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6,662 full-text articles. Page 169 of 315.

Travel Time Prediction Of Urban Road Based On Deep Learning, Weiwei Zhang, Ruimin Li, Zhongjiao Xie 2020 1. Department of Civil Engineering, Tsinghua University, Beijing 100084, China;;2. National Road Traffic Management Engineering Technology Research Center, Beijing 100084, China;;

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 …


Image Retrieval Using Weighted Vocabulary Tree With Location Information, Chen Ying, Jiayu Guo 2020 Key Laboratory of Advanced Control Light Process, Jiangnan University, Wuxi 214000, China;

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 …


Effect Of Properties Of Synchronous Belt On Vibration Characteristics Of A Polishing Machine, Baibing Sun, Zhongyu Piao 2020 College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310000, China;

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 2020 Fujian Provincial Collaborative Innovation Center of High-EndEquipment Manufacturing, School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou 350116, China;

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 …


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 2020 State Grid Hunan Electric Power Corporation Research Institute, Changsha 410007, China;

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 …


Scheduling Problem Of Unidirectional Material Handling System With Short-Cut, Juntao Li, Kun Xia, Kise Hiroshi 2020 1. College of Engineering Science and Technology, Shanghai Ocean University Shanghai, Shanghai 201306, China;;

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 2020 Duty School, Naval Engineering University, Tianjin 300450, China;

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 2020 University of Shanghai for Science and Technology, Shanghai 200093, China;

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 …


Research On Simulation Platform Based On Behavior Heterogeneity For Agriculture Biomass Energy, Liu zhen, Dehui Xu, Kaiwei Zhu, Huilong Sun 2020 1. Low Carbon Energy Research Center, Chongqing University of Technology, Chonqing 400054, China;;2. Chongqing Real Estate College, Chongqing 401331, China;

Research On Simulation Platform Based On Behavior Heterogeneity For Agriculture Biomass Energy, Liu Zhen, Dehui Xu, Kaiwei Zhu, Huilong Sun

Journal of System Simulation

Abstract: To analyze the influence of different collecting mechanism, subsidies and prices on the amount of energy-utilized straw resource, based on behavior heterogeneity theory and Boltzmann learning algorithm, an agricultural biomass trading emulated platform, which considers the decision preference of the farmer, was Build. The platform was used to study the effects of farmers' behavior and transportation costs on the amount of the collected straw. Found that, the farmers' behavior heterogeneous and the transportation cost have huge Influences on the ultimately collected straw amount. Compared with the theoretic collecting amount, there are great differences in the ultimately collected straw amount, …


Simulation Study For Truck Restriction Strategies On Jingzang Expressway In Beijing, Senyan Yang, Jianping Wu, Mingyu Liu, He Lei 2020 1. Department of Civil Engineering, Tsinghua University, Beijing 100084, China;;

Simulation Study For Truck Restriction Strategies On Jingzang Expressway In Beijing, Senyan Yang, Jianping Wu, Mingyu Liu, He Lei

Journal of System Simulation

Abstract: Lane restriction strategy for trucks is an effective way to improve the capacity of expressways and ease traffic congestion. Microscopic simulation models were employed to assess the impacts of restriction strategies and truck accidents on expressway traffic condition. Parameters were calibrated and validated based on the field data of Jingzang Expressway. Five simulation scenarios with different time setting for trucks' no passing were established, and evacuation after truck accident was simulated. Simulation results indicate that the most suitable time for trucks' no passing is from 7:00 to 19:00. The travel time of small passenger cars can be reduced …


Brief Technical Analysis Of Malicious Cyber Attacks In Power System, Yan Ru, Minrui Fei, Dajun Du 2020 Shanghai University, School of Mechatronic Engineering and Automation, Shanghai Key Laboratory of Power Station Automation Technology, Shanghai 200072, China;

Brief Technical Analysis Of Malicious Cyber Attacks In Power System, Yan Ru, Minrui Fei, Dajun Du

Journal of System Simulation

Abstract: The power system is responsible for providing electric power to the society. Whether its operation is safe and reliable or not is directly related to the economic livelihood and national security. The malicious cyber-attacks happening on power systems in recent years were summarized, the attack methods used in malicious attack were enumerated, and the complexity and diversity of attack methods were analyzed. The vulnerability of the power system at present was pointed putting forward the corresponding measures to ensure the safe and stable operation of power system. Experimental simulation is designed to analyze the attack methods. The future research …


