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<title cf:type="text"><![CDATA[Editorial department of the Journal of National University of Defense Technology -->航天工程·计算机科学与技术]]></title>
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<title xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="text"><![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/202401001]]></link>
<description xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="html"><![CDATA[In order to enable high-precision accurate schemes to robustly capture shock waves and quickly obtain high fidelity simulation results of the flow field in supersonic inviscid compressible flow calculations, which usually contains complex structures such as discontinuities and small-scale vortices, a smoothness measurement algorithms based on combinations of sub-stencil derivatives 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(weighted compact nonlinear scheme) 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>2024/1/28 0:00:00</pubDate>
<category><![CDATA[航天工程·计算机科学与技术]]></category>
<author><![CDATA[ZHANG Hao, DENG Xiaogang]]></author>
<atom:author xmlns:atom="http://www.w3.org/2005/Atom">
<atom:name>ZHANG Hao, DENG Xiaogang</atom:name>
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<guid><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401001]]></guid><cfi:id>9</cfi:id><cfi:read>true</cfi:read></item>
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<title xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="text"><![CDATA[Multimodal cross-decoupling for few-shot learning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401002]]></link>
<description xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="html"><![CDATA[Current multi-modal few-shot learning methods overlook the impact of inter-attribute differences on accurately recognizing sample categories. To address this problem, a multimodal cross-decoupling method was proposed 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 category discrimination. Extensive experiments on two benchmark few-shot datasets MIT-States and C-GQA with large attribute discrepancy indicates that the proposed method outperforms the existing approaches, which fully verifies its effectiveness, indicating that the multimodal cross-decoupling few-shot learning method can improve the classification performance of identifying few test samples.]]></description>
<pubDate>2024/1/28 0:00:00</pubDate>
<category><![CDATA[航天工程·计算机科学与技术]]></category>
<author><![CDATA[JI Zhong, WANG Sidi, YU Yunlong]]></author>
<atom:author xmlns:atom="http://www.w3.org/2005/Atom">
<atom:name>JI Zhong, WANG Sidi, YU Yunlong</atom:name>
</atom:author>
<guid><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401002]]></guid><cfi:id>8</cfi:id><cfi:read>true</cfi:read></item>
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<title xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="text"><![CDATA[Fast prediction algorithm of flight pipeline of reentry capsule]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401003]]></link>
<description xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="html"><![CDATA[To meet the computational requirements of safe airspace and the expected landing point in the recovery mission of the reentry capsule, a fast prediction algorithm of the flight pipeline based on the Koopman operator approach was proposed for the reentry capsule and the determination process for safe flight airspace of search and rescue helicopters was provided. The body-parachute dynamic model was constructed. A group of discrete state points was uniformly selected from the random 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 simulation results show that the fast prediction algorithm of the 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>2024/1/28 0:00:00</pubDate>
<category><![CDATA[航天工程·计算机科学与技术]]></category>
<author><![CDATA[ZOU Wen, ZHANG Guobin, FENG Zhiwei, TU Guoyong, LU Xiaofei, ZHANG Qingbin, YANG Tao]]></author>
<atom:author xmlns:atom="http://www.w3.org/2005/Atom">
<atom:name>ZOU Wen, ZHANG Guobin, FENG Zhiwei, TU Guoyong, LU Xiaofei, ZHANG Qingbin, YANG Tao</atom:name>
</atom:author>
<guid><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401003]]></guid><cfi:id>7</cfi:id><cfi:read>true</cfi:read></item>
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<title xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="text"><![CDATA[Joint optimization for heterogeneous multi-UAV configuration and mission planning within SEAD scenario]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401004]]></link>
<description xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="html"><![CDATA[SEAD(suppression of enemy air defenses) is a typical application scenario of multi-UAV cooperation. Based on the characteristics of this scenario, the number of different types of UAV was also used as a decision variable in the task planning problem, fully characterizing the various constraints of the target, mission, and UAV, and establishing a heterogeneous UAV formation path problem model. A two-layer joint optimization method was designed to solve the model:the upper layer was designed with the task connection impact indicator to accurately assess the quantitative requirements of various types of UAVs and guide UAVs configuration adjustments; the lower layer improved the genetic algorithm, which can efficiently handle multiple coupling constraints and can accurately adjust the mission plan in conjunction with UAV quantity changes. The two layers coordinate 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>2024/1/28 0:00:00</pubDate>
<category><![CDATA[航天工程·计算机科学与技术]]></category>
<author><![CDATA[WANG Jianfeng, JIA Gaowei, XIN Hongbo, GUO Zheng, HOU Zhongxi]]></author>
<atom:author xmlns:atom="http://www.w3.org/2005/Atom">
<atom:name>WANG Jianfeng, JIA Gaowei, XIN Hongbo, GUO Zheng, HOU Zhongxi</atom:name>
</atom:author>
<guid><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401004]]></guid><cfi:id>6</cfi:id><cfi:read>true</cfi:read></item>
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<title xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="text"><![CDATA[Influence of satellite differential code bias on BDS-3 dual-frequency precise point positioning]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401005]]></link>
<description xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="html"><![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 of 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>2024/1/28 0:00:00</pubDate>
