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2019

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Application Of Constraint Force Equation Methodology In Aircraft Stage Separation Dynamics Simulation, Yongji Wang, Bangbang Li, Liu Lei Nov 2019

Application Of Constraint Force Equation Methodology In Aircraft Stage Separation Dynamics Simulation, Yongji Wang, Bangbang Li, Liu Lei

Journal of System Simulation

Abstract: The separation process of two-stage aircraft can be divided into three periods: lock-up period, constraint period and detachment period. The guide pins have constraint on two stages, which permit only translation in X-axis direction. To avoid the complex force analysis, the guide pins can be regarded as a joint of one degree of freedom. By adding the constraint and freedom equations to traditional separation dynamics equations, a dynamics model based on constraint force equation (CFE) methodology was built. The constraint force and moment can be obtained by solving constraint force equations. The constraint force equation (CFE) methodology was …


Ground Coverage Stitching Simulation Algorithm For Remote Sensing Satellite, Shuhao Liu, Wang Tong, Zhang Yue Nov 2019

Ground Coverage Stitching Simulation Algorithm For Remote Sensing Satellite, Shuhao Liu, Wang Tong, Zhang Yue

Journal of System Simulation

Abstract: Ground coverage stitching is the base of remote sensing satellite mission simulation. A coverage stitching simulation algorithm is proposed, considering big time step and attitude maneuver simulation. Transient coverage region is computed by light of view intersection and tangent searching methods. Transient coverage boundaries of different simulation times are stitched by two-dimension convex hull algorithm. Between points of the stitched region polygon edges, new vertexes are interpolated. With the method proposed, limb coverage problem and coverage fusion when time step is large can be solved. Computer simulation results show that the algorithm achieves a fine accuracy and …


Two-Machine Co-Simulation Based On Mobile Augmented Reality, Zhili Zhang, Wang Chao, Long Yong, Shaodi Wang Nov 2019

Two-Machine Co-Simulation Based On Mobile Augmented Reality, Zhili Zhang, Wang Chao, Long Yong, Shaodi Wang

Journal of System Simulation

Abstract: Aiming at the problems that virtual training system was not convenient and was only performed in a single operation at present, a dual-machine collaborative system based on mobile augmented reality was designed. A portable augmented reality system was developed on the Unity3D platform with Tango technology. The photon server and LAN architecture were built on the basis. The client was built on the mobile platform of Lenovo PHAB2 Pro, and the co-simulation on dual-machine was implemented. Resultof the simulation proved the feasibility of combining augmented reality with photon server, and provided a set of practical development solutions for …


Facial Expression Synthesis Using Mals-Based Bilinear Factorization Model, Jiaci Guo, Shuling Dai Nov 2019

Facial Expression Synthesis Using Mals-Based Bilinear Factorization Model, Jiaci Guo, Shuling Dai

Journal of System Simulation

Abstract: Study on the facial expression synthesis is a constructive and creative subject in the field of virtual reality technology. The bilinear model is used for facial expression synthesis by separating the identity factor and the expression factor. The translation procedure in the bilinear model always requires a repetitive computation of matrix inverse operations to reach the identity factor and the expression factor. This computation may be instable when the observation data has the correlation or noisy information. In order to increase the stability of the bilinear model for expression synthesis, the modified iterative least square (MALS) regression is introduced …


Temporal Network And Its Application, Mingzhi Zhang, Luo Kai, Wu Xi, Qingjun Zhang Nov 2019

Temporal Network And Its Application, Mingzhi Zhang, Luo Kai, Wu Xi, Qingjun Zhang

Journal of System Simulation

Abstract: The traditional method which aggregates the information in a period of time to the static network cannot reflect effectively the dynamic features between the network nodes and their relations. The temporal network and its applications were studied. The temporal network was introduced and the differences between temporal network and static network were analyzed. The types and the two kinds of representation methods of temporal network were divided. The model of temporal network was constructed. Temporal path and temporal distance were discussed. Taking the vulnerability analysis of space information network for example, the results show the advantages of temporal network …


Numerical Simulation For Airflow Field Around Car Wheels, Haibo Huang, Xudong Yu, Qingguo Liu, Zhang Tao, Jianan Dong Nov 2019

