Numerical Analysis and Scientific Computing Commons^™

Time Domain Vertical Dynamics Model Of Electric Vehicle Considering Electric Motor Vibration, Guoying Tian, Pengyi Deng, Shulei Sun, Yiqiang Peng, Haiying Lu

Journal of System Simulation

Abstract: On the basis of considering the electric motor vibration, a time domain vertical dynamics model of the electric vehicle with 11 DOF is built, and the road roughness input model and the numerical method are given. Aiming at an electric passenger vehicle, the basic characteristics of the typical vehicle dynamics responses under the condition of the impulse and random road roughness inputs are calculated, the influence of the different mount stiffness, damping and motor mass on the motor and the vehicle vibration is analyzed under the condition of the impulse input. The results show that the proposed model is …

Trajectory Planning Of Wheeled Mobile Robot Based On Model Predictive Control, You Bo, Mingrui Wang, Li Zhi, Ding Liang

Journal of System Simulation

Abstract: Aiming at the underactuation of the Wheeled Mobile Robot (WMR) and considering the various limitations and constraints during the actual operation, a trajectory planning method based on the Model Predictive Control (MPC) is proposed.This method can deal with the kinematics constraints, physical constraints and obstacle avoidance constraints unifiedly and effectively. It can generate the feasible trajectories that conform to the characteristics of the car body model and satisfy the various constraints. It fully guarantees the feasibility, safety and efficiency of the autonomous driving of wheeled mobile robots. The simulation results fully verify the effectiveness of the proposed method.

Fault Diagnosis Method Of Vehicle Power Supply Based On Deep Learning And Sequential Test, Li Wei, Bingxiang Zhou, Dongnian Jiang

Journal of System Simulation

Abstract: Focus on the health maintenance of vehicle power supply, a fault diagnosis method of vehicle power supply is proposed, which is based on the long and short time memory LSTM(Long Short Time Memory) network and the sequential probability ratio test SPRT(Sequential Probability Ratio Test). Based on the LSTM network, the multivariate time series model of vehicle power supply is established, and the SPRT method is used to perform the adaptive multi-sample fault diagnosis. The experiment on the vehicle power supply simulation system shows that the LSTM diagnosis model has stronger learning and mapping capabilities, and the fault diagnosis method …

Research On Flight Ground Service Time Prediction Based On Deep Neural Network, Zhiwei Xing, Li Biao, Zhu Hui, Luo Qian

Journal of System Simulation

Abstract: Flight ground service time prediction is one of the key issues in improving the airport operational efficiency and decision making capacity. Taking into account the complexity, particularity and uncertainty of the service process, a Gaussian probability model of flight ground service resource in place time is established, a flight ground service time prediction model based on the deep neural network is proposed. According to the regular changes of operational data, the model parameters are adjusted to reducet the generalization error caused by other factors. The research results show that the average absolute error of time prediction under single …

Unmanned Crane Dispatching System Based On Grid Method In Steel Works, Weigang Li, Wang Xiao, Yuntao Zhao, Zixiang Li

Journal of System Simulation

Abstract: A grid method is used to model a storeroom to solve the problem of the unmanned crane automatic scheduling of the iron and steel industry. An improved A* algorithm is proposed to make the path planning. Different moving costs are assigned for the different route sections in storeroom and the different moving modes of cranes, and the path with the minimum total cost which can avoid the slab obstacles alongside is calculated by the algorithm. A set of intelligent dispatching rules are designed to solve the inefficiency of the manual operation, which can effectively deal with the problems about …

Vehicle Coordination Strategy For Semi-Active Suspension Vehicles, Quanmin Guo, Haowen Zhang, Wang Yan

Journal of System Simulation

Abstract: In order to realize the coordinated control of the vertical, pitch and roll vibration of vehicle, a coordinated control strategy of vehicle semi-active suspension is proposed. In the strategy, the fuzzy PID controllers estimate three adjustment forces according to the vibration state in vertical, pitch and roll directions. Through the designed force coordinator with the control parameters of the front and back axes and the steering control strategy, the expected adjustment forces are coordinated to the four magnetorheological dampers to output the adjustable damping forces and realize the coordinated control of the vehicle vibration in three directions. The experimental …

