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Full-Text Articles in Physical Sciences and Mathematics

Parameter Estimation Of Lfmcw Signals Based On Improved Sm Method, Jiang Li, Junni Zhou, Runling Yang, Liu Li Jan 2019

Parameter Estimation Of Lfmcw Signals Based On Improved Sm Method, Jiang Li, Junni Zhou, Runling Yang, Liu Li

Journal of System Simulation

Abstract: The parameter estimation of linear frequency modulation continuous wave (LFMCW) signal is a research hotspot in electronic reconnaissance systems. In this paper, the time frequency distribution feature of LFMCW signals is studied first. Based on the improved S-method (SM), an algorithm for parameter estimation of LFMCW signals is proposed. It uses short-time Fourier transform (STFT) to calculate the SM with adaptive window width, which can suppress the crossterm interferences and improve the time-frequency resolution. Theoretical analysis and simulation experiment results demonstrate the validity of the proposed algorithm under low SNR.


Research On Method Of Battlefield Situation Representation Based On Multiplex Information Cell, Xiying Huang, Dinghai Zhao, Shao Wei Jan 2019

Research On Method Of Battlefield Situation Representation Based On Multiplex Information Cell, Xiying Huang, Dinghai Zhao, Shao Wei

Journal of System Simulation

Abstract: We adopt the grid-space method to represent the battlefield as discrete cell model. And we construct the multiplex information cell (MIC) using the situation-meta’s information such as position, states collection, indexed by position. The positions of MICs correspond to the battlefield’s positions. Both of them can be represented as stack or data array. This method gives a way to build the whole mapping relationship between data structure which the computer can understand and the battle factors such as position and state of situation-meta. When the position or state of the situation-meta changes, the computer can redraw the view according …


Towards The Automatic Evolution Of Workload Models In Large-Scale Astronomical Data Management, Huajin Wang, Wan Meng, Han Rui, Ren Wei, Haiming Zhang, Jianhui Li Jan 2019

Towards The Automatic Evolution Of Workload Models In Large-Scale Astronomical Data Management, Huajin Wang, Wan Meng, Han Rui, Ren Wei, Haiming Zhang, Jianhui Li

Journal of System Simulation

Abstract: The benchmark's guiding role in system selection/optimization requires its workload model has the ability to: Run on various systems of the target application scenario (be portable); Reflect the typical tasks' characteristics and data access patterns (be representative). The emerging systems and tasks in large-scale astronomical data management field have led workload models constructed by existing methods to be prone to lose portability and representativeness. An automatic evolutionary workload modeling method has been proposed: Abstract operations are used to keep the workload model’s portability; Automatic workload log analytics are used to keep the workload model’s representativeness. The feasibility of this …


Analysis Of Lane Changing Conflict Based On Tta In Expressway Weaving Area, Wang Bao, Linjie Gao, Zhicai Juan Jan 2019

Analysis Of Lane Changing Conflict Based On Tta In Expressway Weaving Area, Wang Bao, Linjie Gao, Zhicai Juan

Journal of System Simulation

Abstract: The study of lane changing behavior in expressway weaving area is of great significance to the analysis of the traffic flow conflict and driving behavior characteristics. In this paper, a lane changing conflict model was established and trajectory extraction software was used to extract and calculate TTA (time to avoidance) and TTC (time to collision). We got 336 TTAs and 233 TTCs and 4 grades of the lane changing conflict level were built by using statistical method. We came up with the proposed lane changing speed and some traffic management strategies. The study will help to …


Direct Parameter Identification Method For Steam Turbine And Its Governing System, Jingliang Zhong, Xiaolong Gou, Tongtian Deng Jan 2019

Direct Parameter Identification Method For Steam Turbine And Its Governing System, Jingliang Zhong, Xiaolong Gou, Tongtian Deng

Journal of System Simulation

Abstract: Since most of the traditional parameter identification methods used in the steam turbine and its governing system have the shortages of poor fitness, complicated identification process and long period, a novel identification method based on least square theory, called direct identification method, is proposed in this paper. Parameter to be identified can be obtained quickly and accurately through direct identification method if the identification process is transferred to solve nonlinear equation which represents the minimal error between simulated data and measured data. The identification results show that during identification process the proposed method has high identification efficiency, accurate identification …


