Abstract:For epoch of more than one billion transistors and 1000 ALUs in one chip, stream architecture based on kernel-stream model has turned out to be a hotspot. In light of this, a discussion on evolution of stream architechture is made. Firstly, the background of stream computation is given and features of the representative stream architechitures are summaries. Then, the architecture, processing model, parallelism, on-chip memory, application of some stream architectures are presented. The current dramatic changes and ongoing development trends of hardware and software design in stream processor are discussed in this paper.

Abstract:Software defined radio (SDR) has won much interest for being considered to be in line with the trend of wireless communication development. Now the digital signal processor (DSP) is the bottleneck of software defined radio. The advantages and disadvantages of diverse architecture of software defined radio digital signal processor are summarized, and then the trends of software defined radio digital signal processor are discussed.

Abstract:Due to technology scaling, radiation-induced soft error has been increasing in VLSI systems. Designers have to consider the problem of reliability caused by soft errors. Selective hardening of vulnerable nodes in circuits using resilient registers is a prevalent solution, which can effectively reduce soft error rate of logic circuits. This paper gives a summary of some soft error immune registers, and then provides quantitative analysis and comparison in reliability of eight kinds of registers. The result concludes that temporal spatial dual modular redundancy structure shows better reliability. The existent reliable registers brings about great overhead that cannot be avoided, so this paper designs a timing shift-based Dynamic Master Temporal Spatial - Dual modular redundancy Register (DMTS-DR). The experiment results show that the proposed register is not only able to immunize SEUs in itself, but can also mask SETs propagated from combinational logic efficiently. Compared to other reliable registers, area overhead and delay penalty of DMTS-DR have been reduced greatly. DMTS-DR has better tradeoff among reliability, area and speed.

Abstract:This paper introduces a large-scale parallel MC-DSP prototype, PolyDSP constructed with heterogeneous super-nodes, and proposes a data speculation technique based on customized data streams transmission control engine (DSTCE). This technique implements high efficient data streams transmissions among different data ports within a super-node and transmissions between neighbor super-nodes. The superiority of this technique is that it can combine a data speculation solution with the programming model of PolyDSP, avoid complex cache coherence problems, thus improving the parallelism between data processing and memory accessing for MC-DSPs significantly. Our simulation results show that, the performance of single super-node of PolyDSP is improved by 22% on average, and the performance of PolyDSP based on DSTCE is 14% higher than that of PolyDSP based on CC-NUMA structure with two super-nodes.

Abstract:In order to resolve the power problem, this paper presents the design and implementation of an embedded heterogeneous dual-core microprocessor (ADTA-1), taking advantage of the low power feature of asynchronous circuits and the Data Triggered Architecture. Through testing, the asynchronous microprocessor is validated with its low power feature in multicore microprocessor, which provides a useful trial for future design of low-power asynchronous multicore microprocessors.

Abstract:The Smith-Waterman algorithm accelerator with backtracking, which has not been implemented in hardware before, is designed and implemented on FPGA platform with systolic array by storing the path data into DRAM. The key techniques of backtracking design and the architecture of algorithm accelerator are discussed in detail. Compared with the conventional scheme, the FPGA-based accelerator with backtracking is more effective, with the acceleration reaching 161.

Abstract:As the CMOS technology enters the deep submicron design era, the richness of the computational resources brings about a lot of problems, such as clock distribution, clock skew and high power dissipation. Asynchronous circuit style is an efficient approach to solve the problems, and it is becoming significantly attractive to the designers. The design of asynchronous pipelines is a very important issue in the process of designing asynchronous microprocessors. In this paper, various pipeline structures are summarized and their asynchronous equivalents are presented, and then an asynchronous flow is proposed, aiming at speeding up the asynchronous circuit design. Finally, the flow is used to design several asynchronous pipelines. The experimental results show that the asynchronous technique can reduce the power consumption of microprocessor effectively.