Simplification And Compression Service Construction Of 3d Model For Complex Products, Junjie Xue, Guoqiang Shi, Junhua Zhou, Huiyang Qu, Tao Luan, Ruiying Pu

Journal of System Simulation

Abstract: A simplification and compression (S&C) service construction method of the 3D model for the complex products is proposed. An improved method of the model data export and spatial index generation is adopted to preserve the assembly tree and label information of the model in the process of model S&C. An adaptive mesh simplification algorithm based on the mesh density is designed and implemented, and the meshes can be simplified adaptively on condition of satisfying the requirement of error for the geometric model. And a model data compression algorithm with the high compression ratio and efficiency is adopted to reduce …

3d Tree Model Matching Based On Tree Shape Space, Liang Shuang, Zuoteng Zhu, Jinyuan Jia

Journal of System Simulation

Abstract: The retrieval of the 3D tree models cannot get the higher accuracy, retrieving efficiency and descripting match. In order to solve the problems, a three-dimensional tree model matching method based on tree space is proposed. By constructing the tree space of the three-dimensional tree model dataset, the method computes the difference between the Euclidean distance and the geodesic distance in the tree space by means of spindle matching, contour matching, and branch matching, and gradually matches the corresponding model. The matching implementation results are displayed in the general model dataset and the self-designed model dataset respectively. …

Nonlinear Least Squares 3-D Geolocation Solutions Using Time Differences Of Arrival, Michael V. Bredemann

Mathematics & Statistics ETDs

This thesis uses a geometric approach to derive and solve nonlinear least squares minimization problems to geolocate a signal source in three dimensions using time differences of arrival at multiple sensor locations. There is no restriction on the maximum number of sensors used. Residual errors reach the numerical limits of machine precision. Symmetric sensor orientations are found that prevent closed form solutions of source locations lying within the null space. Maximum uncertainties in relative sensor positions and time difference of arrivals, required to locate a source within a maximum specified error, are found from these results. Examples illustrate potential requirements …

Storage Management Strategy In Mobile Phones For Photo Crowdsensing, En Wang, Zhengdao Qu, Xinyao Liang, Xiangyu Meng, Yongjian Yang, Dawei Li, Weibin Meng

Department of Computer Science Faculty Scholarship and Creative Works

In mobile crowdsensing, some users jointly finish a sensing task through the sensors equipped in their intelligent terminals. In particular, the photo crowdsensing based on Mobile Edge Computing (MEC) collects pictures for some specific targets or events and uploads them to nearby edge servers, which leads to richer data content and more efficient data storage compared with the common mobile crowdsensing; hence, it has attracted an important amount of attention recently. However, the mobile users prefer uploading the photos through Wifi APs (PoIs) rather than cellular networks. Therefore, photos stored in mobile phones are exchanged among users, in order to …

Visualizing Metabolic Network Dynamics Through Time-Series Metabolomic Data., Lea F Buchweitz, James T Yurkovich, Christoph Blessing, Veronika Kohler, Fabian Schwarzkopf, Zachary A King, Laurence Yang, Freyr Jóhannsson, Ólafur E Sigurjónsson, Óttar Rolfsson, Julian Heinrich, Andreas Dräger

Articles, Abstracts, and Reports

BACKGROUND: New technologies have given rise to an abundance of -omics data, particularly metabolomic data. The scale of these data introduces new challenges for the interpretation and extraction of knowledge, requiring the development of innovative computational visualization methodologies. Here, we present GEM-Vis, an original method for the visualization of time-course metabolomic data within the context of metabolic network maps. We demonstrate the utility of the GEM-Vis method by examining previously published data for two cellular systems-the human platelet and erythrocyte under cold storage for use in transfusion medicine.

RESULTS: The results comprise two animated videos that allow for new insights …

Are These Comments Triggering? Predicting Triggers Of Toxicity In Online Discussions, Hind Almerekhi, Haewoon Kwak, Joni Salminen, Bernard J. Jansen

Research Collection School Of Computing and Information Systems

Understanding the causes or triggers of toxicity adds a new dimension to the prevention of toxic behavior in online discussions. In this research, we define toxicity triggers in online discussions as a non-toxic comment that lead to toxic replies. Then, we build a neural network-based prediction model for toxicity trigger. The prediction model incorporates text-based features and derived features from previous studies that pertain to shifts in sentiment, topic flow, and discussion context. Our findings show that triggers of toxicity contain identifiable features and that incorporating shift features with the discussion context can be detected with a ROC-AUC score of …

Text Analytics, Nlp, And Accounting Research, Richard M. Crowley

Research Collection School Of Accountancy

The presentation covered: What is text analytics and NLP?; How text analytics has evolved in the accounting literature since the 1980s; What current (as of 2020) methods are used in the literature; What methods are on the horizon.

