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Vol 17 Number4 (2005)

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Title Author Abstract
Behavior Model of Computer Generated Forces Based on Cybernetics ZENG Liang, ZHENG Yi, LI Si-kun, ZHANG Hui Behavior Modeling of Computer Generated Forces (CGF) entity is very important to the research of CGF. ESCP, based on cybernetics, is brought forward to fit modeling the behavior of virtual CGF entity in virtual battlefield. ESCP includes Sensor, Performer and Controller. Sensor apperceives battlefield information and interior feedback events, Peformer reflects the effect to battlefield, Controller deals with the apperceived information, and controls the entity behavior. ESCP supports synthesis behaviors, cooperate behaviors, paralled behaviors, and can be reused.
Overall Framework of Object-Oriented Visualized Auto-Modeling Simulation System for Fin-and-Tube Heat Exchanger LIU Jian, DING Guo-liang, DONG Hong-zhou, WU Zhi-gang With help of object-oriented programming technology and OpenGL visualization technology, a visualized auto-modeling simulation system for fin-and-tube heat exchanger is developed, which can be used in the field of chemical engineering and air conditioning system. The software application makes the fn-and-tube heat exchanger design with 3D possible, and it can be used to analyze the effect of various structure, refrigerant circuitry, and operating condition, etc. Because of great interactive characteristics, adaptability and generality, it can effectively shorten the product design period, and improve the quality of heat exchanger.
Behavior Modeling for Application Software Using Hierarchical Automata YANG Tao, XIAO Tian-yuan, ZHANG Lin-Xuan Behavior modeling facilitates inferring users¡¯ intention in real time and offers context-sensitive helps about how to use application software to beginners. Petri Net, Finite State Automata (FSA), IDEF3 and State Charts are traditionally used for behavior modeling. Hierarchical Automata (HA), as an extension of FSA, are characterized by well-structuredness and ease to understand. Most application software has hierarchical graphic user interfaces, which gives full scope to the expressiveness of HA. The formal definition and implementation framework are proposed. A case study of Pro/E is conducted to illustrate the effectiveness of HA in modeling the behavior of application software.
Interorganizational Workflows Modeling and Analysis CUI Li-zhen, WANG Hai-yang,YU Geng Petri net is one of the widely used modeling techniques of workflow. Interorganizational Workflows apply themselves to re-shape business processes beyond the boundaries of individual organizations. A Interorganizational workflows model based on colored Petri net is introduced, and its soundness properties are formalized and analyzed. In addition, some issues can be served as guidelines in other extensions of modeling interorganizational workflows.
K-Nearest Neighbor Nonparametric Estimation Bootstrap Model
for Weather Probability Forecasting		 ZHAI Yu-mei, ZHAO Rui-xing Based on the model identification and analogue forecasting, a new approach for probability weather forecasting is proposed, which is called K-nearest neighbor nonparametric estimation bootstrap model (named KNN-M for short). This model includes a historical database, a procedure of searching for the nearest neighbor subset and its optimization algorithm and the technique of predict and estimation. The case experiments are made on the forecasting of precipitation and cloud amount by using KNN-M. The individual sample test results show that the forecast estimation is stable and the accuracy is high. KNN-M has good prospects in operational weather forecast.
A Review on Modeling Technology to Machining Simulation SHA Zhi-hua, GE Yan-jun, ZHAO Liang, ZHANG Sheng-fang Machining simulation is one of the important applications of computer simulation in modern mechanical manufacturing industry. It is of great significance to produce quality parts more quickly and economically. Modeling is the key aspect of machining simulation, and it is also one of the vital criteria to the simulation system evaluating. Up to now, there are three existed modeling methods to machining simulation mainly, which are analytical modeling method, finite element modeling method and molecular dynamics modeling method. The principle and status of those methods are introduced in detail, and their advantages and current limitations are discussed as well. Then, the developing trend of modeling technology to machining simulation is presented.
GP-based Soft Sensor Modeling XIONG Zhi-hua, ZHANG Ji-cheng, SHAO Hui-he Soft sensors are wildly employed as an effective alternative for physical sensors in industrial processes. And the key problem is to set the model of soft sensors. We propose a novel modeling approach using Gaussian processes(GP). GPs are probabilistic kernel machines. Theoretic analysis and simulation experiment show that GP-based soft sensor is moderately simple to implement and use without loss of performance compared with artificial neural networks (ANN) and support vector machines (SVM), which lays solid basis for advanced control system.
An Investigation of Force Feedback in Interactive Bicycle Simulator HE Qi-chang, FAN Xiu-min, MA Deng-zhe, ZHANG Chong-ming The force feedback system is one of the most important components in interactive bicycle simulator. It simulates the forces generated from pedal and handlebar which feed back to the rider during the riding, which makes the rider on the bicycle simulator feel the forces just as during real riding. This paper designed a set of hardware and software of force feedback system based on the force analysis in real bicycle riding, and described in detail the control method of software which rightly maps forces of the bicycle in the virtual environment to the hardware of force feedback system.
Research of Grid Resource Selection Algorithm Based on Cactus Application DUAN Zhi-yong, ZHANG Da-fang, JI Jie While Grids are used as a computing platform, selecting the best resource set in Grid to meet application requirements is difficult. As a result, it is presented in ref[1] a resource selection algorithm, which extends the Condor matchmaking framework to support both single resource and multiple-resource selection. But because the algorithm selects the most powerful node in Grid at first, it is very easy to fall into partial optimization. We present a new resource selection algorithm to improve the old algorithm. Experimental results show that new algorithm can select the resource set which match user¡¯s resource requests better.