Abstract:Owing to the revolution of GPU architecture and improvement of developing platforms, GPU is widely used in scientific computing nowadays. Relationships among GPU architecture, programming model and memory hierarchy are illustrated by analyzing memory hierarchy and exploring key performance features of GPU. Three basic load balance strategies on mapping applications onto GPU are presented: Prefetch, stream computing, task division. The effective relationships among different factors and optimization efficiency are tested and exposed by experiments.

Abstract:The networks-on-chip(NOC) approach was proposed as a promising solution to on-chip communication problems, but it is by far more resource limited. The input buffers in a typical on-chip router take a significant portion of the silicon area of NOC, and the performance of a NOC is drastically affected by the amount of buffering resources. In this paper, an application-specific buffer planning algorithm that can be used to customize the router design in NOC is presented. More precisely, given the mapping of the target application and the traffic characteristics, the algorithm automatically assigns the buffer depth for each input channel, in different routers across the chip. The experimental results show that the system buffering resources can be utilized more effectively. In contrast with the uniform buffer allocation, about 50% saving in buffering resources can be achieved by automatic buffer allocation using our algorithm without any reduction in performance.

Abstract:In this paper, a semantic shot representation and event query framework for soccer video is proposed. In this framework, various semantic shots are defined and each shot can be described by five properties. In order to solve the problem in traditional event query, a user-defined event query method is also proposed, which utilizes the Semantic Shot Composite Petri-Nets. Based on the representation of the semantic shot, users can define their favorite events by Petri-Nets. The experiment conducted shows that the query method can greatly improve the query efficiency and adjust self-adaptive as the broadcaster varies, but this method requires users to have enough professional knowledge. Experiment data set includes Germany World Cup 2006, English Premier League and Spanish First Division.

Abstract:Traditional discrete cosine transform (DCT) can only sparsely represent the horizontal and vertical edges in images, and the computation complexity of directional prediction DCT (DPDCT), which is of ability to represent more directions, is much higher. To overcome these shortcomings, the fast directional lapped transforms (FDLT) is proposed, in which the transform is performed on the predefined direction mode and the energy in edges lying across blocks is compacted further. In Comparison with DPDCT, FDLT needs no interpolation. So FDLT can sparsely represent the anisotropic edges in images much faster. Furthermore, special lifting algorithm is designed to ensure the perfect reconstruction. The computation of FDLT is no more than 2 times of DCT's. Coding with the same set partition method, PSNR of images compressed with FDLT is 0.5dB higher than that with DCT. FDLT based compression also achieves clearer edges and details in the reconstructed images.

Abstract:The increasing demand for data quality technology has motivated revisions of classical dependencies to capture more inconsistencies in real-life data. A class of integrity constraints, referred to as functional dependencies with built-in predicates (PFDs), is proposed for relational databases and their axiomatization is investigated. In contrast to traditional functional dependencies (FDs) developed mainly for schema design, PFDs generalize the notions of FDs to apply to subsets of relations specified by constraints in the context of interpreted data, and aim at capturing the consistency of data by enforcing bindings of ranges of semantically related values. For the implication analysis of PFDs, which is to decide whether or not a set of PFDs entails another PFD, we provide an inference system analogous to Armstrong's axioms for FDs, and prove the soundness and completeness of the inference system. This work is a step towards a practical constraint-based method for improving data quality since inconsistencies and errors in databases often emerge as violations of integrity constraints.

Abstract:An efficient multi-objective optimization (MO) algorithm named as NSGA-Ⅱ is applied to solve the problem of organizational design of C2. Before introducing the settings of NSGA-Ⅱ, a discussion is made about the shortcomings in forming optimizing objective by weighted method and proceeding procedure like nested GA, which exist in popular algorithms of organizational design of C2. With this MO algorithm, more indexes can be optimized within one procedure which makes it more practical than dealing with single index as usually. Some modifications are made for NSGA-Ⅱ to match the specifications of the experiment, a group of appealing and inductive results are reached, which reveals the effectiveness of NSGA-Ⅱ in the problem of organizational design of C2.

Abstract:The drive force, the rail-coil cross interaction and the system performance of the rail-coil combined electromagnetic gun have been researched, and an improved structure with four rails distributed symmetrically has been proposed. The theoretical analysis and numerical computation of the structure show that the rail-coil cross interaction brings considerable transverse pressure and motion instability to the normal two-rail combined EM gun, while the four-rail combined EM gun successfully eliminates the negative effect of the cross interaction and obtains much better performance.