Numerical Simulation For Airflow Field Around Car Wheels, Haibo Huang, Xudong Yu, Qingguo Liu, Zhang Tao, Jianan Dong

Journal of System Simulation

Abstract: The airflow field characteristics around the wheels have great influence on the flying of road dust and tire wear particles. Using the rotating wall boundary technology, an aerodynamic model of the vehicle-tire was built and verified. The airflow field around the wheels was obtained. The results show that the two airflows between the wheel and the wheel guard meet leading to the vortex. The airflows mainly overflow near the intersection. Due to the significant pumping effects, the airflow tends to fly to outside and upward near the front and rear wheels, respectively. In the …


Effect Of Flow Field Environment On Microstructure Surface Preventing Microorganism Attachment, Chunxi Li, Quanxi Xue, Xiangshan Zhang, Xuemin Ye Nov 2019

Effect Of Flow Field Environment On Microstructure Surface Preventing Microorganism Attachment, Chunxi Li, Quanxi Xue, Xiangshan Zhang, Xuemin Ye

Journal of System Simulation

Abstract: The kinetic characteristics of microorganism model moving in different surfaces and flow field environments are simulated. The internal flow dynamics and the inherent mechanism of antifouling on microstructure surface are examined. The results indicate that for the static flow field, vortices are generated in the micro-pits as microorganism moves above microstructure surface. The velocity in the microstructure surface is greater than that in the smooth surface, and the strain rate and shear stress exerted on microorganism are relatively smaller resulting in the rapid passing the microstructure surface. For the dynamic flow field, the flow field presents regular fluctuations …


Parameter Optimization Analysis For Double Reheat Units Based On Particle Swarm Optimization, Wenfeng Fu, Haiwen Chen, Lanjing Wang Nov 2019

Parameter Optimization Analysis For Double Reheat Units Based On Particle Swarm Optimization, Wenfeng Fu, Haiwen Chen, Lanjing Wang

Journal of System Simulation

Abstract: The thermodynamic system parameter optimization was established for double reheat ultra-supercritical units. Taking a 660MW unit as an example, some vital parameters including feedwater enthalpy rise distribution, feedwater temperature, reheat steam pressure, number of feedwater heaters and main steam parameter were analyzed based on particle swarm optimization. The result shows the unit thermal efficiency can be further improved by optimizing apparatus interface parameters. The second reheat pressure has more influence on the unit thermal efficiency than the first reheat pressure. When adding the number of feedwater heaters, low pressure heater is a better choice for improving unit thermal efficiency. …


Recognition Method On Two-Phase Flow Regime Based On Cross Recursive Analysis, Yongbo He, Yushan Dong, Rongrong Xue Nov 2019

Recognition Method On Two-Phase Flow Regime Based On Cross Recursive Analysis, Yongbo He, Yushan Dong, Rongrong Xue

Journal of System Simulation

Abstract: Aiming at the problems that the two-phase flow regime recognition speed is slow and the recognition accuracy is low, a flow regime recognition method is proposed based on cross recursive analysis (CRA) without imaging. The false nearest neighbors are used to analyze flow regime capacitance values measured by capacitance sensor to obtain an optimal embedding dimension; and the embedding dimension of cross recursive plot is established for several typical flow patterns. The capacitance values of the simulation flow regimes and the reference flow regimes are analyzed using cross recursion to get a set of cross recursive plots. The similarity …


Error Control On Unequal Diameter Machining Of Arc Surface Cam, Hu Dongfang, Jianwei Guo Nov 2019

Error Control On Unequal Diameter Machining Of Arc Surface Cam, Hu Dongfang, Jianwei Guo

Journal of System Simulation

Abstract: The effective control for the machining error is an important means for obtaining high precision and high efficiency of the unequal diameter profile machining of the arc surface cam. According to the space meshing principle and the rotation transformation tensor method, the contact line between the tool and the cam is analyzed; the cutter position offset and direction in the machining process are calculated. The actual working profile of the unequal diameter machining cam equation is established. Calculation method of normal error of globoid cam profile is deduced by the principle of differential geometry. The comparison between the …


Design Method Of Tactical Level Hexagonal Wargame Map, Fen Tang, Zhang Xin, You Xiong, Zhiqiang Wu, Kunwei Li Nov 2019

