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Articles 3361 - 3390 of 6663

Full-Text Articles in Numerical Analysis and Scientific Computing

Virtual Flight Modeling And Simulation Of Air-Launched Anti-Ship Missile, Zhipeng Sun, Guanghong Gong Jun 2020

Virtual Flight Modeling And Simulation Of Air-Launched Anti-Ship Missile, Zhipeng Sun, Guanghong Gong

Journal of System Simulation

Abstract: The relationship between the parameters affecting aerodynamic force was studied, and the aerodynamic coefficient was properly linearly simplified. According to the type of airborne anti-ship missile performance model, the "black box modeling" and extrapolation method was adopted to determine its aerodynamic coefficient, a typical anti-ship missile six degrees of freedom of the simplified dynamic model was established. By studying the flight phases after the missile launch, the flight trajectory model of each flight phase was established by using the control method of the track angle. The whole flight trajectory process of the missile attacking a target was realized and …


Implementation And Application Of Complex System Modeling And Simulation Language Compiler, Zhou Wen, Chi Peng, Bohu Li, Song Xiao Jun 2020

Implementation And Application Of Complex System Modeling And Simulation Language Compiler, Zhou Wen, Chi Peng, Bohu Li, Song Xiao

Journal of System Simulation

Abstract: Simulation language is a key technology of integrated simulation based design software environment. A difficulty of developing simulation language is the compiler that automatically transfers simulation language Semantics to programming language such as C++. The contents and features of CMSL were introduced. And a compiler which could analyze simulation text written in CMSL was implemented. A decouple method for Discrete System was proposed and integrated in the compiler. The features object-oriented and components oriented of CMSL were verified by an example with its ability to describe discrete system.


Research On Visual Objective Test Method Of High-Level Flight Simulator, Zhangfa Liu, Huiyong Li Jun 2020

Research On Visual Objective Test Method Of High-Level Flight Simulator, Zhangfa Liu, Huiyong Li

Journal of System Simulation

Abstract: With the development of commercial aircraft, the demand of high-level flight simulator will increase. In addition to development and production, qualification test is a key link to ensuring the quality of simulator. Visual system plays an important role of flight simulator. In order to meet the requirement of qualification from CAAC, visual objective test based on main qualification test guide of flight simulator was developed. It is very significant that test requirements, test theory and test methods of visual objective test item were researched deeply, including transport delay, field of view, system geometry, surface contrast, brightness, surface resolution, light …


Modeling And Dynamic Research Based On Ritz Series For Ball Screw Drive System, Rongrong Qian, Minzhou Luo, Jianghai Zhao, Li Tao, Li Lu Jun 2020

Modeling And Dynamic Research Based On Ritz Series For Ball Screw Drive System, Rongrong Qian, Minzhou Luo, Jianghai Zhao, Li Tao, Li Lu

Journal of System Simulation

Abstract: To analyze the vibration performance of the ball screw drive system, the finite element model (FEM) of the simplified system by Ansys/Workbench was given to acquire the vibration mode and shape. Based on the vibration shape calculated from FEM, a set of hybrid basis function was used to generate the new Ritz series for building the system motion equation of the axial and torsional vibration. The pitch of the ball screw was considered in the method. A mathematical model which was easy to design the controller was developed. Through the numerical simulation, the modal characteristics and shape of …


Thermal And Electric Load Coupling Analysis And Decoupling Coordinated Control In Heat Supply Units, Tuoyu Deng, Tian Liang, Jizhen Liu Jun 2020

Thermal And Electric Load Coupling Analysis And Decoupling Coordinated Control In Heat Supply Units, Tuoyu Deng, Tian Liang, Jizhen Liu

Journal of System Simulation

Abstract: Due to large scale wind power integration, heat supply units hardly meet the AGC (automatic generation control) requirement by the existed coordinated control system. It is necessary to analyze coupling characteristics of thermal and electric load thoroughly. A transfer function matrix including characteristics of heat supply part was gained by small deviation linearization of a dynamic unit's model. Coupling characteristics was analyzed based on variable pairings of the existed coordinated control system and decouplers were designed. Relative gain matrix measure and simulation were used to compare the coupling extent before and after decoupling. Simulation experiments show that adding static …