Abstract:By combining decomposition topology model of iterative design for mechanical products with modularization, a modular design method for mechanism based on function-principle-behavior-structure is put forward. Product iterative design decomposition principle based on function-principle-behavior-structure is mainly discussed. Portrait iterative process of function(principle(behavior(structure(function evolvement during design decomposition is analyzed. Transverse dynamic modeling means of product design decomposition is clarrified. Basic modular design method for complicated mechanism based on FPBS is established by introducing modulization into the product iterative design composition process.

Abstract:With the fast development of the transportation and navigation technology, the application of multimodal route planning is becoming popular. The routing systems and services are evolving from mono-modal to multimodal. However, it is difficult to apply the traditional data models and algorithms directly to the multimodal situation. A reasonable data model must take the multimodal application background into account, which is considered the critical foundation of the multimodal route planning solution. For the purpose of building such a model, we propose a concept named Switch Point, and a multimodal network model which consists of three components: multimodal graph set, vertices attributes table and switch point matrix. The experiments conducted on the real urban transportation road networks showed the feasibility of our proposed model. Our work can provide a foundation to support the study on multimodal route planning algorithms both theoretically and practically.

Abstract:On-line Autonomous Route Planning is the prerequisite for Unmanned Aerial Vehicles (UAVs) to perform area search mission effectively. Firstly, to satisfy the real-time requirement of UAV search path planning, an autonomous route planning framework which integrates fixed search mode with dynamic search mode is presented. Then, based on basic Rapidly-exploring Random Tree (RRT), a modified RRT-based UAV route planning algorithm is proposed. The modified RRT method has introduced heuristic information, and improved the extension of RRT node, which can reduce the node number in a search tree and time cost. Simulation results demonstrate that the method is real-time and effective.

Abstract:Based on the representation of impulsive sound propagation with the moving source and receiver, a seafloor reverberation signal model is derived from the monostatic sonar moving horizontally in horizontally stratified oceans. Then, a method for simulating reverberation time series is presented with the seafloor divided into range-azimuth cell. It is found that the method can effectively solve the problem that correlated scatter coefficient between different normal modes is difficult to be expressed, and the delay-doppler distance for any cell is less than rated resolution. The power spectrum and the probability density of simulation results show the validity of the modeling and simulation method.

Abstract:Through the comparison of the experiment data with the theory results, the damp influence of the airflow on the vibration system is analyzed. Furthermore, based on the experiment sound source, how the parameters of the vibration system may influence the voice coil amplitude, such as coefficient of elasticity, magnetic flux density, the mass, resistance, inductance and winding strands of the voice coil, is studied using equivalent circuit method. Finally, methods to choose these parameters are presented for the purpose of speech broadcasting or generating low frequency sound waves.

Abstract:At present, borescope inspection is the only technique for in-situ detecting defects in aeroengine laminas, but the inspection performance is poor by using borescope to detect cracks in laminas. Therefore, borescope and eddy current integrative testing technique was presented, combining the advantages of these two techniques. The technique can achieve in-situ detecting defects in aeroengine laminas. A borescope and eddy current integrative testing probe used for aeroengine laminas was developed. A testing example of aeroengine lamina using the probe was given. The testing results show that the inspection performance is high using borescope and eddy current integrative testing techniques, and the cracks can be estimated quantitatively. It was concluded that the integrative testing technique is superior to single borescope inspection, and it is very valuable for practical application.

Abstract:The evolution of detonation waves in cylindrical explosives in driving tube is simulated in this paper. Eulerian finite volume method is used, in which the JWL(Jones-Wilkins-Lee) state equation is used for both explosives and detonation products, while the prefect gas state equation for air, and the ignition and growth model is used to calculate chemical reaction rates. The evolution of wave structures is obtained, which can calculate detonation speed accords well with experiential formula. It is also demonstrated that the peak pressure on the side inboard of the tube is above 800MPa, and due to the converge of shock waves, the peak pressure in the center of bottom is as high as 12.4GPa.