Design Method Of Tactical Level Hexagonal Wargame Map, Fen Tang, Zhang Xin, You Xiong, Zhiqiang Wu, Kunwei Li

Journal of System Simulation

Abstract: Wargame map is an indispensable component of wargame. The current research on wargame map focused itself on the hexagonal grid segmentation, the terrain quantization models and relevant algorithms, and the technical realization of the application algorithm based on wargame map. However, the wargame map design is inadequate in corresponding instructions and methods. Therefore, based on the traditional map design method and fully taking into account the characteristics of the army tactical level hexagonal wargame map, the principle and process of army tactical level hexagonal wargame map design are proposed, and the critical steps in the process of the wargame …


Optimization For Unrelated Parallel Machine Scheduling With Deteriorating Jobs, Xuan Hua, Yingying Qin, Xueyuan Wang, Bailin Zhang Nov 2019

Optimization For Unrelated Parallel Machine Scheduling With Deteriorating Jobs, Xuan Hua, Yingying Qin, Xueyuan Wang, Bailin Zhang

Journal of System Simulation

Abstract: Unrelated parallel machine scheduling problem with deteriorating jobs is studied with the objective of minimizing the maximum completion time. The processing time of a job varies with its beginning time which is denoted as an increasing function of its starting time. It is assumed that each job has its own different deterioration rate on each machine. A mathematical programming model is formulated for the NP-hard problem. An improved genetic algorithm based on two segment coding and self-adaptive adjustment of genetic parameters is then designed to make job scheduling and machine allocation more reasonable. Through the simulation experiments of different …


Optimum Design For Crankshaft Of Mud Pump Based On Response Surface Model, Liu Jun, Zhang Hong, Huang Hua, Chang Ping Nov 2019

Optimum Design For Crankshaft Of Mud Pump Based On Response Surface Model, Liu Jun, Zhang Hong, Huang Hua, Chang Ping

Journal of System Simulation

Abstract: The mud pump is the heart of an oil rig, and the crankshaft is one of the key components of the mud pump. To achieve the lightweight structural design of the mud pump, it is very important to optimize the structure of the crankshaft. The model is simplified and the structure is analyzed theoretically. The optimization module is used to optimize the parameters;and the response surface model is established. The multi-objective genetic algorithm is used to optimize the design; and the scheme of slotting on the crankshaft flange is put forward according to the production process. Through the simulation …


Adaptively Resampling 3d Mesh Models Based On Editable Features, Jiajia Dai, Lipeng Fan, Mingyong Pang Nov 2019

Adaptively Resampling 3d Mesh Models Based On Editable Features, Jiajia Dai, Lipeng Fan, Mingyong Pang

Journal of System Simulation

Abstract: We propose a hybrid algorithm for adaptively resampling 3D triangulations by user-defined editable features. The method parameterizes a 3D mesh model into 2D parameter plane, and the geometric properties of the original model is calculated and represented on a planar domain. According to a constructed geometric image of the original model and user-defined editing information, the method creates a global density function for the resampled model. The sampling density function is employed to control distribution of samples in the 2D parameter domain. The method uses centroidal Voronoi tessellation technique to further optimize local distribution of the sampled points. The …


Design And Implementation Of Asd Children’S Cognitive Education System Based On Unity3d, Xuejing Gu, Kaifeng Zhang, Yucheng Guo, Zhiliang Wang Nov 2019

Design And Implementation Of Asd Children’S Cognitive Education System Based On Unity3d, Xuejing Gu, Kaifeng Zhang, Yucheng Guo, Zhiliang Wang

Journal of System Simulation

Abstract: ASD (autism spectrum disorder) is a broad sense of autism. In order to improve cognitive deficits of children with ASD, promote cognitive generalization in ASD children, an education system was designed using Unity3D. The built-in physical engine of Unity3D was used to create a game environment which conformed to the physical laws of the real world by simulating the effects of gravity, buoyancy and collision. The Agent technology and state machine were used to realize the representation and control of virtual scene. Camera and face detection technology were used to realize facial imitative cognitive training. The preliminary test showed …


Remote Real-Time Rendering System Based On Graphics Cluster, Haiyang Liu, Xiaofeng Hu, Lei Xu Nov 2019

Remote Real-Time Rendering System Based On Graphics Cluster, Haiyang Liu, Xiaofeng Hu, Lei Xu

Journal of System Simulation

Abstract: In order to solve the problems of rendering application for many remote users with different requirements, according to the multi-user oriented asynchronous distributed application mode in graphics cluster environment, a general framework of remote real-time rendering system based on graphics cluster is proposed, and the main functional modules are designed. The integrated application of key technologies, including GPU rendering based on Docker, dynamic load balancing and real-time transmission control of images, is analyzed. The effectiveness of system solution is demonstrated by concrete examples.