Immune Evolutionary Model and Its Application for Optimization Computation YANG Kong-yu, WANG Xiu-feng The intelligent evolutionary mechanisms of immune system are analyzed and two kinds of typical immune computational models are deeply researched. Based on the two models and immune regulation theory, and combined with mechanism of immune memory, a general immune evolutionary algorithm (GIEA) frame is proposed and its basic principles are discussed, and its convergence property and convergence speed is also analyzed. Aiming at the problem of multi-modal optimization, a multi-modal immune optimization algorithm (MIOA) according to this frame is designed. A simulation experiment is performed and its computational complexity is analyzed. The simulation and analysis results show that, compared with similar algorithms, it not only has advantages of less computational magnitude and better validity, but also needs none transcendental knowledge, so it realizes completely adaptive searching.
A Path Planning Algorithm for Autonomous Underwater Robots
in Diving Plane
 GAO Jian, XU De-min, YAN Wei-sheng A path planning algorithm for autonomous underwater robots in diving plane is presented. Using fuzzy inference system (FIS), the desired depth is derived according to the depth and the distance to bottom. The computer simulations proved that this path planning algorithm can successfully control the vehicle to avoid diving too deep/low or crashing on the bottom, and keep the proper height to improve the measurement accuracy of the Doppler velocity log (DVL).
Narrow Interference Rejection by HMM with DSSS System GUO Dao-xing£¬ZHANG Bang-ning It is studied the narrow interference rejection based on HMM for DSSS system. Firstly the principle of the algorithm is quoted, the adapted means for the algorithm are given in special, and the performance simulations are done for special interference modes. Results show that relative to interference rejection technology based on DFT the algorithm can reduce the loss of useful signal. By reducing implementation complexity the algorithm could be used in practical system. It is meaningful for short wave communication system and satellite communication system with DSSS technology.
A New Chaos Optimization Method and Application in Neural Network FEI Chun-guo, HAN Zheng-zhi Through adding Genetic Algorithms (GA) and mutative scale in chaos optimization, a new chaos optimization method is proposed and applied to train neural network. Through simulation research, this method is better than BP. It can satisfy destine error, and has certain generalization. And this method has several merits: small iterative number of training, high precision and convenient realization.
A Kind of Precise and Efficient Algorithm on Judging the Center of Joint Rotation HUANG Hai-ming, LIU Jin-gang The Motion capture technology based on optics has attracted more and more attention. But the precision and speed in converting from the marker space position to human motion parameters is still a problem, in which estimating the center of the joint rotation is the key duty. It is focused on the solid relationship between marker and its relative joint center, adopted the MSQ methodology, and adjusted the material algorithm according the factual system. At last, a Full_Marker_Joint relationship model is established, the precise and rapid judgment on the joint center is realized, and a better result is achieved.
Optimal Method to Minimize the Preventive Maintenance Cost of Parallel Systems MAO Zhao-yong, SONG Bao-wei, LI Zheng, HU Hai-bao By taking into account that failure rate will increase with the rose of maintenance times, the recursion relationship of failure rate before and after preventive maintenance was built up concerning with the concept of age reduction factor. The main contribution is to present an optimal policy research model in finite time horizon for parallel systems based on reliability constrains. Adjacent problem was also theoretically solved, and the change of system¡¯s maintenance cost along with reliability constrain was researched.
Reactive Power Measurement by Wavelet Transform and Hilbert Transform ZHENG Chang-bao, WANG Qun-jing, FANG Bin, SUN Wei, ZHU Ming-xing A new method is presented using Wavelet transform and Hilbert transform to calculate reactive power based on Budeanu¡¯s definition. Hilbert Transform can shift 90¡ãfor every harmonics. 90¡ãshift isn¡¯t limited by frequency range and phase-shift precision is high. RMS, reactive power and active power are calculated most efficiently and most accurately using wavelet transform in time domain. The voltage signal, the current signal and the voltage signal shifted 90¡ãare decomposed using orthonormal wavelet. RMS, reactive power and power can be calculated using coefficients, and reactive power and power in each subband can also be calculated. Simulation using the new method is carried out.
A Global Optimization Algorithm of Localization
for Huge Sculpture Surface Blank		 MA Li-ming, JIANG Hong, YUN Min, WANG Xiao-chun £ºBlanks of sculptured surface usually do not exist positioning references. In order to improve the blank positioning, a global optimization algorithm of localization for huge sculpture surface blank is presented. The algorithm included two steps. The first step is prelocation, translate and rotate the blank to get the largest overlap of the projections of theoretical surface and blank on the false plane. The second step is the optimization of objective function by means of simulated annealing algorithm to get the best localization. The technique is applied to the positioning of a hydroelectric turbine blade. Results show that it is effective and the final positioning result is excellent.
A Parallel Genetic Algorithm for a Single-Machine Dynamic Scheduling Problem with Resource-Constraints WEI Ying-zi, ZHAO Ming-yang We consider the resource-constrained dynamic scheduling problem. Traditional genetic algorithms (GA) often meet the occurrence of slow convergence. We introduce the parallel search mechanism into genetic algorithms to avoid the shortage above-mentioned. Parallel genetic algorithm (PGA) is proposed for solving sequence-constrained problems. We adopt the permutation-based coding with satisfaction of priority requirements. An individual chromosome is given by an activity sequence. The crossover operator is customized by the research project. We also prove that the crossover operator results in a precedence feasible offspring genotype if applied to precedence feasible parent individuals. With the technological permission, single-machine preemptive scheduling will improve the performance of scheduling system. Simulation results show that our parallel genetic algorithm gains excellent effectiveness and efficiency for single-machine dynamic scheduling.
