buffer, APBB uses an unified shadow namespace to map application data into physical in-system storage based on its real namespace of the host application. Besides that, APBB organizes data with locality aware layout and leverages application intent based replacement policy to fully exploit spatial and temporal locality. Furthermore APBB employs concurrency aware policies to optimize data movement between different storage tiers. Evaluations on Milky-2 system show that APBB can improve the performance of typical data-intensive applications dramatically. It can achieve scalable burst I/O bandwidth and smooth sustained I/O bandwidth with high throughput SSD deployed and can be taken as an appropriate candidate for storage solution on emerging leadership supercomputer systems.]]></description>
<pubDate>2014/11/17 16:45:00</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[董勇,,张伟,]]></author>
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<title><![CDATA[Analysis of Seismic Response and Seismic-relieving Design of a Launch Vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201311070000002]]></link>
<description><![CDATA[For a launch vehicle in erect status, an earthquake may bring severe consequence, such as the toppling failure of the launch vehicle. To ensure the safety of a launch vehicle during earthquake, analysis of earthquake time history response is executed in this paper. The distributions of peak moment and peak displacement in longitudinal direction of the launch vehicle are derived. Frequency-domain characteristic of moment response in key positions are researched. Seismic-relieving design is performed on the launch vehicle. Seismic response’s influence disciplines of link stiffness between rocket and launcher, stiffness of isolation bearing are analyzed. The results show that: (1) the maximum of moment response occurs in tail of the launch vehicle, the maximum of displacement response occurs in front of the launch vehicle; (2) the Seismic response can be reduced significantly by changing link stiffness between rocket and launcher or equipping the launcher with isolation bearing.]]></description>
<pubDate>2014/7/23 16:05:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘财芝,唐国金]]></author>
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<title><![CDATA[A preliminary investigation of flow hysteresis in the supersonic curved channel]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201311290000002]]></link>
<description><![CDATA[With the centerline Mach-number distributions provided in advanced，a two-dimensional supersonic wave-cancelled channel has been designed by the Method of Characteristics. The shock train，wall static pressure distributions and separation region have been investigated. The relationship between the shock train and back pressure was investigated. The flow-field had dual solutions when the head of the shock train was in the vicinity of the channel inflection. When the flow evolved into the single-solution domain from the dual-solution domain，the larger separated zone transferred quickly and the shock-train structure evolved fast.]]></description>
<pubDate>2014/7/18 11:11:45</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭善广,王振国,赵玉新]]></author>
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<title><![CDATA[Effects of electrodes configuration on the performance of pulsed plasma thrusters]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201312240000001]]></link>
<description><![CDATA[The electrode is one of the most important components of the pulsed plasma thruster(PPT), it has great influence on PPT performance. This paper analyzed the upper limitation of PPT efficiency theoretically, the results showed that the upper limitation of PPT efficiency increases by increasing the flare angle or decreasing the end width of electrodes. And then the impulse bit and the mass bit of different PPTs were measured by varying the flare angle and the end width of electrodes, the experimental results indicated that the flare angle has different effects on mass bit of PPTs for different electrode shapes; effects of flare angle on impulse bit are similar with effects of flare angle on mass bit for corresponding electrode; the specific impulse increases firstly and then decreases with the increase of flare angle; the influence of electrode shape on the performance of PPTs is different at different flare angles.]]></description>
<pubDate>2014/7/18 10:53:54</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[张华]]></author>
</item>
<item>
<title><![CDATA[Range Safety Control of Suborbital Vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201308230000002]]></link>
<description><![CDATA[The test range for launch vehicle is dedicated for certain launch missions, while land, sea area and airspace are included. The safety issues of test range are complicated and involve many factors. Before rockets’ entry to the outer space, it is forbidden to cross foreign territory or the safety distance have to be guaranteed to the boundary. In addition, falling zones for the re-entry are prohibited to be at the foreign region. In China, with the restriction of territory and to meet the requirements of intercontinental rockets’ full-range flight test, particular trajectory schemes are selected, such as ‘low trajectory’, ‘high trajectory’, to be substitute for full range flights. In this paper, based on the describe the feature of those two trajectory, the anrange control for rocket flight test is analyzed, focused on taking suborbital vehicles as payloads, including re-entry and penetration. Based upon suborbital flight inside China’s territory, the manners for test range safety control are studied. For the low trajactory flight, controlling the angular velocity of the pitch program is a useful manner of range control. For the high trajactory flight, controlling the angle of the pitch program is a useful manner of range control.]]></description>
<pubDate>2014/7/18 10:53:30</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[刘昆,刘兴隆,田继超,徐勤]]></author>
</item>
<item>
<title><![CDATA[The research of the predictor-corrector guidance of gliding phase for hypersonic gliding vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201401060000001]]></link>
<description><![CDATA[To meet the demands of terminal and path constraints during the reentry phase considering the perturbations of the initial values and aerodynamic parameters, an improved MPSP predictor-corrector guidance law is developed which combined rapid generation of three dimensional trajectory and model predictive static programming(MPSP). The kinematic model of the hypersonic gliding vehicle is built based on energy, and the predictor-corrector guidance theory of MPSP is deduced in detail. The initial value generator is founded using the rapid generation of three dimensional trajectory, and based that the influence factors from the initial decent phase to the gliding phase are investigated. The digital simulation is carried out taking advantage of the predictor-corrector guidance in gliding phase considering perturbations of the initial values and aerodynamic parameters. The results turn out to be that the improved MPSP predictor-corrector method could have the advantages of precise initial guess values and strong robustness to the perturbations.]]></description>
<pubDate>2014/5/12 11:05:27</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[丁达理,国海峰,黄长强,肖红]]></author>
</item>
<item>
<title><![CDATA[Multiobjective Optimization Design of Isolator for spacecraft Based on MOEA/D]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201401010000001]]></link>
<description><![CDATA[It is common to use passive isolator to protect the payload from the platform noise in space applications. The design of a passive isolator involves a trade-off between the resonant peak reduction and the high frequency attenuation. Firstly, the equation of motion and transfer function model for single-stage and two-stage connector model is derived, and then the multiobjective optimization model is proposed, where the objective functions are the resonant peak reduction and the high frequency attenuation. Secondly, the multiobjective optimization design method for the design of the passive isolator is proposed based on the multiobjective evolutionary algorithm based on decomposition (MOEA/D). The simulation result shows that the proposed method is effective for the design process of the passive isolator, and can provide multiple candidate solutions for the designer.]]></description>
<pubDate>2014/5/12 10:46:38</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[罗军,唐国金]]></author>
</item>
<item>
<title><![CDATA[Simultaneous localization and mapping aided GPS/DR integrated navigation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201312110000002]]></link>
<description><![CDATA[Considering the performance of Global Positioning System (GPS)/Dead Reckoning (DR) integrated system degrading dramatically when GPS signal is outage or blocked, this paper addresses a Compressed Extend Kalman Filter (CEKF)-based Simultaneous Localization and Mapping (SLAM) aided GPS/ DR integrated navigation method. The error of DR system is restrained with SLAM correction when GPS solutions are unavailable. Accordingly, GPS location corrects the error and improves the uncertainty of SLAM mapping when GPS positioning is accessible. A filter of CEKF-based SLAM/GPS integrated is designed to realize the real time implement of SLAM/GPS in a large scale environment. Compared with the SLAM locating with using the real experiment dataset, the SLAM aided GPS/DR integrated method enhances the system performance of positioning as well as the accuracy of SLAM mapping arisen approximate 10m.]]></description>
<pubDate>2014/5/12 9:11:45</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[程见童]]></author>
</item>
<item>
<title><![CDATA[Range-dependent phase error compensation of Dechirp]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201311130000001]]></link>
<description><![CDATA[To reduce the pressure of data processing, the dechirp operation is adopted. However, dechirp will result in range-dependent phase errors in the beat signal. We propose an algorithm to compensate the range-dependent phase error using the phase error extracted from the transmitted signal with the supposing of that the phase error varies slowly. The compensation approach is executed in two steps: first, compensate the phase error involved by the transmitted signal after dechirp; second, compensate the residual phase error after RVP correction. Both the simulation and the real data experiments suggest that the proposed algorithm is effective.]]></description>
<pubDate>2014/5/12 8:40:36</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[赵志勇]]></author>
</item>
<item>
<title><![CDATA[Modeling and Simulation Analysis of Detection Probability for Space-based AIS System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201311110000001]]></link>
<description><![CDATA[Aiming at solving the low detection probability problem of space-based AIS, the research studied the received signal collision phenomenon and ship detection probability model. Firstly, the difference between Space-based AIS and traditional terrestrial AIS was compared and analyzed. And the new technical challenge of space-based AIS was pointed out. Then, the problem of AIS signals collision from multi SOTDMA cells was studied in detail. The detection probability model based on ship density function was established theoretically. Thirdly, the effects of slot collision, orbit height, antenna swath and Class B ships on detection probability were estimated quantitatively by simulations, which can provide theoretical reference for designing and evaluating the space-based AIS in the future.]]></description>
<pubDate>2014/5/12 8:20:42</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈利虎,陈小前,程云]]></author>
</item>
<item>
<title><![CDATA[A general quasi-optimal demodulation design for FQPSK and SOQPSK]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201310150000004]]></link>
<description><![CDATA[According to the IRIG-106 telemetry standard, FQPSK-JR and SOQPSK-TG are two interchangeable signals, which have almost same power efficiency and bandwidth efficiency. The two signals could be demodulated by the universal receiver of OQPSK. The performance degradation of the symbol by symbol demodulation reaches 2dB compared to the optimal demodulation for ignoring the signals’ characteristics of memory. The 2dB power loss is crucial in the telemetry link for the limit of equipment size and power. The optimum receivers that based on their modulation schemes can improve the power efficiency, but the different system of signal generating will lead to different structure of corresponding optimal receiver. In this paper, FQPSK-JR signal in IRIG-106 standard is approximated by CPM modulation, SOQPSK-TG signal is truncated for an approximate analysis. The result of simulation shows that the two signals can be demodulated by the CPM-based demodulator with small incremental loss, and it also has no need to do signals recognition by using the demodulator, just like by using the OQPSK receiver. In addition, we have taken into account of the implementation complexity.]]></description>
<pubDate>2014/5/7 8:20:33</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[郄志鹏]]></author>
</item>
<item>
<title><![CDATA[Automatic recognition method of radar antenna scan type]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201310240000002]]></link>
<description><![CDATA[In order to recognize radar antenna scan type (AST) automatically, an improved antenna scan pattern simulator is developed in this paper, and features extraction and automatic recognition methods for electronic scan type (EST) and mechanical scan type (MST) are studied respectively. EST is firstly distinguished from MST based on the characteristic parameters extracted from the maximum main beam pulse sequence; then 8 MSTs are automatically recognized based on the parameters extracted from the pulse sequence in a scan period. The simulation results show that it is able to distinguish between one-dimensional EST, two-dimensional EST and MSTs by this method. Moreover, the correct recognition ratio of MSTs by support vector machine decision tree (SVMDT) in this paper is higher than that by decision tree (DT).]]></description>
<pubDate>2014/5/7 8:18:54</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[李程,施龙飞,王伟,王雪松]]></author>
</item>
<item>
<title><![CDATA[Matching Multi-sensor Images Based on Local Tone Mapping]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201311210000004]]></link>
<description><![CDATA[Tone mapping is an efficient image matching algorithm adaptive to brightness and contrast variation. Due to the complex and nonconforming relation between multi-sensor images, tone mapping can hardly be directly used on multi-sensor images with satisfactory result. To improve the matching rate, the local tone mapping algorithm is proposed which includes the following steps. The template map is divided into nonoverlapping blocks. Each block is processed through histogram equalization and weak slice transform. Distance maps are calculated for every block by local tone mapping. The matching result is obtained by fusion all these distance maps. Experimental results show that, the matching rate of local tone mapping significantly outperforms tone mapping and mutual information, while its computation time is slightly longer than tone mapping and less than mutual information.]]></description>
<pubDate>2014/5/7 8:16:19</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李伟建,李壮,涂国勇,张红良]]></author>
</item>
<item>
<title><![CDATA[Research on Variable Rate Modulator and its Implementation on FPGA]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201308060000001]]></link>
<description><![CDATA[A variable modulator scheme is presented. The hardware system adopting the proposed approach is accomplished based on field programmable gate array (FPGA). The proposed system could deal with signals with bit rate even varying from 13.5~300Mbps continuously. By spliting the whole rate range into several small parts and filtering the input data with different interpolation times, the correctness of transfering all rate into the dealing range of digital analog convert (DAC) is ensured. The architecture of system is devised and the difficulties in hardware realization are analysed. The ways to solving the pivotal problem are particularly indicated. Realization on FPGA demonstrates the good performance of the proposed idea. The expansibility of system makes it easy to be applied in more wider rate bound.]]></description>
<pubDate>2014/5/6 16:04:10</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[翟海涛]]></author>
</item>
<item>
<title><![CDATA[Compressive Sensing Theory and Optical Compressive Imaging Systems]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201307150000002]]></link>
<description><![CDATA[Compressive sensing provides a new way for increasing the ability of information acquisition. Compressive sensing asserts that it is possible to accurately reconstruct signals from sub-Nyquist sampling, provided we make some additional assumptions (sparse or compressible) about the signal in question. The compressive imaging technology, which is based on compressive sensing theory, integrates the processes of sensing, compression and processing perfectly, avoiding resource waste caused by a traditional “sample-then-compress” framework. This paper reviews some of the recent progress in compressive sensing theory from the following three aspects: sparsity, the design of measuring matrix and recovery conditions, the reconstruction algorithms. Further, several optical compressive imaging systems have been introduced. And some key challenges in this area have been discussed finally.]]></description>
<pubDate>2014/5/6 15:54:36</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[刘吉英,王泽龙,严奉霞,朱炬波]]></author>
</item>
<item>
<title><![CDATA[Numerical Simulation of Separation of Central Stage and Booster Stage for a Carrier Rocket]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201307100000001]]></link>
<description><![CDATA[This paper applies the dynamic overset method and Eulerian approach to solve the unsteady NS function and 6DOF movement function, and numerically simulate the separation processes of KSR-III rocket’s core and booster with and without additional forces. Major factors that affect the separation processes are also analyzed. The paper shows that our numerical results agree with experimental results, indicating that the dynamic overset assembly method is able to correctly predict the complex flow between the rocket’s core and booster. Furthermore, based on the results of numerical simulations, separation parameters and rules of the booster under different conditions are also obtained.]]></description>
<pubDate>2014/5/6 15:49:00</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[范晶晶,张海瑞,张为华]]></author>
</item>
<item>
<title><![CDATA[Characteristic Analysis of Disturbance Aroused by Solar Array Tracking Drive]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305240000001]]></link>
<description><![CDATA[The disturbance, aroused by sun-tracking drive of solar array, has become one of the major barriers for improving the performance of high-precision spacecraft. With the aim to obtain the regular characteristic of this disturbance, from the aspects of main driving steps, we presented an electromechanical integration model and a dynamic simulation program, based on Simulink software platform, of the coupling system that consists of solar array as well as drive assembly. The correctness was verified by comparing with experiment results, and effects of solar array rigid-flexible coupling and centroid bias to disturbance characteristics were analyzed. The results indicate that rotation speed fluctuation could activate low order torsion modes of solar array, and disturbance spectrums include both frequency characteristics of motor driving and structure vibration, but torsion vibration has little effect on rotation angle. The centroid bias of solar array could motivate translational-rotational coupling vibration, activate out-of-plane bending modes, change the distribution of disturbance spectrum, and increase the amplitude of disturbance.]]></description>
<pubDate>2014/1/7 10:15:13</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[雷勇军,谢燕,朱仕尧]]></author>
</item>
<item>
<title><![CDATA[Neural Network Predictive Guidance Method Based on Pattern of Optimal Guidance]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305220000002]]></link>
<description><![CDATA[In order to solve the contradiction between high guidance accuracy and fast real-time solving in traditional predictive guidance method, this paper presents a neural network predictive guidance method based on pattern of optimal guidance. The method predicts trajectory based on high believable simulation of kinematic aircraft model, and uses optimization theory to iterative solution of guide variable, so as to generate off-line sample data. By means of choosing multi-modal neural network, training neural network based on dispatching management, to complete the design of the neural network prediction guidance controller. CAV as an example to design, results show that: The method is less real time calculation, fast real-time solution and high guidance accuracy, which comprehensive performance is far better than traditional predictive guidance method.]]></description>
<pubDate>2014/1/7 10:14:45</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[董荣华,皮术武,曾庆华]]></author>
</item>
<item>
<title><![CDATA[An Improved Approach for Positioning of Ground-Based Pseudolite Navigation System based-on Receiver’s Clock Error Restriction]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201307030000002]]></link>
<description><![CDATA[When using ground-based pseudolite navigation system for vehicle, there will be some bad geometric configuration situations because of the area restriction for pseudolites. If the traditional single positioning algorithm is used with pseudo range only as usual, the precision of positioning for vehicles will be low. In this paper, we indicate that the inaccurate solution of receiver’s clock error affects the precision of positioning to a great extent. To this situation, we proposed an improved approach to get a better precision of positioning through increasing the accurateness of solution of receiver’s clock error. The main idea is to get the observation model of the receiver’s clock error and then adding the model to the positioning equations. The simulation results indicate that the approach is feasible and effectual.]]></description>
<pubDate>2013/12/30 10:56:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[吕汉峰,吴杰,张良]]></author>
</item>
<item>
<title><![CDATA[Giant magnetoimpedance (GMI) magnetic sensor based on orthogonal lock-in differential amplifier]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201307020000001]]></link>
