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2021

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Articles 601 - 630 of 844

Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

Cyclic Damage Accumulation In The Femoral Constructs Made With Cephalomedullary Nails, Farah Hamandi, Alyssa Whitney, Mark H. Stouffer, Michael J. Prayson, Jorn Rittweger, Tarun Goswami Feb 2021

Cyclic Damage Accumulation In The Femoral Constructs Made With Cephalomedullary Nails, Farah Hamandi, Alyssa Whitney, Mark H. Stouffer, Michael J. Prayson, Jorn Rittweger, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Background: The purpose of this study was to evaluate the risk of peri-prosthetic fracture of constructs made with cephalomedullary (CM) long and short nails. The nails were made with titanium alloy (Ti-6Al-4V) and stainless steel (SS 316L). Methods: Biomechanical evaluation of CM nail constructs was carried out with regard to post-primary healing to determine the risk of peri-implant/peri-prosthetic fractures. Therefore, this research comprised of, non-fractured, twenty-eight pairs of cadaveric femora that were randomized and implanted with four types of fixation CM nails resulting in four groups. These constructs were cyclically tested in bi-axial mode for up to 30,000 cycles. All …


Mapping Of The Information Flow Of The Valle Occidental Coffee Region: A System-Of-Systems Perspective, Irene Campos Feb 2021

Mapping Of The Information Flow Of The Valle Occidental Coffee Region: A System-Of-Systems Perspective, Irene Campos

CESUN Conference

Uncertainty is a characteristic of many of the contemporary environments that our systems inhabit. In the case of farming systems, uncertainty has always been present in the form of unpredictable weather conditions, disease outbreaks and evolving societal and economic factors. Uncertainty poses a challenge for communication and information alignment, which is especially important for a farming system responding to disasters. A first step towards finding solutions for problems of information alignment in systems is mapping and identifying information links in them. The goal of this research is to map the information flow and feedback dynamics of the Valle Occidental coffee …


Exploring How Prize Challenges Complement An Organization's Innovation Efforts, Ademir Vrolijk, Zoe Szajnfarber Feb 2021

Exploring How Prize Challenges Complement An Organization's Innovation Efforts, Ademir Vrolijk, Zoe Szajnfarber

CESUN Conference

prize challenge, open innovation, crowdsourcing, NASA, 3D Printed Habitat Challenge, additive manufacturing


Risk Management Decision Making For Security And Trust In Hardware Supply Chains, Zachary A. Collier, Thomas L. Polmateer, James H. Lambert Feb 2021

Risk Management Decision Making For Security And Trust In Hardware Supply Chains, Zachary A. Collier, Thomas L. Polmateer, James H. Lambert

CESUN Conference

Modern cyber-physical systems are enabled by electronic hardware and embedded systems. The security of these sub-components is a concern during the design and operational phases of cyber-physical system life cycles. Compromised electronics can result in mission-critical failures, unauthorized access, and other severe consequences. As systems become more complex and feature greater connectivity, system owners must make decisions regarding how to mitigate risks and ensure resilience and trust. This paper provides an overview of research efforts related to assessing and managing risks, resilience, and trust with an emphasis on electronic hardware and embedded systems. The research takes a decision-oriented perspective, drawing …


The Challenges And Opportunities Of Teaching Systems Engineering For Large Scale Engineering Systemse, Edward Pines, Dennis Engi Feb 2021

The Challenges And Opportunities Of Teaching Systems Engineering For Large Scale Engineering Systemse, Edward Pines, Dennis Engi

CESUN Conference

In this paper, we discuss a course in large scale systems engineering that was developed as part of a twelve-credit Graduate Certificate in Systems Engineering for part-time and returning students. Our focus was on how to work on big, unmanageable, messy problems. Teaching systems engineering for large-scale engineering systems is challenging for many reasons. One of the main challenges is the breadth of material to be addressed within one or two courses. Other challenges result from how students learn about the transitions from the development of a conceptual framework to systems architecture through engineering design, mathematical analysis and eventual construction …


What Tesla’S $1.5 Billion Bet On Bitcoin Means For Crypto Legitimacy, Singapore Management University Feb 2021