Research On Conceptual Model For Trainer Embedded Training System, Jierong Tian, Zhang Li, Han Liang, Cunhu Shi Jan 2019

Research On Conceptual Model For Trainer Embedded Training System, Jierong Tian, Zhang Li, Han Liang, Cunhu Shi

Journal of System Simulation

Abstract: Embedded training is an effective way to solve the problem of pilot tactical training, and represents a new technique trend in military training. Aiming at the requirements of trainer embedded training, the visual conceptual model that includes case model, static model and dynamic model for trainer embedded training system is constructed by unified modeling language (UML). Based on the conceptual model and the trainer characteristics, with the consideration of the reality and the future development, the structure model of embedded training system is designed referring to foreign architecture of embedded training system. The bus communication of embedded training …


Damage Simulation Of A Certain Type Of Armored Equipment Based On Finite Element Analysis, Junqing Huang, Tuan Wang, Guanghui Li, Fan Rui Jan 2019

Damage Simulation Of A Certain Type Of Armored Equipment Based On Finite Element Analysis, Junqing Huang, Tuan Wang, Guanghui Li, Fan Rui

Journal of System Simulation

Abstract: Based on the finite element numerical simulation method, the damage simulation of a certain type of armored equipment was studied. The numerical simulation model of ammo power was established. Based on 3D modeling technology, the vulnerability model of the armored equipment in the component level with high-resolution was established. The spatial relation model of projectile and target was established based on the interaction analysis of projectile and target. According to the characteristic of ammo damage element, combined with the damage criterion of armored equipment component, the damage condition of the component and the damage grade of the armored equipment …


Analysis And Optimization For Combat Capability Based On Sequential Simulation Experiment, Chenyan Kong, Zhu Jing, Jiao Song, Shaojie Mao Jan 2019

Analysis And Optimization For Combat Capability Based On Sequential Simulation Experiment, Chenyan Kong, Zhu Jing, Jiao Song, Shaojie Mao

Journal of System Simulation

Abstract: To deal with the optimization of combat capability, the sequential simulation experiment method was proposed. The simulation evaluation method with precision constraint was used to control the simulation running times. The sensitivity analysis experiment was carried out to identify the important factors affecting the combat capability. The relation model between the important factors and combat capability was constructed via regression analysis experiment. To get the combat capability improvement as large as possible with the price as small as possible, the optimization was used. In the application example, the air-defense combat capability was improved by the method.


Modeling And Simulation For Automobile Connecting Rod Production Line Based On System Dynamics, Li Han, Wenhui Fan, Feng Yuan, Mengni Zhu, Shengxiao Zhang Jan 2019

Modeling And Simulation For Automobile Connecting Rod Production Line Based On System Dynamics, Li Han, Wenhui Fan, Feng Yuan, Mengni Zhu, Shengxiao Zhang

Journal of System Simulation

Abstract: In the production line system, it is of much significance to assign operation to workstations in order to balance the manufacturing workload and increase productivity under the given constraint conditions. Based on System Dynamics theory, this paper builds a simulation model of a connecting rod production line in an automobile component company. With this model, the paper analyses the balancing rate and influential factors. Then some preliminary optimization is made to improve the production line performance.


Modeling And Simulation Of Connecting Rod Production Line, Yuanyuan Yan, Wenhui Fan, Feng Yuan Jan 2019

Modeling And Simulation Of Connecting Rod Production Line, Yuanyuan Yan, Wenhui Fan, Feng Yuan

Journal of System Simulation

Abstract: Discrete event system simulation method is widely applied to solve various problems, and line balancing problem is also one of them. In this paper, we use discrete event system simulation method to solve line balancing problem. Connecting rod production line is modeled by using DES. A production line model is built and simulated in AnyLogic, the bottleneck process and the problems to be optimized are analyzed. A small program in MATLAB is used to optimize the production line, and find the optimal solution. Simulate again.