<description><![CDATA[Based on the giant magnetoimpedance (GMI) effect found in the amorphous wire, and utilized the CoFeBSi amorphous wire as the sensing material, a novel differential-type high sensitively sensor adopted the technology of orthogonal lock-in amplifier was designed in this paper. Firstly, the concept of the GMI effect and the magnetic sensing head based on the double-sensing-elements and differential-type structure, are briefly instructed. Secondly, the principle of the conditioning circuit of the sensor based on orthogonal lock-in amplifier is analyzed in detail. Thirdly, based on the impedance magnitude and phase characteristics of the amorphous wire, an approximate algorithm was brought forward to calculate the envelope of the output of the orthogonal lock-in amplifier for simplifying the arithmetic circuit. Experiment results show that the sensitivity of the sensor can achieve about 748mV/Oe with the full measurement range of -2.0Oe~ 2.0Oe, and the linearity error is about 0.98%FS, while the average noise power spectral density is about 0.8nT/Hz<sub>1/2</sub>.]]></description>
<pubDate>2013/12/30 10:53:26</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[聂新华,潘仲明,苏绍璟,张大厦,张文娜]]></author>
</item>
<item>
<title><![CDATA[System Design and Method Research for Optical Measurement Images Real-time Interpretation in Test Ranges]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201307010000001]]></link>
<description><![CDATA[We research on some key issues of real-time interpretation for optical measurement images in test ranges to design and realize a real-time interpretation and estimation system. Automatic Target capture, tracking and high precision location for interpretation features are the problem questions. This paper respectively uses shape similarity analysis, online region tracking and learning, and iterative contour registration to locate multiple interpretation points to solve it. Based on the characteristics of real-time processing, such as high efficiency requirement, strong parallelism capability, and rigorous sequence in time, the software architecture design pattern of distributed framework with business process management is adopted to achieve the centralized administration of data and process, multiple sites parallel interpretation, data-driven auto estimation method selection and friendly user interface. Take the aerial launching tests of the air ranges as an example, the feasibility and efficiency of the system is checked by the experiment. The system can be extended to various test ranges to meet the users’ need of weapon test data’s real-time gain and analysis.]]></description>
<pubDate>2013/12/30 10:49:47</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[丁少闻,郭鹏宇,田尊华,张红良,张小虎]]></author>
</item>
<item>
<title><![CDATA[Cutting Force Model for Fabrication of Micro-Grooves by Single Point Diamond Flycutting]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201306210000001]]></link>
<description><![CDATA[Ultra-precision single point diamond flycutting is a novel method to manufacture the microstructures with grooves. In the flycutting process, the cutting force is an important physical quantity. It is tightly associated with cutting quality and tool wearing.  To develop the cutting regularity, a flycutting force model based on the theory of orthogonal microcutting was presented. The cutting force model on rake and flank face is achieved. The shear angle in flycutting process is analyzed based on the kinematical regularity. The value of the shear angle in specific processing parameters is achieved by single-turn flycutting experiments. To verify the flycutting force model, overlapping flycutting experiments with variant parameters are carried out. The validity of the force model is demonstrated with the accordance of experiments and theoretical analysis.]]></description>
<pubDate>2013/12/30 10:44:32</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[关朝亮,李圣怡,刘勇,尹自强]]></author>
</item>
<item>
<title><![CDATA[Numerical simulation of the impacts of block modes on the flow field of isolator]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201306200000001]]></link>
<description><![CDATA[It is commonly used in simulating the impacts of backward pressure on the isolator flow field that a blockage adjustor is designed at the exit. Numerical simulation is adopted to study the effects of different block modes. Three modes are compared, including installing a flat on the ramp side wall, a flat on the cowl side wall and a wedge in the middle of the flow field. The results show that due to the asymmetric boundary layer on the ramp wall and cowl wall, the shock trains formed by them are all next to the cowl side. The intensity of the shock train generated by the second mode is stronger and the boundary layer separates more evidently, which chocks the isolator more easily. And it is not suitable for experimentally studying the shock train. The other two modes can generate similar flow field, but the first one can be realized more easily.]]></description>
<pubDate>2013/12/30 10:43:38</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈植,全鹏程,武宇,易仕和]]></author>
</item>
<item>
<title><![CDATA[Study and implementation of sounding-rocket picture capture and compression system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201306190000001]]></link>
<description><![CDATA[As what is required by Sounding rocket utilization, this paper studies and realizes a real-time multi-channel picture capture and compression system applied in sounding rocket, and introduces two key techniques applied in the system. The system bases its architecture on ARM and FPGA, and adopts a dedicated video-compression chip as the core processing unit. By way of improving reliability of time division multiplexing of cameras and optimizing control schemes of compression ratio, the system satisfies the requirement of low power consumption and high compression ratio in sounding rockets. It has compact circuit framework, high integration level and great flexibility. Practical tests show that, the system has some good features, such as light-small, low-power, and low-cost. In the experiment named Space Environment Vertical Exploration, the system shot important scenes, including the separation of rocket head and engine, as well as the deployment of electric field detection boom. By adoption of contour volume evaluation methods, it is concluded that the pictures shot during the flight have sufficient definition for scientific research and engineer application.]]></description>
<pubDate>2013/12/30 10:41:03</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈萍,,,,]]></author>
</item>
<item>
<title><![CDATA[Low Angle Tracking Algorithm Using Frequency Diversity for Array Radar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201306180000002]]></link>
<description><![CDATA[The low angle tracking problem is investigated, for shipborne X-band array radar working at frequency diversity mode. Firstly, the receiving array signal model with multi-frequency is established in multi-path environment based on the relation between complex reflection coefficient (CRC) and grazing angle of seawater at X band. Then, the MFML (Multi-Frequency Maximal Likelihood) elevation spectrum is brought forth, where the elevation ambiguity is alleviated by frequency diversity. The spacing between spectrum peaks is presented. The influence on elevation spectrum of frequency width is analyzed. Lastly, the probability of exact peak selection is proposed to describe the elevation estimation performance. Elevation estimation performance is evaluated by simulation, related to SNR and target elevation. Given target elevation, the minimal SNR is obtained for a certain angular accuracy, which is not strictly monotone downtrend with target elevation.]]></description>
<pubDate>2013/12/30 10:40:15</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄坦,肖顺平,熊子源,徐振海]]></author>
</item>
<item>
<title><![CDATA[Research Advances in SAT-based Error Localization Methods on Circuits]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201306180000001]]></link>
<description><![CDATA[With the growing complexity of VLSI designs, functional verification and debugging has become a resource-intensive bottleneck in modern CAD flows, consuming as much as 60% of the total design cycle. Error localization in circuits is difficult and time-consuming. Therefore an efficient error debugging and localization method is necessary for hardware design. Recently there are many different contributions to research on error localization in circuits. In this paper, the categories and workflow of error debugging method are firstly introduced. The fundamental principles of SAT-based error localization method are described. Then the existing algorithms are introduced and analyzed. Further, we present our research works about extract unsatisfiable subformulae, which can strongly improve the efficiency and accuracy of error localization. Finally, we discuss the current challenges, and outline the future research directions of error localization in circuits.]]></description>
<pubDate>2013/12/30 10:39:44</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[黎铁军,李思昆,张建民,张峻]]></author>
</item>
<item>
<title><![CDATA[Research on Encoding Algorithms for QC-LDPC Codes with Dual-diagonal Parity Check Matrix]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305310000001]]></link>
<description><![CDATA[Two efficient encoding algorithms, matrix decomposition encoding algorithm and cumulative recursion encoding algorithm, for the LDPC codes based on quasi-cyclic dual-diagonal parity check matrix were studied. This paper point out that the two algorithms from the implementation point of view is equivalent, and the cumulative recursion encoding algorithm is straightforwardly facilitate to hardware parallel implementation. A partly parallel encoding architecture is proposed for the QC-LDPC codes with dual-diagonal parity check matrix. The LDPC encoder compatible with IEEE 802.11n standard is designed. FPGA implementation results show that the hardware overhead of the proposed LDPC encoder is low, while its throughput can reach up to 13Gbps.]]></description>
<pubDate>2013/12/30 10:39:03</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[刘冬培,刘衡竹,张波涛]]></author>
</item>
<item>
<title><![CDATA[Differential flatness based rapid trajectory planning for hypersonic glide vehicle]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305280000001]]></link>
<description><![CDATA[Concentrating on the on-board trajectory generation problem for hypersonic glide vehicle, we proposed a differential flatness based three-degree-of-freedom trajectory rapid planning approach. Based on the flatness analysis for the simplified longitudinal motion model, the reference longitudinal trajectory planning problem was mapped into the flat output space to improve the solving efficiency by reducing the planning space’s dimension and eliminating the dynamical constraints. And then the initial problem was transformed into a nonlinear programming problem utilizing global polynomial approximations to the flat outputs. To compensate for the effects of the Earth rotation, a terminal sliding mode control based reference trajectory tracking controller was designed with finite-time convergence capability. Integrating the lateral motion determined by the error corridor of heading angle based bank angle revision, the three-degree-of-freedom gliding trajectory was ultimately generated. Numerical simulations were conducted to validate the feasibility and effectiveness of the approach presented here.]]></description>
<pubDate>2013/12/30 10:38:22</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[蔡伟伟,刘新建,杨乐平,朱彦伟]]></author>
</item>
<item>
<title><![CDATA[Configuration Optimization Design of Hypersonic Gliding Lifting Body]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305270000002]]></link>
<description><![CDATA[The large number of configuration parameters of the hypersonic vehicle makes its aerodynamic shape design very complicated. To overcome this difficulty, a lifting body shape parametric design method is proposed. This method is based on class function/shape function transformation (CST) and power function expression, whose design variables are limited to six and which makes it very convenient for configuration analysis and design. By means of orthogonal experiment analysis, influence of the configuration parameters on volume efficiency and lift-drag ratio of the lifting body is studied, the ones with the great influence are obtained. Meanwhile, the experiment results found that the configuration parameters have conflict influence on the volume efficiency and lift-drag ratio. Thus, to search for the best configuration parameters, a Kriging surrogate model based multi-objective genetic algorithm is applied to design the lifting body shape, in which the volume efficiency and lift-drag ratio are taken as the two conflict objectives under the constraints of the longitudinal stability and vehicle volume. Numerical results show the efficiency of the method and a uniform Pareto front was obtained. The volume efficiency and lift-drag ratio of the typical optimized shape have increased by 17.31% and 11.94%, respectively, when compared with the baseline. Differences of the results gained from the Kriging surrogate model and real physical model are less than 4%. Furthermore, the influences of leading edge blunting on aerodynamic character are researched. The results indicate that, the lift-drag ratio of the lifting body decreases significantly with the increase of blunting radius. It is also found that the optimized results can be extrapolated to leading edge blunting shapes when aerodynamic character is the unique concern.]]></description>
<pubDate>2013/12/30 10:36:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[马洋]]></author>
</item>
<item>
<title><![CDATA[Experimental Investigation on Injection Characteristics of Assembled Transverse Injectors in Supersonic Crossflow]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305270000001]]></link>
<description><![CDATA[The injection, mixing and atomization characteristics of transverse liquid jet in liquid-fueled scramjet are the determining factors for the efficiency of the combustion chamber. An origin image analysis method, without any threshold choosing section, was developed in house to get the unique unstable boundary of the transverse jet without any manual effects. The lateral extension boundary capturing method, which is based on PIV technique and the corresponding image analysis method, was developed to illustrate the lateral outer boundary of the jets. Results from targeted and comparative experiments indicate that: compared with the single jet case, the penetration heights and lateral extension get larger in the assemble jets cases. A larger distance between the streamwise assembled double injectors contributes to a higher penetration height of the jet.]]></description>
<pubDate>2013/12/30 10:33:14</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李春,李清廉,仝毅恒,吴里银]]></author>
</item>
<item>
<title><![CDATA[Vibration reduction of payloads on spacecraft base on structure parameters of spacecraft-bracket system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305240000002]]></link>
<description><![CDATA[The dynamical interaction of payload brackets and spacecraft frame structure could observably magnify the responses of payloads. Vibration reduction studies usually focus on component-level payload brackets, but spacecraft frame structure and payload brackets were considered as a whole system (Spacecraft-Bracket System) in this paper. A certain spacecraft was modeled with finite element method. With structure parameters extracted from this model, a system-level lumped parameter model was built, and the univariate analysis for structure parameters was done in this paper. The results indicate that the lumped parameter model could expose the coupling pattern of payload brackets and spacecraft frame structure clearly, and that the sensitivity for responses of payloads related to frequency parameters of both structures are evidently higher than that related to damp and mass parameters. Consequently, for improving the dynamic environment of payloads, the frequency relationship of payload brackets and spacecraft frame structure should be anatomized in spacecraft structure design stage.]]></description>
<pubDate>2013/12/30 10:30:16</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[雷勇军,朱仕尧]]></author>
</item>
<item>
<title><![CDATA[Multi-viewpoint Image Mosaicing Algorithm for roughly Planar Scenes]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201307080000001]]></link>
<description><![CDATA[Aiming at applications of small unmanned aerial vehicle (UAV) in earth observations, this paper discusses multi-viewpoint image mosaicing problems for roughly planar scenes. When coarse camera poses are known, a method for integrating camera poses and feature correspondences is proposed, in which direct sparse Cholesky factorization algorithm is used to solve the global optimization problems of mosaicing. Global distortions do not exist in the obtained mosaics and local mosaic errors are suppressed effectively. When the camera poses are unknown, a structure-from-motion (SFM) system is used to recover the cameras poses and sparse structure of the scene firstly. Then, the sparse global adjustment is used to refine the transformations. The proposed algorithm is validated using sand table images and real aerial images.]]></description>
<pubDate>2013/12/30 10:27:40</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[龚文全,苏昂,徐玉华,张小虎,张跃强]]></author>
</item>
<item>
<title><![CDATA[Influence of Thermal Deformation of the Spiral Bevel Gear Transmission System on Gear Backlash under Normal Lubrication Condition]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201306050000001]]></link>
<description><![CDATA[Taking the spiral bevel gear transmission system of a helicopter tail reducer as research object, based on a computation model for the temperature field simulation,the steady-state temperature field distribution was derived under normal lubrication condition.The spiral bevel gear could be equivalent to the spur gear in basis on equivalent gear theory,and its gear backlash could be reflected at the transverse plane of the equivalent spur gear .The influence of thermal deformation of the spiral bevel gear transmission system on the gear backlash was computed and analyzed under normal lubrication condition using the thermo-elasticity theory.The results provided a theoretical basis for the design correctness of backlash considering thermal deformation ,to ensure the working accuracy of the spiral bevel gear.]]></description>
<pubDate>2013/12/30 10:21:39</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[李源,谭培峰,闫希杰,袁杰红]]></author>
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<title><![CDATA[A Real-time Video Stabilization Algorithm based on Homography Trajectory]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201308200000001]]></link>
<description><![CDATA[Motivated by the demands of real-time video stabilization, a real-time video stabilization algorithm based on homography trajectory is proposed. For each input frame, our approach re-generates four short homography trajectories by applying inter-frame homography transformations to the four corners of image rectangle. An associate Kalman filter is then performed to smooth these transformational trajectories. Finally, at the stage of image composition, constraints of inclusion and similarity are considered for selecting a visually plausible stabilized video. The proposed method can offer real-time video stabilization and it’s removed the delays for caching coming images. In addition, our method doesn’t rely on sophisticated 3D reconstruction or long-range feature trucking and it’s effectively relieved the errors introduced by using homography to model the video motion. Experiments show that our approach can offer real-time stabilizing for videos with 2D scenes or the 3D scenes with moderate depth variation.]]></description>
<pubDate>2013/12/24 11:20:01</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[董晶,杨夏,于起峰]]></author>
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<item>
<title><![CDATA[A Capture Initial Information Solution Method for ISLs of Navigation ConstellationBased on Ephemeris-aided]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305200000001]]></link>
<description><![CDATA[In view of the large dynamic and fast acquisition requirement of inter-satellite links (ISLs) signal, a capture initial information solution method is presented for ISLs of navigation constellation. This method evaluates time-delay and Doppler frequency based on ephemeris. The analysis shows that this method has higher estimate precision of nanosecond and lower computing cost. This paper analysis aiming at BeiDou navigation system and can provide reference for our country’s ISLs design.]]></description>
<pubDate>2013/11/20 11:32:32</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈建云,李献斌,王跃科]]></author>
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<title><![CDATA[Mixed-clock third-order DDS applied in signal Doppler frequency shift simulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201309040000002]]></link>
<description><![CDATA[Doppler frequency shift simulation is a key technique in high dynamic satellite navigation signal simulator. Considering the features of field programmable gate array (FPGA), a mixed-clk third-order direct digital synthesizer (DDS) simulation model is built, and its output phase expression is derived. The calculation method for initial control word for each stage DDS is given, and it’s point out that the same-clk third-order DDS simulation model is only a special case of mixed-clk simulation model. After analyzing the signal phase error caused by mixed-clk, the word length design method for each stage DDS is discussed. Comparison with same-clk third-order DDS, mixed-clk third-order DDS can reduce both resource and power consumption. Simulation results indicate that the proposed method can be used to simulate signal Doppler is of high precision.]]></description>
<pubDate>2013/11/18 16:25:12</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄仰博,李彩华,欧钢,张国柱,张鑫]]></author>
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<title><![CDATA[Relaxation effects of reflection of SV waves at surface of saturated porous thermoelasticity]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201310280000002]]></link>
<description><![CDATA[Based on the Biot's wave theory and thermoelastic theory for saturated porous medium, three relaxation factors are introduced and the generalized thermoelastic theory for saturated porous medium is developed. Reflection of SV waves at the surface of the plane is used to analyze the influence of relaxation effect on the reflection, the expressions of the reflection coefficient for the p1 wave, p2 wave, T-wave and S-wave are derived. Numerical results are obtained and used to discuss the difference of reflection amplitude for four kinds of reflection waves among the generalized thermoelastic theory(G-TE), L-S theory, and G-L theory. The effect of the relaxation time factors is also discussed. It is indicated that there is apparent effect of G-TE), L-S theory, and G-L theory on the results and is different for p1 wave, p2 wave and S-wave. In addition, there is greater effect of relaxation time on p2 wave, and less effect on p1wave, and the effect can be omitted on the S wave.]]></description>
