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2019

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Articles 1411 - 1440 of 15927

Full-Text Articles in Physical Sciences and Mathematics

Future Traffic Accident Risk Investigation Based On Human-Machine-Environment Factors, Yuan Quan, Gao Yan, Chenlu Qiu Nov 2019

Future Traffic Accident Risk Investigation Based On Human-Machine-Environment Factors, Yuan Quan, Gao Yan, Chenlu Qiu

Journal of System Simulation

Abstract: Based on the theory of human-machine-environment system engineering, this paper investigated the developing trends of autonomous vehicles and the types of traffic crashes in China, and integrated changing human-vehicle-road factors of traffic system to speculate the possible new types and scenarios of traffic crashes. The recent occurred crash cases involving autonomous vehicles were concerned and investigated. In future, some new affecting factors such as the mix traffic with various autonomous vehicles and piloted vehicles, the switching of driving behavior between human and machine, and the information security of intelligent traffic system, may cause traffic crashes. Among these, the human …


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.


Novel Silica Filled Deep Eutectic Solvent Based Nanofluids For Energy Transportation, Changhui Liu, Hui Fang, Xinjian Liu, Ben Xu, Zhonghao Rao Nov 2019

Novel Silica Filled Deep Eutectic Solvent Based Nanofluids For Energy Transportation, Changhui Liu, Hui Fang, Xinjian Liu, Ben Xu, Zhonghao Rao

Chemistry Faculty Publications and Presentations

Liquid range of nanofluids is a crucial parameter as it intensively determines their application temperature scope. Meanwhile, improved thermal conductivity and stability are of great significances and comprise the main fundamental research topics of nanofluids. In this work, 2- butoxy-3,4-dihydropyran (DP), produced from a convenient one-pot three-component reaction in water, was employed as dual lipophilic brusher and metal nanoparticle anchor. It was found that DP was able to enhance the dispersing ability and thermal conductivity of SiO2 nanoparticle filled deep eutectic solvent (DES) based nanofluids simultaneously. The key to the success of this protocol mainly relies on the electrophilic property …


Reconstructing Geographic And Trophic Histories Of Fish Using Bulk And Compound-Specific Stable Isotopes From Eye Lenses, Amy A. Wallace Nov 2019

Reconstructing Geographic And Trophic Histories Of Fish Using Bulk And Compound-Specific Stable Isotopes From Eye Lenses, Amy A. Wallace

USF Tampa Graduate Theses and Dissertations

The present research examined the viability and utility of eye lenses as a source of lifetime stable-isotope records in fish. It is presented in three sections. The first section compared bulk isotopic variation (bulk analysis) within fish eye-lenses at two temporal resolutions and compared patterns obtained from left and right eyes. The first temporal resolution was lower in an attempt to expose broad-scale isotopic changes during life while reducing effort and cost. This approach did reveal lifetime patterns, but tended to miss certain life events, particularly during early life. The second resolution was higher and provided detail that was missed …


From Digital Twin To Digital Engineering Modeling And Simulation Entering A New Era, Zhang Bing, Li Xin, Xinxin Wan Nov 2019

From Digital Twin To Digital Engineering Modeling And Simulation Entering A New Era, Zhang Bing, Li Xin, Xinxin Wan

Journal of System Simulation

Abstract: In the digital new era, all kinds of things and even the whole world can be digitized as a model. Simulation activities are conducted for various purposes, and the results can provide intelligent support for various decision-making. Digital twin is an important form of modeling and simulation application in the digital new era; it has been widely used in intelligent manufacturing, factories, buildings, smart cities and many other fields, showing a strong vitality; and its next step in the development direction is a comprehensive digital engineering. This paper reviews the history of the development of digital twin technology, analyzes …


Model And Simulation Of Taxi Market With E-Hailing Application, Tian Qiong, Jingtao Zhang Nov 2019

Model And Simulation Of Taxi Market With E-Hailing Application, Tian Qiong, Jingtao Zhang