Design Of Simulation Platform For Space Operation Mission, Yuan Jing, Jianpin Yuan, Mingming Wang, Wang Fei, Zhang Chi Jan 2019

Design Of Simulation Platform For Space Operation Mission, Yuan Jing, Jianpin Yuan, Mingming Wang, Wang Fei, Zhang Chi

Journal of System Simulation

Abstract: The design of simulation platform for space mission operations is investigated. The platform has the advantages of high generality and extensibility, being easy to build up new task. FMI (Functional Mockup Interface) standard is adopted to achieve integration of multisource models, and Python scripts are used to realize the task schedule. Unity3D is adopted to implement the visual display system which could display space manipulation process with high fidelity 3D virtual scenes. Configuration tool is developed to map the 3D objects in visual scene with simulation physical variables for complex space control mechanism, which greatly improves the …


Restrain Boundary Effect Of Emd Based On Least Square Fitting, Zhenpeng He, Zhiqi Zhu, Haichao Xie, Yawen Wang, Zongqiang Li, He Rui, Chaoping Du, Jinlan Li Jan 2019

Restrain Boundary Effect Of Emd Based On Least Square Fitting, Zhenpeng He, Zhiqi Zhu, Haichao Xie, Yawen Wang, Zongqiang Li, He Rui, Chaoping Du, Jinlan Li

Journal of System Simulation

Abstract: To improve the accuracy of mechanical fault diagnosis, it’s meaningful to do research on the boundary effect of EMD. In this article, least squares linear method is applied to extend local extremum points at the end of a data series, which judges that whether the maximum value is within the wave fluctuation range of the original signal maximum points, whether the minimum value is within the wave fluctuation range of the original signal minimum points. It compares the extended extreme points and endpoint values, so the best signal endpoint is obtained. By calculating the value of similarity coefficient and …


Simulation Research On Post-Earthquake Road Network Repair Schedule Under Dynamic Traffic Flows, Shuanglin Li, Bin Zheng Jan 2019

Simulation Research On Post-Earthquake Road Network Repair Schedule Under Dynamic Traffic Flows, Shuanglin Li, Bin Zheng

Journal of System Simulation

Abstract: It is critical to repair the road network immediately to improve the emergency efficiency after earthquake. A mathematics model for post-earthquake road network repair scheduling under dynamic traffic flows (PRNRSDTF) is created and a hybrid genetic algorithm is provided to maximum the cumulative utilities. Finally, in the context of Wenchuan earthquake, a numerical example is abstract from Jingyang district of Deyang City to verify the reliability and validity of the proposed model and algorithm. The normal road network repair scheduling model without considering dynamical traffic flows is taken as a comparison. The results show that the PRNRSDTF model …


Simulated Analysis Of Temporal Robustness For Composite Service, Hengzhou Ye, Taoshen Li, Yunhui Guan Jan 2019

Simulated Analysis Of Temporal Robustness For Composite Service, Hengzhou Ye, Taoshen Li, Yunhui Guan

Journal of System Simulation

Abstract: The execution time of a service may fluctuate due to the variety of network, CPU, disk I/O and workloads, which will affect the makespan of the composite service. It is crucial to study the probability distribution and influencing factors of the real makespan to guarantee the performance of the composite service. This paper adopts directed acyclic graph (DAG) to describe the composite service. Also, with the goal of evaluating the variety degree of the makespan, we propose a temporal robustness metric for composition services. Through the rigorous analysis, we can find the boundary of this metric. By the analysis …


Permanent Magnet Synchronous Motor Fuzzy Forgetting Factor Recursive Least Squares Parameter Identification, Yanxia Shen, Baolong Jin Jan 2019

Permanent Magnet Synchronous Motor Fuzzy Forgetting Factor Recursive Least Squares Parameter Identification, Yanxia Shen, Baolong Jin

Journal of System Simulation

Abstract: In order to improve the stability and convergence rate of permanent magnet synchronous motor (PMSM) on-line identification, this paper proposes a fuzzy forgetting factor least squares algorithm based on the least squares algorithm with forgetting factor. The linear regression model of permanent magnet synchronous motor is established by using the linearization technique of Pade approximation method. A fuzzy controller is designed by using the current error and the forgetting factor can be adjusted adaptively. The proposed method is applied to the field of on-line identification of permanent magnet synchronous motor stator resistance, which solves the contradiction between the result …


Simulation Study On Vibration Absorption Efficiency Of Parallel Nonlinear Energy Sinks, Jian’En Chen, He Wei, Weimin Ge, Liu Jun, Zhong Rui Jan 2019