Understanding The Relation Between Repeat Developer Interactions And Bug Resolution Times In Large Open Source Ecosystems: A Multisystem Study, Subhajit Datta, Reshma Roychoudhuri, Subhashis Majumder

Research Collection School Of Computing and Information Systems

Large‐scale software systems are being increasingly built by distributed teams of developers who interact across geographies and time zones. Ensuring smooth knowledge transfer and the percolation of skills within and across such teams remain key challenges for organizations. Towards addressing this challenge, organizations often grapple with questions around whether and how repeat collaborations between members of a team relate to outcomes of important activities. In the context of this paper, the word ‘repeat interaction’ does not imply a greater number of interactions; it refers to repeat interaction between a pair of developers who have collaborated before. In this paper, we …

Preparing For The Future: The Effects Of Financial Literacy On Financial Planning For Young Professionals, Tanay Singh

Senior Theses

Purpose – Many people between the age of 20 and 34 have not considered planning financially for the future in any significant capacity and in doing so, they limit their potential savings. The purpose of this study is to examine what financial expectations are for people in the early stages of their career and determine if improving financial literacy and revealing financial realities helps to produce more accurate or realistic expectations. Ultimately, the goal is to better prepare participants in the study for the working world and increased responsibilities outside of the college/university environment by getting them to start thinking …

Incorporating A Reverse Logistics Scheme In A Vehicle Routing Problem With Cross-Docking Network: A Modelling Approach, Audrey Tedja Widjaja, Aldy Gunawan, Panca Jodiawan, Vincent F. Yu

Research Collection School Of Computing and Information Systems

Reverse logistics has been implemented by various companies because of its ability to gain more profit and maintain the competitiveness of the company. However, extensive studies on the vehicle routing problem with cross-docking (VRPCD) only considered the forward flow instead of the reverse flow. Motivated by the ability of a VRPCD network to minimize the distribution cost in the forward flow, this research incorporates the reverse logistics scheme in a VRPCD network, namely the VRP with reverse cross-docking (VRP-RCD). We propose a VRP-RCD mathematical model for a four-level supply chain network that involves suppliers, cross-dock, customers, and outlets. The main …

Designing A Smart Internet Of Things Solution For Point Of Use Water Filtration Management System In Residential, Commercial And Public Settings, Tristan Lim, Hwee-Pink Tan, Chin Sin Ong, Rahul Belani, Siddhant S. K. Agrawal

Research Collection School Of Computing and Information Systems

The use of water filtration Point-of-Use (POU) systems are extensive, ranging from water dispensers in public estates, to household POU water systems. Manufacturers typically recommend filtration cartridges to be changed (i) after their useful life, or (ii) when the water flow volume have exceeded certain capacity, whichever is earlier. However, filtration mechanisms are typically not changed with sufficient regularity. Overused filters can result in negative health effects, over and above the deterioration and loss of filtration benefits of the POU water system. Presently most existing water purification systems do not have smart connected Internet of Things (IoT) means of informing …

Statistical Modeling Of Harassment Against Reddit Moderators, Hamad Bin Khalifa University, Haewoon Kwak

Research Collection School Of Computing and Information Systems

Despite the dedication that some volunteer moderators of online communities display when performing their moderation duties, they become targets of hate and harassment by other users. To understand what causes the change in moderator role from heroes to victims, we analyze the responses of 1,818 moderators on Reddit to an online survey about moderation practices and harassment. We built a statistical model and found 6 significant independent variables that affect harassment on moderators, such as the knowledge of community norms, which increases harassment on moderators the most. Our findings imply that vulnerable moderators in toxic communities need countermeasures against harassment.