<pubDate>2013/11/18 11:03:35</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘干斌,唐国金,郑荣跃]]></author>
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<item>
<title><![CDATA[Data yard based system effectiveness evaluation and decision support method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201306270000002]]></link>
<description><![CDATA[With the development of information technology, the increase of system information brings new problems to the military system effectiveness evaluation. Aiming at nonlinear, high dimension and strong coupling data of system effectiveness analysis, a data yard based system effectiveness evaluation and decision support method is proposed. Data recovery, subtraction, refinement and reconstruction operations are applied to simulation data processing, then a data yard cube is built up to meet multiple demands for system analysis of different levels and data dependency has been reduced. Taking task-oriented networked fire control system for example, system effectiveness evaluation, timeliness evaluation and indices analysis are carried out, and practicability and validity of the method is verified in three levels. Applying data mining technology to the simulation system effectiveness evaluation decision-making, makes it get more extensive application.]]></description>
<pubDate>2013/11/15 15:44:18</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈晨,王赟]]></author>
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<item>
<title><![CDATA[Optimal Guidance with Maneuver for Hypersonic Vehicle in Dive Phase]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303040000002]]></link>
<description><![CDATA[To solve precise guidance and maneuver penetration problems for hypersonic vehicle in dive phase, the optimal guidance method with maneuver was proposed. As to the problem that traditional guidance law based on zero-LOS angle rate can debase penetrative ability, it designed reference motion for the rate in diving-plane and turning-plane. Besides, in order to enhance penetrative ability farther and realize precise guidance, it taken advantage of optimal control with the optimal index of maximum terminal velocity to track the LOS angle rate, and pseudo control variable was introduced to simplify the resolution of optimal control problem. At last, it analyzed the guidance capability for this method. The results of CAV-H vehicle test show that the algorithm can realize maneuvering flight, and can satisfy terminal impact point and falling angle constraints. Therefore, they can offer references for high precision guidance and maneuver penetration for hypersonic vehicle in dive phase.]]></description>
<pubDate>2013/11/7 16:50:54</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[包为民,刘鲁华,汤国建,朱建文]]></author>
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<item>
<title><![CDATA[Electromagnetic Vortex based Radar Target Imaging]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201308150000001]]></link>
<description><![CDATA[Amplitude/frequency/phase modulation of electromagnetic(EM) wave are the common ways of carrying information. However, it has received intensive attention recently when the wave front acts as EM vortex for information modulation. In this paper, the progress on the information modulation capability of EM vortex is systematically summarized and its potential on radar information acquisition is also introduced. Aiming at the circular phased array, the echo signal model of ideal point target is established under the illumination of EM vortex wave. Once the echo signal phase of each antenna element is shifted with the same mode as applied for submission and integrated along the circular path, one can obtain the output signal of the radar array. The output signal can be modeled as the linear superimposition of Fourier basis with the amplitude modulated by squared Bessel function. According to the spectrum characteristic of Bessel function, the approximate dual relationship between the mode number of orbital angular momentum(OAM) and the variable of azimuthal angle is analyzed. Finally, the back projection(BP) algorithm and filtered FFT based algorithm are applied to image the target. Simulations show that electromagnetic vortex wave has the potential to acquire the cross-range profile of the radar target. The research in this paper may act as a reference to the design of new mechanism radar and the development of target recognition technology.]]></description>
<pubDate>2013/11/6 18:18:25</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[杜小勇,郭桂蓉,胡卫东]]></author>
</item>
<item>
<title><![CDATA[Optimized Improved Gaussian Process Model based on Artificial Bee Colony Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201308190000001]]></link>
<description><![CDATA[Gaussian Process(GP) is characterized by non-linear, which leads to too high training time complexity for a large sample. And hyper-parameters directly affect the prediction accuracy of Gaussian Process. For two issues above, improved Gaussian Process Regression (GPR) model optimized by artificial bee colony (ABC) algorithm is proposed. Improved GP constructs model by selecting a sub-sample of training samples to reduce training time. The conjugate gradient method has the disadvantages of difficult determination of iteration steps, too strong dependence of optimization effect on initial values,easily falling into local optimum in the process of searching for the optimal hyper-parameters. Artificial Bee Colony algorithm was used to optimize the hyper-parameters of the GPR. First improved GPR model is constructed by selecting a sub-sample of training samples, followed by ABC algorithm searching the optimal hyper-parameters of improved GPR, finally using the test sample to predict and output prediction accuracy.The model is applied to solve maritime long-range precision sea strike (LPSS) system-of-systems operational effectiveness evaluation issues, and MATLAB simulation experiments verify the validity of the model by comparing with other evolution algorithm.]]></description>
<pubDate>2013/11/4 9:48:29</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[刘忠,任雄伟,张建强,张乐]]></author>
</item>
<item>
<title><![CDATA[ISAR imaging of stepped-frequency based on image contrast optimization]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305190000001]]></link>
<description><![CDATA[In stepped-frequency high resolution ISAR imaging radar, target motions produce the range-Doppler coupling which has a serious effect on the ISAR image. Consequently, a novel motion-parameters estimation method based on the image contrast optimization is proposed in this paper. Firstly, the effect of radical velocity and acceleration on Doppler profile contrast function is analyzed. Secondly, after constructing phase compensation term, the radical acceleration is estimated by the Doppler profile contrast function. After the radical acceleration compensation, the radical velocity is estimated by the range profile contrast function. Finally, after motion compensation and range-Doppler algorithm, the high resolution ISAR image can be obtained. This method has some advantages of high accuracy and fast computation speed. The experimental results demonstrate the effectiveness of the proposed method.]]></description>
<pubDate>2013/10/31 9:49:10</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈杰,范红旗,宋志勇,肖怀铁]]></author>
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<item>
<title><![CDATA[A PDμ Motion Controller Design Method For PMLM]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305150000002]]></link>
<description><![CDATA[Recently, with the improvement of non-integer order calculus theory, fractional order calculus receives more and more attentions in the application of controlling. Especially, the fractional order PIλDμ controlling is applied in many fields. For the traditional PD controller which is usually used in motion control system, a kind of designing and tuning method of PDμ controller is proposed. Since there is explicit corresponding relation between phase margin and overshoot of the designed system, by designing the rate of change of phase the system’s phase can be made stable around cut off frequency and the influence of open loop gain’s variations on the overshoot can be reduced. Cut off frequency and phase margin given are considered as design specifications in this method. PDμ’s derivation order and derivation coefficient can be derived from system’s phase equation and rate of change equation. And proportional coefficient can be obtained from the magnitude equation on the cut off frequency. At last, this method is applied to a linear motion control experiment platform. By simulations and experiments comparing with integer order ITAE-optimal method, the effectiveness and excellence of this method is verified. From the results, it can be noticed that the controlling system designed in this method has a good inhibition effect on the overshoot variations caused by the fluctuations of the system parameters on the premise of meeting the design specifications.]]></description>
<pubDate>2013/10/31 9:48:38</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[陈兴林,李晓杰,王一光]]></author>
</item>
<item>
<title><![CDATA[Study on Ship Modeling Method of Shaft-ELFEin Shallow Sea]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305140000001]]></link>
<description><![CDATA[Take the basic simulation unit—time-harmonic horizontal electric dipole for example, solve the Hertz vector potential according to the uniqueness principle combined with boundary conditions. the electromagnetic field in  shallow seawater are derived from the relational expression between Hertz vector potential and  electromagnetic field. the electromagnetic field distribution of DC dipole  in  three media was solved, the space The simulated results show that the horizontal electric cell can be used to computing the harmonic cell at sufficiently low frequencies between 1Hz and 7Hz. The conclusion has been farther confirmed in lab, utilized horizontal electric cell and the horizontal harmonic electric cell source in man-made seawater. Finally, the shallow  marine environment and horizontal time-harmonic electric dipole were simulated in the laboratory, the electric field distributions of time-harmonic electric dipole and DC dipole were compared. The results show that the time-harmonic electric dipole electric field distribution is consistent with the theoretical calculation, which proved that the derivation and analytical expression are correct; the horizontal time-harmonic current model can be replaced by horizontal DC dipole when envelop of shaft-ELFE was simulated, and has a higher accuracy and practicability.]]></description>
<pubDate>2013/10/31 9:48:15</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[熊露]]></author>
</item>
<item>
<title><![CDATA[Rendezvous Control of Spacecraft Formation Based on Cyclic Pursuit Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305130000001]]></link>
<description><![CDATA[Rendezvous control of spacecraft formation based on cyclic pursuit algorithm is researched. The mathematical model of cyclic pursuit algorithm is established and deduced, A new control law for spacecraft formation rendezvous is proposed, in which planar cyclic pursuit algorithm and normal proportional derivative method are combines. Rendezvous control for a formation including three spacecrafts adopting linear and nonlinear cyclic pursuit algorithm respectively is simulated. Simulation results show that, the proposed control law based on cyclic pursuit can meet the rendezvous requirement of spacecraft, spacecrafts rendezvous at the reference center determined by their initial position along clockwise trajectories, changing process of relative distance and relative velocity between them is consistent, and consumption of velocity gain is lesser. All those can provide theoretical reference for research of formation control for spacecrafts.]]></description>
<pubDate>2013/10/31 9:47:16</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[杨  涛,杨希祥,张为华]]></author>
</item>
<item>
<title><![CDATA[Heterogeneous Parallel Compressible Flow Solver Based on MPI CUDA]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305090000001]]></link>
<description><![CDATA[We establish compressible flow heterogeneous parallel solver based on MPI CUDA on CPU/GPU heterogeneous system. Then we discuss different parallel computing models and optimizing methods of compressible flow parallel computing algorithm. This solver runs codes which are complex or low computing density on CPU, while runs codes which are simple and high computing density on GPU. we compare heterogeneous system’s computing results and efficiencies with homogeneous system through several problems. At last, we apply heterogeneous algorithm to hypersonic flow, the result shows the algorithm is robust and computing efficiency is improved ten times more than homogeneous algorithm.]]></description>
<pubDate>2013/10/31 9:46:44</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李桦,刘  枫,潘沙,田正雨]]></author>
</item>
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<title><![CDATA[Research On Guidance Law with Multiple Constraints of Hypersonic Vehicle for Cruise Phase]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305080000005]]></link>
<description><![CDATA[The equilibrium condition of hypersonic vehicle during cruise phase is modeling, under which the vehicle could maintain constant speed and altitude. Whether the vehicle could satisfy the condition or not has been analyzed. Based on the equilibrium condition, a guidance law with multiple constraints and terminal course angular constraint is proposed, while the analytic solution has been concluded. The method is adaptive since the guidance command is obtained through analytic expression in real time. In the end, simulations under different deviation have proved the method is available.]]></description>
<pubDate>2013/10/31 9:46:23</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈克俊,刘鲁华,万雨君,吴杰]]></author>
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<item>
<title><![CDATA[Optimizing and Configuring the Operational Support Equipment of theAntimissile Guided Missile Based on the Improved PSO]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305070000002]]></link>
<description><![CDATA[The model of optimizing and configuring the operational support equipment of the antimissile guided missile is founded and it is translated into RACP (resource availability problem). The traditional method to solve RACP is to translate it into some RCPSP (Resource-Constrained Scheduling Problem), and the process is complicated. In this paper, it is first time to use the displacement and vector expression to coding the support task, then, the improved PSO is used to solve the problem, and then, a new way to repair the swarm is put forward, at last the process solving the problem is predigested. It is shown in the case that Optimization method has significant value to solve RACP and the outcome has actual engineering significance.]]></description>
<pubDate>2013/10/31 9:45:39</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[郭波,雷洪涛,齐建军,张涛]]></author>
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<item>
<title><![CDATA[THO-MAC: A Low-Latency and Energy-Efficient MAC Protocol with Two-Hop Optimization in WSNs]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305030000002]]></link>
<description><![CDATA[Two major problems that are primarily considered in the design of medium access control (MAC) protocols in wireless sensor networks (WSNs) are energy consumption and latency. This paper presents a new low-latency, energy-efficient and receiver-initiated asynchronous duty-cycle MAC protocol in WSNs. In the proposed THO-MAC protocol, each node determines its periodical wakeup time based on the pseudo-random number sequence that is generated by its pseudo-random number generator. By predicting the receiver’s wakeup time accurately, THO-MAC protocol schedules the sender’s wakeup time to listen to the channel on demand and reduces the sender’s idle listening, therefore THO-MAC protocol can reduce the energy consumption of the sensor nodes. Furthermore, in order to achieve the low packet end-to-end delivery latency, THO-MAC protocol chooses the best forwarders in two-hop forwarders set to minimize two-hop forwarding latency based on the character of dense sensor nodes deployment in WSNs. This paper evaluates the performance of THO-MAC protocol through detailed NS2 simulation. The simulation results show THO-MAC protocol always can achieve low packet end-to-end delivery latency and low sensor energy consumption compared with two state-of-the-art WSNs MAC protocols--RI-MAC and AnyMAC.]]></description>
<pubDate>2013/10/31 9:45:15</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[唐宏伟]]></author>
</item>
<item>
<title><![CDATA[A Velocity and Height Estimation Method Based on Vision/Inertial for Aircraft in Unknown Environments]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305030000001]]></link>
<description><![CDATA[For aircraft navigation in unknown environments, this paper describes a velocity and height estimation method based on vision/inertial integrated navigation. An extended inertial navigation state equation was formulated, which contains several aircraft’s positions at latest several imaging times, and a linear vision measurement equation based on two view epipolar geometry constraint was adapted to correct inertial velocity error using a Kalman filter. And then, the coordinates of ground features were estimated by stereo vision method, which were used to estimate height of the aircraft. Simulation has been implemented using typical cruise trajectory of the aircraft and the result shows that our method works well for correcting the velocity and height errors, which makes velocity and height not drift with time, as a result, it can also suppress the position error of the aircraft.]]></description>
<pubDate>2013/10/31 9:40:33</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[雷志辉,刘海波,苏昂,张跃强,朱宪伟]]></author>
</item>
<item>
<title><![CDATA[Cascade Channel Estimators of Amplify-and-Forward Relaying System Based on Bayesian Theory]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304280000003]]></link>
<description><![CDATA[This paper deals with cascade channel estimation of Amplify-and-Forward (AF) relay system using Bayesian framework. According on maximum a posteriori (MAP) and minimum mean of square error (MMSE) rules, two estimators are derived combining the received training signal with the probability distribution function (PDF) knowledge that cascade channel comprises two independent Rayleigh channels. Due to the intractability of exact Bayesian Cramer-Rao Bound (CRB), alternatively, the approximated Bayesian one is obtained based on the principle of maximum entropy to compare with the CRB of MLE. Numeral simulation demonstrates that the new MAP estimator presents significantly improved performance, especially in the low signal-to-noise ratio regime.]]></description>
<pubDate>2013/10/31 9:39:13</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[刘海滨]]></author>
</item>
<item>
<title><![CDATA[A low-thrust trajectory optimization method based on motion synthesis]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304280000002]]></link>
<description><![CDATA[A novel method based on motion synthesis was proposed for low-thrust trajectory design and optimization. Firstly, the representation of the low-thrust trajectory was obtained by using the motion synthesis technique. In this representation, we decomposed the equations of motion into three independent motions and deduced the analytical expressions of the three motions separately. Then the approximate analytical expression of the low-thrust trajectory was obtained by the synthesizing of the three motions. Secondly, based on this representation, the original problem was converted into a nonlinear programming problem. Finally, the method was applied to three rendezvous missions: from the Earth to the asteroid 1989ML, to the Mars, and to the Venus. It is shown that the transfer orbits satisfy the mission constraints. Numeral results fully validate the availability and high efficiency of the method.]]></description>
<pubDate>2013/10/31 9:38:38</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[蒋小勇,汤国建,张洪波]]></author>
</item>
<item>
<title><![CDATA[The Equivalence Prove of Least-Square Solutions for Two Single-Point Positioning Models]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304260000002]]></link>
<description><![CDATA[For the least-square solutions of two positioning models in single-point position, the process of proving equivalence of position estimation and its precision is given. The basic positioning model and single-difference positioning model are described respectively, then it arrange single-difference positioning model into three cases, and the least-square solution of each case is proved equal to that of basic positioning model. Finally, the equivalence of the two models checks out by processing the experiment data, and the efficiency of least-square arithmetic for the two models is compared with each other.]]></description>
<pubDate>2013/10/31 9:38:17</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[吕汉峰,吴杰,张良]]></author>
</item>
<item>
<title><![CDATA[A scheduling algorithm for multi-core based on critical path and task duplication]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304250000001]]></link>
<description><![CDATA[According to the problem of current scheduling algorithm for multi-core did not consider that the nodes on the critical path have a major impact on the ending time of tasks, led to task completion time delayed; a scheduling algorithm based on critical path and task duplication (CPTD) was proposed. Firstly duplicated fork-nodes to change the task graph into products processing tree, then found the critical path in the processing tree, and made the father nodes of the nodes on critical path began to work at the earliest time. These operations can advance the start time of nodes on critical path. The purpose of the above operation is to shorten the implementation of the mandate of the total time. Theoretical analysis shows that the algorithm can achieve a single task fully parallel processing on multi-core, also can shorten the completion time of the tasks.]]></description>
<pubDate>2013/10/31 9:37:52</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[韩英杰,齐永红,谢志强,杨静]]></author>
</item>
<item>
<title><![CDATA[Reconstruction Error of Azimuth Multiple-Phase-Center SAR]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304230000002]]></link>