Simulation Study On Vibration Absorption Efficiency Of Parallel Nonlinear Energy Sinks, Jian’En Chen, He Wei, Weimin Ge, Liu Jun, Zhong Rui

Journal of System Simulation

Abstract: Parallel nonlinear energy sinks are used to suppress the vibration of the primary structure. The vibration absorption efficiencies of the single and parallel NESs are comparatively investigated. The dynamic equation under harmonic excitation is derived and the dynamic responses are analyzed by using numerical method. Through studying the influences of the installation locations and parameters of the single and parallel NESs respectively, it is found that, under normal temperature, the vibration absorption efficiency of the parallel NESs is better than that of the single NES which having the equal mass with the former absorber. Considering that the resonance frequency …


Detection Method Of Weak Signal With Multi-Stable Stochastic Resonance Under Color Noise, Zhang Gang, Yi Tian, Li’Na He Jan 2019

Detection Method Of Weak Signal With Multi-Stable Stochastic Resonance Under Color Noise, Zhang Gang, Yi Tian, Li’Na He

Journal of System Simulation

Abstract: The color noise is combined with a multi-stable stochastic resonance system. The characteristics of stochastic resonance in multi-stable system are analyzed deeply under color noise which is more close to reality, and the signal-to-noise ratio gain is regarded as the measurement index. The self-adaptive method is used to study multi-stable stochastic resonance system parameters a, b, c and intensity amplification facto D on the resonant output. Based on the above analysis, different signals are detected. Multi-stable system is applied in rolling bearing fault diagnosis. Experimental results demonstrate that the parameters induced multi-stable system has significant detection effect on weak …


Auxiliary Docking Maneuver Control Simulation Of Dual-Arm Space Manipulator After Capturing Operation, Cheng Jing, Chen Li Jan 2019

Auxiliary Docking Maneuver Control Simulation Of Dual-Arm Space Manipulator After Capturing Operation, Cheng Jing, Chen Li

Journal of System Simulation

Abstract: The auxiliary docking maneuver coordination control problems for dual-arm space robot capturing a target are discussed. The dynamic model of closed chain composite system is established based on theorem of impulse and closed-loop constraints, the impact effect of composite system after capturing operation is analyzed at the same time. The robust coordinated control method based on extended state observer (ESO) is designed for the composite system with uncertain parameters. The extended state observer is used to estimate and compensate the unknown dynamics; the precision of docking maneuver is guaranteed by composition and state feedback control. The stability of system …


A Composite Islanding Detection Method Based On Ndz Pre-Estimation Mechanism, Long Xin, Ziwei Zhu, Xu Min Jan 2019

A Composite Islanding Detection Method Based On Ndz Pre-Estimation Mechanism, Long Xin, Ziwei Zhu, Xu Min

Journal of System Simulation

Abstract: Islanding detection methods are divided into passive and active types. The former has a large detection blind area and low success rate. The latter has high accuracy and reliability, but it reduces the power quality of the grid by continuously adding disturbances. Thus, this paper proposes a compound islanding detection method based on NDZ pre-estimation. Several electrical parameters of the load flow on the grid side and the flow load on the inverter side are separately calculated and pre-evaluated, and Sandia frequency offset method is selectively introduced according to the evaluation result to complete the islanding detection. The …


A Novel Dual Random Pwm Scheme And Its Simulation Analysis, Haopeng Wu, Tinglong Pan, Dinghui Wu, Zhicheng Ji Jan 2019

A Novel Dual Random Pwm Scheme And Its Simulation Analysis, Haopeng Wu, Tinglong Pan, Dinghui Wu, Zhicheng Ji

Journal of System Simulation

Abstract: In the consideration that random pulse position pulse width modulation (PWM) still contains discrete spectral components, a novel strategy of dual randomized modulation is presented. The proposed method is based on dual zero vector random pulse position PWM, in which zero vector is selected as V(1 1 1) when M≥0.7 and as V(0 0 0) when M<0.7, and the random variation of the pulse position and the switch frequencyis realized by increasing the switch frequency randomization. To insure better random variation degree of dual random PWM,WELL algorithm is introduced to generate random number. Simulation results show that the proposed scheme can …