What Tesla’S $1.5 Billion Bet On Bitcoin Means For Crypto Legitimacy, Singapore Management University

Perspectives@SMU

Some significant issues need to be resolved before Tesla can accept Bitcoin as a legitimate method of payment, says UNSW Business School's Mark Humphery-Jenner


Structural Identification And Damage Detection In Bridges Using Wave Method And Uniform Shear Beam Models: A Feasibility Study, Mehran Rahmani, Manan Naik Feb 2021

Structural Identification And Damage Detection In Bridges Using Wave Method And Uniform Shear Beam Models: A Feasibility Study, Mehran Rahmani, Manan Naik

Mineta Transportation Institute

This report presents a wave method to be used for the structural identification and damage detection of structural components in bridges, e.g., bridge piers. This method has proven to be promising when applied to real structures and large amplitude responses in buildings (e.g., mid-rise and high-rise buildings). This study is the first application of the method to damaged bridge structures. The bridge identification was performed using wave propagation in a simple uniform shear beam model. The method identifies a wave velocity for the structure by fitting an equivalent uniform shear beam model to the impulse response functions of the recorded …


Better And Faster: How To Leverage Award-Winning Operations Management Techniques, Carrie Beam Jan 2021

Better And Faster: How To Leverage Award-Winning Operations Management Techniques, Carrie Beam

Operations Management Presentations

The INFORMS Franz Edelman Award for Achievement in Advanced Analytics, Operations Research, and Management Science identifies innovative applications of operations management in fields as diverse as sewer district management, school bus scheduling, polio vaccinations, and of course transportation. In this seminar, 2021 Edelman Prize Chair Dr. Carrie Beam will introduce the keys of stakeholder engagement, iterative development, and scaled-up implementation of operations management techniques and how they apply to the Franz Edelman Award and to MSOM courses.


Assessment Of Heavy Metal Concentration In Soils Around Geita The Gold Mine, Tanzania, Mariam G. Mgendi, Mkabwa L. K Manoko, W.J.S. Mwegoha, C. Southway C. Southway Jan 2021

Assessment Of Heavy Metal Concentration In Soils Around Geita The Gold Mine, Tanzania, Mariam G. Mgendi, Mkabwa L. K Manoko, W.J.S. Mwegoha, C. Southway C. Southway

Journal of Humanities and Social Sciences

Health issues related to gold mining cannot be underestimated. Gold mining produce acid mine drainage (AMD), which in turn releases heavy metals into the nearby environment, hence causing environmental pollution. Heavy metals are naturally very toxic, thus pose a great health concern especially when their concentration exceeds the recommended permissible limits. In this study, concentrations of five heavy metals—including Pb, Ni, Cr, Cu and Zn—were assessed in the soil around Geita Gold Mine (GGM). A total of 17 sampling sites were established from which the soil samples were collected at 0-15cm and 15-30cm soil depth. The concentration of both total …


Improved Wolf Pack Algorithm For Distribution Of Molds On Molds Table, Zhonghua Han, Yuehan Liu, Li Man, Liangliang Sun, Hongzhi Zheng Jan 2021

Improved Wolf Pack Algorithm For Distribution Of Molds On Molds Table, Zhonghua Han, Yuehan Liu, Li Man, Liangliang Sun, Hongzhi Zheng

Journal of System Simulation

Abstract: In order to solve the problem of the distribution of molds on the mold table in the production process of concrete prefabricated components, a method combining Bottom-Left Algorithm (BLA) and Improved Wolf Pack Algorithm (IWPA) is proposed. Improved Wolf Pack Algorithm is for optimizing the order of upper line and the mold used for each member is sequentially assigned to the mold table according to the upper line. BLA is used to determine the direction and position of the molds on the molds table. The WPA safari behavior is improved by introducing Levi's flying ideas and the Hamming …


Simulation Research On Abandonment Rate Of Contact Center Based On Patience Threshold, Junxiang Li, Wanbin Zang Jan 2021

Simulation Research On Abandonment Rate Of Contact Center Based On Patience Threshold, Junxiang Li, Wanbin Zang