Mathematical Model Research on Aircraft Landing Gear XU Dong-ling, LI Yu-ren It is investigated the composition and the principle of the aircraft landing gears, and the model structure of it is set up. It is simulated in the MATLAB/SIMULINK, the result of the aircraft anti-skid system is also presented and the effect on the aircraft anti-skid system is analysed in details. The result shows that the aircraft landing gear system model established is basically rational and correct. It is helpful to design the aircraft anti-skid braking system, and to improve the braking efficiency and the braking performance.
Simulation of Dynamic RCS Data of Radar Targets ZHANG Ju-feng, FENG De-jun, WANG Xue-song, CHEN Zhi-jie According to the kinetic characteristic of targets in midcourse and the RCS data of static measurement of the model, a simulation method for dynamic RCS data of radar targets is proposed. After the ballistic trajectory of midcourse simulated and the azimuth angle of target in flight calculated, the dynamic characteristics of RCS of the target under the given scene are obtained. Compared with the theory analysis, simulation results show the effectiveness of the method.
An Improved Method of Wavelet Denoising from Its Wavelet
Transform Modulus Maxima		 YUAN Hua, ZHANG Wei-ning, LU Jun, PAN Jin-feng Based on multiscale analysis, it is introduced the compensation factors given by Mallat to wavelet coefficients of each scale to reduce the influence of scale discretization. The algorithm determines the modulus maxima caused by noise according to the Lipschitz, and then processes the area between its adjacent modulus minima. What¡¯s more, the method of threshold denoising is combined with scale trading theory by Witkin to recover the coefficients of 1-scale efficiently. Simulation result shows this improved method has a better effect on denoising, can protect the original information, and needs fewer computations.
Plot-track Association Algorithm Based on Hierarchical and Density Clustering Analysis CONG Rong, WANG Xiu-kun, LI Jin-jun, YANG Nan-hai Plot-track association is an important problem in the field of multi-sensor data fusion. Based on clustering analysis, a similarity function of target¡¯s observed data has been set up, and a plot-track association algorithm based on hierarchical and density clustering analysis has been established. Experimental results show the algorithm can yield more effective association within shorter time, and it can improve the performance of multi-sensor system.
Wavelet Transform Base Neural Network Fault Diagnosis System and Its Application REN Wei-jian, LIU Tie-nan, ZHAO Yong-ling, ZHANG Zheng-gang Aiming at the questions of pump-jack fault diagnosis method backward and diagnosis information lack of, it is proposed a kind of wavelet transform based neural network fault diagnosis system. The system first performs discrete wavelet transform for input signals and treats the multi-scale discrete detail signals achieved by Mallat arithmetic as fault characters. Then the transformed signals are sent to the neural network to classify the fault modes. In order to raise the correct rate of fault diagnosis, on one hand the structure of the neural network is optimized, and on the other hand conjugated gradient method is used with learning rate self-adjusting to train the network weight values. In the practice, the system is used to diagnose up to 32 fault pump-jacks, and the correct rate of diagnosis is above 95%. The results show that the proposed scheme is very effective.
A Linear Transformation Model on Face Image and Its Application in Recognition U Yong, ZHANG Chong-Yang, YANG Jing-Yu Under different illumination conditions, image on an individual may vary dramatically, as a result face recognition becomes more difficult because of this factor. In this paper, a linear transformation model on face image is proposed. The model is feasible, simple and tractable in computing. Moreover, it is very effective to weaken the aftereffect of varying illumination. To illustrate the application on the model, experiments are performed on YaleB and AR face image databases.
Research of Cochannel Signal Recovery Algorithm and Sensitivity to System Error in Parallel Multistage Constant Modulus Array LI Jun, LI Rong, CHANG Hong-sen, BAO Zong-ti The parallel multistage constant modulus (CM) array has been widely researched in the domain of cochannel signal recovery as it employs the signal characteristic of having constant modulus and has the simple structure. However, current algorithms are mostly analyzed under ideal situations and often require the knowledge of angel of arrival of the desired signal accurately or convergence to the same solution occasionally, and then more than one stage captures the same source. To overcome this loss, a method based on initialization prediction is presented. And the system performance under the situation with system error is described using numerical simulation. Computer simulations are conducted to illustrate that the method does not require array calibration and that the parallel multistage CM array is more robust to element-space errors than look direction error and element failure.
High Efficient and Precise OFDM Carrier Frequency Acquisition and Channel Estimation Algorithms ZHANG Wei1, DU Yan, LI Jun, ZHANG Yong-sheng Carrier frequency acquisition and channel estimation algorithms with easy deployment and high precision are always the most challenging areas in OFDM. We propose new carrier frequency acquisition and channel estimation algorithms based on the time-domain analysis of OFDM system. The algorithms can finish carrier frequency acquisition and channel estimation in one training sequence, which improves the spectrum efficiency and usability. The simulation results show that the new algorithms are immune from the timing error with a high precision and low computation cost.
Study on Methods of GPR Image De-noising Based on Multi-wavelets Transform ZOU Hai-lin, SUI Ya-li, XU Jun-yan, NING Shu-nian The influence on ground penetrating radar (GPR) image de-noising with the multi-wavelets pre-processing methods and multi-wavelet function is discussed and investigated. A novel thresholding function is presented based on the wavelet shrinkage put forward by Donoho D L and Johnstone I M, and the processing by using an improved thresholding function is analyzed and compared. The results of simulation experiment indicate that the de-noising effect of GPR image with DGHM and STT multi-wavelets based on proper pre-processing methods is better than those traditional methods.