System Methodology Of Digital Transformation In Military Manufacturing Industry, Daolin Yu, Wenhai Zhu, Qing Xiao, Guoqiang Shi

Journal of System Simulation

Abstract: Focusing on the lack of the understanding and the solutions to the digital transformation of the military manufacturing enterprises and service providers, the background of the digital transformation in the military manufacturing industry is analyzed. By studying the advanced manufacturing models, the core competitiveness, the value chains and the production (productivity) factors, the (generalization) goals of the digital transformation in the military manufacturing industry are identified, and some urgent problems and the suggestions to solve the complex system problems are provided. The digital transformation in the military manufacturing industry is a long-term strategic action and should be continuously optimized …

Wind Power Generation Hardware-In-Loop Simulation System Based On Rapid Control Prototype Technology, Aihua Wu, Buhui Zhao, Jingfeng Mao, Haiqun Shen, Xudong Zhang

Journal of System Simulation

Abstract: In order to improve the efficiency and effectiveness in the design and testing process of the wind power generation MPPT controller, a rapid control prototype (RCP) system based on the LabVIEW FPGA platform is proposed. The real-time simulation model of wind speed, wind turbine and PMSG, as well as MPPT rapid control prototyping are designed by using PXI-FPGA architecture on the LabVIEW RT real-time operation platform. The power converter, the real-time simulation model and the MPPT rapid control prototyping are connected together to construct a hardware-in-loop (HIL) test system. The simulation results on the gradient wind speed condition and …

Emergency Evacuation Simulation For Dense Passenger Flow In A Rail Transit Transfer Station, Xu Hui, Tian Cheng, Wang Yong

Journal of System Simulation

Abstract: The rail transit is one of the important modes of the public transportation, and its safety operation is crucial. Based on the passenger volume and structure features that have been obtained through the field investigation in Chongqing Lianglukou railway station in China, a multi-level rail transit transfer station simulation model is built to analyze the evacuation process of pedestrians in the consideration of explosion and other emergencies by the software AnyLogic. The evacuation routes and evacuation time of passengers during emergency evacuation in a rail transit transfer station are studied. The research aims at verifying the emergency evacuation capacity …

Research On Emergency Risk Decision Simulation Based On Multi-Agent And Prospect Theory, Wang Jian, Chenqi Situ, Shengqiang Yuan

Journal of System Simulation

Abstract: Focusing on the modeling and the simulation of emergency response risk decision that multi-sections involve in, a simulation model and simulation framework based on multi-agent and prospect theory are proposed. By introducing agent theory, the multi-agent architecture model of emergency risk decision is described and the decision agent are modelled. By introducing prospect theory, following the dynamic evolution of emergencies, the impact of the psychological changes of the decision-makers have on the decision results is studied. The multi-agent emergency risk decision simulation framework is designed and implemented. Taking the risk decision of a fire emergency in the petrochemical plants …

Research On Evolution Model Of Online Public Opinion Based On Temporal Network, Li Feng, Wei Ying

Journal of System Simulation

Abstract: With the in-depth study on the social medias, the social networks of online platforms are recognized gradually as the time-varying temporal networks. In order to compare and analyze the information diffusion process and the result, the analysis method of computer simulations is adopted, a temporal network is generated, and the SIR model is used as the online public opinion diffusion model. The simulation results based on multi-agent approach show that the uncertainty of information diffusion on the social platforms comes from the complicated structure of the temporal networks and the SIR model. In addition, the misunderstanding of the social …

Performance Balanced Opportunistic Routing And Simulation Analysis Based On Cooperative Game, Huahong Ma, Honghai Wu, Guoqiang Zheng, Baofeng Ji

Journal of System Simulation

Abstract: Opportunistic transmission mode of “store-carry-forward” is usually used to make routing in mobile opportunistic network. Currently, there have been many researches in this area. However, the existing opportunistic routing mechanisms pay much attention to the single index of delivery success ratio, but neglect the constraints on other performance indicators, which may lead to the extreme imbalance of network performance. Aiming at this issue, the diffusion of data packets between multiple nodes are modeled as a cooperative game with the goal of maximal performance balancing, and an opportunistic routing protocol based on the cooperative game for performance balancing is proposed. …

Parallel Computing Of Multi-Agent System In Spatially-Explicit Modeling And Simulation, Hongchun Qu, Xianhui Yao, Yin Li