Journal of System Simulation

Abstract: The emergence and popularity of e-hailing applications offer a new way for taxi drivers and passengers to communicate on line, which not only changes the behaviors of passengers and reduce the idle rate of taxi, but also brings the cost of information for taxis and passengers. Referring to the classic circular city model and combining with the characteristics of new way to take taxis and the cost of information, a model of taxi market with e-hailing application is formulated, which describes the behavior of passengers waiting for idle taxis and taxis cruising for un-served passengers. We provided an algorithm …


Spatiotemporal Characteristics Of Air Pollutants, Meteorology And Traffic During Heavy Haze Pollution In Beijing, Dongmei Hu, Jianping Wu, Kun Tian, Lüchao Liao, Yiman Du Nov 2019

Spatiotemporal Characteristics Of Air Pollutants, Meteorology And Traffic During Heavy Haze Pollution In Beijing, Dongmei Hu, Jianping Wu, Kun Tian, Lüchao Liao, Yiman Du

Journal of System Simulation

Abstract: We analyzed the spatiotemporal characteristics of air pollutants, meteorology, and average road speed during a heavy haze pollution period; and explored the combined impacts of temporary traffic restrictions and meteorological conditions on air quality. The results showed that five pollution stages were identified with remarkable variation patterns based on the evolution of PM2.5 concentration and weather conditions; and it also showed that the southern sites experienced heavier pollution than the northern sites. Stage P3 exhibited a combined effect of meteorology and traffic restrictions with delayed functions. A good AQI was more likely with higher temperature and lower humidity. …


Stereo Matching Based On Enhanced Message Passing For Investigation Of Traffic Accident Scenes, Jingzhou Huang, Houpan Zhou, Liliang Wang, Xiaofang Huang, Li Na Nov 2019

Stereo Matching Based On Enhanced Message Passing For Investigation Of Traffic Accident Scenes, Jingzhou Huang, Houpan Zhou, Liliang Wang, Xiaofang Huang, Li Na

Journal of System Simulation

Abstract: The investigation of traffic accident scenes requires restoring real scenes in a given time, and it can be implemented through binocular vision technique. For its core procedure—stereo matching, we studied the popular hierarchical belief propagation (HBP) algorithm and presented an improved approach which contained two modules: optimization in the native level and cost transmission between adjacent levels. The optimization ability is improved by enhancing the impact of message passing within and between levels for estimating disparities of unmatched points and correcting wrong disparities. Experiment results show that the optimization ability of the improved approach has been enhanced, and …


Simulation Analysis Of Self-Driving Travelling Routes, Sun Ling, Ya Dong, Liu Wei, Guanyun Yang Nov 2019

Simulation Analysis Of Self-Driving Travelling Routes, Sun Ling, Ya Dong, Liu Wei, Guanyun Yang

Journal of System Simulation

Abstract: China's tourism industry develops rapidly. By building self-driving traveling plan model and using traversal algorithm and stochastic optimization algorithm, the area optimal travel plans with Matlab simulation are obtained. If traveling time is too long in one area, the K-mean clustering algorithm can be used to divide it into two parts for simulation. A case study of 5A attractions in China is used for establishing a national self-driving traveling plan model. The concept of the Time Value is proposed. By comparing the travel modes of plane, train and car, the common model is established. The sensitivity analysis of Time …


No-Collision Curling Trajectory Simulation System, Tian Yu, Xu Ming Nov 2019

No-Collision Curling Trajectory Simulation System, Tian Yu, Xu Ming

Journal of System Simulation

Abstract: In just a few decades, China’s curling accomplished splendid work. But it’s scientific research falling behind a lot. Applying computer simulation technology in sports training can effectively help the athletes to understand the problems that exist in the training. When curling stone slides on the ice, it can be regarded as two-dimensional motion of rigid body, which can be decomposed into two parts: translation of the center of mass and rotation of a fixed axis around the center of mass. Using computer simulation technology to simulate the curling trajectory, and with the help of this system, the athletes can …


Dynamic Interference Detection Algorithm For Bearing With Scar, Jinyuan Jia, Naihao Zheng Nov 2019

Dynamic Interference Detection Algorithm For Bearing With Scar, Jinyuan Jia, Naihao Zheng