Image Segmentation Method Based on Wavelet Decompositon and Neural Network ZHANG Jian-xun, ZHANG Jia-wan, SUN Ji-zhou Firstly, the image was decomposed by wavelet transform to multiresolution image. Multiresolution image pyramid was constructed by multiresolution image. Secondly, the noise of image was better reduced in wavelet transform domain. Finally, the image was segment by classification method of Kohonen neural network that increases speed and accuracy of classification.
Design Pattern and Software Framework for Agent-Based Modeling and Simulation LIAO Shou-yi, DAI Jin-hai An Agent-Based Modeling and Simulation design pattern, ABMS design pattern, is proposed creatively. The ABMS design pattern will be helpful to build dialogue and communications between the domain of modeling and simulation and software development community. Based on the ABMS design pattern, a distributed simulation software framework for ABMS called ABDSF, including agent simulation service model (ServerAgent) and agent simulation model (ASM), is proposed. The framework uses HLA for reference. With this framework, one can share the models and simulation technologies, improve the reusability and interoperability of the models. And we can also conduct large-scale agent-based simulation for complex systems, including military systems and space operations under the framework.
A Data Description Code Extension for HLA RTI ZHAO Xiao-rui, GAO Xiao-guang, XIAO Bu-yu, CHEN Jun A Data Description Code (DDC) Extension is introduced to HLA RTI, which forwards refined Data filtering and Aspect Oriented Framework (AOF) to HLA simulation system. The section 1 and 2 respectively present the rationales of DDC based data filtering and AOF, and a design of DDC Extension and its test bed are detailed in the section 3 and 4. The DDC extension can improve run time efficiency and the architecture design of large scale HLA simulation system, while still holding the interfaces of both the local RTI Component (LRC) and the federate to keep compatible with conventional applications.
Design of AGVS Simulation Software Based on UML and Multiple Threads ZHAN Yue-dong, LI Li, SHI Yang Based on Timed Colored Petri Net and Directed Graph model of Automated Guided Vehicle System, using Object-Oriented method and Unified Modeling Language (UML), design a simulation tool of Automated Guided Vehicle System, which has the animated simulation function of multiple threads technique. The design focuses on Process View and Design View. An AGVS simulation tool used in the research of path optimization has been successfully implemented based on this design.
Research on Intelligent Agent Environment Based on HLA YIN Quan-jun, DU Xiang-yu, ZHANG Qi, HUANG Ke-di, QIU Xiao-Gang Intelligent Agent has been an important approach of studying complex adaptive systems. High Level Architecture (HLA) offers a common infrastructure for modeling and simulation of complex systems. But the means of data exchange offered by HLA/RTI can¡¯t satisfy the requirements of communication among agents. A simulation environment that supports intelligent agents¡¯ communication is presented. The environment is based on the integration of HLA/RTI and KQML. The intelligent agents can communicate and cooperate in the environment. A scenario tests the performance of the environment.
The Status & Development of Modern Simulators WANG Jing-ye, ZHANG Xiao-chao Simulators synthetically embody the simulation technology, and it is one of the practical applications of system simulation theory. It also is the main form by which Simulation serves the society and one of important components of simulation subject. It is presented the status of current simulator in integration from 5 aspects: military, transport, energy, economy and education. The common architecture of simulators is given and the characters of simulators are discussed. At the end, a prospect of the development of simulators is made and several new conceptions are given, such as Complex-System Simulator, Intelligent Simulator, Aided Decision-Making Simulator and Integrated, Multifunctional, Distributed-Interaction Simulator.
Design of Object Model and Research of Latency about Torpedo Weapon Simulation System LI Hao, KANG Feng-ju The distributed interactive simulation system on torpedo weapon is developed under the circumstance of mak RTI and VR-Link which can support HLA. Mostly SOM/FOM is built, and latency is researched. This simulation system has been of value for designing of torpedo weapon system.
OpenGL Based Experimental Platform for Simulation of
Reconfigurable Planetary Robot System		 ZHANG Zheng, MA Shu-gen1, LI Bin, ZHANG Li-ping, CAO Bing-gang A 3D experimental platform for simulation of RPRS (Reconfigurable Planetary Robot System) is introduced. The architecture and the simulation technology of RPRS are also discussed. OpenGL and Visual C++ based modeling method has been used to establish the simulation platform. The principle of RPRS, the work space, the multi-robot motion coordination, and the system integration can be explored and verified by this platform. A multi-robot system has been used to verify the practicability of the developed platform. The effectiveness of the developed experimental platform and the architecture of RPRS are successfully demonstrated by the simulation results.
Study on Integrated Simulation Engine of Strategic Decision-Making YANG Jing-yu, SI Guang-ya, HU Xiao-feng FAN Bo-tao According to characteristics of the strategic decision-making simulation, the concept of the Integrated Simulation Engine (ISE) is described. Based on this concept, the three-levels architecture and two work modes of the ISE are proposed. A prototype system for the Strategic Decision-Making Integrated Simulation Engine is designed and implemented. The strategic course of action planning tools and task-based simulation schedule arithmetic are designed to realize the synthesis driven of XOD (X on demand) services, and the situation intervening manner is presented to implement multi-essential integrated mechanism of XOD services.
Functional Implementation of Object-Oriented Visualized Auto-Modeling Simulation System for Fin-and-Tube Heat Exchanger DONG Hong-zhou, DING Guo-liang, LIU Jian, WU Zhi-gang In order to realize the practical utilization of the fin-and-tube heat exchanger simulation software, OpenGL visualization technology, auto-modeling technology for fluid net, and fast calculation technology for refrigerant thermodynamic properties, are introduced base on the functional implementation of the software. It is pointed out that the combination of the above three technologies can provide the key technical supports to the practical application of heat exchanger software.