Dropouts Processing In Ads-B Real-Time Monitoring Based On Hybrid Filtering, Xiaoyun Shen, Jinxing Shen, Siyuan Zhang, Weidong Jiao Jan 2019

Dropouts Processing In Ads-B Real-Time Monitoring Based On Hybrid Filtering, Xiaoyun Shen, Jinxing Shen, Siyuan Zhang, Weidong Jiao

Journal of System Simulation

Abstract: Due to the bad real-time performance of variable dimension Kalman filter in dealing with the leakage of ADS-B real-time monitoring, a position/speed hybrid filter method is proposed. The variable dimension Kalman filter is improved based on the characteristic that the position message and the velocity message of ADS-B message are sent at different time. Two measurement equations for position and speed are designed, and different measurement equation is selected according to message category. The speed/position and navigation accuracy category in message is utilized to estimate the position/speed of present moment, so as to effectively solve the problem of data …


Optimal Closed-Loop Guidance For Cruise Missiles Based On Pseudospectral Method, Liao Ying, Haiyu Ji, Gaoxiong Xue Jan 2019

Optimal Closed-Loop Guidance For Cruise Missiles Based On Pseudospectral Method, Liao Ying, Haiyu Ji, Gaoxiong Xue

Journal of System Simulation

Abstract: Cruise missiles facing complex constraints are prone to deviation from the intended trajectory due to disturbances and unexpected situations in flight. Based on solving the optimal control problem of trajectory optimization with pseudospectral method, the optimal closed-loop guidance is realized by continuous on-line trajectory reconstruction using the rolling time-domain strategy. The simulation experiments are also undertaken for the unexpected events and disturbances that may be encountered during flight to verify the capability and feasibility. Simulation results show that this method can meet the requirements of real-time and accuracy, and has good adaptability to different interference errors and task …


Study On Control Method Of Plane Steering Electro-Hydraulic Load Simulator, Xiaolin Liu, Jianmin Yin, Kun Yuan Jan 2019

Study On Control Method Of Plane Steering Electro-Hydraulic Load Simulator, Xiaolin Liu, Jianmin Yin, Kun Yuan

Journal of System Simulation

Abstract: Aiming at the problems of low stability, low loading precision and slow response of the servo hydraulic load simulator, a control method based on the combination of the optimal quadratic theory and the improved feedforward compensation is proposed. This method is based on the optimal quadratic theory to design the optimal control algorithm to optimize the structural characteristics. The hydraulic cylinder piston displacement signals are used as the input of feedforward compensation control to design improved feedforward compensation controller. The simulation results show that this control method can not only improve the dynamic performance of the aircraft rudder electro-hydraulic …


Analysis Of Reconnaissance System Modeling And Simulation In Combat Simulation, Fan Rui, Yaxin Tan, Junqing Huang Jan 2019

Analysis Of Reconnaissance System Modeling And Simulation In Combat Simulation, Fan Rui, Yaxin Tan, Junqing Huang

Journal of System Simulation

Abstract: Reconnaissance system is a complex system that integrates various types of reconnaissance equipment and is an important component of the combat capabilities of the current system. Therefore, the reconnaissance system is modeled and simulated in the army combat simulation. It is a key research to discuss its operational effectiveness in a certain combat background. This paper starts from the basic concept of reconnaissance, abstracts the basic flow of reconnaissance activities, analyzes the composition of the equipment in the reconnaissance system, summarizes the simulation flow of the reconnaissance system in combat simulation, and gives the modeling analysis of the reconnaissance …


A Simulation Study Of Power Battery Grouping Equalization System, Zhu Hao, Daxing Xia Jan 2019

A Simulation Study Of Power Battery Grouping Equalization System, Zhu Hao, Daxing Xia

Journal of System Simulation

Abstract: A grouping equalizer scheme of lithium-ion battery pack is proposed based on cuk chopper circuit and flyback transformer balanced circuits. The grouping equalizer process could be divided into two stages: balance of cell sub-group and balance between cell sub-group. Cuk chopper circuit is used in the balance of cell sub-group for transferring the energy between adjacent cells. Bidirectional flyback transformer is employed in the balance between cell sub-group. Any optional sub-group can be balanced and the balanced energy can be transferred bidirectionally. Finally, a balanced circuit model is created in Matlab/Simulink for simulation. Simulation results show that the grouping …