Attention Mechanism In Battlefield Situation Awareness, Yisi Kong, Xiaofeng Hu, Zhu Feng, Jiuyang Tao Jun 2020

Attention Mechanism In Battlefield Situation Awareness, Yisi Kong, Xiaofeng Hu, Zhu Feng, Jiuyang Tao

Journal of System Simulation

Abstract: Battlefield situation awareness (BSA) is the basis of C2 and decision making. Research on BSA can clarify the mechanism and lay the foundation for designing intelligent model and algorithm to assist commanders with situation awareness. Taking attention mechanism as the point, the relevant discussion in psychology was summarized, a framework of the attention mechanism in BSA was put forth, and its application in operational target value assessment was explored.


Target Combination Selection Optimization Method Of Joint Operations Based On Fuzzy Genetic Algorithm, Suike Li, Jianhua Xiang, Haijun Wang, Mingzhi Zhang, Li Yi Jun 2020

Target Combination Selection Optimization Method Of Joint Operations Based On Fuzzy Genetic Algorithm, Suike Li, Jianhua Xiang, Haijun Wang, Mingzhi Zhang, Li Yi

Journal of System Simulation

Abstract: Under the condition of informatization, it is necessary to use intelligent model and optimization method to realize the cooperation and fusion of multi arms combat firepower. Aiming at the problem of target decision-making and firepower allocation in joint operations, the fuzzy multi-objective programming model was constructed to achieve the overall goal of achieving the maximum and the best firepower as a dual goal. In the model solving algorithm, the possibility theory was used to transform the fuzzy number, the model was transformed into the multi-objective programming model in the deterministic form. In order to improve the efficiency of …


Motion Reconstruction And Simulation Using Sparse Inertial Sensors, Lijun Cui, Tianyu Huang, Feng Feng, Zhang Jie, Yang Kai, Liu Dong Jun 2020

Motion Reconstruction And Simulation Using Sparse Inertial Sensors, Lijun Cui, Tianyu Huang, Feng Feng, Zhang Jie, Yang Kai, Liu Dong

Journal of System Simulation

Abstract: A method was proposed to reconstruct high-dimensional full-body motion sequences from low-dimensional control data collected by sparse inertial sensors. The approach solved the mapping problem from low dimension to high dimension. A numerical similarity- geometrical similarity-time continuity model was setup to ensure the reconstructed motion candidates in numerical-logical similarity. The gap between angle and angular acceleration was eliminated by acceleration reconstruction. An energy function was introduced to optimize the reconstructed results which guaranteed the accuracy. The analysis and comparison experiments show that the proposed method can reconstruct nature and credible motions in real-time and can be applied …


Artillery Company Firepower Assignment Model And Algorithm, Xuezhi Lü, Lisheng Chang, Xianwen Wang, Xinhui Zhao Jun 2020

Artillery Company Firepower Assignment Model And Algorithm, Xuezhi Lü, Lisheng Chang, Xianwen Wang, Xinhui Zhao

Journal of System Simulation

Abstract: In view of deficiency of traditional firepower assignment method and characteristics of modern artillery, the model and algorithm of firepower assignment of artillery company were studied. The firepower assignment problem of artillery company was described, and the resolving concept was discussed. Three firepower assignment modes based on resolving concept were introduced. The idea of getting optimal solution of firepower assignment with Monte Carlo simulation and golden section search were analyzed. The model and algorithm were validated with an example.


Business Process Modeling Algorithm Based On Ontology Language, Huang Ying, Kangshun Li, Li Wei, Keqing He Jun 2020

Business Process Modeling Algorithm Based On Ontology Language, Huang Ying, Kangshun Li, Li Wei, Keqing He

Journal of System Simulation

Abstract: In the view of problem in lack of information sharing mechanisms at the semantic level among processes, a business process modeling algorithm based on ontology language using concept hierarchy as background knowledge was proposed. The business process modeling by traditional business process languages can be transferred to ontology language (OWL) description so as to realize the semantic sharing of business process. The approach has two main advantages compared with traditional methods: (1) accelerating the building process, minimizing the conversion cost; (2) background knowledge guides the extraction of knowledge resided in database. As a way of validating the approach, part …