Journal of System Simulation

Abstract: Customer abandonment rate is an important indicator to measure the service level of contact center. Customers in a traditional call center follow the principle of first come, first served, but some customers will be lost in the queuing process because of their limited patience. In this regard, by setting the customer's patience threshold and considering adding a specific agent channel to the member customers, or adjusting the number of agent channels under the original staffing, a new contact center queuing model is established based on the traditional call center model. The ProModel simulation software is used to study the …


Research On Virtual Simulation Training System For Multi-Position Collaborative Operation In Oilfields, Xianmei Liu, Jia Di, Liu Fang Jan 2021

Research On Virtual Simulation Training System For Multi-Position Collaborative Operation In Oilfields, Xianmei Liu, Jia Di, Liu Fang

Journal of System Simulation

Abstract: Aiming at the demands of multi-position collaborative operation in oilfields, the virtual simulation training system for multi-position collaborative operation in oilfields is studied. It shows the development mode and architecture of the system which uses the user perception environment to obtain data for the autonomous decision, and uses the collision detection process to simulate the interaction between user and device. The co-simulation strategy and the network communication protocol are designed. The room management is used to ensure that the scenes in the group are consistent in real time and the scenarios between the groups are independent. The Non-Player Character(NPC) …


Study On Ultimate Carrying Capacity And Regulation Methods Of Urban Atmospheric Environment, Guangqiu Huang, Wenxin Wang Jan 2021

Study On Ultimate Carrying Capacity And Regulation Methods Of Urban Atmospheric Environment, Guangqiu Huang, Wenxin Wang

Journal of System Simulation

Abstract: In order to solve the calculation problem of the ultimate carrying capacity of the atmospheric environment, the calculation formula of the ultimate carrying capacity of the atmospheric environment is proposed, and the system dynamics model with the ‘pollution index-energy' compliance as the constraint is constructed according to the urban energy planning, namely the PI-E-SD(Pollution Indicator-Energy-System Dynamics) model. In this model, the linear regression method is used to determine the pollution index, which solves the non-uniformity problem. The SD-modeling method is used to construct the “energy-economy-environment” simulation system, so that the government measures can be quantified to make the prediction …


Traversal Path Planning And Simulation Of Robot Based On Radiation Scanning, Bin Lin, Guanghui Han, Chenchen Song, Yajing Zhang Jan 2021

Traversal Path Planning And Simulation Of Robot Based On Radiation Scanning, Bin Lin, Guanghui Han, Chenchen Song, Yajing Zhang

Journal of System Simulation

Abstract: Aiming at the high repetition rate and many turns of robot paths based on BINN algorithm, an ITPPA combining the template model and the RS algorithm is proposed. The BINN algorithm is used to formulate the non-obstacle walking strategy. Multiple obstacle avoidance path templates are designed to ensure that the robot could avoid obstacles in an orderly manner. RS algorithm is used to guide the robot to escape the dead zone quickly. Simulation results show that, compared with BINN algorithm, ITPPA could not only effectively reduce the path repetition rate and the number of turning and energy consumption …


Joint Low Rank And Sparsity-Based Channel Estimation For Fdd Massive Mimo, Zhou Jin Jan 2021

Joint Low Rank And Sparsity-Based Channel Estimation For Fdd Massive Mimo, Zhou Jin

Journal of System Simulation

Abstract: Channel estimation of millimeter wave communication needs large system load. In order to reduce the load, a low-rank and sparse feature of the wireless channel is combined, and a channel estimation algorithm framework based on non-convex low-rank approximation is proposed. Aiming at the large computation of the channel model-based dictionary learning algorithm, a dictionary learning algorithm for deep neural network channel feature classification is designed. The simulation shows that the average square error of the proposed method is better than the channel model-based dictionary learning method, the channel estimation method under the Bayesian framework, and the compressed …


Research On Precision Parking Control Method For Emu Inbound Process, Zhongqi Li, Yueshuang Xing Jan 2021

Research On Precision Parking Control Method For Emu Inbound Process, Zhongqi Li, Yueshuang Xing