<description><![CDATA[Influence of array errors of azimuth multiple-phase-center (AMPC) synthetic aperture radar (SAR) on signal reconstruction performance is investigated. The array errors are modeled as stochastic process. In combination with least-square (LS) algorithm, we derive the analytical expression of the reconstruction error power spectrum. Then, we obtain the analytical expressions of signal to noise ratio (SNR) and azimuth ambiguity to signal ratio (AASR). Experiment results confirm the validity of the theoretical analyses. Analytical results indicate that the image quality of AMPC SAR can be improved by decreasing the reconstruction coefficient when pulse repetition frequency (PRF) increases. The approaches and results benefit system design and image quality evaluation of AMPC SAR.]]></description>
<pubDate>2013/10/31 9:37:26</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[董臻,何峰,梁甸农,马喜乐,孙造宇]]></author>
</item>
<item>
<title><![CDATA[Performance Analysis on A Special Uniform Array of Underwater Monitoring System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304220000001]]></link>
<description><![CDATA[A special uniform circular array (SUCA) is fixed on underwater monitoring system’s floater system; The paper creates SUCA’s model based on SUCA’s particularity. Then half-power beamwidth and unambiguous condition of SUCA are reseabased by theory of mode-space. Results show that half-power beamwidth and unambiguous condition’s scope of SUCA is wider than UCA, and SUCA is practicable in engineering application.]]></description>
<pubDate>2013/10/31 9:36:57</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[王跃科,赵慎]]></author>
</item>
<item>
<title><![CDATA[Research on an Improved Ephemeris Algorithm of BeiDou GEO Satellite for User]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304210000001]]></link>
<description><![CDATA[The orbital inclination of 5°coordinate rotation is required in the GEO ephemeris algorithm for user. Aim at this step, this paper presents an improved method that the BeiDou GEO satellite position is calculated directly by using the classical broadcast ephemeris algorithm for user, and meanwhile, gives the corresponding broadcast ephemeris fitting algorithm based on the second class of non-singularity orbit elements. In this method, the classical orbit elements are replaced by the second class of non-singular orbit elements, which solves the problem that coefficient matrix is non-positive in the process of the classical broadcast ephemeris fitting algorithm because of the small inclination angle. This avoids the orbital inclination of 5°coordinate rotation process, decreases the calculating steps time and enhances the GEO ephemeris algorithmic efficiency. The simulation results show that the accuracy of the improved method is as much as the original algorithm in the satellite orbit fitting process and is reduced slightly in the satellite orbit extrapolation process. But it can still meet the requirement of navigation and position for users. Finally, the validity of the improved algorithm is verified by using orbital data of the actual BeDou GEO broadcast ephemeris.]]></description>
<pubDate>2013/10/31 9:36:36</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[谢小刚,曾大治,]]></author>
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<title><![CDATA[Study of statistical characteristics of carbon fiber and effects on mechanical properties of carbon fiber composite cores]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304180000004]]></link>
<description><![CDATA[Single fiber and fiber bundle tensile strengths of Chinese-made carbon fiber were tested and its average single fiber tensile strength was described by Weibull statistical method. Carbon fiber reinforced composite core was made by pultrusion process with the Chinese-made carbon fiber. The bending and shearing properties of the composite core were studied. Results show that, compared with the Toray T300 carbon fiber from Japan, Chinese-made carbon fiber has almost the same average single fiber tensile strength, lower discrete property and a little lower average fiber bundle tensile strength. The aggregation property of the Chinese-made carbon fiber is not good enough. Carbon fiber yarns were nipped and fluffed when being drawn out. No significant difference can be found for the mechanical properties of the composite cores made with the Chinese-made carbon fiber and the Toray T700 carbon fiber from Japan.]]></description>
<pubDate>2013/10/31 9:35:35</pubDate>
<category><![CDATA[材料科学与工程]]></category>
<author><![CDATA[杜刚,江大志,肖加余,徐洋]]></author>
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<title><![CDATA[Angular Variation Analysis of Spacecraft Assembly Based on State Space Model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304180000003]]></link>
<description><![CDATA[Variation modeling is one of the most important tool for assembly variation analysis. Considering dimension and geometric precision, and part situation precision, the deviation source that affects assembly accuracy is clustered into two types: deviation of geometric location and orientation, variation of geometric form. And unify these different types of variation or deviation by Virtual Fixture. So a 3D rigid assembly state space modeling technique is developed for stream of variation analysis (SOVA) in multi-station processes. And a-missile-cabin-assembly process is analyzed in this model. It enhances the applicability in modeling complex assemblies. The developed methodology outperforms the current simulation based techniques in computation efficiency, not only in forward analysis of complex assembly systems, but it is also more powerful in backward analysis. The model is validated using Monte Carloseries Simulations.]]></description>
<pubDate>2013/10/31 9:34:38</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[李欣,尚建忠]]></author>
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<title><![CDATA[An Extensible Description Model of Cyber War System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304180000001]]></link>
<description><![CDATA[he research is focus on the modeling technology of cyber war system. A new idea is proposed for cyber war simulation, based on which a integrated logical evolving network model of cyber war system is proposed. The model regards all of the entities which belong to different forces as components of a whole system, and represents them with verticals of the network, all kinds of interactive behaviors between distinct entities which include the cooperative behaviors, parallel behaviors and confrontational behaviors are represented with edges of the network uniformly. A entity description model based on ontology and A behavior description model based on OO-LAMBDA language are built to describe the verticals and the edges respectively. At last, an simulation experiment is conducted using a scenario of a real operation, the results of the experiment validate that our methods are validity and advantage.]]></description>
<pubDate>2013/10/31 9:34:16</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[白亮,邓志宏,老松杨,杨征]]></author>
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<title><![CDATA[Numerical simulation for the performance of a New Type Dual-rotor Piston Engine]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304170000002]]></link>
<description><![CDATA[Dual-rotor piston engine (DRPE) is a new type of differential rotary engine, with the pistons moving in a circle, rather than linearly. Compared with the conventional engines, the complex valve systems can be omitted, and its power density is higher, et al. In order to study the major performance indicators of DRPE, Matlab/simulink is used to simulate the zero-dimension model of its thermodynamic process. With regard to the characteristics of DRPE’s working process, establish the differential equations. Taking into account various period features, simplifies the equations. Find the ways to solve the major boundary conditions. Values of the mass, pressure and temperate are calculated according to different shaft angles. Then calculate DRPE’s indicated mean effective pressure and power to weight ratio. Compared to some conventional internal combustion engines, the volume of DRPE’s chamber is used more efficiently, and its integral structure is more compact.]]></description>
<pubDate>2013/10/31 9:33:57</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[陈虎,潘存云,徐小军,邹腾安]]></author>
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<title><![CDATA[Design and optimization of new high-speed and dynamic following cutting device of bar]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304170000001]]></link>
<description><![CDATA[According to the insufficiencies of inability to adjust supporting radius and control cutting precision and shape of cutting blade in existing high-speed and dynamic cutting device of bar, The mathematical model between supporting radius, cutting error and cutting parameters such as cutting mode,number of blades and so on was established based on the analysis of cutting principle, and new adjustable support device was designed using slider-crank mechanism.The curvilinear equation between the shape of cutting blade and grinding parameters such as cutting diameter and installing angle of grinding wheel was built by means of homogeneous coordinate transformation,then new adjustable grinding device was designed.Speed of cutter,cutting error and other parameters were selected as optimization objects,the nonlinear multi-objective optimization of parameters of the two-blade and two-cutting cigarette cutting device was achieved using Matlab optimization toolbox.The project of new high-speed and dynamic following cutting device of bar was proposed, new device adopts the cut mode of four-blade and two-cutting, it has better cutting performance and cutting quality when the cutting efficiency is constant,and the device proves possible after simulation.]]></description>
<pubDate>2013/10/31 9:33:28</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[李斯明,刘子建,吴玄皓]]></author>
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<title><![CDATA[Optimal Guidance for Terminal Phase of Approaching Observation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304110000001]]></link>
<description><![CDATA[Approaching observation is a new way of space-based inspection . Precisely steering the flight vehicle to the observing point nearby the target is one of the key technologies. An optimal terminal guidance is presented for the terminal approaching. Firstly, the process of approaching observation is transformed to an optimal control problem by founding equations of relative motion in inertial coordinate systems and performance index which synthesizes the fight time and fuel consuming. Then optimal thrust direction, nozzle working hours, and time-to-go are derived, based on which a scheme of optimal guidance is designed. Finally, simulations are conducted and results demonstrate the guidance algorithm can meet the requirements of approaching observation mission with the high precision. The study herein also has a significance for Deep space exploration and rendezvous and docking.]]></description>
<pubDate>2013/10/31 9:32:47</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李广华,汤国建,张洪波]]></author>
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<title><![CDATA[A “Burn-Coast-Burn-Coast” Deorbit Guidance Approach Based on Energy and Angular Momentum Indices]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201307040000001]]></link>
<description><![CDATA[The problem of “burn-coast-burn-coast” deorbit trajectory guidance with finite thrust is studied. The entry interface conditions are transformed into indices of energy and angular momentum, based on which the critical geocentric distance of “burn-coast” deorbit problem is derived and the relationship between entry interface conditions and deorbit strategy is analyzed. Then, relative changing law of energy and angular momentum of spacecraft in the burn arc is derived, and the guidance equation is derived by the idea that the energy and angular momentum decrease synchronously in the same relatively rate. According to the entry interface conditions, the trajectory is supposed to be a “burn-coast-burn-coast” style. The first burn needs no guidance, and the direction of the thrust is opposite to the velocity direction. The second burn uses the guidance law. Simulations of different altitude and different entry interface conditions are implemented. The results indicate that the method can effectively solve the deorbit guidance problem that the single “burn-coast” method can’t solve, and the computational effort is not large.]]></description>
<pubDate>2013/10/31 9:28:50</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[汤国建,张洪波,邹毅]]></author>
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<title><![CDATA[Confidentiality and integrity dynamic union model based on pre-authorization mechanisms]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201307150000003]]></link>
<description><![CDATA[With the current access control model, a reasonable unified control over confidentiality, integrity and availability cannot be achieved; especially the dynamic random access request control is far from perfect, not only always leaving some weak points open to possible attacks, but also bringing some unavoidable security problems caused by user errors in practical applications. A kind of confidentiality and integrity access control model based on the pre-authorization mechanisms is put forward in this paper. By making BLP model and Biba model be combined, introducing the pre-authorization mechanisms, reasonable control can be achieved over the dynamic random accesses activities. By making use of the condition control, the authority of subject performing the task is monitored timely, and granted or canceled dynamically. So the system’s confidentiality and integrity can both be realized, while guaranteeing its high availability, which is advantageous to the two-way flow of information. At last, the application example of the model is given and its security is proved.]]></description>
<pubDate>2013/10/31 9:25:01</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[冯昌林,孟庆德,徐鲁威,张俊]]></author>
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<title><![CDATA[Modeling of the Electric Field Generated by Metal Body Moving under Seawater]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304100000001]]></link>
<description><![CDATA[A mathematical models were proposed to calculate the electric fields induced by the motion of metal body across the earth’s magnetic field, according to derive the expressions of electric fields induced by the vertical and horizontal DC current under seawater using the mirror image method. The magnitude and spatial distribution characteristics of the electric fields were analyzed, the results show that in the 30m depth, the magnitude of the electric field induced by a 20m’s long metal ellipsoid sailing 10m below water surface at the velocity of 4m/s is nV/m, and the spatial distribution has apparent characteristics.]]></description>
<pubDate>2013/10/31 9:20:38</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[龚沈光,熊露,张伽伟]]></author>
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<title><![CDATA[Thermal analysis of refractive secondary concentrator of solar thermal thruster based on regenerative cooling]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304090000001]]></link>
<description><![CDATA[Solar thermal propulsion is a high efficiency propulsion system, utilizing concentrated sunlight radiation to heat low molecular weight working fluid and providing high specific impulse. With regenerative cooling, an integration of the second concentrator and thruster can cool down the former to 1600K and preheat the propellant to 600K, improving the energy conversion efficiency of the propulsion system. The thermal radiation simulation shows that the flowing propellant is of little influence to the cavity temperature and the cavity can maintain high temperature between 2400K and 2600K.]]></description>
<pubDate>2013/10/31 9:18:50</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[程谋森,黄敏超,刘  昆,邢宝玉]]></author>
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<title><![CDATA[Jamming imaging radars based on pulse separation and retransmission]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305020000001]]></link>
<description><![CDATA[Multiple false-target images deception are the thorny points in the jamming against broad-band imaging radars. In this paper, a jamming approach of applying pulse separation and retransmission to the usual LFM signal of imaging radar is presented. Combined with the scatter-wave jamming model, the imaging of the jamming signal is expounded, and the ways to achieve a train false-target images along the down-range are analyzed. Based on the divided number and the retransmitted order, the number and the resolution of false-target images are described. At last, simulation results are presented and addressed. This work is beneficial to the deception jamming against imaging radars.]]></description>
<pubDate>2013/10/18 16:44:33</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[潘小义]]></author>
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<title><![CDATA[Research on Path Selecting Strategy in LEO Satellite Network]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304170000003]]></link>
<description><![CDATA[The transmission delay and the number of hops in path are the two main factors which should be considered when designing a routing algorithm for a specific network. The paths generated by the different routing strategy are called least delay path (LDP) and least hop path (LHP). In satellite network, the algorithm for LHP is much simpler, but there is limited research achievements for the rationality of LHP. In this paper, we have a detailed theoretical analysis for the differences between LDP and LHP in polar circular LEO satellite network. Basing on the results of our analysis, we propose a simplified LHP path selecting strategy with an idea of horizontal transmitting priority (HTP) by using the features of horizontal link length. The simulation results prove that our path selecting strategy can quickly find out the shortest path among all the LHP between every two nodes. It provides a foundation for the research of routing algorithms in LEO satellite network.]]></description>
<pubDate>2013/9/22 11:38:44</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[段思睿,胡鹤飞,李虎,刘元安]]></author>
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<title><![CDATA[Adaptive fuzzy sliding mode stabilization control for floated inertial platform]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304070000002]]></link>
<description><![CDATA[A control algorithm of adaptive sliding mode control based on fuzzy logic is proposed for the inertial stabilization problem of the floated inertial platform (FLIP). The sliding mode control is using to solve the parameters uncertainness and unmodeled dynamics of the FLIP, which guarantees the stability and rapidity of the system. Then, focusing on the design problem of the sliding mode control, the gain of a sliding mode control was adjusted by using the fuzzy logic with an adaptive tuning algorithm，which enhanced the adaptability for random uncertainty and improves the robust performance and the stabilization accuracy of the controller. Finally, the stability and convergence of the control system were proven by using the Lyapunov method．The simulations results demonstrate the proposed method can eliminate the input chattering of the sliding mode control efficiently and the inertial stabilization of the FLIP is realized with the accuracy higher than .]]></description>
<pubDate>2013/9/22 11:05:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[白锡斌,蔡洪,李安梁]]></author>
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<title><![CDATA[Flocking behavior method with multiple leaders in obstacle environment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304060000001]]></link>
<description><![CDATA[Aiming at the agents group consisting of multiple leader agents and multiple follower ones, a flocking behavior method with multiple leaders in obstacle environment is proposed. Belonging to a distributed control method, this method drives the follower agents to be controlled by the leader agents of the group. Simultaneously, the center and average velocity of the follower agents exponentially converge to weighted average position and velocity of the leader agents respectively. And the weight is dependent on the number of follower agents which are leaded by the leader agents. Moreover, by introducing a class of agents which are denoted as “ β-agent” at the border of the obstacles, the follower agents possess the capacity of avoiding collision with the static and dynamic obstacles. In this way, believable flocking behavior with multiple leaders in obstacle environment is generated. Simulation results with virtual humans being the members of the group demostrate the effectiveness of the proposed method.]]></description>
<pubDate>2013/9/22 11:04:31</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[梁加红]]></author>
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<title><![CDATA[Dynamic Trajectory Planning Based on Vehicle Steady Dynamics]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304030000001]]></link>
<description><![CDATA[A dynamic trajectory planning algorithm based on vehicle steady-state dynamics for driver assistance systems (ADAS) under high dynamic environment was proposed in this paper. The algorithm builds a ‘search space’ on the basis of traffic vehicle trajectory prediction and uses of the vehicle steady-state kinetic model as a trajectory generator. Every trajectory produced by the generator was evaluated in the search space and the optimal trajectory under optimal conditions was selected. In order to realize the closed-loop dynamic simulation, corresponding trajectory tracking algorithms and vehicle dynamics model were also proposed in the article. A simulation platform under Simulink environment was built for simulation tests. The results show that in the intelligent overtaking test case, the proposed algorithm was able to overtake safely and meet the needs of intelligent assistance systems.]]></description>
<pubDate>2013/9/22 11:04:03</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[孙浩,]]></author>
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<title><![CDATA[An Enforceability Probability Estimation Model for Satellite Observing Tasks]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304020000001]]></link>