Travel Time Prediction Of Urban Road Based On Deep Learning, Weiwei Zhang, Ruimin Li, Zhongjiao Xie Jun 2020

Travel Time Prediction Of Urban Road Based On Deep Learning, Weiwei Zhang, Ruimin Li, Zhongjiao Xie

Journal of System Simulation

Abstract: Travel time prediction of urban road is a significant support for urban intelligent transportation system. Four types of LSTM neural network architecture were selected to predict the urban road travel time. The number of nodes in the LSTM hidden layer was fixed to determine the optimal input length of the model. The input length of the model was fixed and the predictive performance of the four LSTM models under different hidden layer nodes and considering spatial correlation were tested respectively. The performance of spatial LSTM model was compared with four traditional models, for example, BP neural network. The results …


Measurement Error Correction Model Of Tof Depth Camera, Le Wang, Luo Yu, Haikuan Wang, Minru Fei Jun 2020

Measurement Error Correction Model Of Tof Depth Camera, Le Wang, Luo Yu, Haikuan Wang, Minru Fei

Journal of System Simulation

Abstract: 3D data intuitively reflects the full view of the target or scene. Time of Flight (ToF) camera is a range imaging sensor that can provide 3D geometric information of targets immediately, thus it is widely applied in the robot positioning and navigation, 3D reconstruction and other aspects etc. Due to the operational principle of the camera itself, there are variety measurement errors of the source data obtained by ToF, resulting in image distortion. The measurement errors in the imaging process of ToF camera were analyzed and summarized, and the cubic spline interpolation method combined with look-up table was proposed …


Doa Estimation Method Of Uniform Circular Array Based On Improved Smoothed L0 Norm, Wang Biao, Chen Feng, Lu Li Jun 2020

Doa Estimation Method Of Uniform Circular Array Based On Improved Smoothed L0 Norm, Wang Biao, Chen Feng, Lu Li

Journal of System Simulation

Abstract: To solve the problems of the narrow-band signal DOA method, such as low resolution and unsuitable for applications with small number of snapshot and array elements, etc, DOA of uniform circular array based on improved smoothed l0 norm was proposed after analysis of the characteristics of UCA model and signal airspace sparse, combining with improved the smooth l0 norm algorithm. For reconstructing the signal, the method used the combined continuous function as the approximation to l0 norm by sparse matrix processing array manifold, which improved the convergence speed. It was also extended to the UCA DOA …


Image Retrieval Using Weighted Vocabulary Tree With Location Information, Chen Ying, Jiayu Guo Jun 2020

Image Retrieval Using Weighted Vocabulary Tree With Location Information, Chen Ying, Jiayu Guo

Journal of System Simulation

Abstract: Aiming at the positional information ignorance problem in image retrieval based on SIFT feature matching, an image retrieval approach using weighted vocabulary tree based on the spatial location information was proposed. The vocabulary tree is used in the method to quantify SIFT features as the visual words, converting the image match into the visual words' weight vector match. Because only visual words' weight match ignored the mutual position effect, SIFT points' spatial location information was generated, and was classified into the position effect of visual words according to affiliation between SIFT points and visual words. The spatial location information …


Best Viewpoint Selection For 3d Visualization Using Particle Swarm Optimization, Panpan Jia, Yanyang Zeng, Yunxia Feng Jun 2020

Best Viewpoint Selection For 3d Visualization Using Particle Swarm Optimization, Panpan Jia, Yanyang Zeng, Yunxia Feng

Journal of System Simulation

Abstract: The viewpoint selection is to automatically select one or more approximate optimal viewpoints in the viewpoints of multiple views, at the same time, it is related to the evaluation of the quality of the viewpoint. 3D visualization best viewpoint selection method based on particle swarm optimization algorithm was proposed. The viewpoint quality was evaluated by using the image information entropy and the image edge entropy, and the viewpoint was selected by the multi-objective intelligent optimization method. The basic flow begins with the initial viewpoint set, finding the best viewpoint by means of coding, particle evaluation, and particle update, which …


Real-Time Modeling Of Interaction Between Floating Objects And Large-Scale Water, Xiaolong Yang, Hongtao Liang, Fengju Kang, Gu Hao Jun 2020

Real-Time Modeling Of Interaction Between Floating Objects And Large-Scale Water, Xiaolong Yang, Hongtao Liang, Fengju Kang, Gu Hao