Journal of System Simulation

Abstract: To solve the dynamic interference detection problem of scar bearing in visual assembly, an efficient dynamic interference inspection algorithm for scar bearing is proposed. The first step is to perform vertex management on the 3D reconstructed scar bearing model through the quad-tree; the second step is to select the appropriate algorithm for the calculation of the maximum interference distance by considering bearing shape and its motion characteristics. The research shows that the algorithm can quickly and efficiently test the dynamic interference and calculate the interference distance for the bearing with scar, which can effectively improve the efficiency of bearing …


System Analysis Method Based On Simulation Big Data, Guangya Si, Wang Fei, Liu Yang Nov 2019

System Analysis Method Based On Simulation Big Data, Guangya Si, Wang Fei, Liu Yang

Journal of System Simulation

Abstract: Wargaming and exploratory simulation with large-scale simulation systems produce massive simulation data. These data contain many complexity patterns of war, and are significant samples for studying the mechanism of war. Based on the definition of simulation big data, an analysis framework based on simulation big data is proposed, which is divided into three levels: simulation environment and data planning, big data acquisition and storage, and analysis and mining. The simulation data planning and analysis and mining are briefly introduced.


Optimal Compensation Control Strategy For Four-Axle Vehicle With All-Wheel Steering System, Baohua Wang, Yu Chao Nov 2019

Optimal Compensation Control Strategy For Four-Axle Vehicle With All-Wheel Steering System, Baohua Wang, Yu Chao

Journal of System Simulation

Abstract: Aiming at the problem of poor stability of traditional multi-axle commercial vehicles, an optimal control strategy for multi-axle steering wheel is proposed. Through the establishment of the four-axis vehicle model, the wheel angle proportional feed-forward control algorithm and the yaw rate feedback control algorithm are studied. The optimal compensating control algorithm of the wheel angle proportional feed-forward and yaw rate feedback is proposed, and the control strategy is also verified through joint simulation. The results show that the full-wheel steering optimal compensation control strategy can keep the center-of-mass skew angle close to zero at all vehicle speeds, …


Robustness Analysis Of Interdependent Networks For Cascading Failure, Congdong Li, Wenbo Li, Cejun Cao, Wang Yu Nov 2019

Robustness Analysis Of Interdependent Networks For Cascading Failure, Congdong Li, Wenbo Li, Cejun Cao, Wang Yu

Journal of System Simulation

Abstract: For guiding interdependent system construction and improving its vulnerability, it is helpful to research on the robustness of interdependent networks. Based on the related works, the cascading failure model of interdependent networks coupled by nodes’ betweenness was built, which considered comprehensively the nodes’ overload, interdependent nodes’ failure, and links’ loss. The robustness of interdependent networks was studied from the perspective of different coupled intensities, coupled patterns, and different nodes’ failure. Simulation results manifest that the robustness of assortative link interdependent networks is the best, the robustness of disassortative link interdependent networks is the worst. The robustness of interdependent networks …


Potential Users Of Battery Electric Vehicle Based On Big Data Of Floating Vehicles, Kong Yuan, Yiman Du, Jianping Wu, Kezhen Hu Nov 2019

Potential Users Of Battery Electric Vehicle Based On Big Data Of Floating Vehicles, Kong Yuan, Yiman Du, Jianping Wu, Kezhen Hu

Journal of System Simulation

Abstract: Nowadays, the Chinese government is strongly pushing the adoption of new energy vehicles, so it is of great significance to find the most suitable users of EV (Electric Vehicle). This paper did a data mining work to find out target user group of EV based on two-month traveling data, driver information and vehicle attribute information of 12,000 floating vehicles in Beijing. The results show that residential area is more suitable to push the adoption of EV than other functional areas; adding charging piles in the destination area can turn the 9.2% of drivers who are not suitable for EV …


Simulation Estimation On Directional Green-Wave Traffic Control In Nanning City, Yiman Du, Hongfan Su, Chen Yu, Longfei Liu, Jianping Wu Nov 2019

Simulation Estimation On Directional Green-Wave Traffic Control In Nanning City, Yiman Du, Hongfan Su, Chen Yu, Longfei Liu, Jianping Wu

Journal of System Simulation

Abstract: Due to the noticeable development of Nanning city, traffic congestion has become a serious problem, especially during the peak hours along the Binhu road. The development of Nanning city is restricted by the imbalance distribution of traffic flow. In order to ease the overload burden of traffic along the Binhu road during the peak hours, the current problems are analyzed and some solutions with directional green-wave traffic control are proposed. Traffic microscopic simulation software is used to estimate the improvement between before and after implementations of the solutions.


