Engineering Commons^™

Multigrid For The Nonlinear Power Flow Equations, Enrique Pereira Batista

Mathematics Theses and Dissertations

The continuously changing structure of power systems and the inclusion of renewable
energy sources are leading to changes in the dynamics of modern power grid,
which have brought renewed attention to the solution of the AC power flow equations.
In particular, development of fast and robust solvers for the power flow problem
continues to be actively investigated. A novel multigrid technique for coarse-graining
dynamic power grid models has been developed recently. This technique uses an
algebraic multigrid (AMG) coarsening strategy applied to the weighted
graph Laplacian that arises from the power network's topology for the construction
of coarse-grain approximations to …

Research On Recovering Of Complex Networks Based On Boundary Nodes Of Giant Connected Component, Zhe Wang, Jianhua Li, Kang Dong

Journal of System Simulation

Abstract: Network recovery is an important way to solve the inevitable failure,and the reasonable recovery strategy can reduce the cost of resource and improve the network robustness.In order to study the dynamic behavior of recovery process and the relationship between recovery and network robustness,a Recovery Model of Boundary Nodes (RMBN) based on boundary of giant connected component is proposed,and two network Recovery strategies,Average Recovery of Boundary Nodes (ARBN) strategy and Priority Recovery of Boundary Nodes (PRBN) strategy are designed.The simulation results of different recovery strategies on three network models show that with the increase of recovery ratio,the …

Non-Cooperative Target Feature Point Cloud Registration Optimization Based On Icp Algorithm, Wei Liang, Muyao Xue, Huo Ju, Jinjie Zhang

Journal of System Simulation

Abstract: Aiming at the pose measurement caused by non-cooperative targets in visual measurement that cannot provide cooperation information,the ICP(Iterative Closest Point) algorithm is used to register the point cloud down-sampling data acquired at different times to complete the relative pose measurement of the target.The point cloud data of the target at the current moment is obtained using the structure from motion algorithm and the feature point matching algorithms are compared based on threshold matching and optical flow matching method.The extracted feature points are reconstructed by triangulation.The relative pose changes of the object at different times are calculated by using …

Frequency Regulation Signal Reduction Methods For Aluminum Smelters, Zejian Feng, Shengfei Li, Shouzhen Zhu, Zhiyun Li, Xiaomin Bai

Journal of System Simulation

Abstract: The motion delay of tap changer of aluminum smelter rectifier downgrades frequency response precision in following high frequency regulation signals.Aiming to improve the regulation performance of aluminum smelter loads based on adjusting dynamics,a fast regulation signal reduction technique is proposed,which is motion control threshold-based.A simulation-based decision technique of threshold values of the signal reduction algorithm's is devised to improve the performances of frequency response.Simulation results verify the efficacy of the techniques in promoting the frequency response precision to a certain production level,and contribute a practical way to support aluminum smelter‘s provision of frequency regulation services …

Research On Fuzzy Control And Optimization For Traffic Lights At Single Intersection, Jiajia Liu, Xingquan Zuo

Journal of System Simulation

Abstract: Aiming at the traffic signal control at urban single intersection,a fuzzy control method for traffic lights is presented.The method is based on a four-phase phasing sequence to control the traffic lights at a single intersection.Inputs of the fuzzy controller are the number of vehicles in line and the arrival rate of vehicles,and the output is the green light extension time of the current green light phase.A genetic algorithm (GA) is used to optimize fuzzy rules and membership functions of the fuzzy control system to improve the performance of the fuzzy controller.The fuzzy control method is realized by using …

Research On Dissemination And Control Of Public Opinion Based On Multilayer Coupled Network, Chen Shuai

Journal of System Simulation

Abstract: In order to study the influence of information interaction between multi-platforms on the dissemination and control of public opinion,taking Wechat and Weibo for example,a public opinion communication and control model based on multi-layer coupled network including Wechat layer,Weibo layer and control layer is constructed using multi-agent modeling method and improved SEIR model.On Anylogic platform,a simulation experiment was conducted on the event that “the use of materials by the Hubei Red Cross Society raises doubts”,and the effects factors such as single/dual platform,control range,control dynamics,control time and interaction between platforms were analyzed.The media guidance and government intervention strategies under multi-platform …

Amorphous Sio2/Si Interface Defects And Mechanism Of Passivation/Depassivation Reaction, Zhuocheng Hong, Zuo Xu

Journal of System Simulation

Abstract: The amorphous silicon dioxide/silicon (a-SiO₂/Si) interface is an important part of semiconductor devices.The passivation and depassivation process of silicon dangling bond defects (P_b-type defects) at the SiO₂/Si interface has a significant impact on semiconductor devices.Based on molecular dynamics and first-principles calculation methods,a-SiO₂/Si(111) interface model is constructed based on a-SiO₂ and crystalline Si.The CI-NEB (Climbing Image-Nudged Elastic Band) method is used to study the passivation and depassivation reactions of H₂ and H atoms of P_b defects at the a-SiO₂/Si(111) interface. The curves,barriers,and transition state structures of …

Collaborative Optimization Of Production And Energy Consumption In Flexible Workshop, Ding Yu, Wang Yan, Zhicheng Ji