Journal of System Simulation

Abstract: By analyzing the relationship between braking force and speed during the stop-stop process of high-speed EMU(Electric Multiple Units), the multi-point dynamics model of EMU is constructed. The Smith predictor is introduced due to the delay effect on the system caused by the braking force generated during the late braking, and the RBF(Radial Basis Function) neural network-based PID control strategy is combined with the Smith predictor to achieve tracking control of a given speed during braking. Simulation analysis shows that the error of train speed and set speed controlled by RBF neural network PID-Smith controller is less than ±1 …


Overview Of Optimization Problems Regarding Emergency Organization Allocation Based On Mathematical Programming, Cejun Cao, Congdong Li Jan 2021

Overview Of Optimization Problems Regarding Emergency Organization Allocation Based On Mathematical Programming, Cejun Cao, Congdong Li

Journal of System Simulation

Abstract: To improve the utilization of human resources in large-scale natural disasters and reduce various losses, how to use mathematical programming approach to optimize emergency organization allocation strategy is the currently urgent and critical issue. A decision framework or conceptual model for emergency organization allocation optimization is proposed. The current status of mathematical programming model for emergency organization allocation is presented from the perspective of task sequence and objective quantity. An overview on the exact and heuristic algorithm to solve the proposed model is conducted. Potential issues for in-depth study with respect to simulation and modeling of emergency organization allocation …


Uncertainty Quantitative Analysis In Risk Assessment Of Returning To School In The Post-Covid-19 Era, Haibin Li, Jialiang Wang, Haiyan Li Jan 2021

Uncertainty Quantitative Analysis In Risk Assessment Of Returning To School In The Post-Covid-19 Era, Haibin Li, Jialiang Wang, Haiyan Li

Journal of System Simulation

Abstract: After the epidemic, taking the spread of the epidemic in returning to school as an example, a quantitative risk assessment study is conducted. Taking the activity trajectory description of the whole process of susceptible individuals from infection to isolation as a clue, an epidemiological model for risk assessment is established. The number of infected persons in the risk indicators of returning to school is quantified based on the quantified model parameters. According to the value characteristics of the parameters, the number of infected persons is taken as a function of discrete random variables. The probability distribution of the infected …


Evolutionary Simulation Of Online Public Opinion Based On The Bert-Lda Model Under Covid-19, Muni Zhuang, Li Yong, Tan Xu, Taitian Mao, Kaicheng Lan, Lining Xing Jan 2021

Evolutionary Simulation Of Online Public Opinion Based On The Bert-Lda Model Under Covid-19, Muni Zhuang, Li Yong, Tan Xu, Taitian Mao, Kaicheng Lan, Lining Xing

Journal of System Simulation

Abstract: The construction of a large-scale online public opinion evolution simulation model has guidance value for differentiated emergency management and public opinion guidance in the worst-hit areas in Wuhan and the other areas in China during the outbreak of the COVID-19. In order to realize the fine-grained simulation of the public sentiment evolution of the topic, the LDA topic model is deeply integrated with BERT word vector to optimize the topic vector and power the text topic clustering. At the same time, on the basis of improving BERT pre-training task, the deep pre-training task is superimposed to improve the accuracy …


Research On Particle Filter Algorithm Based On Improved Grey Wolf Algorithm, Weigang Li, Li Yang, Yuntao Zhao, Baokang Yan Jan 2021

Research On Particle Filter Algorithm Based On Improved Grey Wolf Algorithm, Weigang Li, Li Yang, Yuntao Zhao, Baokang Yan

Journal of System Simulation

Abstract: The traditional particle filter algorithm is prone to particle depletion and weight degradation, and a large number of particles are needed to make an accurate estimation of non-linear system. A novel particle filter algorithm based on grey wolf optimization algorithm is proposed. The particles are employed to characterize the individuals of grey wolf and simulate the process of wolf hunting, which makes the particles move to the high likelihood region of posterior probability and improve the rationality of the distribution of the particles. Levy flight strategy is introduced in grey wolf algorithm to improve the convergence speed. The adaptive …


A Quantization-Based Integration Method For Stiff Ordinary Differential Equations, Zhihua Li, Jiang De, Chenjia Wu, Zhihua Fan Jan 2021