Journal of System Simulation

Abstract: Aiming at the synchronization in the spatially-explicit parallel simulations, a limited optimistic synchronization algorithm based on Agent sensing region is proposed. The algorithm inherits the advantages of the optimistic synchronization algorithm and the security-guaranteed conservative synchronization algorithm. The algorithm categories all simulated agents into the security agent region and non-security agent region. The simulation is performed through the collaboration between the dispatch server and the execution servers where simulation tasks are scheduled and executed. The dispatch server determines whether an agent is in a security zone according to the security radius. The execution servers are responsible for performing the …

Visualization Of Tropical Cyclones Based On Digital Earth, Shuoben Bi, Yucheng Gong, Mingyue Lu, Zhou Hao, Tang Zhi

Journal of System Simulation

Abstract: Tropical cyclones are often accompanied by heavy rains, storm surges and so on, which have serious impact on the southeast coast of China. Visualization of tropical cyclones can directly demonstrate its motion state, occurrence process and internal structure, and support the research and prediction on it. This paper builds digital earth platform based on Cesium(an open source library),introduces the system architecture, verificates the applicability of point cloud method to the visualization of cloud field data, proposes an improved wind field visualization method based on particle tracking, with includes the calculation of wind field particle properties, the drawing of wind …

Optimization Simulation Of Feeder Airport Runway Structure For Pollutant Discharge Control, Jiang Bo, Yunfan Zhou, Chenglong Li, Zhang Hao

Journal of System Simulation

Abstract: Air pollutant discharge in the LTO (Landing and Take-off) cycle of the civil aviation transport is harmful to the ground personnel and the near-ground environment, which can be restrained primarily by reducing the ground taxi time. Considering the structure of the single-taxiway-single-runway in the common feeder airport, a method for calculating the aircraft ground taxi time is presented. Based on this method, an evaluation index of the pollutants is proposed and an assessment model of aircraft pollutants emission in feeder airport is established. Taking a feeder airport as an example, the taxiway crossing position with the smallest pollutant evaluation …

Maritime Radar Terrain Echo Simulation Based On Dem And Sar, Yongfeng Suo, Shenhua Yang, Guoquan Chen, Zhuqiang Xiang

Journal of System Simulation

Abstract: Due to the huge amount of work required for terrain database building, the application of navigation radar simulation on the reflectivity of land object has been greatly limited. A novel radar simulation method is proposed based on the DEM(Digital Elevation Model) data and the same-band SAR(Synthetic Aperture Radar) reflection data. The target reflectance information is obtained, which is used as the basis for the surface radar reflectivity simulation. In combination with the radar equations, the surface reflectivity model of the navigation radar is established. Taking into account the elevation shielding relationship of the radar echo topography, an algorithm of …

Rapid Simulation And Volume Rendering Of Electromagnetic Environment Based On Geographic Coordinate System, Yuguo Wu, Beibei Han

Journal of System Simulation

Abstract: Considering the earth's curvature, the spherical regular grid model is used to organize the electromagnetic field data. In order to reduce computational complexity of ITM model, the terrain reuse is proposed to improve the efficiency of the simulation. The Multithread and the terrain reuse are combined to improve the efficiency of the multi-radiation source. Considering that the traditional ray casting algorithm which takes the cube model as the bounding box cannot draw spherical regular grid data directly, a ray casting algorithm which uses the dome model as the bounding box is proposed. Experiments show that even considering the influence …

Spatial Structure Optimization Of Natural Forest Based On Bee Colony-Particle Swarm Algorithm, Dongsheng Qing, Xiaofang Zhang, Jianjun Li, Guo Rui, Qiaoling Deng

Journal of System Simulation

Abstract: The natural forest spatial structure contains the spatial location information of the forest, which affects the growth, competition and stability of the forest development. Its optimization is a multi-objective programming problem. A bee colony particle swarm optimization (ABC-PSO) hybrid algorithm is proposed, which improves the initial particle generation mechanism, the number of follow bees and the circulation mechanism. The algorithm is applied to the multi-objective optimization of the spatial structure of natural forest. An optimization model which takes account of the tree distribution grid, tree size segmentation and tree competition is established. The simulation results show that the bee …