Research and Implementation of HLA Based Training Aircraft Simulator HUANG Xiao-dong, HE You, OYANG Wen, ZHOU Qiang The aircraft simulator capable of synthetic battle training needs not only to simulate flying and avionics, such as radar, inertial navigator, but also to generate the high fidelity visual image and voice of war field situation. Besides this, it must simulate the interactivities and collaborations among the subsystems. Based on HLA/RTI architecturally, the interoperation and reusability of the device simulators, which are subsystems of the aircraft simulator, are assured, and the aircraft simulator becomes more flexible and extendible. By the use of the electromagnetic reflection information of targets and ground in database, the radar detection model can generate radar image dynamically. Based on the techniques of blackboard model and virtual machine, a CGF system is implemented, which is easy to modify and evolve.
Brainstem Auditory Evoked Potential Modeling with Genetic Programming LI Xiao-ou, FENG Huan-qing Brainstem auditory evoked potential (BAEP) is of important significance in neurology and audiology. Function relations between ¢õ peak latency and stimulus intensity, between ¢õ/¢ñ, ¢õ/¢ó amplitude ratio and stimulus intensity in BAEP are investigated with genetic programming (GP). Models are obtained automatically to guide the clinic application. Sub-population migration and tree inflation controlled by the complexity penalty are applied in GP besides basic operators. Modeling results show that the fitting error is smaller, and the performance exceeds traditional GP and least-squares algorithm. The quantitative analysis related with the curve fitting is helpful to the clinic detection of BAEP and disease diagnosis.
Recent Developments and Expectation of Iterative Learning Control Theory LI Shu-chen, LI Ping, XU Xin-he, HU Yu-e : Iterative learning control (ILC), as a branch of the intelligent control, had gained plentiful achievements not only in the theory research, but also in the applications for twenty years. ILC appeared gradually its superiority in the process control. The algorithms and present status of ILC are analyzed in detail. In addition, the existing problems and research directions of ILC are indicated.
Testing and Analysis of Run-Time Infrastructure Performance SUN Shi-xia, HUANG Ke-di Run-Time Infrastructure (RTI) is the key underpinning software for High Level Architecture (HLA) simulation systems, and the performances of RTI connect directly with the success of simulation. The RTI performances are analyzed roundly, testing methods of each item from data exchange performances and RTI service performances are discussed, and testing results of KD-RTI, pRTI and RTI1.3NG-V6 are introduced, with focus on KD-RTI. Comparison analyses are conducted among the three RTI performances. The results show that KD-RTI not only has met software performance requirements, but also can be used in generic real time simulations and has better performances in data loss and transformation velocity.
An Algorithm to Simulate the L-Shaped Tile of Double-loop Networks G(N;1,s) FANG Mu-yun, ZHAO Bao-hua, QU Yu-gui An Algorithm to simulate the L-Shaped Tile of Double-loop Networks G(N;1,s) is presented, and is executed with VB6.0 serving as programming language and SQL Server2000 serving as Database. The L-Shaped Tile and parameter of such family of Double-loop Networks whose N is given random and s varied from 2 to N-1 can be simulated and calculated respectively. The L-Shaped Tile of such family of Double-loop Networks has such characters (from rectangle to L-Shaped Tile) and the diameter of such family of Double-loop Networks has such characters (maximum values, minimum values, and symmetry). For any given N, many s make G(N;1,s) tight optimal.
The Structure Analysis of Virtual Scene Explore System ZHANG Xiao-chao, WANG Jing-ye Virtual Scene Technology is one of the important parts of VR systems. It takes charge of Vision issue in VR systems, and is the most important fact to affect the immersive of the system. It is briefly described the use of VS tech, pointed out it¡¯s characteristics and the difference between VS and common 3D Movies, and based on this, analysed it¡¯s essentiality. The general structure of VS Explore System is analyzed and demonstrated, and connection between different parts of VS Explore System in system construction process is explained from system viewpoint. Several key techniques such as Terrain Matching, Intersection Checks, Explore Control and Screen-To-World, etc, are also given in detail.
Scene Design of Middle/Miniature Type Virtual Reality Training System Scene Design of Middle/Miniature Type Virtual Reality Training System The Virtual Reality Training System is the development orientation of military training means. It is requested reality and objective because of the objective condition in order to cause ¡°immersion felling¡± for the trainee. The preferable effect can be achieved for the mini-type training system constructing the scientific simulation model by means of 3-D means and the DirectX technology.
Virtual Battlefield Technique on Attack-Defense Countermeasure Simulation YANG Jian-hua, WU Zhao-hui, PAN Yun-h The research on the virtual battlefield attack-defense countermeasure simulation (VBADCS) has received more and more attraction in the framework of simulation with higher and higher requirement of simulation techniques. We present the connotation and architecture of VBADCS and the status quo; we mainly introduce the multi-sensor-multi-dataflow collection simulation flat in the complicated environment of virtual battlefield, tremendous data mining and cooperative decision intelligent simulation flat on mobile agent and big scale VBADCS distributed display flat on the 3D solid space. At the same time, we describe the key techniques and technical problems. At last, we give a summary of the developing tendency of VBADCS.
Research of Assembly Motion Navigation in Assembly Simulation System WU Chang-sheng, WANG Dai-yong, DAI Ying-ming It is put forward a method of component motion navigation in the process of assembly simulation. Based on the assembly feature and body element feature, this method can solve the problem about how to locate component precisely in the process of interactive assembly. We described the design idea of this method and the implementation process. We also explained some key technologies for this method in detail, including the information collection for the body element feature, automatic recognition of user intention, constrained motion of the component, collision detection and construction of constraints between assembly parts.