A Quantization-Based Integration Method For Stiff Ordinary Differential Equations, Zhihua Li, Jiang De, Chenjia Wu, Zhihua Fan

Journal of System Simulation

Abstract: QSS(Quantized State System) has advantages over the traditional time-discrete integration methods in solving general ordinary differential equation (ODE) systems, but it is not suitable for solving the stiff ODE systems. To effectively solve the stiff ODE systems, a step-correction optimization algorithm based on QSS (SCOA based-on QSS) is proposed, which combines the ideas of the QSS method and the implicit trapezoidal integral method. The simulation results of three typical stiff ODE cases show that the SCOA based-on QSS algorithm has advantages over other algorithms, and the simulation accuracy can be significantly improved by appropriately reducing the quantum size.


Cold Load Prediction Model Based On Improved Pso-Bp Algorithm, Junqi Yu, Wenqiang Jing, Anjun Zhao, Yanhuan Ren, Zhou Meng, Xinle Huang, Yang Xue Jan 2021

Cold Load Prediction Model Based On Improved Pso-Bp Algorithm, Junqi Yu, Wenqiang Jing, Anjun Zhao, Yanhuan Ren, Zhou Meng, Xinle Huang, Yang Xue

Journal of System Simulation

Abstract: Aiming at the low correlation between input and output data and the error of prediction model in PSO-BP neural network prediction model, a combined prediction method based on JMP, PSO-BP neural network and Markov chain is proposed. The method first uses JMP data processing software to process the input data and eliminating the low coupling degree samples, then conducts PSO-BP neural network training to obtain the cold load prediction results, and finally uses markov chain to eliminate the random errors generated by the system to obtain the final prediction results. The results show that the combined prediction method has …


Research On Intelligent Design And Simulation Method Of Screw Machine Process, Guodong Sun, Qichang He Jan 2021

Research On Intelligent Design And Simulation Method Of Screw Machine Process, Guodong Sun, Qichang He

Journal of System Simulation

Abstract: Aiming at the difficulty during the process design of the automatic screw machines, such as low efficiency and poor quality, a screw machine process design and verification system is developed. Supported by image recognition technology, the system would automatically obtain the quantity and the locations of the screwing holes from the top view. An optimization model will be established to optimize the tightening sequence of the screw according to RSA (Radar Spiral Algorithm) and improved genetic algorithm. An integration is conducted into Tecnomatix to simulate those optimized sequence in case of collision. The results indicate that the …


Research On Double Input Motion Somatosensory Algorithm Based On Logic Control, Wang Hui, Yingtao Liu Jan 2021

Research On Double Input Motion Somatosensory Algorithm Based On Logic Control, Wang Hui, Yingtao Liu

Journal of System Simulation

Abstract: Aiming at the two-input classic washout algorithm in the flight simulator, there are problems such as loss of perceived angular velocity signal, phase error, and insufficient fidelity. A logic control washing-out algorithm is proposed. Based on the vestibular system theory, the classic washout algorithm is used to improve the high-pass angular velocity channel structure. A logic controller and an angular displacement continuous generator are designed to optimize the coupling angular velocity in the high-pass angular velocity channel and the tilt coordination channel and stabilize the jump change washout angular displacement, so the improved algorithm is more consistent with the …


Visualization Of Finite Element Analysis Deformation Results Based On Hololens, Jinli Xu, Zhou Zheng Jan 2021

Visualization Of Finite Element Analysis Deformation Results Based On Hololens, Jinli Xu, Zhou Zheng

Journal of System Simulation

Abstract: An UWP application of virtual review of the finite element analysis based on Microsoft HoloLens is developed by using Unity3D software. A set of programs are completed to realize three-dimensional solid static finite element analysis in Matlab. To realize the visualization of the deformation effect, the useful information of the finite element analysis result is extracted and exported to VTK file, then converted into DAE file. A vertex shader is written in Unity3D software to realize the color display and the visualization of deformation effect of one-sided model, and finally the UWP application is released to HoloLens. The test …


Safety Evaluation And Risk Level Prediction Of Driving Behavior Considering Multi-Factors Influence, An Yu, Pengpeng Jiao, Zixiu Bai Jan 2021