A New Memristor Chaotic System And Its Application In Image Encryption, Shuanghui Qu, Zhihong Yang, Xuwei Rong, Shuhua Wu Nov 2019

A New Memristor Chaotic System And Its Application In Image Encryption, Shuanghui Qu, Zhihong Yang, Xuwei Rong, Shuhua Wu

Journal of System Simulation

Abstract: A new memristor chaotic system is designed by the method of bringing an ion migration memristor into the Chen system equation. The basic dynamic characteristics of the memristive system are investigated via bifurcation, Lyapunov exponent et al, which proves the validity of the new system. The new memristor system is applied in the image encryption to improve the security of the encryption key. A dual encryption algorithm is used, which makes every pixel value of plaintext influence all pixel values of ciphertext. Although there is no direct link between plaintext and ciphertext, the sensibility of ciphertext varying with …


Lpv Controller Design Of Wind Turbine With Maximum Power Point Tracking, Zheng Yang, Dinghui Wu, Zhicheng Ji Nov 2019

Lpv Controller Design Of Wind Turbine With Maximum Power Point Tracking, Zheng Yang, Dinghui Wu, Zhicheng Ji

Journal of System Simulation

Abstract: A design method of the polytopic controller under the maximum power point tracking (MPPT) is proposed in addressing the low efficiency of the wind turbine under rated wind speed and uncertainty of the wind speed. Considering high nonlinearity of the aerodynamic system, the Jacobi linearization and the convex decomposition technique are employed to transform the wind turbine system into a polytopic linear parameter varying (LPV) model with the bias torque of the aerodynamic torque as the scheduling variable. By solving the linear matrix inequalities (LMIs), a polytopic LPV controller is obtained. The simulation results show that the designed controller …


Spatial Spectrum Estimation Method Of Flank Twin-Line Array Based On Cross-Spectrum Correlation, Zhizhong Li, Wang Sen, Zhongliang Xu, Weiguo Dai, Qijun Liu Nov 2019

Spatial Spectrum Estimation Method Of Flank Twin-Line Array Based On Cross-Spectrum Correlation, Zhizhong Li, Wang Sen, Zhongliang Xu, Weiguo Dai, Qijun Liu

Journal of System Simulation

Abstract: Considering the structural features of the flank twin-line array, researches on spatial spectrum estimation of twin-line array based on adaptive beam-forming and cross-spectrum correlation were carried out. A spatial spectrum estimation method based on cross-spectrum correlation is proposed according to the theory of cross-spectrum. The study of spectrum estimation performance comparison of the twin-line array was finished by that method combined with the conventional beam-forming and the adaptive beam-forming respectively. The results prove that the method based on cross-spectrum correlation has a better capability in noise suppression; and the method, which combined adaptive beam-forming with cross-spectrum correlation, is the …


Sliding Mode Auto Disturbance Rejection Control Of Pmsm Without Speed Sensor, Limin Hou, Yifu Ren, Hengfei Liu, Lin Dong Nov 2019

Sliding Mode Auto Disturbance Rejection Control Of Pmsm Without Speed Sensor, Limin Hou, Yifu Ren, Hengfei Liu, Lin Dong

Journal of System Simulation

Abstract: Aiming at the problem of parameter setting and response speed of the traditional ADRC method, a kind of novel sliding mode auto disturbance rejection speed controller is designed, and a sliding mode adaptive speed control system of PMSM without speed sensor is established. The nonlinear disturbance observer (NDOB) is used to replace the extended state observer (ESO) integrated disturbance estimation. The sliding mode control is introduced in the nonlinear state error feedback control; the sliding mode ADRC current controller and speed controller are designed; and the stability is proved by using Lyapunov theory. The rotor position and speed of …