Journal of System Simulation

Abstract: Large scale water is an integral part of nature and of high interest for interactive 3D applications, e.g., computer games and virtual environments. Allowing the water to interact with floating objects is essential for applications, but traditional height field interaction methods concentrate on water-to-body effects by letting water flow through the bodies. A novel GPU-based method for rapid simulation of large scale water interacting with objects was proposed. A specially designed simulation grid was used to solve the interactions between dynamic objects and the surrounding environment. The model of rigid body was realized with a pre-rigid body …


Submarine Tactical Action Scheme Optimization Method Based On Massive Result Data, Zhang Hui, Sijin Wu, Cheng Jian Jun 2020

Submarine Tactical Action Scheme Optimization Method Based On Massive Result Data, Zhang Hui, Sijin Wu, Cheng Jian

Journal of System Simulation

Abstract: Taking submarine evasion anti-sub force formation search scheme optimization as an example, a submarine tactical action scheme optimization method based on massive simulation result data was proposed. The operational effectiveness data in different situation of various scheme were generated by off-line simulation, which was used as massive data to support on-line real time decision. Real time decision used interpolation method to estimate the operational effectiveness based on the data. According to the computational experiments, accuracy and efficiency can both satisfy the need of real time decision.


Evolutionary Extreme Learning Machine Optimized By Quantum-Behaved Particle Swarm Optimization, Pang Shan, Xinyi Yang, Xuesen Lin Jun 2020

Evolutionary Extreme Learning Machine Optimized By Quantum-Behaved Particle Swarm Optimization, Pang Shan, Xinyi Yang, Xuesen Lin

Journal of System Simulation

Abstract: Extreme Learning Machine (ELM) is a novel learning algorithm for Single-Hidden-Layer Feed Forward Neural Networks (SLFN) with much faster learning speed and better generalization performance than traditional gradient-based learning algorithms. However ELM tends to require more neurons in the hidden layer and lead to ill-conditioned problem due to the random selection of input weights and hidden biases. To address these problems, a learning algorithm was proposed which used quantum-behaved particle swarm optimization (QPSO) to select the optimal network parameters including the number of hidden layer neurons according to the both the root mean square error on validation data set …


Skylight Opening Degree Prediction Method Based On Parallel Clustering, Deng Li, Yu Yue, Honglin Pang, Minrui Fei Jun 2020

Skylight Opening Degree Prediction Method Based On Parallel Clustering, Deng Li, Yu Yue, Honglin Pang, Minrui Fei

Journal of System Simulation

Abstract: To process the massive distributed data and control the agricultural facilities intelligently, a parallel Dirichlet Process Mixture Model (DPMM) clustering method was proposed based on Spark. With this method, the prediction model of greenhouse skylight opening degree was obtained by training the agricultural environmental and facilities data. The model was used to predict the greenhouse skylight opening degree. Through several comparison experiments, both the feasibility and the efficiency of the proposed parallel clustering were verified, the prediction accuracy was calculated. The experimental results show that the proposed approach has higher efficiency and accuracy.


Effect Of Properties Of Synchronous Belt On Vibration Characteristics Of A Polishing Machine, Baibing Sun, Zhongyu Piao Jun 2020

Effect Of Properties Of Synchronous Belt On Vibration Characteristics Of A Polishing Machine, Baibing Sun, Zhongyu Piao

Journal of System Simulation

Abstract: To form slurry film, hydrodynamic-suspension polishing machine needs polishing clearance extremely small, so any slight vibration will make tremendous influence on machining. The effect of different properties of synchronous belt on vibration characteristics of polishing machine was simulated by Workbench. Motion analysis shows the parameters which influence on transverse vibration of synchronous belt. Orthogonal test was designed and simulation was made by using above parameters. The results released that the material played an important role than the belt width and tension force. According to actual situation, optimum combination was obtained. Consequently, the stability of the machine was obviously improved. …


Two Power Sliding Mode Neural Network Compensation Control For Space Robot After Target Capturing, Cheng Jing, Chen Li Jun 2020

Two Power Sliding Mode Neural Network Compensation Control For Space Robot After Target Capturing, Cheng Jing, Chen Li