<category><![CDATA[航天工程·计算机科学与技术]]></category>
<author><![CDATA[DU Yanjun, JIA Xiaolin, YAO Wanqiang, XU Jin]]></author>
<atom:author xmlns:atom="http://www.w3.org/2005/Atom">
<atom:name>DU Yanjun, JIA Xiaolin, YAO Wanqiang, XU Jin</atom:name>
</atom:author>
<guid><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401005]]></guid><cfi:id>5</cfi:id><cfi:read>true</cfi:read></item>
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<title xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="text"><![CDATA[Numerical dissipation of upwind schemes in contact discontinuity and their induced error]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401006]]></link>
<description xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="html"><![CDATA[The numerical experiments of three upwind schemes in contact discontinuity were carried out on the numerical dissipation under different flow field parameters, and the mechanism of numerical dissipation was analyzed. The numerical calculation results and theoretical analysis show that when the flux vector splitting scheme is used for contact discontinuity calculation, if the flow field is static or there exists a subsonic region in the flow field, the generation of density dissipation will induce numerical perturbation errors moving with characteristic velocity. These errors have no effect on the magnitude of numerical dissipation, but it will affect the distribution of velocity and pressure parameters in the flow field, 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 bring 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 the flux vector splitting scheme to calculate the flow field will generate numerical errors, making it difficult to reach the second order of computational accuracy.]]></description>
<pubDate>2024/1/28 0:00:00</pubDate>
<category><![CDATA[航天工程·计算机科学与技术]]></category>
<author><![CDATA[HAN Fang, WEI Yanxin, LIU Jun]]></author>
<atom:author xmlns:atom="http://www.w3.org/2005/Atom">
<atom:name>HAN Fang, WEI Yanxin, LIU Jun</atom:name>
</atom:author>
<guid><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401006]]></guid><cfi:id>4</cfi:id><cfi:read>true</cfi:read></item>
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<title xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="text"><![CDATA[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/202401007]]></link>
<description xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="html"><![CDATA[In order to solve the problems of very few research literatures on the accuracy of different forecast wind intensity and the corresponding accuracy of the maximum aerodynamic load forecast value, the accuracy characteristics of different forecast wind intensity and the corresponding maximum aerodynamic load forecast value were respectively analyzed on the basis of the actual wind in a certain area, and the multiple linear regression method was used to establish a revised model. The results show that within 1～11 days 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 the 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>2024/1/28 0:00:00</pubDate>
<category><![CDATA[航天工程·计算机科学与技术]]></category>
<author><![CDATA[CHENG Huhua, WU Shuai, ZHANG Rucai, XIAO Yunqing, ZHAO Liang]]></author>
<atom:author xmlns:atom="http://www.w3.org/2005/Atom">
<atom:name>CHENG Huhua, WU Shuai, ZHANG Rucai, XIAO Yunqing, ZHAO Liang</atom:name>
</atom:author>
<guid><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401007]]></guid><cfi:id>3</cfi:id><cfi:read>true</cfi:read></item>
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<title xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="text"><![CDATA[Trajectory planning and control of continuous observation missions for geosynchronous orbit spacecraft fly-around]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401008]]></link>
<description xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="html"><![CDATA[For high-definition observation of GEO(geosynchronous orbit) 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 ICW(improved CW) 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>2024/1/28 0:00:00</pubDate>
<category><![CDATA[航天工程·计算机科学与技术]]></category>
<author><![CDATA[ZHANG Haitao, WANG Weilin, ZHANG Yasheng, WANG Hao, LI Zhi]]></author>
<atom:author xmlns:atom="http://www.w3.org/2005/Atom">
<atom:name>ZHANG Haitao, WANG Weilin, ZHANG Yasheng, WANG Hao, LI Zhi</atom:name>
</atom:author>
<guid><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401008]]></guid><cfi:id>2</cfi:id><cfi:read>true</cfi:read></item>
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<title xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="text"><![CDATA[Experimental on space charging and discharging effect of flexible thermal control films of satellite]]></title>
<link><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401009]]></link>
<description xmlns:cf="http://www.microsoft.com/schemas/rss/core/2005" cf:type="html"><![CDATA[In view of the conductive/insulating multilayer composite structure and micro/nano-size thickness of flexible thermal control film materials, a test was conducted on the charging and discharging characteristics of kapton-based secondary surface mirror film materials using 10~70 KeV electron irradiation. The key parameters such as surface charging potential and electrostatic discharge frequency were obtained. The transport law of irradiated electrons in multilayer thin film materials was studied by Monte Carlo method. The results show that there is no electrostatic discharge when the irradiated electron energy is 10 KeV due to the particularity of the kapton-based secondary surface mirror film structure. With the continuous increase of the electron energy, the surface charging potential amplitude of the film material and the electrostatic discharge frequency show a trend of first increasing and then decreasing. The space charging and discharging effect is most significant when the electron energy is 25 KeV.]]></description>
<pubDate>2024/1/28 0:00:00</pubDate>
<category><![CDATA[航天工程·计算机科学与技术]]></category>
<author><![CDATA[CHEN Yifeng, WANG Jinxiao, FENG Na, QIN Xiaogang, YANG Shengsheng, JI Qizheng, HAN Yanhui, LIU Qing]]></author>
<atom:author xmlns:atom="http://www.w3.org/2005/Atom">
<atom:name>CHEN Yifeng, WANG Jinxiao, FENG Na, QIN Xiaogang, YANG Shengsheng, JI Qizheng, HAN Yanhui, LIU Qing</atom:name>
</atom:author>
<guid><![CDATA[http://journal.nudt.edu.cn/gfkjdxxben/article/abstract/202401009]]></guid><cfi:id>1</cfi:id><cfi:read>true</cfi:read></item>
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