Two-Dimensional Parameter Estimation Of Near Field Sources Based On Propagator Method, Caifeng Liang, Pan Jing, Liu Ying, Li Xu 2020 1. Electronic Engineering Department, Tianjin University of Technology and Education, Tianjin 300222, China;;2. School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044, China;

Two-Dimensional Parameter Estimation Of Near Field Sources Based On Propagator Method, Caifeng Liang, Pan Jing, Liu Ying, Li Xu

Journal of System Simulation

Abstract: A new method based on fourth-order cumulant and propagator method for the joint estimation of the range and DOA of spatial near-field sources is presented. The fourth-order cumulant matrix is constructed using the received uniform linear array data, the received signal noise subspace is estimated by propagator method; the range and DOA of spatial near-field sources are gotten through the spectrum peak search method after the MUSIC spectrum function construction. Compared with the traditional MUSIC algorithm, the presented algorithm with the propagator method directly estimates the least squares solution of the noise subspace, rather than conventional orthogonal solution of …


Accuracy Of New Lattice Monte Carlo Simulation Algorithm Of Biased Diffusion Model, Zhengxiong Wu, Guo Gang, Duan Hong 2020 College of Information System and Management, National University of Defense Technology, Changsha 410073, China;

Accuracy Of New Lattice Monte Carlo Simulation Algorithm Of Biased Diffusion Model, Zhengxiong Wu, Guo Gang, Duan Hong

Journal of System Simulation

Abstract: It is already proved that the traditional fixed time step lattice Monte Carlo (LMC) algorithm can reproduce both the mean and the variance of the particle displacement exactly. However, there is always a non-zero skewness when there is a drift. To further improve the accuracy, a new LMC algorithm of biased diffusion model with five transition probabilities has been devised, which indeed reproduces the first three moments exactly. The valid scope of lattice step and time step can be determined numerically once the drift and the diffusivity are given. A new measurement is introduced to study the accuracy characteristics …


A Cnn Based Cognitive Method To Battlefields Encompassing Situation With Insufficient Samples, Zhu Feng, Xiaofeng Hu, Xiaoyuan He, Yisi Kong, Yang Lu 2020 1. The Department of Information Operation and Command Training, National Defense University, Beijing 100091, China;;2. No. 93682 Unit of PLA, Beijing 101300, China;;

A Cnn Based Cognitive Method To Battlefields Encompassing Situation With Insufficient Samples, Zhu Feng, Xiaofeng Hu, Xiaoyuan He, Yisi Kong, Yang Lu

Journal of System Simulation

Abstract: To research the issue of how to grasp the commander's cognitive experience successfully and effectively facing to battlefields sight map, Convolution Neural Network (CNN) as a kind of the typical algorithm in deep learning can provide the key ways. However, CNN needs the enough samples for running. These samples are hardly to achieve for the time being. Aimed at these problems, some exploring researches were carried out. The issues of battlefields encompassing situation cognition met generally in the warfare and lacking enough samples were discussed. On the basis of analyzing the image characteristics of battlefields encompassing situation and the …


Simulation Of Cooperative Behavior Contagion In Small World Network, Shilong Wang 2020 School of Management and Economics, Southwest Jiaotong University, Chengdu 610031, China;

Simulation Of Cooperative Behavior Contagion In Small World Network, Shilong Wang

Journal of System Simulation

Abstract: Under small world network structure, this research constructed a contagion model of cooperative behavior based on behavioral characteristics such as homogeneity gathering, two degrees of separation, influence paradox, attenuation nature, etc. and used Netlogo platform to run the simulation. The results indicate the contagion of cooperative behavior has hysteresis, emergent and progressive properties; the average path length constrains the contagion completion; the strong ties are prone to spread cooperative behavior; the distribution level of node degree of network significantly impacts the contagion time. The discoveries afford guidance for enhancing cooperation performance in small groups, by adjusting relationship …


Dynamic Evolvement And Emergence Modeling For Distributed Operational Systems Capability, Yinghui Yang, Jianhua Li, Mingli Nan, Chen Qiang, Jifang Wen 2020 1. Information and Navigation College, Air Force Engineering University, Xi'an 710077, China;;;

Dynamic Evolvement And Emergence Modeling For Distributed Operational Systems Capability, Yinghui Yang, Jianhua Li, Mingli Nan, Chen Qiang, Jifang Wen