Simulation Analyses Of A Method For Extracting Dynamic Parameters From Forced Vibration Responses, Yumiao Wei, Zhili Zhang, Zhengjun Chang, Junyang Zhao, Xiangyang Li Nov 2019

Simulation Analyses Of A Method For Extracting Dynamic Parameters From Forced Vibration Responses, Yumiao Wei, Zhili Zhang, Zhengjun Chang, Junyang Zhao, Xiangyang Li

Journal of System Simulation

Abstract: To characterize the dynamic features of electromechanical system, a method is researched for dynamic parameters extraction from the forced vibration responses. The forced vibration response signals are processed by HVD method, and the free damped oscillation components are acquired. The SSA-FREEVIB analysis is conducted for the obtained components to measure the dynamic characteristics. The equalization procedures are implemented for the backbones and damping data, the resonance frequency and Q value are therefore accurately estimated. Simulation results show that the calculated resonance frequency and Q value coincide well with the theoretical values. A good anti-noise performance of the proposed …


Study On The Matching Mediation Method Between Virtual Maintenance Personnel And Work Steps, Yunrong Zhang, Zhili Zhang, Xiangyang Li, Weichang Xu, Kuixia Han, Li Liang Nov 2019

Study On The Matching Mediation Method Between Virtual Maintenance Personnel And Work Steps, Yunrong Zhang, Zhili Zhang, Xiangyang Li, Weichang Xu, Kuixia Han, Li Liang

Journal of System Simulation

Abstract: Aiming at the problem that each maintenance worker cannot play a full role in dealing with the concurrent conflict of maintenance steps, this paper puts forward a matching mechanism between maintenance steps and maintenance workers according to the level of authority, expounds the status information of maintenance workers, divides the difficulty level of maintenance steps, and gives the matching process between maintenance workers and maintenance steps. The matching process is modeled and simulated by using colored Petri nets and CPN tools. The simulation results show that the matching mechanism can solve the problem that the role of …


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 …


Multi-Agent Modeling And Simulation On China's Marine Energy Channel Security, Yongchen Guo, Shen Yang Nov 2019

Multi-Agent Modeling And Simulation On China's Marine Energy Channel Security, Yongchen Guo, Shen Yang

Journal of System Simulation

Abstract: Security factors influencing China's offshore energy channel are analyzed, and the actual situation of China's oil import and transportation is described. Based on multi-agent modeling and simulation method, and starting at the micro level, the energy transport process is simulated and a multi-agent model of China's offshore energy channel (middle east lines) is built; and the simulation program on the NetLogo platform is conducted. The results show that the quantity of China’s VLCC is far from enough; the security impact of tropical cyclones is more serious than that of pirates; the increase proportion of carrier’s quantity is usually lower …


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 …


Simulation Of Gas-Liquid Mixing Flow In A Stirred Tank With Inverted Umbrella-Type Surface Aerator, Wenli Wei, Weili Lou, Panpan Li, Yuling Liu Nov 2019

Simulation Of Gas-Liquid Mixing Flow In A Stirred Tank With Inverted Umbrella-Type Surface Aerator, Wenli Wei, Weili Lou, Panpan Li, Yuling Liu

Journal of System Simulation

Abstract: The way of computational fluid dynamics with k-ε turbulence model as well as multiple reference frame method was used to simulate the hydraulic characteristics of gas-liquid mixing flow in a stirred tank installed with an inverted umbrella-type surface aerator. The inverted umbrella aerator consists of eight blades, and rotates at 5.23rad/s. The main purpose of this simulation is to study the distributions of air volume fraction and characteristics of mixing flow. The simulation results show that the distribution of the mixing flow is symmetrical; the change rules of the gas distribution at different positions along the axis direction are …