Influence Of Composite Materials Surface Metal Mesh On Helicopter Lightning Stroke Effects, Junling Huang, Jiayu Xie Nov 2019

Influence Of Composite Materials Surface Metal Mesh On Helicopter Lightning Stroke Effects, Junling Huang, Jiayu Xie

Journal of System Simulation

Abstract: The metal wire mesh is usually adopted to prevent the lightning stroke on composite materials. The effects of different materials and different thickness of metal mesh on helicopter lightning electromagnetic effect are compared. According to the method recommended by SAE-ARP5416, a numerical simulation software is used for carrying out the high current injection simulation. The results show that the surface mount metal mesh can effectively reduce the harm of lightning electromagnetic coupling effect; the difference between aluminum and copper on anti-lightning stroke effect is not obvious; when the thickness of aluminum grid is less than 0.15 mm, the …


Harold Brown, Harold Brown Nov 2019

Harold Brown, Harold Brown

Oral History

Harold Brown, PhD, taught philosophy as a faculty member at Pace University from 1969 to 2019.


Signal Control Strategy And Simulation For Vehicles Alternatively Passing Construction Area Of Two-Lane Road, Haipeng Shao, Binbin Zheng, Linxu Long Nov 2019

Signal Control Strategy And Simulation For Vehicles Alternatively Passing Construction Area Of Two-Lane Road, Haipeng Shao, Binbin Zheng, Linxu Long

Journal of System Simulation

Abstract: The construction area of the two-lane roads can form the road bottlenecks easily, leading to the capacity of the road reducing. Aiming to keep the vehicle passing the construction area safely and efficiently, we added the strategy of signal control in the construction area. We built a suitable signal control model for the construction area of the two-lane road. By using the simulation software of Vissim, we established the related simulation models. By using the control variable method to change the simulation parameters and by changing the arrival traffic and speed, we got the influences and rules to the …


3d Mesh Editing Method For Virtual Double Eyelid Surgery, Guan Tong, Juntao Ye, Guanghui Ma, Xiaopeng Zhang Nov 2019

3d Mesh Editing Method For Virtual Double Eyelid Surgery, Guan Tong, Juntao Ye, Guanghui Ma, Xiaopeng Zhang

Journal of System Simulation

Abstract: A virtual cosmetic surgery system involves lots of human-computer interactions,and the achieved effects rely on the skills of the operator. Virtual double-fold eyelid surgery is a function that is either missing or implemented with less accuracy in commercial software. To solve these problems, we propose an algorithm that can automatically generate virtual double-fold eyelid path taking advantage of geodesic line. In terms of algorithms, this method adopts a self-adaptive subdivision strategy to avoid losing shapes of the deformation outcomes. Results of experiments show stability, high efficiency and usability of our method.


Thermodynamic Simulation Of Carbonitride Precipitation In Micro-Alloyed Steel, Weigang Li, Yang Wei, Liu Chao, Baokang Yan Nov 2019

Thermodynamic Simulation Of Carbonitride Precipitation In Micro-Alloyed Steel, Weigang Li, Yang Wei, Liu Chao, Baokang Yan

Journal of System Simulation

Abstract: A mathematical model for calculating the precipitation of carbonitride in the process of hot rolling of composite micro-alloyed steel is established, and the interaction between the carbonitride and AlN is considered. In view of the difficulties of the thermodynamic model that the variables are multiple, the equations are nonlinear and the boundary conditions are determined difficultly, the Newton-Raphson numerical algorithm characterized by coupled problem is adopted. The precipitation starting temperature and precipitation sequence of carbonitride and AlN at different compositions are determined. The equilibrium composition of elements in austenite, the composition and mass fraction of carbonitride precipitates, as well …


Serious Game Human-Computer Interaction Design For Rehabilitation Training, Jiajia Wu, Liu Zhen, Huihuang Xu, Tingting Liu, Wang Jin, Yanjie Chai Nov 2019

Serious Game Human-Computer Interaction Design For Rehabilitation Training, Jiajia Wu, Liu Zhen, Huihuang Xu, Tingting Liu, Wang Jin, Yanjie Chai