Abstract:Coherent structures of two-dimensional supersonic turbulent mixing layer with engineering background are investigated by using the method of Large Eddy Simulation (LES). Chaos characteristics of evolution status are obtained by the non-linear time series analysis of pseudo-phase portrait, Lyapunov exponent and correlation dimension. The results show that the pseudo-phase portrait of pressure can denote the stability of mixing layer. The distribution of correlation dimensions can be used to measure the evolution status of mixing layer quantificationally, and the distribution of maximal Lyapunov exponents can be used to validate the measure results above. In corresponding experiments for mixing layer, the universality of studies on evolution status of mixing layer by the method of non-linear time series analysis is testified.

Abstract:The factors affecting collision probabilities between formation-flying satellites are discussed and generalized, for the purpose of increasing the accuracy of the collision detection and forecast. A difference equation of Hill's equation is derived for the Kalman filter, which is used to estimate the target satellite's status. Based on these equations, such four factors as model errors, measurement errors, malfunctions and accidental events are analyzed in detail. Several simulation scenarios are also executed for the factors. The simulation results show that the controller always-functioning malfunction is the worse collision factor, which needs further researches for a specific collision avoiding scheme.

Abstract:The multi-impulse glideslope guidance algorithm for close range rendezvous of spacecraft is presented. The algorithm takes the fuel economy and the constraints of field-of-view of navigation facilities, the minimum interval of impulses, and the maximum value of impulse into consideration. Furthermore, a consolidated model of glideslope algorithm to guide close range rendezvous (both proximity and departure) is described. By designing the relationship of exponential function between distance and speed of ideal rendezvous trajectory, the algorithm can be applied to any specified rendezvous time, and satisfies the need of decelerating during the proximity operation and accelerating during the departure operation. By defining the logarithmic mapping function, the optimized impulses can be obtained. Finally, several scenarios of the proximity and departure operations are simulated. In some scenarios, compared with the optimization method, the using of logarithmic mapping function can also economize fuel at a cost of low computational complexity. The other scenarios illustrate that the guidance algorithm can ensure a close range rendezvous motion in any direction, at any time with the fuel economy and under the constraints as well.

Abstract:By means of adding surfactant, controlling the pH value and introducing the ultrasonic wave field, the NaCl particles were prepared. The particles perform uniformity granularity with the granularity scope ranging from 1 to 11μm. The product was characterized by SEM and XRD. The results show that the particles appear cubic crystal outline and sodium chloride characteristic band. Finally, the growth mechanism of the ultrafine sodium chloride particles was studied.

Abstract:The isothermal differential scanning calorimetry(DSC) method was used to determine the relationship between curing degree and time of a epoxy resin of CYD-128 with GA-327 as curing agent. An AR 2000EX rolling rheometer was used to measure the resin viscosity in a range of isothermal temperatures. Comparing the isothermal conversion-time relation with that of the isothermal viscosity-time, the isochronous relation of the isothermal viscosity-conversion was set up correspondingly. Results suggest that under the individual influence of the chemical mechanism of viscous increase, the viscosity of the resin system slowly increases with the increase of isothermal conversion, and then increases quickly when the conversion reaches a certain extent. Changing the isothermal viscosity-conversion relation to the relation of viscosity-temperature under the constant conversion, it shows that under the individual influence of the physical mechanism of viscous falling, the resin viscosity decreases with the temperature increased, and the viscosity descendent extent of the resin system increases with the conversion increased. These two mechanisms are separated from each other, which is the technical base of the accurate prediction for the reactive resin system.

Abstract:Vacuum diodes are among the most important parts of high electron beam accelerators. In order to make vacuum sealing good, outgassing properties of materials for a ceramic insulated diode is investigated. A pumping model including the influence of flow conductance was set up to simulate the material outgassing rate and pump down time. Finally, the outgassing characteristics of materials between normal temperature and heated state are compared in experiment. Results show that heating can efficiently accelerate the outgassing rate and raise the vacuum sealing time.