Safety Evaluation And Risk Level Prediction Of Driving Behavior Considering Multi-Factors Influence, An Yu, Pengpeng Jiao, Zixiu Bai

Journal of System Simulation

Abstract: In order to study the influence of multi-factors of human-vehicle-road on driving behavior and vehicle safety status in road traffic system, a simulated driving comparison test of six scenarios combined by multiple factors is designed. Driving simulator, physiography and eye tracker are used to collect 19 indicators related to driving behavior respectively. The differences of sample data are compared by variance analysis. The nonlinear SVM(support vector machine) is used to classify and predict the sample data. The driving behavior risk level prediction model is established, and the validity of the model is verified by the experimental data. The …


Collision Simulation Analysis Of Sam Movable Guardrail, Hongjun Cui, Sixue Li, Minqing Zhu, Li Xia Jan 2021

Collision Simulation Analysis Of Sam Movable Guardrail, Hongjun Cui, Sixue Li, Minqing Zhu, Li Xia

Journal of System Simulation

Abstract: Aiming at the problem of low anti-collision grade of the movable guardrail at the opening of the central divding belt of the expressway, a SAm-level concrete movable guardrail and a new connecting device are proposed. Based on the finite element method, the collision model between the vehicle and the guardrail is established, and the collision process is also calculated by LS-DYNA. According to the collision results of different vehicle types, the safety performance of the guardrail is evaluated in terms of cushioning, blocking and guiding performance. The OIV value is less than 12 m/s for small vehicles' collision with …


Real-Time Prediction Of Primary Flow By Mpc Method In Heating System, Zhongbo Li, Jia Meng, Kang Yan, Haihong Wang, Li Miao, Lü Qing, Jingjing Xie, Dajun Fang Jan 2021

Real-Time Prediction Of Primary Flow By Mpc Method In Heating System, Zhongbo Li, Jia Meng, Kang Yan, Haihong Wang, Li Miao, Lü Qing, Jingjing Xie, Dajun Fang

Journal of System Simulation

Abstract: Based on the model predictive control method, this paper uses the discrete controlled autoregressive model to establish the dynamic heat transfer delay model of the secondary network and the thermal station model. The polynomial fitting method of machine learning algorithm is applied to identify and calibrate the parameters of the secondary network model and the thermal station model. The primary flow rate of the heating station under future operating conditions is predicted based on the model results, which provides a basis for the quality-based regulation of heating system. The model is verified by measured data, and the actual …


Research On Sins/Gnss/Train-Speed Integrated Navigation Algorithm, Wang Ke, Ligang Liu, Bin Zhou, Zhiyong Bu Jan 2021

Research On Sins/Gnss/Train-Speed Integrated Navigation Algorithm, Wang Ke, Ligang Liu, Bin Zhou, Zhiyong Bu

Journal of System Simulation

Abstract: The precise train positioning under complicated railway environment has been a key technical challenge for train navigation currently. In the conventional solutions, in case of satellite signals being weak or indiscernible, the task of positioning has to be undertaken by SINS alone. This will cause some serious error-accumulation problems, especially when low-cost inertial devices are used. In order to solve this problem, we propose a novel integrated train navigation algorithm, which includes two working modes. The SINS/GNSS mode is designed for the situation that satellite signals are valid, whereas the SINS/wheel-speed mode is for the weak signal environments. Both …


Threat Assessment For The Defense Penetration Paths Of Air Strike Aircrafts Based On Radar Chart, Shengli Liu, Wang Gang Jan 2021

Threat Assessment For The Defense Penetration Paths Of Air Strike Aircrafts Based On Radar Chart, Shengli Liu, Wang Gang

Journal of System Simulation

Abstract: Threat assessment for the defense penetration paths of air strike aircrafts provides important evidence for evaluating and improving the deployment of air defense. Considering that traditional threat assessment methods are difficult to intuitively reflect the threat degree of each path and the value of each evaluation indicator, a novel method of threat assessment for defense penetration paths based on radar chart is proposed. The threat assessment indicator system for the defense penetration paths of air strike aircrafts is put forward. The weights of threat assessment indicators are calculated by the group decision analytic hierarchy process (AHP) and the method …