VR-based Online Passenger-Car Customization System WANG Jiang-chun, ZHANG Shen-sheng, LUO Jian-qiang, SU He-feng To provide for customers¡¯ contentment with the special product, it¡¯s a necessary trend for the modern enterprises pursuing the competing advantage. In order to facilitate the information communication between customers and an enterprise, we propose a VR-based customization system, which utilizes the CAD model as a draft and displays 3D car body with an applet in Brower (for example, IE) to gain the aim of customization configuration on cars. It¡¯s implemented with the data- fusing of customized nonparametric data and product models in web site.
Research on Cable Harness Modeling and Assembly Planning
in Virtual Environment		 GAOJI Kai-da, LIU Jian-hua, NING Ru-xin, YAO Jun Cable harness assembly planning is a complex problem to resolve. The particularity of cable harness in its modeling and assembly planning is analyzed. Also we point out the limitation of the current CAD tools used to design and route cable harness. In terms of the peculiarity of the virtual environment, we put forward the Discrete Control Point Modeling technology (DCPM), by which a cable harness prototype is converted into continuous flexed line segments connected by a series of section center points. Based on previous work, we have developed a cable harness assembly planning module, which has been discussed lastly.
Fuzzy Logic-based Anti-Swing and Position Control for Bridge Cranes WANG Xiao-jun, SHAO Hui-he Recently, many approaches have been implemented for anti-swing control of overhead cranes in order to improve the operational efficiency. It is proposed a fuzzy logic-based anti-swing and position control of overhead cranes considering the nonlinearity and uncertainty of the crane model, where two fuzzy controller are designed to control the trolley position and to load swing separately. The fuzzy position controller is based on a simple speed reference trajectory to control the position and velocity of the trolley; and in the fuzzy anti-swing controller, the fuzzy rules are devised to resemble the experience of human crane operators for eliminating the load swing. Simulation results verify the feasibility of the method, and compared with linear quadratic regulator (LQR), this method is of good performance and robust to different rope length and load mass.
Adaptive Fuzzy PID Control of PEMFC System Electric Output Characteristic LIU Cheng-ze, ZHU Xin-jian The PEMFC dynamic characteristics under quick variance of power demand are discussed. Wavelet neural networks are adopted in the identification of the characteristic curve to predict the voltage, and the system control scheme of the voltage and power is introduced. The corresponding control schemes for voltage and power are studied. MATLAB/SIMULINK is used to simulate the control system. The results reveal that the control schemes adopted have attained the expected effects. The corresponding anti-disturbance and robustness simulation are also implemented. The simulation result reveals that the implemented control schemes have relatively better robustness and adaptive ability.
Fuzzy Variable Structure Control Design for Anti-Ship Missiles GU Wen-jin, ZHAO Hong-chao, WANG Feng-lian, PAN Chang-peng In order to reduce chattering phenomenon of variable structure control, a fuzzy variable structure control method is adopted and applied in the overload control system design of anti-ship missiles. Firstly, the missiles¡¯ control law is designed by the variable structure control method. Because the switching control term of variable structure control can cause the chattering phenomenon, a fuzzy controller is adopted to adjust it; thus a fuzzy variable structure controller is constructed. Then simulations to design the overload control system are conducted, in which the conventional variable structure control method and the fuzzy variable structure control method are applied respectively. The comparing of simulation results shows the superiority of the latter.
Research of Steady Control of Tail Fin of Robotic-fish YU Jing-hu, ZHU Chang-an, ZHU Jia-xiang, ZHONG Xiao-qiang, CHENG Gang, CHEN Hong, ZHANG Y High stability is the precondition of the high propulsive efficiency for robotic-fish and the steady control of the tail fin is the mail method to increase the stability of the robotic-fish. It is established the dynamic model of robotic-fish through the theory of planar wave plank and validated the dynamic model through experiment. On the basis of the dynamic model, it is calculated the value of the drive moment produced by the hydrodynamic and inertial force, and the relation between this value with the kinetic parameters of robotic-fish is analyzed. Our work prepare the academic base for the steady control of robotic-fish.
A New Approach of Spatial Channel Generation LI Yan1, ZHU Xia, XU Jia-dong The spatial channels for different antenna elements are usually correlated where the correlation is determined by the azimuth dispersion of the incoming rays.It is presented a new method for simulating spatial channels under correlated Rayleigh fading for antenna array. This method, based on Jakes¡¯ method, generates the correlated fading waveforms directly from knowledge of the power azimuth spectrum (PAS) and the angle of arrival (AOA). Simulation results show that the new method matchs the analytical result very well.
Delay Estimation Based on Independent Component Analysis in DS-CDMA Downlink LI Xiao-hui, WU Xiao-pei, WUI Bei Independent Component Analysis (ICA) techniques are considered in DS-CDMA communication system. Comparing the matrix CDMA signal model with the matrix noisy linear ICA model shows that it has the same form as the ICA model. Therefore, we propose a method of delay estimation in a block fading CDMA downlink based on ICA. The mixture matrix of multi-path channel can be estimated using a fast fixed-point algorithm, and then the delay information of channel can be obtained. The simulation results show that the proposed method has better performance compared with matched filter (MF) method.
Robust Active Vibration Control for a Flexible Plate Based on Frequency Domain Identified Model LAI Sheng, WANG Yong, SUN De-min Large space structures are infinite-dimensional distributed-parameter systems, which theoretically have infinite number of vibration modes. A reduced order model of a flexible plate is derived by frequency domain identification, and then a robust H¡Þ feedback controller is designed. Simulation results show that this method can suppress the vibration of this flexible plate and improve closed-loop system robustness effectively.