Dynamic Demand Forecast Of Emergency Materials For Flood Disasters Based On Improved Gm (1,1) Model, Zhongjun Hu, Yanqiu Liu, Li Jia Nov 2019

Dynamic Demand Forecast Of Emergency Materials For Flood Disasters Based On Improved Gm (1,1) Model, Zhongjun Hu, Yanqiu Liu, Li Jia

Journal of System Simulation

Abstract: The sudden and uncertainties of the flood disaster make it difficult to collect large sample data for forecasting the demand of emergency materials quickly and accurately. Based on this, this paper proposes an improved GM (1,1) dynamic forecasting model based on the gray system theory; constructs the dynamic demand model of emergency materials in combination with the inventory management method; and takes the real flood disaster in March 2016 as a case study. The validity of the model proposed in this paper is verified. The results show that the improved GM (1,1) model is feasible and practicable, and …


Two-Level Spare Parts Support Effectiveness Evaluation Model Under (S-K, S) Supply Strategy, Songshi Shao, Wei Yong Nov 2019

Two-Level Spare Parts Support Effectiveness Evaluation Model Under (S-K, S) Supply Strategy, Songshi Shao, Wei Yong

Journal of System Simulation

Abstract: Spares are one of the important factors of the operational readiness and the mission success. The (S-K, S) supply strategy is proposed based on the multi-level supply mode according to spares’ reliability and price. Simulation model is established to evaluate the support effectiveness of spare parts by the principle of discrete event simulation. The analytical evaluation model is also established by Gamma distribution characteristics. An approximate model is verified and compared in an example; the results show that the calculation results of the two models are consistent; and the results of approximate model are …


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 …


Colored Petri Net Based Modeling On Warship Command And Control Information Flow, Xueguang Zhou, Weidong Lü, Zhimin Yuan Nov 2019

Colored Petri Net Based Modeling On Warship Command And Control Information Flow, Xueguang Zhou, Weidong Lü, Zhimin Yuan

Journal of System Simulation

Abstract: Aiming at the current problems of the complexity, influence of human factors, reusability and others, this paper built a warship command and control (C2) information flow model and obtained the warship C2 model with command and feedback information flow. This paper also defined standard information flow and position structure, and solved the reusing issue. The authenticity of information flow guaranteed the objectivity of this model, which met the demands of different kinds of vessels, and promoted the compactness and fitness between C2 system and warship reality on the model level.


Dynamic Data Reserved Modeling Method Based On Steady-State Component Estimation And State Tracking, Dong Ze, Erxin Yin Nov 2019

Dynamic Data Reserved Modeling Method Based On Steady-State Component Estimation And State Tracking, Dong Ze, Erxin Yin

Journal of System Simulation

Abstract: Aiming at the existing problems of conventional industrial system modeling methods, a dynamic data reserved modeling method based on steady-state component estimation and state tracking is proposed. The dynamic response data of the system is selected as the modeling data. The input value at the end of the selected data is chosen as steady-state component, and the steady-state component value of output is artificial given. Steady-state component of the modeling data is removed according to the steady-state component of input and output, and the modeling data is divided into three sections. The prediction model and the state observer are …


Identification And Prediction Of Room Temperature Delay Neural Network Model For Vav Air Conditioning, Xiuming Li, Jili Zhang, Tianyi Zhao, Tingting Chen Nov 2019

Identification And Prediction Of Room Temperature Delay Neural Network Model For Vav Air Conditioning, Xiuming Li, Jili Zhang, Tianyi Zhao, Tingting Chen

Journal of System Simulation

Abstract: Aiming at the problem of mathematical description for dynamic response characteristic of indoor temperature time-delay system, the fundamental principle of neural network model identification is introduced in regulation process of variable air volume (VAV) air conditioning system. Considering the model structure of Elman neural network, this paper presents an optimal selection algorithm for layer delay coefficient in order to determine delay time between indoor temperature and regulation parameters; and a multiple-step prediction model of indoor temperature time-delay system based on Elman neural network is built. The effectiveness of the proposed method is validated through the simulation experiment.


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 …