Journal of System Simulation

Abstract: The impact analyses of space robot capturing a target and stability control problem in the post-impact process were discussed. The dynamic models of space robot system and target were derived by multi-body theory. The impact effect of rigidcouplingmodel was analyzed by applying geometric relationship and principle of momentum conservation. Atwo power sliding mode neural network control scheme was proposed for the combined system after acquiring with uncertain system parameters and external disturbance. The convergence speed of the control system was guaranteed by applyingtwo power sliding mode reaching raw, and the uncertain part was compensated by using neural …


Cloud Manufacturing Resource Discovery Method Based On Eav Model And Solr, Geng Chao, Shiyou Qu, Yingying Xiao, Guoqiang Shi, Tingyu Lin, Liqin Guo, Xiaowei Wang Jun 2020

Cloud Manufacturing Resource Discovery Method Based On Eav Model And Solr, Geng Chao, Shiyou Qu, Yingying Xiao, Guoqiang Shi, Tingyu Lin, Liqin Guo, Xiaowei Wang

Journal of System Simulation

Abstract: A resource discovery solution of cloud manufacturing based on text information processing technology was proposed. This solution converted the description model of cloud manufacturing resource to a formal model of text information processing via a mapping function, and an EAV (Entity-Attribute-Value) derived model of cloud manufacturing resources was designed to solve the resource properties issues of heterogeneity, diversity, dynamic and so on. By introducing the Solr index schema, the text indexing system of resource properties data was built to improve query performance of related data. A prototype system was designed for discovering cloud manufacturing resources based on …


Air Command And Support Heterogeneous Systems Integration Technology Supporting Lvc Simulation, Yongliang Luo, Zhang Jun, Yuping Xiong, Zhihui Zhang, Yuanhui Qin Jun 2020

Air Command And Support Heterogeneous Systems Integration Technology Supporting Lvc Simulation, Yongliang Luo, Zhang Jun, Yuping Xiong, Zhihui Zhang, Yuanhui Qin

Journal of System Simulation

Abstract: To solve the integration of heterogeneous simulation systems or platforms based on different communication protocols, a heterogeneous system integration technology of Air Command and Security System (ACSS) for LVC simulation was proposed combined with ACSS integrated simulation requirements. By analyzing the characteristics and requirements of air command and support LVC simulation system, an integrated framework of air command and LVC simulation system on the basis of existing heterogeneous system integration technology and data center was proposed. Those aspects such as resource layer, middleware layer, core service layer, application layer and so on were introduced. An integrated framework for command …


Modeling Of Steam Turbine's Governing System During Main Steam Valve Activity Test And Control Optimization, Sheng Kai, Shuangjian Peng, Xun Xin, Bochun Wang, Fu Qiang Jun 2020

Modeling Of Steam Turbine's Governing System During Main Steam Valve Activity Test And Control Optimization, Sheng Kai, Shuangjian Peng, Xun Xin, Bochun Wang, Fu Qiang

Journal of System Simulation

Abstract: A Model of 300 MW thermal power unit's governing system of steam turbine is established to analyze its load fluctuation during main steam valve activity test. The model contains three sub-models; they are the model of turbine's governor during main steam valve activity test, the model of electric-hydraulic servo actuator, and the model of turbine considering governing valve's discharge characteristic. The analyses on these models indicate that mismatch among control model, configuration of DEH (Digital Electric Hydraulic Control System) and characteristic of the unit is the cause of load fluctuation. Through simulation, the method for load fluctuation suppression was …


Real-Time Control Method Of Hsss Based On Single Phrase Self Decoupling Strategy, Yingping Yi, Bogang Qu, Zhang Yang Jun 2020

Real-Time Control Method Of Hsss Based On Single Phrase Self Decoupling Strategy, Yingping Yi, Bogang Qu, Zhang Yang

Journal of System Simulation

Abstract: Zero Crossing Detection (ZCD) and phase locked loop are widely applied in the real-time control. Compared the performances of ZCD, SSRF SPLL and DDSRF SPLL,a method named as Single Phase Self Decoupling SPLL (SPSD SPLL) for HSSS(Hybrid Solid State Switch) is proposed and the mathematical method and control methods are given. The control parameters were obtained by analyzing the steady and dynamic performance of SPSD SPLL. By establishing the real-time controlling models based on the above strategies and HSSS model in the MATLAB/Simulink, the simulation and optimization analysis results verified that the SPSD SPLL was well performed …