<description><![CDATA[The enforceability probability of satellite observation is timely and accurately estimated to provide the fundamental basis for satellite task planning and scheduling. An 　　The enforceability probability of satellite observation is timely and accurately estimated to provide the fundamental basis for satellite task planning and scheduling. An estimation model of the enforceability probability of satellite earth observation is established based on the Logistic regression method. Firstly, the influence factors of observation enforceability probability are analyzed, including the property of observation task, resources limitation, competitive relations among tasks, etc. Secondly, independent variables are extracted and their quantitative methods are given, then the Logistic regression model is established. Thirdly, experiments are implemented on the planning and scheduling system of satellite imaging observation to obtain the sample data of independent variables and planning results. Lastly, the sample data is analyzed by using the Logistic regression method, and then the variables and parameters of the model and the function forms are all determined. Moreover, the effectiveness of the model is validated.]]></description>
<pubDate>2013/9/22 11:03:25</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[郭少阳,李志猛,刘刚,谈群]]></author>
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<title><![CDATA[Fault Diagnosis Method for Liquid-propellant Rocket Engines based on the Cloud Sorter]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303270000001]]></link>
<description><![CDATA[Through transforming the fault diagnosis into the pattern classification of fault characteristics, this paper achieved a fault diagnosis method based on the cloud sorter for liquid-propellant rocket engines. The method synthesizes the study on cloud model and the cloud transform, which can deal with the uncertainty and the hard partition of domain boundary for the quantitative attributes existed in the traditional classification methods. Results with test data show that the method can recognise the fault modes in the startup process of the engine timely and precisely.]]></description>
<pubDate>2013/9/22 10:56:51</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[程玉强,刘垠杰,彭小辉,吴建军]]></author>
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<title><![CDATA[A new landmine discrimination approach based on sequential aspect features]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303200000003]]></link>
<description><![CDATA[Low-frequency ultra-wideband synthetic aperture radar (UWB-SAR) is a promising technology for landmine detection. According to the scattering characteristics of body-of-revolution (BOR) targets along with azimuth angles and incident angles, a Hidden Markov model (HMM) discrimination algorithm is proposed which uses sequential features such as double-hump distance and notch frequency. First, the algorithm estimates the target scatterings in all azimuths based on regions of interest (ROI). Second, Sequential aspect features are extracted by sparse time-frequency representation. Then the HMM parameters are trained with labeled samples and the probability of occurrence is computed to discriminate suspicions targets. The experimental results indicate that the proposed algorithm is effective in BOR target discrimination.]]></description>
<pubDate>2013/9/22 10:56:15</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄晓涛,施云飞,宋千,王建,王玉明]]></author>
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<title><![CDATA[Anti-occlusion object tracking research based on two-level ISM model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303200000001]]></link>
<description><![CDATA[A target tracking algorithm based on two-level implicit shape model is proposed to solve the tracking problem under occlusion and improve the location accuracy. Firstly,partial key points about the target and surrounding areas are extracted to build the codebook dictionary by Fast Hessian detector, the feature description vectors of the codebook are constructed by SURF descriptor to establish the codebook support model.Secondly,the symbiotic relationship between the codebook dictionary set and target is established through the generalized hough transform,and updated online by the implicit shape model. Finally,by finding the maximum value in the voting space to locate the target.According to the occlusion states in the tracking process,different voting weights are assigned to the codebook of target itself and surrounding area respectively, to improve the location accuracy under different occlusions. Experiments show the algorithm can locate the target robustly even though the target is occlusive or even not visible or come back to the field of view after missing.]]></description>
<pubDate>2013/9/22 10:55:46</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[韩建涛,李飚,王鲁平,张路平]]></author>
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<title><![CDATA[The Transmission Characteristics Research of Radio Wave In The Plasma Based on Finite Difference Time Domain]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303150000002]]></link>
<description><![CDATA[According to the basic principles of the finite difference time domain (FDTD) method, this paper firstly analyzed the physical field characteristics and the numerical calculation of the plasma, and then introduced the reentry plasma sheath formed and plasma relative dielectric constant of the wave attenuation, last but not the least simulated the propagation of electromagnetic waves in the plasma with three-dimensional FDTD method and two-dimensional FDTD method, and proved the FDTD method was an effective method to solve the electromagnetic wave propagation in the complex medium, and explored the theory and methods of aircraft communication in the reentry blackout zone.]]></description>
<pubDate>2013/9/22 10:55:13</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[郭彤,彭坚,]]></author>
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<title><![CDATA[A Method about Backsteping Control for Waverider Slide Hypersonic Vehicle with Large Envelope]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303240000001]]></link>
<description><![CDATA[Waverider slide hypersonic vehicle would be very useful for transport and as a weapon in the future. The flight environment is very complex as the hypersonic vehicle’s high speed and wide range, the control system of the hypersonic vehicle should be adaptability. As decoupling pseudolinear system does not have fine dynamic performance, the paper established the attitude model of the hypersonic vehicle, used the discoupling method and Block Backstepping theory to design the control system. The paper proved the stability of close-loop system and finished the simulation with large flight envelope and large-scale parameters perturbation. The results showed the method had made sure the stability of close-loop system’s Lyapunov functions. With functional agility and responding rapidly, the control system could solve the problem bring by large flight envelope and large-scale parameters perturbation, and enhance the system’s robustness.]]></description>
<pubDate>2013/9/22 10:54:20</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李健,张为华,郑伟]]></author>
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<title><![CDATA[Multiplicative Filtering for Spacecraft Attitude Determination]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303140000002]]></link>
<description><![CDATA[Multiplicative extended Kalman filter (MEKF) has been widely applied in the vast majority of spacecraft attitude determination missions. For the arbitrary reference frame, the linear quaternion kinematics equation and the dynamical model of three-component attitude errors are formulated, and gyro-aided and gyro-free attitude determination schemes are designed. The typical basic equation of the MEKF is developed, including the detailed models for vector measurements, quaternion measurements and Euler angle measurements, which can provide theory reference and technique support for spacecraft missions.]]></description>
<pubDate>2013/9/22 10:53:08</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[张力军]]></author>
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<title><![CDATA[UAVs formation rendezvous method based on differential geometry and Lie group]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303140000001]]></link>
<description><![CDATA[Under the leader-follower formation pattern, a method for UAV formation rendezvous was developed based on the pursuit strategy. Firstly, the UAV non-decoupling 3D kinematics models were established using the curve theory of differential geometry and the Frenet-Serret frames, where the curvature and the torsion were considered as the control effort. Secondly, the mathematical descriptions of the three-dimensional formation rendezvous were provided with the models, where the impact angular constraint in missile guidance was mapped to a flight path angle of the follower in formation rendezvous, and an additional azimuth angular constraint was introduced. Thirdly, the orientation deviation between the leader and the follower was measured using an element of the special orthogonal group, and the element was mapped to a twist in an Lie algebra space corresponding to the Lie group by local coordinate mapping. Then, a geometric guidance law for formation rendezvous was developed using the twist, and the corresponding curvature command and torsion command were presented. Finally, the numerical simulation for multi-UAVs formation rendezvous was carried out, under the leader flying straightly and making a turn, respectively. The simulation results show that the follower can track the orientation of the leader successfully and converge to a specified configuration, which indicates that the proposed method is available.]]></description>
<pubDate>2013/9/22 10:52:29</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[安宏雷,李杰,彭双春,沈林成,相晓嘉]]></author>
</item>
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<title><![CDATA[Research on the Multi-Donor Kidney Exchange Problem]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303100000001]]></link>
<description><![CDATA[The kidney for transplantation is in serious shortage. To alleviate this problem, more and more countries have started various kidney exchange programs. The kidney exchange problem is generally modeled as a cooperative game (KE). Each player represents an incompatible patient-donor pair. A patient may have more than one incompatible donor in reality. Define the multi-donor kidney exchange game (MDKE). Analyze the structures of MDKE’s feasible solutions and stable solutions. Prove that donating multiple kidneys is useless in joining in a better stable solution. Extend the TTC algorithm, the NP-hardness of a stable solution and the inapproximability of a maximum cover stable solution of KE to MDKE. Experiments show the high effectiveness of MDKE.]]></description>
<pubDate>2013/9/22 10:51:32</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[骆志刚,王刚]]></author>
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<item>
<title><![CDATA[Geometric Sliding Mode Observer Design with Application to Angular Velocity Estimation of Quadrotor UAV]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303060000002]]></link>
<description><![CDATA[Traditional quaternion-based sliding mode observer for angular velocity estimating must introduce the process of mandatory rescaling which reduce the tracking performance of the observer algorithm. In this work, a sliding mode observer design framework is proposed based on the Lie group method of numerical integration on manifolds for angular velocity estimation of quadrotor attitude. The algorithm constructs sliding mode feedback in the space of equivalent Lie algebra of homogeneous manifolds on the basis of equivariant mapping ideological. It avoids the complexity of constructing sliding mode feedback in homogeneous space directly, and eliminates the process of mandatory rescaling which the traditional methods need in each integration step. The simulation results show that the algorithm of geometric sliding mode observer is effective.]]></description>
<pubDate>2013/9/22 10:50:08</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[安宏雷,李杰,马宏绪,王建文,王剑]]></author>
</item>
<item>
<title><![CDATA[High order upwind compact schemes based on TVD algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303040000001]]></link>
<description><![CDATA[Using the same stencils, the compact schemes can get higher accuracy and resolution compared to the traditional ones. But it will come in to spurious oscillations if use the compact schemes directly. There are some methods to settle this problem. We chose the TVD algorithm in the paper. Firstly, we introduced two five order upwind compact schemes and use Fourier analysis to compare their dissipation and dispersion characteristics. Secondly, we applied two different TVD methods to Euler equations. The performance of the numerical algorithm has been assessed by performing preliminary simulations on some problems, such as the oblique shock reflection problem. The algorithm applied here is proven to have good resolution properties and robust of capturing shock waves and contacts, but still has some problems of accuracy degreed and lack of dissipation.]]></description>
<pubDate>2013/9/22 10:49:09</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李桦,王文龙]]></author>
</item>
<item>
<title><![CDATA[A Fast Jamming Method for False Uniformly-Moving Scene Against SAR-GMTI]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303150000003]]></link>
<description><![CDATA[The deceptive stationary scene jamming is not effective for coutering synthetic apreture radar (SAR) and ground moving target indication (GMTI) radar systems. To solve this deficiency, this paper proposes a method which transforms the stationary scene jamming signals to uniformly-moving scene jamming signals in real time. First, the echo models of moving target and stationary target are analyzed. Then, a formula which describes the relationship between moving target echo signal and stationary target echo signal is derived. Based on this formula, the three implementation steps of this method are presented as delay operation in range time domain, stretching transformation in azimuth time domain and phase compensation. Next, the computational complexity is analyzed. Finally, the simulation results indicate that the proposed method is effective to produce false uniformly-moving scene，through which the stationary scene and important ground moving targets can be protected against SAR-GMTI.]]></description>
<pubDate>2013/9/4 19:37:12</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[林晓烘,刘培国,薛国义]]></author>
</item>
<item>
<title><![CDATA[Parallel Processing Framework for Huge Geographic Raster Data]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201307050000001]]></link>
<description><![CDATA[With the technology advance, geographic raster data’s amount kept increasing. Single process cannot process large raster data efficiency, so it is necessary to adopt parallel processing. Traditional development method mix algorithm, process scheduling, memory management and data I/O together, this propose a higher requirements to programmers and code quality is difficult to control. This study proposed a Huge Geographic Raster Data Parallel Processing Framework (HGRDPPF). With the use of core class’s real read and virtual read method, framework can achieve large raster data’s fast loading and writing by steps or blocks, and formed parallel task scheduling, data transfer and specific algorithm stage into tasks; through this framework, we can split raster file into sub-tasks according to the ability of computer in the cluster, and separate the raster processing algorithm from MPI API, disk IO and logic, developers can concentrate in the algorithm itself, and achieve higher program quality. Experiments show that this framework can significantly reduce the amount of code while improving software quality, and to achieve better parallel performance.]]></description>
<pubDate>2013/9/4 19:31:29</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[杨典华]]></author>
</item>
<item>
<title><![CDATA[The causalSanalysis and preventive measures for the fuel-oil accessories rear cover in the aero-engine]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305150000003]]></link>
<description><![CDATA[For the problems as the cracks appeared in batches?in the fuel-oil accessories rear cover, a new evadable?measure for the crack guide and devolvement is put forward. By researching the main cause of the cracks?and analyzing the extent of the damage caused by the cracks in different positions in the fuel-oil accessories rear cover for the aero-engine , It has changed the pristine support construction, so the new stress concentration point has formed and the stress amplitude in the key part of the stress concentration area has reduced, which makes the crack faults being transferred from the unrepaired key part to the repairable non-critical part. Through the computer simulation, the optimal parameters for the crack guided gap have been determined and the simulation result has showed that the evadable?measure for crack guide and devolvement is reasonable and practicable..]]></description>
<pubDate>2013/9/3 9:30:17</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[冯逸飞,罗成,徐小军]]></author>
</item>
<item>
<title><![CDATA[A Fast Approach to Remove the Haze from a Single Bayer Image]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303310000002]]></link>
<description><![CDATA[In order to reduce the bad effect in the outdoor visibility system in foggy days and get the real-time dehazing effect, a fast and effective method, which is based on Bayer pattern image and dark channel prior, is developed to remove the haze from single image. The color image processing pipeline is improved during this approach. Bayer pattern image is the raw data captured by digital camera and costs low memory. According to the characteristics of Bayer pattern image, the original dark channel prior algorithm is optimized and improved. The atmospheric light is estimated based on the quad-tree subdivision. In the optimization process of the transmission map, the coarser estimation is refined using Guided Filter, which is modified with the property of Bayer pattern image. At last, the RGB image, which is displayed by the device, is recovered from the haze removal Bayer image using the demosaic algorithm. The experimental results show our new single image haze removal method achieves better image quality with very little time.]]></description>
<pubDate>2013/9/2 11:35:56</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[李永乐,娄静涛,王炜,张茂军]]></author>
</item>
<item>
<title><![CDATA[Numerical study of a coaxial transit-timeoscillator with travelling-wave output structure]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201302260000001]]></link>
<description><![CDATA[A coaxial transit-time oscillator with travelling-wave output structure is proposed in this paper. The extractor of this device adopts an extended interaction cavity loaded with washer-like structure, which has advantage of high beam-wave interaction efficiency and low space charge potential energy. The extractor operating at 3π/2 mode not π-like mode improves the group velocity of wave, which is favorable for RF extraction. The loaded quality factor of the buncher is increased by introducing a reflector before it, which can obviously reduce the starting time of microwave. The device is designed and optimized by a PIC (particle-in-cell) code. With the voltage 530 kV，the current 12.8 kA and the guiding magnetic field 0.7 T, the output power is 2.41GW at the main frequency 7.76GHz, and the efficiency of beam-to-microwave power conversion is about 35.5%.]]></description>
<pubDate>2013/8/29 17:41:43</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[张建德]]></author>
</item>
<item>
<title><![CDATA[Fast Unstructured Mesh GenerationBased on Arbitrary polyhedron]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201302030000001]]></link>
<description><![CDATA[Mesh generation is the key to the numerical simulation in CFD with complex aerodynamic shapes. The algorithm of mesh generation needs to be fast and robust. At first, this framework establishes efficient initial tetrahedron arithmetic based on viewed-able face which is fit to arbitrary polyhedron. Then, improves Delaunay generation method to refine meshes and discusses the effect of different mesh quality criterion and closes down the divergence with Delaunay face swapping. Finally, we optimize mesh with vertex spring model. The results indicate the way this paper establishes is efficient and stable.]]></description>
<pubDate>2013/8/29 17:41:10</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李　桦,刘  枫,潘  沙,田正雨]]></author>
</item>
<item>
<title><![CDATA[Accelerating RNA secondary structure prediction applications based on CPU-GPU hybrid platforms]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301290000001]]></link>
<description><![CDATA[Prediction of ribonucleic acid (RNA) secondary structure remains one of the most important research areas in bioinformatics. The Zuker algorithm is one of the most popular methods of free energy minimization for RNA secondary structure prediction. However, general-purpose computers including parallel computers or multi-core computers exhibit parallel efficiency of no more than 50% on Zuker. In this paper, a CPU-GPU hybrid computing system that accelerates the Zuker algorithm applications for RNA secondary structure prediction is proposed. The computing tasks are allocated between CPU and GPU for parallel cooperate execution. Performance differences between the CPU and the GPU in the task-allocation scheme are considered to obtain workload balance. To improve the hybrid system performance, the Zuker algorithm is optimally implemented with special methods for CPU and GPU architecture. A speedup of 15.93? over optimized multi-core SIMD CPU implementation and performance advantage of 16% over optimized GPU implementation are shown in the experimental results. More than 14% of the sequences are executed on CPU in the hybrid system. To the best of our knowledge, our implementation combining CPU and GPU is the only accelerator platform implementing the complete Zuker algorithm. Moreover, the hybrid computing system is proven to be promising and can be applied to accelerate other bioinformatics applications.]]></description>
<pubDate>2013/8/29 17:39:25</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[金国庆,夏飞,朱强华]]></author>
</item>
<item>
<title><![CDATA[Parameter identification for magnetic bearingbased on online dynamic balancing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301240000002]]></link>
<description><![CDATA[Based on online dynamic balancing, a novel parameter identification method is proposed for magnetic suspending rigid rotor system. Two unbalancing masses with given magnitude and phase are added to the rotor and used as vibration exciter. The displacement stiffness and current stiffness are identified from the unbalancing response detected by balancing monitor. The proposed method is experimentally validated with a magnetic suspending control moment gyroscope, and the displacement stiffness and current stiffness of its magnetic bearings are obtained for a certain rotational speed interval, which demonstrates the correctness and feasibility of the method. The experimental results show that the displacement stiffness and current stiffness decrease notably with the increased rotational speed for an outer rotor magnetic bearing.]]></description>