Utilizing Transaction to Realize Data Consistency in Multi-tier Architecture ZHANG Yu-zhen It is firstly analyzed the transaction in database management system, and then analyzed multi-tier architecture and the realization of multi-tier architecture in Delphi. Finally it is discussed how to realize the consistency of data by utilizing the transaction in each tier of multi-tier architecture, that is, to realize the consistency of data, how to obviously utilize the transaction in client tier and how to secretly utilize the transaction in middle tier and how to utilize the transaction of trigger in remote database server.
A New Algorithm of Attack Digital Watermarking Using Fractal IFS Coding ZOU Bei-ji, GONG Li, SUN Jia-guang An important issue in watermarking refers to attack and its counteraction. So far, most existed attack algorithms are all kinds of compressions (e.g. the JPEG), geometric transformation, filtering, and noise imposing. A new algorithm of attack digital watermarking based on fractal IFS coding is presented. Image blocks with particular watermark information are substituted by other randomly selected Hausdorff-similar blocks under compression map, and removed by evaluating and impairing the watermark¡¯s affection during the attacks. All experiments are done upon different types of images under DCT domain and wavelet domain and results show that these watermark detection score are degraded effectively after the attacks, and better results can be gotten when the attacks are combined with other signal processing operations.
Attitude Control of Flexible Satellite Using H£€-based Robust Control Law SONG Bin, MA Guang-fu, LI Chuan-jiang, CHEN Ying For flexible satellite disturbed by neglected dynamics, parametric uncertainties and external torque disturbance, attitude control problem was converted into an H£€ mixed sensitivity problem through choosing suitable weighting functions. The controller was designed by H£€ optimization. Satellite attitude was eventually studied by simulation. The results show that the robust stability and the disturbance rejection performance of the attitude control system with the robust controller are much better than that with PID controller.
Nonlinear Position Tracking Control of Pneumatic Servo System Based on Feedback Linearization ZHAO Hong, LIN Li, DONG Xia, LIN Ting-qi A position tracking control method for a nonlinear pneumatic servo system is proposed. The established control system has the inner pressure feedback linearization loop and the outer state feedback control loop with the friction compensator. Simulation results demonstrate that the control strategy has simple structure, high tracking precision and perfect control effect in applications.
Study on General Situation Assessment Method Based on Search Strategy ZHANG Xiao-dan, ZHAO Hai, WANG Gang, WEI Shou-zhi, WANG Xiao-ying A general situation assessment search strategy, based on the representation of situation transfer graph, is proposed, and the process of situation assessment is looked upon that of identification and search of situation path in the graph. In the proposed algorithm, Bayesian path classifier is used to classify target situation that is probably reached, Parzen window algorithm is used to modify the conditional probability density of each situation path, and the search in situation graph is realized via the improved depth-first search algorithm. In the experiment, the method had been successfully applied in the running state assessment system of Hydro-generators of Hydroelectric Simulation System of Jilin Fengman. The performance takes precedence over that of the traditional method.
Qualitative Prediction on Group Evacuation via Feedback Analysis SHAO Chen-xi, ZHANG Yi, ZHANG Jun-tao, BAI Fang-zhou During the course of group evacuation, group behaviors are predicted by considering the interaction between different group, based on system dynamic feedback analysis, and by utilizing the predictive capacity of the interactive group matrix on group behavior. By exerting disturbance on the variable, the interaction and feedback are observed between variables to analyze the consistency between qualitative prediction matrix and quantitative prediction matrix of the system. By analyzing the stability of the system to make sure if the structure of the system is right. Higher stability is right, and lower stability needs to adjust the system structure to reduce the collision in the course of evacuation.
Simulation & Realization of Satellite TT&C Resources Scheduling
Based on Event Scheduling Method
 YANG Yong-an, FAN Heng-hai, FENG Zu-ren, WANG Bo, LUO Yong-jin It is discussed the problem of serious conflicts between the Tracking, Telemetry and Command (TT&C) resources of ground stations and the requirements of spacecraft TT&C missions for the resources, which are resulted from the fact that there are less TT&C station equipments and more satellites in the ground-base TT&C network. Focusing the Low-Earth Orbit (LEO) and Medium-Earth Orbit (MEO) satellites, the satellite TT&C resources scheduling strategies are studied by use of the Event Scheduling (ES) method, which is one of the discrete event system simulation method. The mathematical models and algorithm for avoiding the TT&C conflicts are established, and the basic approaches to solving the problem are given. Finally, simulation result is evaluated by using integrate estimate method. The method of satellite TT&C resources scheduling has been tested in some TT&C engineering programs. The approaches are proved to be useful and ensure the TT&C resources of the ground-base TT&C network to be allocated reasonably.
Simulation and Analysis of FM Linearity Effect on Range Resolution of Chirp Signal LI Bao-guo, WANG Yuan-mo, ZHAO Hong-zhong, FU Qiang FM nonlinearity can cause the range resolution degradation of LFM pulse compression signal (chirp signal). The noise modulation in the phase term is a main kind of FM nonlinearity. When FM nonlinearity exists, it is very difficult to derive the analytical form of the pulse compression result and the range resolution. Computer simulation and analysis are performed on this problem and a series of much valuable conclusions are drawn.
Simulation Research of SARS Control Strategy: SARS Control Strategy and Basic Parameter XIE Zhong-lun, YANG Nan, SUN Chen-ying, KAN Pei-xiang, WEI Xin-jie, GUO Xiao-bo,
SHEN Chao-jian, ZHANG Zhi-cheng
 It is presented the optimization and control project of SARS, the function and influence of the two kinds of control measures (expand the treatment ranges of suspected case and limit population flows freely) to SARS, the general judgment standard of the measure whether the diffusion trend of SARS is restrained, the delaying time of the control measure, the blind area of control and so on. And it is also pointed out that in the early times of SARS, taking both measures at the same time can control the SARS effectively, and that in later stage, in order to lighten the economic influence, the measure limit population flows freely can be properly relaxed. These not only have the vital significance to the control of SARS, but also have the extensive reference function to other epidemic disease.