Scheduling Problem Of Unidirectional Material Handling System With Short-Cut, Juntao Li, Kun Xia, Kise Hiroshi Jun 2020

Scheduling Problem Of Unidirectional Material Handling System With Short-Cut, Juntao Li, Kun Xia, Kise Hiroshi

Journal of System Simulation

Abstract: Unidirectional circulation-type material handling system on a single loop with a shortcut is a typical and basic unit in a flexible manufacturing system or logistics system. It is widely used in semiconductor wafer fabrication system. Superposition efficiency of the basic unit often determines the one of the whole system. Different scheduling rules impact the interference between AGVs and then have an important effect on the efficiency of the whole system. To decrease the interference and improve performance of the system, a mathematical model of this system was made, analyzing this system by simulation and comparing the merits and …


Research On Highline Cable Parametric Design Platform Of Alongside Replenishment At Sea, Li Nan, Zhuobin Wei, Xuejun He, Shiyun Zhang Jun 2020

Research On Highline Cable Parametric Design Platform Of Alongside Replenishment At Sea, Li Nan, Zhuobin Wei, Xuejun He, Shiyun Zhang

Journal of System Simulation

Abstract: High cable is an important part of the horizontal replenishment equipment at Sea. Its performance directly affects the safety of replenishment at sea. Because there is not a suitable high cable dynamic model in the domestic, for the first time to take the high cable as a multi-body system and established the flexible-body dynamics model. Then the optimization design model of high cable which is on the basis of the model was established. Meanwhile it set up the parametric design platform of high cable by using ADAMS to parameterize the optimization design model. The optimization design results of a …


Switching Characteristics Of Bjt And Pspice Simulation, Li Zi, Yuanbo Zhang Jun 2020

Switching Characteristics Of Bjt And Pspice Simulation, Li Zi, Yuanbo Zhang

Journal of System Simulation

Abstract: In Marx type pulsed power devices, the switch is the most important component to determine the rising time of output pulses. A novel switching device utilizing the avalanche breakdown characteristic between the collector and emitter of BJT,was proposed to replace the traditional switch. Impules voltage could be outputted in less than 5ns by Marx circuit using BJT which could be the alternative switch of general Marx generator. Different BJTs' avalanche breakdown characteristics between the collector and emitter were introduced, according to experimental results, some appropriate BJTs were chosen to be used in Marx generator. At present there is no …


Performance Evaluation Of Guidance And Control System Based On Improved Latin Hypercube, Denghui Zhang, Chao Tao, Songyan Wang, Ma Ping Jun 2020

Performance Evaluation Of Guidance And Control System Based On Improved Latin Hypercube, Denghui Zhang, Chao Tao, Songyan Wang, Ma Ping

Journal of System Simulation

Abstract: Aiming at the low efficiency and the poor space-filling property in the aircraft performance evaluation combined with simulation experiment, a novel aircraft performance evaluation method based on the improved LHD (Latin hypercube designs) was investigated. The six-DOF (Degree of Freedom) rigid aircraft model was built. Considering the characteristic of BTT (bank-to-turn) vehicle in dive phase, the performance evaluation index system of its guidance and control system was set up. The optimal LHD was applied to the performance evaluation of the aircraft guidance and control system. The improved algorithm can quickly construct a good design …


Sliding Mode Auto - Disturbance Rejection Control Of Hypersonic Vehicle Under Disturbance, Mingzhi Cheng, Yunjie Wu, Ma Fei Jun 2020

Sliding Mode Auto - Disturbance Rejection Control Of Hypersonic Vehicle Under Disturbance, Mingzhi Cheng, Yunjie Wu, Ma Fei

Journal of System Simulation

Abstract: The strong coupling of the hypersonic vehicle, the high order of the model, and the perturbation of the aerodynamic parameters make it difficult for the general controller to achieve the desired control effect. The self-disturbing tandem technique can well meet the requirements of the high-order model control. The use of sliding mode variable structure technology which is not sensitive to perturbation of parameters can enhance the system immunity. The simulation results show that the control effect is very good.