<pubDate>2013/8/29 17:38:55</pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[侯二永,刘昆]]></author>
</item>
<item>
<title><![CDATA[Targets Detection and Classification Based on WSN]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301240000001]]></link>
<description><![CDATA[Aiming at the issue about the targets detection and classification in target monitoring system based on WSN, the study proposed a multi-sensor data fusion method based on intuitionistic fuzzy reasoning (IFR). The property functions of two status variables are designed according to the method of fuzzy reasoning. The study construct the inference rules of the system after acoustic energy attenuation model and the variety of magnetic field model are built, and the rationality of constructed rules is checked. The comparison between theoretical analysis and simulation result show that intuitionistic fuzzy reasoning can classify targets uncomplicatedly and effectively. Because of its less calculation, the method can apply on WSN node, which calculation capacity is weak.]]></description>
<pubDate>2013/8/23 16:44:21</pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[潘仲明,张恒]]></author>
</item>
<item>
<title><![CDATA[Optimizing design of clamp band joint based on parameter modeling method]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301230000001]]></link>
<description><![CDATA[A new application based on the parameter modeling method of MSC.Patran and generation algorithm was proposed to design the clamp band joint. First, finite element techniques for 2-dimension axisymmetric analysis of clamp band joints were developed, including the modeling of V-clamp, strap pre-tension and loads, and the optimizing constrains and objectives were also introduced. Then a clamp band joint with the diameter being 3m was designed via the presented method. Finally, a 3-dimension finite element model of the designed clamp band joint was established and analyzed. It indicates that: (1) the method is applicable to the design of clamp band joints; (2) the connective stiffness is strengthened by increasing the length and height of the inner ring of the interface rings; (3) the modeling methods are proved to be valid by the agreements of the finite element analysis results of 2-D model and 3-D model.]]></description>
<pubDate>2013/8/23 16:43:18</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[雷勇军,李谨,刘观日,武新峰]]></author>
</item>
<item>
<title><![CDATA[Resolution Analysis of MIMO SAR Based on Generalized Ambiguity Function]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304070000001]]></link>
<description><![CDATA[Recent years, a new SAR concept based on Multi-Input Multi-Output (MIMO) configuration has drawn much attention. However, it is an urgent and difficult problem to characterize the resolution and ambiguity due to waveform diversity and spatial diversity. In this paper, we extend the generalized ambiguity function of the conventional SAR into MIMO SAR case. Detailed analysis shows that the resolution of MIMO SAR not only depends on the parameters of the waveform and synthetic aperture length, but also the array geometry of the multiple transmitters and multiple receivers. Simulations with a variety of parameter combinations demonstrate the derivation and analysis.]]></description>
<pubDate>2013/7/17 4:18:07</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[周伟]]></author>
</item>
<item>
<title><![CDATA[Numerical analysis of plume field of a pulsed plasma thruster]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201302270000002]]></link>
<description><![CDATA[Considering the effect of magnetic field on the plasma plume, a hybrid particle-fluid model combining DSMC and PIC methods was developed to study the plume characteristics of a pulsed plasma thruster. By incorporating a magnetohydrodynamic code to provide inlet conditions, this model was applied to simulate the three-dimensional plume field. The calculation results were validated by an experiment based on triple Langmuir probes. Investigations show that there are substantial differences between the expansion dynamics of various species. It is indicated that the oscillation of discharge current will lead to the generation of a population of low-velocity ions, together with the aggravation of backflow of ions. Electromagnetic acceleration is demonstrated to be the primary mechanism of plasma acceleration, and the magnetic field plays an important role in the diffusion of the thruster plume.]]></description>
<pubDate>2013/7/15 10:28:10</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李自然,谢泽华,张锐,周进]]></author>
</item>
<item>
<title><![CDATA[Study on the Flow Fields of Supersonic Mixing Layer with Splitters of Different Geometric Configurations]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301170000001]]></link>
<description><![CDATA[Through combination of experiment and numerical simulation, a study was carried out on supersonic mixing layer with splitters of different geometric configurations, which is under condition of  Ma1=1.5,Ma2=2.5,T0,1=300K,T0,2=1200K and matched pressure  p1=p2=86KPa. In the experiment, it was discovered that the thickness of mixing layer in the flow field with splitters in which a cavity is mounted grows as the ratio of the length to depth of the cavity becomes larger; Splitters with sawtooth trail show great effect of mixing enhancement and making the flow field highly unsteady. In the numerical study, It was demonstrated that the mixing-enhancement effect of splitters with cavity is due to the cavity shear layer’s reattachment to the trail of the splitter, and splitters with sawtooth trail due to induced large-scale streamwise vortexes.]]></description>
<pubDate>2013/7/5 10:36:46</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[刘彧,晏至辉,周进]]></author>
</item>
<item>
<title><![CDATA[A method for self-estimating the depth of maneuvering AUV based on the grey particle filter]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301130000001]]></link>
<description><![CDATA[A grey particle filter (GPF) that incorporates the grey prediction algorithm and wavelet transform into the particle filter (PF) is presented in this paper. The GPF self-estimates the depth of maneuvering autonomous underwater vehicle (AUV) using the data measured by sensors equipped in the AUV under the condition that the prior maneuvering information is unknown and the measurement noise is time-varying. To implement the proposed method, the particles are sampled by standard sampling and grey prediction to insure the particles contain enough information about the true state of the maneuvering AUV. In addition, the measurement noise covariance is modified by wavelet transform in real time. Therefore, the GPF can effectively correct the prior distribution and likelihood function of the particles and then alleviate the sample degeneracy problem which is common in the particle filter. We employ a high accuracy depth trajectory that tracking by the outside position sensor as the true depth of the maneuvering AUV, then the performance of the EKF, MMPF and GPF are evaluated through the experimental data. The results show the effectiveness and robustness of the GPF.]]></description>
<pubDate>2013/7/5 9:42:38</pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[黄芝平,李婷,,赵德鑫]]></author>
</item>
<item>
<title><![CDATA[Mission reliability analysis of space TT]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301090000001]]></link>
<description><![CDATA[A methodology is proposed to evaluate the mission reliability of TT]]></description>
<pubDate>2013/7/5 9:42:20</pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[武小悦,杨晓松]]></author>
</item>
<item>
<title><![CDATA[Defect modes in the phononic crystal based on Helmholtz resonators with point defect]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301040000001]]></link>
<description><![CDATA[Defect mode can be created by introducing point defect in the one-dimensional crystal containing Helmholtz resonators. Based on acoustic transfer matrix method and finite element method, the relationship between the defect mode and the geometrical parameters of the defect cell is studied as well as the acoustic field distribution in the structure at the frequency of the defect mode. The results show that the defect mode moves to the edges of the local resonant forbidden band with the increase of the coupling effect between the defect cell and the perfect cells. In addition, acoustic energy localization is also observed due to the existence of the defect state. This work will be of help for designing new acoustic filters and energy concentrators.]]></description>
<pubDate>2013/7/5 9:41:48</pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[高东宝,曾新吾]]></author>
</item>
<item>
<title><![CDATA[Research on mission assignment of on-orbit servicing spacecraft]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301030000001]]></link>
<description><![CDATA[One mission of on-orbit servicing can be fulfilled in many ways, and priority must be given to mission assignment. First, the reachable domain of service spacecraft is resolved and the target spacecraft which satisfy the reachable domain are filtered. Then the paper studies the assignment of servicing based on the optimization of multi objective including time, fuel consumption and priority. The best plan is achieved by building the model of 0-1 integer programming and taking the NSGA-Ⅱ algorithm with the constraint of time and fuel consumption. Finally two examples of simulation are given, one demonstrating the general results of the above method, either compared with another algorithm. The simulation results indicate that the above method is effective in solving the problem of mission assignment for on-orbit servicing.]]></description>
<pubDate>2013/7/5 9:41:27</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[梁彦刚,王伟林]]></author>
</item>
<item>
<title><![CDATA[A Multi-Objective Particle Swarm Optimization based Virtual Network Embedding Algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303150000001]]></link>
<description><![CDATA[Aim to the problem of unified resource optimized allocation when executing multi-virtual network embedding synchronously, a multi-objective particle swarm optimization based virtual network embedding method is proposed to increase the performance of resource utilization and global load balance of the substrate network resource. We put forward a multi-objective optimization model for virtual network embedding, on the basis of which the single virtual network embedding is considered as a swarm and the information exchange among different swarms so as to evolve corporately by employing multi-swarm coordination optimization method, then increasing the performance of global resource allocation. The simulation results show that the proposed method maintains the best performance of the substrate network resource utilization ratio and virtual network request acceptance ratio compared with typical methods.]]></description>
<pubDate>2013/7/5 9:39:35</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[戴一奇,郭智恩,薛海伟]]></author>
</item>
<item>
<title><![CDATA[A Fault Diagnosis Approach Research Based on LPS Model for Flight Control System]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304160000001]]></link>
<description><![CDATA[The traditional fault diagnosis method is generally based on the measuring signal, without considering the actual physical connection characteristics, but this characteristics effects the diagnosis results. With the wide application of professional electric system design software, system designers easily obtain the physical connection characteristics and logical connection characteristics. By analyzing the signals of product layer or system layer, physical connection and its interconnected relationship, the paper presents a set of logical physical synthetically (LPS) model which willSunify abstract signal and physical connection, and to study the LPS model instantiation method based on wire table and net table, and develops a set of intelligent fault detection software. An example for validation show: fault diagnosis method based on LPS model could isolate the fault to the specified product level, with great engineering application value.]]></description>
<pubDate>2013/7/5 9:03:21</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[陈龙志,黄哲志,贾涛,曾庆华]]></author>
</item>
<item>
<title><![CDATA[Reconstruction of array output and Direction-of-Arrival estimation via L1 -analysis sparse recovery]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301110000002]]></link>
<description><![CDATA[The array manifold matrix was constructed as a redundant dictionary in which the array receiving signals were sparse through the appropriate spatial sparse division, and the corresponding L1-analysis sparse recovery model was established to reconstruct the array output data. The core of this paper is the fact that it was proved that the manifold matrix was a tight frame and satisfied the condition which guaranteed accurate recovery of signals through L1-analysissparse recovery so that it was reasonable enough to use L1-analysissparsity optimization to reconstruct the array output data. The upper bound of reconstruction error was given. The effectiveness of this presented method for improving the performance of DOA estimation with low SNR were verified by the experiments using the actual measurement data received in microwave darkroom through MUSIC algorithm.]]></description>
<pubDate>2013/7/4 9:09:47</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[林波]]></author>
</item>
<item>
<title><![CDATA[The Weekly Task Scheduling Model and Solving Algorithm of Imagining Satellites]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301020000001]]></link>
<description><![CDATA[Satellite weekly task scheduling is an important procedure for the Satellite Run and Management System, and it has influence on the effectiveness of satellite system. Different from the function and the characteristic of daily task scheduling, weekly task scheduling includes not only the technology problem but also the management problem. The paper mainly expounds three respects of work: firstly, analyzing the demand and the characteristic of weekly task scheduling, explaining four main functions of weekly scheduling, then constructing a hierarchical scheduling framework; secondly, summarizing optimization objects and constraint conditions, and building the weekly task scheduling model with considering the task overloading factor; thirdly, with instigating the heuristic rules and introducing distributed parallel computing strategy, combing the Gene Algorithm and the Simulated Annealing Search to solve the model.]]></description>
<pubDate>2013/7/4 9:08:50</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[于渤]]></author>
</item>
<item>
<title><![CDATA[Description of the First Debris Clouds Formed by Hypervelocity Impact]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201212300000001]]></link>
<description><![CDATA[The numerical simulation way studied hypervelocity impact has been discussed. Damage mechanism, the process of the debris cloud forming and expanding has been studied with the SPH method of ANSYS/AUTODYN code when spherical projectile hypervelocity impact thin shield. Tungsten alloy, RHA(Rolled Homogeneous Armor) and aluminum material models and parameters have been given, using the modeling methods, material models and parameters of the numerical simulation results in good agreement with the experimental results. The debris cloud parameters such as Vx,max, Vy,max and the half-angle of maximum radial extension(θ1) are obtained with numerical simulation, and these parameters with the variation of the initial impact conditions have been studied. The empirical equations that relate these parameters to impact parameters such as velocity, material parameters of projectile and target and plate thickness are obtained based on dimensional analysis.]]></description>
<pubDate>2013/7/4 9:08:14</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[李必红,汪庆桃,吴克刚,张庆明]]></author>
</item>
<item>
<title><![CDATA[Formulae for Finding All Roots of Quadratic  One-sided Polynomials  over Quaternions]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201212270000001]]></link>
<description><![CDATA[Quaternion algebra has been widely applied to many subjects such as quantum mechanics, control theory and inertial navigation. With this it has been paid attentions by many scholars to effectively obtain the roots of a quaternionic polynomial. Recently, Janovska and Opfer have provided theoretically a method of finding all zeros of a simple quaternionic polynomial of degree n. Furthermore, Feng and Zhao have given a formula of finding all zeros of a general simple quaternionic polynomial of degree n in terms of solving polynomials over the field of complex numbers. Basing on the results given by Feng and Zhao, in this paper, we discuss and classify the roots of a quaternionic one-sided polynomial with degree 2, and produce a quadratic formula for quaternions by help of  the Ferrari's quartic formula over the field of complex numbers. Comparing with the results in literature, the formula we built in this paper presents its advantages in many aspects.]]></description>
<pubDate>2013/7/4 9:07:41</pubDate>
<category><![CDATA[数学]]></category>
<author><![CDATA[许伟]]></author>
</item>
<item>
<title><![CDATA[EFFECTS OF SHIELDING ON HELCAL COILGUN INDUCTANCE GRADIENT]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201212240000001]]></link>
<description><![CDATA[The inductance gradient is the most important parameter for coilgun design. In present article, by establishing a two-dimensional finite element model, effects of four shield materials with different dimensions and distance between coils and shield on inductance gradient were investigated. The coil’s current distribution and magnetic field distribution under different shields were presented. Analysis shows that the inductance gradient is affected both by material conductivity and permeability. The conductivity determines the induced eddy current in the shield. The permeability determines the degree of strengthening the main magnetic field. Reducing the distance between driving-coils and shield, the magnetic materials enhance the magnetic flux better, but more eddy currents are induced in the shield conductor. Increasing the thickness of the shield, the magnetic materials enhance the magnetic flux better, but more eddy currents are induced in the conductive materials due to the decreasing resistance. In order to achieve the maximum inductance gradient, high permeability silicon steel sheets can be used as the shield, the distance between coils and shield should be reduced, and the thickness of silicon steel sheets should be as small as possible to reduce eddy current effects.]]></description>
<pubDate>2013/7/4 9:07:09</pubDate>
<category><![CDATA[物理学]]></category>
<author><![CDATA[蒋雅琴,刘振祥,欧阳建明,沈志,杨栋,杨丽佳]]></author>
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<title><![CDATA[An Authentication Scheme Based on Fair Equality-Determination Protocol in Cloud Computing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201212120000001]]></link>
<description><![CDATA[Mutual authentication between the user and the cloud is essential requirement for the user to access the public cloud in cloud computing. In order to solve the problems of password-based identity authentication scheme in cloud computing environment and improve the efficiency of authentication in environments of mass users, a fair equality-determination protocol is presented by developing an equality-determination protocol of constant complexity. This protocol can compare the passwords between the user and the cloud fairly and secretly. Based on the protocol, a two-party privacy-protected identity authentication scheme based on semantically secure algorithm—Bresson algorithm is further presented. Finally, the correctness of the scheme is proved and the security of it is analyzed.]]></description>
<pubDate>2013/7/4 9:06:36</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[刘婷婷,王文彬]]></author>
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<title><![CDATA[Research on Tabletop Collaboration Method Using Territoriality-based Pattern]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201212110000001]]></link>
<description><![CDATA[Territoriality-based collaboration is one of the ways to realize situation awareness in tabletop collaboration. This paper first proposed the implementation pattern of territoriality-based collaboration, and three territorialities i.e. storage territory, private territory, public territory, were described. The realization mechanism of territoriality-based collaboration was given afterwards, including multi-touch points management, display management and conflict processing mechanism. Finally, situation awareness platform using territoriality-based collaboration was implemented, whose performance was verified through user testing experiments.]]></description>
<pubDate>2013/7/4 9:06:02</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[燕厚仪,]]></author>
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<title><![CDATA[A Robust Goalmouth Detection Method in Field-Ball Game Video]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201211280000002]]></link>
<description><![CDATA[Recently, goalmouth detection has become the basis of highlight summarization and a hot topic in high-level semantic concept detection, as the appearance of goalmouth indicates a high likelihood of exciting action in field-ball game video. In addition, machine learning for object detection is a promising research frontier. In this paper, a robust method is proposed to detect the presence of goalmouth frame in field-ball game video based on fuzzy decision trees. Balance process is added in training procedure. The experimental results show that our algorithm (F-measure>95%) can improve the classification performance when comparing with the threshold based algorithm and the decision tree based algorithm. Fuzzy rules can also be easily deduced from the constructed tree to interpret the classification model.]]></description>
<pubDate>2013/7/4 9:04:28</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[廖东升,郑彬]]></author>
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<title><![CDATA[Research on the method for orbit determination of single satellite observation based on constringent estimation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201209270000002]]></link>
<description><![CDATA[Feasibility of Space based Tracking Telemetry and Command System (TT C) based on single satellite is analyzed. A new orbit determination method based on constringent estimation is proposed according to the mode of single satellite observation. In the process of the orbit determination, the law matrix is availably transformed by the constringent estimation to restrain error of singularity cased by law matrix. It is proved that the precision of constringent estimation is higher than traditional method on the given conditions. Then the error transmitting coefficient (ETC) of observation was researched on, on the base of ETC and constringent estimation, the algorithm of orbit determination is put forward. Finally the validity of the new method is proved with simulation experiments.]]></description>