Journal of System Simulation

Abstract: Constructing a human-computer interaction environment which can effectively enhance users’ experiences of serious game. By integrating the rehabilitation training process into an interactive game story, users can do their mental and body rehabilitation training in the community. The prototype of the game is realized by the game engine. Experimental results showed that using mouse to roam in the system is easier than other interaction method and the somatosensory interaction is convenient for exercising the limb. By designing emoji for virtual characters, it is easy for users to learn other people's emotions and the comfortable distances for others. The results …


Comparison And Analysis Of Output Performance Of Different Pv Structures Under Shadows, Yonghong Xia, Mengru Li, Jianbo Xin, Zen Fanpeng, Yunjun Yu Nov 2019

Comparison And Analysis Of Output Performance Of Different Pv Structures Under Shadows, Yonghong Xia, Mengru Li, Jianbo Xin, Zen Fanpeng, Yunjun Yu

Journal of System Simulation

Abstract: The output power of PV array not only depends on the irradiance intensity of the partial shadows, but also on the shadows shape. For the serious power loss under partial shadows of the traditional SP (Series-Parallel) and TCT (Total-Cross-Tied) structures, an optimized TCT structure is proposed. Output capacity comparison was made based on the three structures in five shadow modes under the circumstances of the severe shadows and uneven irradiation. By using Matlab/ Simulink software, the output performance of the three structures was simulated under different shadow shapes in symmetrical and asymmetric arrays. The results show that PV array …


Ship Speed Optimization Based On Multi-Objective Particle Swarm Algorithm, Jinfeng Zhang, Taoning Yang, Weihao Ma Nov 2019

Ship Speed Optimization Based On Multi-Objective Particle Swarm Algorithm, Jinfeng Zhang, Taoning Yang, Weihao Ma

Journal of System Simulation

Abstract: Ship speed optimization is an effective means to reduce operational costs in the downturn of shipping. To deal with the conflict between reducing the operating cost and reducing the ship emissions, the multi-objective ship speed optimization model is proposed based on the influence of the actual wind and wave. The MOPSO algorithm is introduced to solve the Pareto optimal solution set, and the compromise speed is an effective tradeoff based on the improved TOPSIS algorithm. The operational shipping route is selected as an example to simulate and verify the model. The results show that the operating costs and …


Modeling And Simulation Of Missile Trajectory Based On Practical Sampling, Wu Shuai, Xiaohua Zhou, Lili Wang, Xingzhong Yao Nov 2019

Modeling And Simulation Of Missile Trajectory Based On Practical Sampling, Wu Shuai, Xiaohua Zhou, Lili Wang, Xingzhong Yao

Journal of System Simulation

Abstract: Aiming at the problem of lacking the proper simulation method for missile trajectory in combat simulation training, this paper analyzes the limitations of the 6D and 3D simulation models, proposes a method of trajectory simulation with missile kinematics model and history measured data, and taking an air-to-surface ballistic missile with midcourse-terminal guidance as an example, describes the model construction process in detail. Through the verification, validation and simulation experiments, it shows that this method can simulate various types of missile trajectory with high confidence on both sides of “red and blue”, which has an important reference meaning for missile …


Cloud-End Cooperative Manufacturing And Simulation Application In Electrical Equipment Industry, Ruijie Shi, Zou Ping, Xike Wu, Liu Gang, Gao Chen, Junyuan Zhang, Li Lin, Guo Li Nov 2019

Cloud-End Cooperative Manufacturing And Simulation Application In Electrical Equipment Industry, Ruijie Shi, Zou Ping, Xike Wu, Liu Gang, Gao Chen, Junyuan Zhang, Li Lin, Guo Li

Journal of System Simulation

Abstract: Electrical equipment manufacturing industry hopes to achieve cloud-end cooperative manufacturing of the whole industry chain services by means of national network e-commerce cloud platform. On the basis of explaining the role of simulation in cloud-end cooperative manufacturing, this paper analyses the practical problems faced by enterprises in electrical equipment industry to realize cloud-end cooperative manufacturing, and presents effective solutions and overall solution; all kinds of the necessary application services are provided, which coincide with the actual requirement of electrical equipment manufacturing industry; and the research results of the key problems for realization about them are introduced. The overall industry …