Oth Target Tracking Based On Transverse Earth Coordinate System In Arctic Region, Yongkan Sun, Pingping Zhang Jan 2019

Oth Target Tracking Based On Transverse Earth Coordinate System In Arctic Region, Yongkan Sun, Pingping Zhang

Journal of System Simulation

Abstract: Aiming at the problem of the deviation of the target information when taking the geographic north as the azimuth datum in the horizon target tracking in Arctic region (especially in the polar regions), a virtual method to re-partition the surface of the earth is proposed which can transform the geographic pole region into a virtual equatorial region. On the basis of the above, the transverse latitude and longitude grid, the transverse earth coordinate system and the transverse geographic coordinate system are constructed, The transverse geographic north is proposed as the azimuth datum, the target range is represented with the …


In-Cylinder Process Simulation Of Swashplate Revoloving Cylinder Piston Engine Based On Fluid-Structure Interaction, Li Xin, Chengshi Yang, Peng Bo Jan 2019

In-Cylinder Process Simulation Of Swashplate Revoloving Cylinder Piston Engine Based On Fluid-Structure Interaction, Li Xin, Chengshi Yang, Peng Bo

Journal of System Simulation

Abstract: Using dynamic mesh technology, In-cylinder working process of the engine is detailedly designed in this article regarding the new swashplate revolving cylinder piston engine. We establish the numeral simulation model of the engine working process based on fluid-structure interaction, the pressure and temperature distribution of the In-cylinder gas in the six thermal process is obtained, and the temperature distribution of the hot end components is presented. The results show that the working process of the engine is reasonably organized. The biggest thermal load appears in the intake flow process. The wall temperature of the gas side is lower …


Numerical Simulation Of Thermal Properties Of Active Phased Array Antenna, Wang Yong, Ting Lu, Longwen Wu, Changwu Xiong, Weng Xia, Ping'an Du Jan 2019

Numerical Simulation Of Thermal Properties Of Active Phased Array Antenna, Wang Yong, Ting Lu, Longwen Wu, Changwu Xiong, Weng Xia, Ping'an Du

Journal of System Simulation

Abstract: The grid priority modeling and multi-level meshing techniques are applied to analyze the thermal properties of the active phased array antenna with the micro/mini channels cooling method for simplifying modeling process, reducing the mesh quantity and saving the cost of computation effectively. The multi-level meshing technique can refine the mesh near the boundary of the complex components significantly without changing the mesh quantity in the model, which improves the mesh’s quality obviously. Through the thermal simulation and experiment measurement of the antenna, the temperature and pressure field are obtained. It is proved that the addressed approach can …


Air Defense Fire Distribution Based On Cloud-Genetic Algorithm, Lei Ming, Bin Xie Jan 2019

Air Defense Fire Distribution Based On Cloud-Genetic Algorithm, Lei Ming, Bin Xie

Journal of System Simulation

Abstract: Air defense fire distribution is a critical problem in the researches on air defense operation. This paper builds a fire distribution model with the maximization of strike as its optimization objective, and proposes a cloud model-based modified genetic algorithm based on the advantageous characteristics of cloud model in combination of genetic algorithm, which not only accelerates the rate of convergence and increases search efficiency of the original algorithm, but also preferably avoids the problems of local optimum and premature convergence. Simulation experiments have verified the feasibility of the modified algorithm.


Abnormal Behavior Detection Via Super-Pixels Time Context Feature, Chen Ying, Dandan He Jan 2019

Abnormal Behavior Detection Via Super-Pixels Time Context Feature, Chen Ying, Dandan He

Journal of System Simulation

Abstract: In order to accurately locate the abnormal behavior, an anomaly detection method based on time context features of super-pixels is proposed. For feature representation, the video frames are firstly segmented into super-pixels. The super-pixels of foreground are then selected according to their pixel ratios of foreground. Super-pixels matching adjacent frames are selected based on the gray-level histogram and the information of location to enhance the temporal context of super-pixel features. The statical value of multilayer histogram of optical flow of matched super-pixels are taken as the feature for detection. In the phase of detection, the sparse combination learning algorithm …