<pubDate>2013/7/4 9:03:32</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[王炯琦,刘靖]]></author>
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<title><![CDATA[The scale adaptive feature compressed tracking]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201212260000001]]></link>
<description><![CDATA[In order to track target accurately during a long term in complicated environment, an adaptive scale feature compressed tracking algorithm is presented in the paper. A number of  scanning windows with different scales and positions are obtained by construction constraint sampling. To reduce the feature dimension and improve processing speed, the sparse random perceived matrices of different scales which can be easily computed offline are adopted to extract the features of different sampling image patches with relevant scales online.The sampling patch having a maximal classification score is regarded as the new tracking result by classifying the compressing feature via a naive bayes classifier and updating the parameters through online learning,which realize the adaptive update of tracking location and scales. Experimental results show that the algorithm can adapt the basic attitude and scale change, which is robust and does not depend on the scale selection of the initial tracking area .]]></description>
<pubDate>2013/7/4 9:01:44</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[韩建涛,李飚,王鲁平,张路平]]></author>
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<title><![CDATA[A Novel Generation Method of 2-D ISAR Group Targets Based on Intermittent-Sampling Repeater Jamming (ISRJ)]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201212060000001]]></link>
<description><![CDATA[Based on Intermittent-Sampling Repeater Jamming (ISRJ), a novel generation method of 2-D ISAR group targets is presented. In this method, escort free-flight jammer is used to intermittently sample and repeater target echo, which can generate vivid 2-D group targets in ISAR. By adjusting jammer and target’s relative space position, 2-D group targets are able to simulate target’s attitude angle dynamically. After the theory of ISRJ is expounded, the principle of escort free-flight jamming is introduced. Meanwhile, a theoretical study is carried out to determine the requirement for jammer’s power and position. Then, the theoretical reason of 2-D group targets is emphatically analyzed. Moreover, The key factor of false targets distribution and attitude angle is explored. At last, the simulation demonstrates that the above method is effective. The results obtained from this research would help to provide better guidance for the design and engineering application of ISAR jammer.]]></description>
<pubDate>2013/7/4 8:59:06</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[冯德军,王雪松,徐乐涛,张文明]]></author>
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<title><![CDATA[Laminar combustion model of pulverized magnesium particle cloud in powdered fuel ramjet]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201211230000001]]></link>
<description><![CDATA[The combustion process of pulverized magnesium particle cloud in powdered fuel ramjet preburner has been studied. A one-dimension premixed laminar combustion model of pulverized magnesium particle cloud was established. The studies show that the laminar flame propagation of pulverized magnesium particle cloud is very stable, and the flame structure is almost invariable in the combustion process; the combustion zone thickness is very thin and the preheat zone thickness is about 2-3 times as much as the former. It is the direct cause of flame and the key of flame propagation that the magnesium particles vaporization and the homogeneous reaction of magnesium vapor and oxygen in particle cloud; the preheat zone gas temperature rising depends mainly on the thermal conductivity of the combustion zone and the reaction heat of magnesium vapor which diffuse from combustion zone and oxygen while the preheat zone particle temperature rising depends on the convective heat transfer from gas phase to particle phase mostly. The effects of the interior parameters on the combustion of the magnesium particle cloud were analyzed. The effect of particle relative concentration on combustion of particle cloud is complex. When the particle relative concentration is low, increasing particle relative concentration is helpful for speeding up the particle cloud combustion process; when the particle relative concentration is high, increasing particle relative concentration is adverse to speeding up the particle cloud combustion process. With the increase of the particle size, the flame propagation speed is reduced, the flame temperature increases, the thickness of preheat zone increases. With the increase of the initial temperature of particle cloud, flame propagation speed and flame temperature are linear growth, preheat zone thickness is parabolic growth. The tendencies obtained by numerical simulation coincides well with that of the experimental results from the literature.]]></description>
<pubDate>2013/7/1 8:05:31</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[胡建新,夏智勋,杨晋朝]]></author>
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<title><![CDATA[The Simulation on The Delay Jitter of SpaceWire]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201304220000002]]></link>
<description><![CDATA[SpaceWire is the new space bus standard proposed by ESA, which has been successfully applied in many projects. Delay jitter is the key parameter to reflect the network transmission performance, which measures the difference between the maximum transmission delay and the minimum transmission delay from end to end. Through theoretical calculations and modeling simulations, this essay carried out quantitative analysis and research for the delay jitter of the SpaceWire under specific application scenarios. Theoretical calculations get the delay jitter under particular scenarios by theoretical derivation. Modeling simulations, on the other hand, established simulation model by Opnet, and obtained the maximum transmission delay and minimum transmission delay by simulation. In this way, it is possible to calculate the delay jitter, qualitatively and quantitatively. By comparison, we obtain the parameters which have key impact on delay jitter. Recommendations and methods to improve the delay jitter are given by analyzing the conclusions. The research results of this article can provide a reference for the SpaceWire design to build a low delay jitter SpaceWire network.]]></description>
<pubDate>2013/6/29 8:20:20</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈晓敏,侯剑儒]]></author>
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<title><![CDATA[GNSS emergency positioning method and research on the accuracy estimation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301280000002]]></link>
<description><![CDATA[Abstract: Under the harsh environment in which the number of visual satellite is fewer than four and traditional navigation solution cannot be completed, navigation receiver could enter the emergency auxiliary positioning mode by equipping the user with external elevation barometer providing for elevation information, or with internal punctuality module providing for clock bias. The traditional navigation and positioning error propagation model cannot be applied to analyze the error in this emergency assisted positioning mode. To solve this problem, this paper focus on the basis of several emergency auxiliary positioning principles, such as three satellites combined with the elevation, three satellites combined with clock bias, two satellites combined with elevation and clock bias, and gives a new error propagation analysis model of emergency auxiliary positioning, verifying the correctness of the model by simulation example. Finally, through the positioning accuracy analysis, concluding that the present method could quantify the optimal magnitude relations between pseudorange measurements and the accuracy of the auxiliary information in accordance with the satellite distribution characteristics, whose positioning accuracy improvement can be realized with minimum cost. This conclusion can guide the choice of external auxiliary devices for navigation receiver.]]></description>
<pubDate>2013/5/27 4:23:22</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[刘文祥,王飞雪,吴鹏]]></author>
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<title><![CDATA[Fluid-solid coupled heat transfer and flow simulation of platelet heat exchanger in thermal thruster]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301110000001]]></link>
<description><![CDATA[Thermal propulsion system includes solar thermal propulsion and nuclear thermal propulsion, and it is a significant issue to improve the heat transfer efficiency of the thermal thruster.  Based on fluid-solid coupled heat transfer, the paper utilized the platelet heat transfer characteristic to simulate the heat transfer and flow field of the platelet passage. A coupled system includes the coupled flow and heat transfer between fluid and solid parts,besides coupled heat transfer among solid parts．Simulation result shows that the fluid-solid coupled method can solve the steady heat transfer in the platelet structure, and the propellant can be heated to the design temperature of 2300K for the thermal propulsion system.]]></description>
<pubDate>2013/5/26 10:53:05</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[程谋森,黄敏超,刘昆,邢宝玉]]></author>
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<title><![CDATA[A new method of moving target detection and parameter estimation for spaceborne HRWS SAR]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201211070000001]]></link>
<description><![CDATA[In this paper, a ground moving target indication (GMTI) method for spaceborne high resolution wide swath (HRWS) synthetic aperture radar (SAR) systems is presented. First, the space time adaptive processing is adopted for clutter suppression followed by the traditional SAR imaging yielding the ambiguous images. Then all the moving targets including the real one and ghost ones are detected by the CFAR technique, and the real one is distinguished from all the imaging targets based on the space relationship of the ambiguous images. Finally, the moving velocity is obtained according to the azimuth position shift which can be deduced from the range history of the moving target. The advantages of the method are its low computational burden and high accuracy. The spaceborne simulation data confirms its validity.]]></description>
<pubDate>2013/5/24 5:14:33</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[吴明宇]]></author>
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<title><![CDATA[Research of Re-radiating Spoofing Technique to GNSS Timing Receiver]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201301280000001]]></link>
<description><![CDATA[To supply accurate stand time signal, timing receivers are used to acquire high performance time by processing satellite navigation signals. A re-radiating spoofing technique is proposed in this paper, which conducts the target receiver’s timing uncertainty by controlling the signal delays and positioning antenna precisely. Once the timing receiver is controlled by the spoofing signals, the host system could be collapsed. Simulation results validate the effectiveness of the proposed spoofing technique.]]></description>
<pubDate>2013/5/24 4:59:39</pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[龚航①,黄龙①,王飞雪①,朱祥维①]]></author>
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<title><![CDATA[A Method of Specific Image Scene Detection based on Local Invariant Features]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305220000007]]></link>
<description><![CDATA[Automatic image scene detection is very important to image annotation and semantic retrieval. In this paper, according to the requirement of application, eight specific image scenes such as meeting, mass, beach, etc. are focused on. First, to extract the local features of images, local key points are detected and reduced, and then SIFT feature descriptors are calculated. Second, a multi-classifier based on support vector machine is constructed and features for training are selected to achieve relatively accurate detection results. The experiments are designed to mainly focus on two problems, namely the decision of kernel function of classifier and the strategy of feature selection. Experimental results show that the method can achieve relatively accurate and robust results by using radial basis kernel function to construct classifier and the feature extraction strategy of selecting the top n key points by the scale size order. This method is simple and fast, and can not only satisfy the actual requirements of application, but also promise the relatively high precision.]]></description>
<pubDate>2013/5/22 4:46:37</pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[陈丹雯,栾悉道,谢毓湘,张芯]]></author>
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<title><![CDATA[Study of Control Momentum Gyroscopes Assisting Maneuver]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201211280000001]]></link>
<description><![CDATA[A new large-angle space station attitude maneuver technique concept: Control Momentum Gyroscopes Assisting Maneuver (CMGs AM) technique is proposed, which employs both the Control Moment Gyroscopes (CMGs) and the thruster Reaction Control System (RCS) as the actuator. The fuel-optimal control problem of CMGs AM is formulated, using a two-step solving strategy which utilizes an improved pseudo spectral knotting method, the fuel-optimal solution is obtained, the results are compared to the fuel-optimal solution and constant-rate eigenaxis maneuver of thrust maneuver technique. It is shown that the CMGs AM technique inherits and further enhances the advantages of thruster maneuver and Zero Propellant Maneuver (ZPM) techniques. It significantly saves fuel compared as the thrust maneuver and shortens the maneuver time greatly with greater robustness compared to ZPM.]]></description>
<pubDate>2013/4/15 2:10:43</pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[黄海兵,唐国金,章胜,赵乾]]></author>
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<title><![CDATA[Improve the radiation efficiency of bow-tie antenna by exploiting the energy in end reflections]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201211270000002]]></link>
<description><![CDATA[The bow-tie antenna, which is widely used in impulse ground penetrating radar (GPR), has very low radiating efficiency. It is because that, nearly 70% of the radiated energy exists as the form of end reflection, which is harmful to probe objects. In order to keep the probing ability, the remarkable energy in end reflections is usually dissipated by resistive loading. We find that, in this paper, if the exciting pulse is bipolar and monocycle, the radiation efficiency can be significantly improved by utilizing the energy in end reflection. And the improvement can be implemented by optimizing the antenna length. The simulated results show that, the radiation efficiency can be increased nearly 100%. And the measured results validate the proposed method again. Additionally, the proposed method is easy to be carried out in applications and of great use.]]></description>
<pubDate></pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[黄春琳,李禹,陆珉,粟毅,王建]]></author>
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<title><![CDATA[Clustering Cadet Recruiting Plans based on Labeled Trees]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303060000001]]></link>
<description><![CDATA[Cadets recruiting plan is a kind of important rule to prescribe source and quantity of officer. It is significant for construction and development of officer. With accumulation of recruiting plans, it is meaningful to analyze and evaluate the plans. This paper utilized clustering technic to analyze recruiting plans, which will provide a quantitive approach to analyze fluctuation of plans and to understand and evaluate closeness of plans with policies. Firstly, the paper summarized characteristics of recruiting plans. And then it proposed a solution which utilized labeled tree to represent recruiting plan and extracted representative subtrees to participate in clustering. Finally, it uses co-occurrence idea to form clustering cores then classify the plans to finish the clustering process. Experimental results reveal that the method can provide better clustering results and be efficient.]]></description>
<pubDate></pubDate>
<category><![CDATA[管理科学与工程]]></category>
<author><![CDATA[钱高祥,张翀,张维明]]></author>
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<title><![CDATA[An efficient and balanced load allocation model based on non-uniform balls-into-bins]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201209200000002]]></link>
<description><![CDATA[In balanced load allocation problem in complex systems like large-scale data center and P2P overlay network, the various load allocation methods have been proposed. But in order to achieve better balanced load index, many methods are in pursuit of more and more complicated algorithms. Which make the time and algorithm complexity hard to control. Based on the study of the original balls-into-bins model, Azar balls-into-bins model and balls into non-uniform bins model, the paper brings forward an efficient and balanced non-uniform balls-into-bins load allocation model, which is provided with heterogeneous balls, heterogeneous bins and different bin selection probabilities. The model can achieve rational largest load with high probabilities, in a little time and algorithm complexity cost.  The model is extensible and can be applied in lots of domains.]]></description>
<pubDate></pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[皇甫先鹏,罗雪山]]></author>
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<title><![CDATA[Structural Recognition of Sketched Irregular Military Marking Symbols]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201209270000001]]></link>
<description><![CDATA[Sketch-based military marking diagrams consist of many linear and regional symbols. Typically, these symbols are irregularly shaped because they are drawn according to specific terrain or battle scenario with freehand. Therefore, they are also called irregular symbols. Traditional appearance-based methods are not appropriate for recognizing these symbols. A structural recognition method for sketched irregular military marking symbols was proposed. Symbols were decomposed and represented by 9 types of primitives together with 4 types of spatial relationships among them. By matching the primitive counting vector and the primitive relationship matrix of the unknown symbol with those of the templates, the class label could be recognized, and their primitive correspondences could also be estimated. Experimental results demonstrate that the proposed method is effective and efficient for recognizing sketched irregular military marking symbols.]]></description>
<pubDate></pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[邓维,宋汉辰,吴玲达,张友根]]></author>
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<title><![CDATA[Effects of Ionospheric irregularities on spaceborne P band SAR Imaging]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201211200000001]]></link>
<description><![CDATA[Spaceborne SAR imaging at lower Frequencies such as P/UHF/VHF band are severely affected by ionospheric irregularities induced signal scintillation  . Mutual coherence function of signals penetrating through the ionosphere is deduced. Electron density in the ionosphere is modeled by Rino's power density function. Patterns are studied that how spaceborne P band SAR image performances varies with parameters of ionospheric irregularities. Study shows that irregularities in ionospheric will defocusing the image, and causing considerable gain loss of the imaging. Increases in irregularity strength parameter CkL, outer scale Lo, and index of the power density function will further degrade the image. The study is validated by numerical simulation based on phase screen technic.]]></description>
<pubDate></pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[董臻,李力,梁甸农,张永胜]]></author>
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<title><![CDATA[Multifractal Cross-Correlation Analysis of Sea Clutter and Target Detection Based on Q-MMSPF]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201209280000001]]></link>
<description><![CDATA[A novel method, that is Qth order Mixed Moment Structure Partition Function (Q-MMSPF) method, is proposed in this paper for the detection of long-range cross-correlations and multifractality. With this method, the multifractal cross-correlation characteristic of sea clutters is investigated. The analysis, based on the real sea clutter data, shows that the cross-correlation multifractality is quite weaker between the two sea clutter series, and the multifractality is significant between two time series of target plus sea clutter. Whereas the multifractality would be in the middle for the case which is between target time series and sea clutter time ones. Consequently, an approach is suggested to detect the targets in sea clutter. The test results show that the target could be clearly distinguished from the sea clutter background with the proposed feature-based method.]]></description>
<pubDate></pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[金钢,孙康,孙理,朱晓华]]></author>
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<title><![CDATA[Synthetic Evaluation for Power Quality Based on Improved Combination Weighting Radar Chart]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201209210000002]]></link>
<description><![CDATA[Improved combination weighting radar chart method is provided and applied in synthetic evaluation of power quality. The optimization model is established based on minimizing the deviation between the vectors of evaluation weights before and after the combination weighting. In the improved method, the sector area is ranked and the angle of the sector area is distributed by the weighting. Moreover, the diagonal of sector area is employed by using the radar chart as index axes. The unattached weighting of every index is not only reflected by the whole hog, but also the interactant is incarnated. Synthetic evaluation of power quality is completed by the area and girth of the radar chart. Verification results show that the reliability and validity of the method.]]></description>
<pubDate></pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[李  辉,欧阳华,乔鹏程,吴正国]]></author>
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<title><![CDATA[The Spatiotemporal Model and Driving Pattern in Military Mission Rehearsals]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201209280000002]]></link>