Scheduling Re-entrant Lines Based on GA and Integrated Rules LU Wen-yan, DANG Yan-zhong It¡¯s NP hard to schedule re-entrant lines for its complexity. Genetic algorithm and heuristic scheduling rules are integrated to schedule re-entrant lines. A class of integrated rules named B-T rules is proposed according to the characteristics of the system¡¯s re-entrant. And a class of schedule strategy based on grouped devices and multi-phases are given as well. Genetic algorithm and simulation are integrated here to optimize the combination of integrated rules. The priority of the proposed strategy is proved by simulation.
Modeling and Application of CGF based on Semi Autonomous Agent YANG Ke-wei, WANG Zheng-yuan, CHEN Zhi-cheng, TAN Yue-jin CGF is an important element in the modern Combat Simulation. We introduce the semi-autonomous agent into the modeling of the aggregation CGF, and propose a federate of cooperative weapon cells based on it. It properly uses the properties unifying both autonomy and constraint in one semi-autonomous agent to represent lively action of combatants in the battlefields. Such a CGF is High Level Architecture (HLA)-compliant. We also discuss and practice the combination of aggregate level CGF based on semi-autonomous agent and platform CGF. What we have done is mainly used in the Armed Tank combat simulation and efficiency evaluation.
Modeling and Simulation of Passively Controlled Anti-rolling Tank ZHANG Hong, ZHAN Xing-qun, ZHANG Yan-hua, LI Guo-bin The control equation is developed after analyzing air pressure. The mathematical model of passively controlled anti-rolling tank is set up based on theories of U-type passive anti-rolling tank. The bases of best control strategy are obtained according to mathematical model. Both routine control strategy and best control strategy are applied in the simulations toward system that disturbed by regular wave and irregular wave. Simulation results show that stabilizer effect adopting best control strategy is better than that using routine control strategy in the non-resonance range. The passively controlled anti-rolling tank can obtain wider stabilizer range if control time is suitable especially in low frequency range.
Modeling and Simulation of Passively Controlled Anti-rolling Tank ZHANG Hong, ZHAN Xing-qun, ZHANG Yan-hua, LI Guo-bin The control equation is developed after analyzing air pressure. The mathematical model of passively controlled anti-rolling tank is set up based on theories of U-type passive anti-rolling tank. The bases of best control strategy are obtained according to mathematical model. Both routine control strategy and best control strategy are applied in the simulations toward system that disturbed by regular wave and irregular wave. Simulation results show that stabilizer effect adopting best control strategy is better than that using routine control strategy in the non-resonance range. The passively controlled anti-rolling tank can obtain wider stabilizer range if control time is suitable especially in low frequency range.
Research on Collision Detection in Tube Bending Simulation LV Bo, TANG Cheng-tong, NING Ru-xin Based on the tube composed of straight and circular segments in our Tube Bending Simulation System, an algorithm for interference and collision detection is proposed. The interference model culled the non-interference object-pairs in the simulation environment and the extended OBB tree converted the collision detection of shaping tube into the collision detection of the shaped tube segments, avoiding the reconstructing of the tube OBB tree. Finally, an algorithm of triangle intersection based on the non-linear programming is provided.
Simulation and Analysis of System Performance of GALILEO
and Integrated GPS-GALILEO		 VZHAO Chun-mei, OU Ji-kun, WEN Yuan-lan Satellite motion equation is established based on design parameters of Galileo system and software are compiled to simulate Galileo constellation. Based on twenty-five stations of Crustal Moment Observation Network of China, satellite visibility and positioning creditability based on GPS, GALILEO and integrated GPS-GALILEO are analyzed deeply. Simulation results reveal that global stability and creditability of GALILEO are superior to GPS in temporal and spatial domain. Given positioning accuracy, horizontal positioning creditability of GALILEO is consistent with that of GPS, but vertical positioning creditability of GALILEO is superior to that of GPS obviously. Integrated GPS-GALILEO is superior to single system from aspects of satellite availability and creditability.
Study on Simulation and Evaluation Method of Helicopter Flying Performance LIAO Ying, ZHUANG Jing-zhao, LIANG Jia-hong A method of simulation aiming at maintaining helicopters based on their current performance and state is introduced to execute a calculation and evaluation of helicopters¡¯ flying performance. First the flying performance is calculated on a model of the turboshaft; then an evaluation of the simulation results and a prediction of the helicopter's performance are carried out; finally, the software system based on the method developed above is briefly introduced, and an example on it is shown synchronously.
Study on Modeling and Simulation of Switched Reluctance Motor Control System Based on Matlab JI Zhi-cheng, XUE Hua Based on the mathematical model of switched reluctance motor (SRM), a novel method for modeling and simulation of SRM control system based on Matlab has been proposed. In Simulink, the independent functional blocks, such as Moter model block, Speed controller block, Current controller block, Angle selection block, ect., have been modeled. By the organic combination of these blocks, the model of control system can be established easily. In the double loop of control system, a PI controller is adopted in the speed loop and a compound current controller is adopted in the current loop. In order to obtain expected performance, above base speed a speed angular position controller works in current closed-loop, and below base speed a current chopping controller works. The reasonability and validity have been testified by the simulation results and this novel method offers a new thoughtway for designing and debugging actual motors.

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