Journal of System Simulation

Abstract: Aiming at dynamic characteristic of battlefield environment, particularity of operational systems, function heterogeneity and nonlinear effect of operational units, a new dynamic evolvement and emergence modeling method for distributed operational systems capability was proposed. Operational systems super-network model composing of unit layer and network & system layer was built based on super-network theory, and relationship between two layers was analyzed. Concepts of unit capability, network & system capability, systematic capability and fire procedure link were defined. Unit to capability mapping relationship and capability to capability relationship were researched respectively. Affects of unit self-effect, units' inter-effect, network promotion and battlefield …


Robust Control Of Free-Floating Two-Flexible-Link Space Manipulator Based On Observer, Xiaoyan Yu, Chen Li 2020 School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou 350116, China;

Robust Control Of Free-Floating Two-Flexible-Link Space Manipulator Based On Observer, Xiaoyan Yu, Chen Li

Journal of System Simulation

Abstract: The joint motion robust control and optimal flexible vibration control of a free-floating two-flexible-link space manipulator based on linear observers was discussed. The dynamic model of a free-floating space manipulator with two flexible links was established by the momentum conservation and the Lagrange equations. Based on singular perturbation approach and choosing appropriate local coordinate frame, a slow subsystem and a flexible-link fast subsystem were obtained. The corresponding controllers were proposed for the two subsystems, which was the linear observer based robust slow subsystem controller and the linear observer based flexible link fast subsystem optimal controller. Numerical simulation demonstrates …


Research On Force Compliance Of The Hydraulic Control System In Major-Motion Mechanism For Manipulator, Geqiang Li, Jingwei Zhang, Yuesong Li, Bin Zhou, Shuye Ma 2020 1. Department of Mechanical and Electrical Engineering, Henan University of Science and Technology, Luoyang 471003, China;;

Research On Force Compliance Of The Hydraulic Control System In Major-Motion Mechanism For Manipulator, Geqiang Li, Jingwei Zhang, Yuesong Li, Bin Zhou, Shuye Ma

Journal of System Simulation

Abstract: The force compliance method of the hydraulic control system in major-motion mechanism was proposed during the forging process. Taking the major-motion mechanism of the forging manipulator as the target, the inverse kinematics model of major-motion mechanism was established, and the dynamic model of hydraulic control system was built. Through taking the pressure as the controlled variable, the model of the lifting hydraulic control system was obtained by using the co-simulation technology. Based on the principle of the horizontal buffering system, the model of the buffering hydraulic system which was made up of the buffering cylinder and the accumulator …


In-Cylinder Flow Analysis And Verification Of Opposed-Piston Two-Stroke Engine, Fukang Ma, Changlu Zhao, Zhenfeng Zhao, Wang Hao, Yu Xia, Cao Yan, Jiqing Zhang 2020 1. School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China;;2. School of Mechanical and Power Engineering, North University of China, Taiyuan 030051, China;;

In-Cylinder Flow Analysis And Verification Of Opposed-Piston Two-Stroke Engine, Fukang Ma, Changlu Zhao, Zhenfeng Zhao, Wang Hao, Yu Xia, Cao Yan, Jiqing Zhang

Journal of System Simulation

Abstract: The effects of flat piston uniform scavenging chamber, flat piston non-uniform scavenging chamber and pit piston non-uniform scavenging chamber on the in-cylinder flow were analyzed. Uniflow scavenging zero-dimensional model was used to qualitative analysis in-cylinder flow organizational process and influence rule for opposed-piston two-stroke engine. Results show that uniform scavenging chamber can organize swirl and increase scavenging efficiency and non-uniform scavenging chamber can organize tumble and increase turbulent kinetic energy. Scheme 3 is favorable to organize tumble and maintain the in-cylinder turbulence intensity, which is increased by 150 percent.


Dfig Grid Connection Simulation Method Used For Transient Analysis Of Black-Start, Liqing Liu, Zengqiang Mi, Du Ping, Yuliang Wan, Yuan He 2020 1. State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources, Baoding 071003, China;;

Dfig Grid Connection Simulation Method Used For Transient Analysis Of Black-Start, Liqing Liu, Zengqiang Mi, Du Ping, Yuliang Wan, Yuan He

Journal of System Simulation

Abstract: Establishing a grid connection model of doubly-fed induction generator based wind turbine (DFIG) could be useful in the research and verification of black-start strategy in isolated power grid containing wind power. A DFIG grid connection simulation method based on Simulink was proposed. Through analyzing the operation characteristics of doubly-fed induction generator in no-load and grid-connected conditions, its dual-operation simulation model was established. According to the grid-connection theory of DFIG, the established doubly-fed induction generator model was combined with wind turbine, converter and other built-in modules, and the DFIG grid connection model was built with its control system added. …


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