<description><![CDATA[Aiming at the rehearsal demand in military information system, an efficient and integrated mission rehearsal method based on Spatiotemporal Event Series (SES) is proposed. First the mission expression based on hiberarchy decompounding and materialization strategy by capability are put forward, and then a mission-oriented data application model is advanced for data customization which minimize the integrative spatiotemporal dataset according to the least demand of battle mission, after that the event definition model of SES and its data driving pattern are illustrated; finally the application method is discussed with specific emulation example. The experimental prototype system proves their validity and feasibility.]]></description>
<pubDate></pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[孔龙星,李 欢,马伯宁]]></author>
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<item>
<title><![CDATA[An Improved Collision Avoidance Behavior of Multiple Agents]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201210090000002]]></link>
<description><![CDATA[An improved collision avoidance behavior of multi-agents was presented due to the fact that the existing methods lack reality and universality. By introducing the role parameter and personality parameter, the agents adjust their collision avoidance behaviors based on these parameters. The improved method constructs a link between collision avoidance behaviors and the attributes of real humans. In this way, the consistency and smoothness of humans’ motion is retained. So it fits real humans’ collision avoidance behavior more tightly. Also it is more hominine and universal than existing methods. Simulation tests show that the improved collision avoidance behavior accords with the characteristics of the real people. So it can be used in virtual crowd simulation, multi-robot system and multi-agent system more efficiently.]]></description>
<pubDate></pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[李猛,李石磊,梁加红]]></author>
</item>
<item>
<title><![CDATA[Repeat jamming against LFM radars based on pulse separation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201210260000001]]></link>
<description><![CDATA[The time delay of output signal is sensitive to the frequency of input signal in LFM pulse compression radars. In light of this, a novel repeat jamming is presented based on pulse separation in which the separated pulses are retransmitted in a rearranged order. After the matched filtering, a set of false targets are induced. The jamming technique is detailedly explained with group delay theory. Formulas of separation number on condition that false targets hold amplitude dominance and retransmitted order with the maximum number of false targets are presented. The theoretical analysis is verified by simulation results.]]></description>
<pubDate></pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[潘小义]]></author>
</item>
<item>
<title><![CDATA[A Parallel Region Matching Algorithm for Large Scale HLA Simulation]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305220000008]]></link>
<description><![CDATA[In HLA simulation, data distribution management (DDM) service provides data filtering capability, it can effectively reduce the transmission and reception of redundant data. During the advancing of large-scale HLA simulation system, much region matching calculation is needed. However, in most of the existing regional matching algorithms, all regions are calculated in every matching calculation process, which resulting in a waste of computing resources. Meanwhile, the current matching algorithms are mostly based on serial region matching, and the advantage of multi-core cannot be fully taken. Aiming at the limitation of existing algorithms, a parallel region matching algorithm for large-scale HLA simulation is proposed. By this algorithm, the matching process of multiple regions which changed in the same simulation advancing can be calculated in parallel, the advantage of parallel computing environment can be taken. During the process of matching calculation, a method which based on intersecting information is used. By the history of moving regions, matching calculation only happened within a limited range, and the redundant calculation can be avoided. Theoretical analysis and experimental results showed that the algorithm is particularly suitable for large-scale distributed simulation applications which executing on multi-core computing platform.]]></description>
<pubDate></pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[梁洪波,刘步权,慕晓冬,杨勇,姚益平]]></author>
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<title><![CDATA[On-line news event detection based on TF.IEF model]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303200000002]]></link>
<description><![CDATA[We propose a new online news event detection (ONED) method which is based on TF?IEF model to improve the performance of detection. This method is motivated by TF?IDF, and calculates the weight of terms directly which present the event to establish a new incremental event model. There are two stages involved in our method. In the first stage, similar reports collected in a certain period are clustered into micro-clusters by Single-Pass. In the second stage, the micro-clusters are matched with existing events, and then the event model is updated by recalculating the VSM of event. Experiment shows that the proposed method improves the efficiency and accuracy of ONED with lower complexity and less feature information loss.]]></description>
<pubDate></pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[李国辉,,]]></author>
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<title><![CDATA[Discriminative and Collaborative Representation for visual classification based on Compressive sensing]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201211070000002]]></link>
<description><![CDATA[In this paper, we proposed a low computation complexity, yet very efficient representation of image for visual classification tasks. We combine the collaborative representation with discriminative ingredient together in a unified framework, which is an extended version of collaborative representation based classification. The coefficients of collaborative representation of test samples are sparsely and robust to occlusion or other disguises based on redundant and over-complete dictionary. Besides, the discriminative information is exploited by minimizing the within-class scatter and maximizing the between-class scatter, which is very helpful for visual classification tasks. Experimental results on some widely used benchmark datasets indicate that the proposed method could achieve competitive performance with other existing works.]]></description>
<pubDate></pubDate>
<category><![CDATA[计算机科学与技术]]></category>
<author><![CDATA[王正志,,袁兴生]]></author>
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<title><![CDATA[Transient Temperature Field Simulation Analysis of Spiral Bevel Gear Transmission System by Simulink in the Condition of Loss of Lubrication]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201211150000001]]></link>
<description><![CDATA[According to heat transfer theory and thermal network method, taking the spiral bevel gear transmission system of a helicopter tail reducer as research object, the calculation model of the temperature field Simulink simulation was established. Based on the model, the steady-state temperature field of the transmission system was calculated in the normal lubrication, and with it as the initial condition the transient temperature field of the transmission system was calculated and analyzed in the condition of loss of lubrication. It provides the theoretical foundation of predicting the survivability of the gear transmission system in the condition of loss of lubrication.]]></description>
<pubDate></pubDate>
<category><![CDATA[机械工程]]></category>
<author><![CDATA[林泽锦,,]]></author>
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<title><![CDATA[On-line calibration and compensation of heading-sensitive error for triad constant-rate biased RLG system]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201211190000001]]></link>
<description><![CDATA[Based on a triad constant-rate biased RLG system, a mathematic model of the heading-sensitive error induced by calibration parameter variation errors in stationary initial alignment was set up. To tackle the problem that calibration parameters cannot be determined separately, installation misalignments are treated as a whole under field test conditions, and then the heading-sensitive error coefficient can be calibrated on-line using least square algorithm without external references. Utilizing the postulate system, field tests are done to estimate on-line compensation accuracy of the heading-sensitive error coefficient by the on-line calibration method. The results of the experiments show that the on-line calibration and compensation method can eliminate the heading-sensitive error evidently and improve yaw angle estimation precision in the initial alignment.]]></description>
<pubDate></pubDate>
<category><![CDATA[控制科学与工程]]></category>
<author><![CDATA[于化鹏]]></author>
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<title><![CDATA[Estimation Method of BDS On-Board Clock Short-Term Stability Combining Satellite Two-Way with One-Way Carrier Ranging]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201302050000001]]></link>
<description><![CDATA[Usual estimation method of satellite on-board clock short-term stability demands continuous observation of large ground monitoring network and complex algorithm, which is not suitable for single station observation. In this paper, based on analysis of short-term frequency stability estimation method of satellite on-board clock using observation from one single station, a simpler method combining satellite two-way carrier ranging with GNSS one-way carrier phase observation is proposed. This method is based on GNSS carrier phase observation eliminating geometric distance between satellite and receiver, which is determined by satellite two-way carrier ranging. Performance of this method is evaluated using BDS data. The estimation result of this method agrees well with result of complex algorithm, and is very close to smoothed broadcast ephemeris method (SBE method) for average time of 1~1000 seconds with relative error less than 10%, but better than SBE method for average time above 1000 seconds.]]></description>
<pubDate></pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[刘虎,,,]]></author>
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<title><![CDATA[The Edge Point Registration Method of SAR Images Based on the Joint Similarity]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201210290000001]]></link>
<description><![CDATA[An edge point matching method of SAR image based on the joint similarity is presented. First, the matching similarity criterion and the joint similarity ——SSJF(Square Summation Joint Feature) are constructed based on the grad and direction of each edge point in images. Next, a modified ROEWA edge detector is proposed to get the edge intensity and edge direction with the eight directional templates. Then, parameters of the transform model between the matching SAR images are calculated with the modified GA which is used to obtain the global optimum solution of the similarity. Finally, the performance of the method is validated with SAR image registration experiments.]]></description>
<pubDate></pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[陈天泽,李燕]]></author>
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<title><![CDATA[Analysis of a Dielectric-Covered SIW Longitudinal Slot]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201210130000001]]></link>
<description><![CDATA[A dielectric cover is usually needed in waveguide slot arrays for protection or thermal insulation purposes, and furthermore improves the antenna performance with a proper choice of the cover parameters. In this paper, the properties of a SIW longitudinal slot with a dielectric cover are extensively investigated using equivalent relationship between SIW and conventional waveguide together with Method of Moment, as a first step to the design of a SIW slot array and its integrated radome. The accuracy and efficiency of our method has been assessed against Ansoft HFSS. The computational time is significantly reduced by a one-order magnitude with acceptable computational accuracy. Finally, effects of the dielectric-cover are extensively investigated through three typical cover configurations and some instructional conclusions are drawn, which find further application for the optimization design of the dielectric covers to improve the antenna performances.]]></description>
<pubDate></pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[Giorgio Montisci,金祖升,卢俊麒,毛钧杰,杨 虎]]></author>
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<title><![CDATA[Single-channel Spectrum Sensing Technique Based on Sub-Nyquist Sampling]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201210260000002]]></link>
<description><![CDATA[Spectrum sensing technique for wideband analog signals has been applied widely in cognitive radio. This paper is based on the idea of time-division. Firstly, sampling time is divided into time slices which have fixed length. Secondly, the signal is multiplied by a bank of periodic waveforms which are modulated by pseudorandom number generators, and the product is low-pass filtered and sampled at sub-Nyquist rate. Finally, the samples are used to evaluate frequency support. Compared with the multi-channel structure, this paper’s single-channel structure is much simpler and has the ability to spectrum sensing with low-rate samples. Numerical simulations show that, this algorithm can effectively use samples sampling at sub-Nyquist rate to finish the task of spectrum sensing in scenarios that the spectral support is unknown in advance.]]></description>
<pubDate></pubDate>
<category><![CDATA[电子科学与技术]]></category>
<author><![CDATA[樊昀,黄知涛,姜文利,柳征,杨鹏]]></author>
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<title><![CDATA[Minimum Mean Square Error Bound for State Estimation of Maneuvering Targets]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201303080000001]]></link>
<description><![CDATA[Several adaptive filtering algorithms based on the polynomial model are widely used in the field of maneuvering target tracking, but there is no uniform evaluation criterion to measure the quality of these tracking algorithms. Due to the existence of time-varying unknown inputs, the maneuvering target state estimation is actually biased. The minimum mean square error bound calculation method for polynomial model Kalman filters is derived based on the minimum mean square error criterion, and the process noise variance law minimizing the state estimation mean square error is obtained. The proposed algorithm provides a unified evaluation standard for maneuvering target tracking algorithms based on the polynomial model, and also provides the basis for the setting of the actual process noise variance in maneuvering target tracking. The effectiveness of the proposed algorithm is demonstrated by the simulation results.]]></description>
<pubDate></pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[薄涛,,]]></author>
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<title><![CDATA[Research on non-linearity compensation of air-modulated speaker based on the nonlinear filtered-x PEM algorithm]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201305130000002]]></link>
<description><![CDATA[Aimed at the harmonic distortion problem in the air-modulated speaker (AMS), the AMS behavioral model was represented by a Hammerstein structure, and the research on predistortion of AMS based on this model was made. As the DC offset exists in the nonlinearity of the Hammerstein model, a predistortion algorithm considering the DC offset compensation was developed. The validity of the algorithm and the necessity of the DC offset compensation were verified by computer simulation. In the experiment, a single sinusoidal excitation signal was first used to identify the Hammerstein model. Then, using the identified system parameters, the NFxPEM algorithm was perform to obtain the parameters of Wiener predistorter and predistort the excitation signal. From the experiment results, it is found that our approach is effective in reducing the harmonic power with a relatively small upgrade in the fundamental frequency power.]]></description>
<pubDate></pubDate>
<category><![CDATA[光学工程]]></category>
<author><![CDATA[龚昌超,孙海洋,田章福,曾新吾,周泽民]]></author>
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<title><![CDATA[Multimodal Image Registration based on Orientation-Moment]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201405060000002]]></link>
<description><![CDATA[Multimodal image registration between visible, infrared and SAR images is the key technology to all-weather high-precision navigation and guidance. Based on an invariant feature designed at the pixel level, the orientation-moment, which describes the similarity of a pixel with its neighbors in different orientation, a multimodal image registration algorithm, that matches multisensor images by analyzing such similarities, is proposed. In matching tests, including visible, infrared and SAR images, it has reached a success rate of more than 90%. Comparing with traditional multimodal image registration algorithms, this method greatly improved the success rate, and had broad application prospects in navigation and guidance.]]></description>
<pubDate></pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李想,尚洋,于起峰,朱遵尚]]></author>
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<title><![CDATA[Ignition Algorithm for Kinetic Interceptor Attitude Control Using Solid-Propellant Nozzles]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201405270000003]]></link>
<description><![CDATA[Using solid-propellant nozzles is one of the best schemes for attitude control with a fast response and high precision. A mixed searching algorithm for ignition combination is presented for a novel configuration of attitude control solid-propellant nozzles on the kinetic interceptor. Firstly, the configuration of solid-propellant nozzles is described, and spin requirements of the kinetic interceptor is analyzed. Then the mixed searching algorithm is designed by a combination of sorting method and region search method. Sorting method is selected when the number of nozzles available is small and region search method is chosen on the contrary. Finally, Simulations using the algorithm for torque approximation and application in attitude control are conducted. Simulation results suggest that the algorithm can track the reference torque effectively and achieve attitude tracking quickly and with a high precision.]]></description>
<pubDate></pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[李广华,汤国建,张洪波]]></author>
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<title><![CDATA[Simulation Research on Natural Convection Characteristics inside Near Space Airship]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201504140000003]]></link>
<description><![CDATA[Aiming at the near space airship, the natural convection characteristics of the helium inside an airship are simulated numerically. First, based on the computational fluid dynamics method and User-Defined function, external temperature boundary condition is led into the wall grids for the simulation. Then, under conditions of different steady states, the motion characteristics and influence regulation of natural convection inside the airship are analyzed by the characteristic parameters of flow field such as distribution of pressure, temperature, speed. Besides, the process of an unstable state is also studied preliminarily. The simulation results show that under environment of the near space, natural convection inside an airship has some active influence on heat exchange for helium; but the influence is very weak on stress of skin and structural safety.]]></description>
<pubDate></pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[张俊韬]]></author>
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<title><![CDATA[Hardware Reinforcement Designs and Reliability Analyses of UAV Autopilots]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201411100000001]]></link>
<description><![CDATA[The autopilot is the crucial device of an UAV to implement autonomous flights and missions. Most of the existing commercial autopilots have no hardware reinforcement, which will lead to a risk in carrying out some significant tasks. The control resolver is analyzed as the module which performs the greatest impact on the security and the reliability in the composing of an autopilot. With the increasing fault-tolerance requirements, 4 reinforcements are respectively designed, namely, the single resolver reset reinforcement, the dual resolver hot backup reinforcement, and the dual host systems switched by hardware and software. Several simple devices such as reset chips, counters, inverters and selectors, and additional codes inside the resolvers are used to build the reinforcements. The reliabilities varying with time of the reinforcements are emphatically studied. With the simulation of the working mechanisms, the fault-tolerance performances such as the abnormal output durations of the reinforcements in fault treatments are analyzed. The calculations show that all the reinforcements can obviously enhance the reliability of the autopilot, of which the dual host systems increase the most. This research provides a meaningful direction to the tradeoff of the fault-tolerance performance, complexity, and cost in high reliability autopilot designs.]]></description>
<pubDate></pubDate>
<category><![CDATA[航天工程]]></category>
<author><![CDATA[郭天豪,侯中喜,姜汉卿,姜晶菲]]></author>
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<title><![CDATA[The comparison and analysis of the imaging properties between circular SAR and linear SAR]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/201411190000001]]></link>
<description><![CDATA[with its intrinsic characteristics, circular synthetic aperture radar has lately become of particular interest to the radar community. The difference of imaging processing between the circular synthetic aperture radar and linear trajectory synthetic aperture radar are compared and analyzed in this paper. Specifically, the detailed comparisons contain the size of the observed area, the point spread function, and the properties of spectrum are carried out. It is learnt that the difficulty of the imaging processing of single-pass circular synthetic aperture radar lies on its space dependence. To overcome this difficulty, the plane circular synthetic aperture radar and multi-baseline circular synthetic aperture radar imaging models are presented in this paper. Simulation test is carried out and the corresponding results prove the proposed analysis is valid.]]></description>
<pubDate></pubDate>
<category><![CDATA[信息与通信工程]]></category>
<author><![CDATA[常文革,贾高伟]]></author>
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