Journal of System Simulation

Abstract: Considering the problem of the multi-objective constrained flexible job-shop,the NSGA-Ⅱalgorithm based on hybrid mutation operator is proposed.In view of NSGA-II algorithm being prone to premature convergence,poisson average and gaussian operators are introduced to improve the global and local optimization ability of the algorithm.The optimal scheme is selected from the set of pareto solutions by adopting the strategy of FAHP-IEVM,which is the combination of subjective and objective evaluation method. The modified algorithm is tested and compared by a series of ZDT test functions.The results show that the convergence and diversity of the revised algorithm are improved obviously.The effectiveness of …

Application Of Simulation Technology In Football Overall Attack Training, Xu Nuo, Shuanglong Liu, Fugao Jiang

Journal of System Simulation

Abstract: Simulation technology has a broad prospect in the field of football application.At present,football attack training is mainly based on audio-visual,experience and on-the-spot practice,but it lacks professional scene representation and systematic theoretical support. Visual C++ development platform and simulation programming method are used to virtualize the football training and reproduce the overall attack drill of football under different training scenes.The results show that the simulation technology can achieve more training situations. It can be used as an auxiliary tool for football overall attack training,enrich the training means,help players accurately understand the tactical system,and promote the scientific development of football training.

Optimization Algorithm For Planar Led Distribution And Connection, Fei Yue, Zhiqiang Gui, Yuyou Yao, Benzhu Xu, Liping Zheng

Journal of System Simulation

Abstract: The distribution and grouping of planar LED can be modeled as a multi constraint optimization problem.A novel algorithm based on the centroidal capacity-constrained power diagram for LED distribution is proposed,to achieve the goal of uniform illumination of planar LED.An optimization algorithm of LED combination and connection based on the greedy strategy is proposed to save materials.The experiment results show that the proposed algorithms are simple,effective in layout and grouping with rapid convergence,and can be used in practical applications.

Multi-Agent Behavior Simulation For Metro Station Passenger, Zequn Li, Fengting Yan, Zhicai Shi, Yumei Jian, Changhua Hua, Yongzhan Si, Xiang Yang

Journal of System Simulation

Abstract: Metro station is a typical public place with large crowd density.The characteristics of crowd behavior and the guidance based on the characteristics of crowd behavior can effectively train the crowd for emergency evacuation.Adopting the method of multi-agent and characteristics by measuring station building scene,analyzing the influence factors of passenger behavior characteristics,based on the passenger conformity rule,the single-agent passenger route choice behavior model is established.The multiple agents behavioral decision system in the virtual metro stations is established,the WebVR experiment is used to research the influencing factors of passenger herd behavior and decision-making behavior,which provides a theoretical basis for …

Parallel Finite Element Simulations On Radiation Damage Effects Of Lateral Pnp Bjts, Wang Qin, Zhaocan Ma, Hongliang Li, Linbo Zhang, Benzhuo Lu

Journal of System Simulation

Abstract: The Zlamal finite element discretization is applied in the drift-diffusion model for the simulations of semiconductor devices.Combined with the coupled ionization damage model,the ionization damage effects of lateral PNP (LPNP) bipolar junction transistors (BJT) are simulated.The model and algorithm are implemented based on the three-dimensional parallel adaptive finite element toolbox PHG (Parallel Hierarchical Grid).The phenomena of excess base current and current gain degradation in LPNP BJTs are successfully simulated via numerical calculation. A large-scale numerical experiment with 100 million elements and 1 024 MPI processes is carried out,demonstrating the good parallel scalability of the algorithm.

Analyzing Dispatching Wave Policies For E-Commerce Logistics Based On The Multi-Agent-Based Simulation, Zhiqiang Niu, Chaoyang Li, Hongyu Dong, Zhang Feng, Lingyun Meng, Tong Lu, Shengnan Wu

Journal of System Simulation

Abstract: To provide superior on-line shopping experiences and maintain sustained profitability,e-commerce logistics companies need design an effective dispatching wave policy strategy to handle the tradeoff between the advantage of economies of scale and fast-pace delivery services.A multi-agent-based simulation framework is proposed,where business processes in logistics are built as different nodes in the simulation network.Case studies are conducted to test the order delivery process with various wave strategies in the Beijing metropolitan area.Experimental results show that situation-dependent wave strategies are sensitive to different patterns of online shopping demands.

Fault Diagnosis For Bearings Of Unbalanced Data Based On Feature Generation, Minglu Fan, Wang Yan, Zhicheng Ji

Journal of System Simulation

Abstract: Focus on the sample imbalance and insufficiency caused by the difficulty to obtain a sufficient number of fault samples in actual production.A model for rolling bearings by combining Convolutional Neural Networks and Synthetic Oversampling is presented.The frequency domain signals is used as the input of the model,and the features are extracted by the Convolutional Neural Network.The new features are generated by Synthetic Oversampling and the data equalization is realized.The model completes the classification by putting all of the features into the Support Vector Machine,and the fault diagnosis of the rolling bearings is carried out.The comparison experiments results …

A Simulation Credibility Assessment Method Based On Improved Fuzzy Comprehensive Evaluation, Peizhi Ran, Li Wei, Bao Ran, Ma Ping

Journal of System Simulation

Abstract: Aiming at the problems of inaccurate evaluation results caused by experts in the process of simulation credibility evaluation based on traditional fuzzy comprehensive evaluation according to personal preferences or expectations,and unreasonable selection of fuzzy synthetic calculations,a simulation credibility evaluation method based on improved fuzzy comprehensive evaluation is proposed.For the tree-like assessment index system,the fuzzy comprehensive evaluation matrix is used to determine the weight of each index in the assessment index system based on the minimum membership weighted average deviation;in the fuzzy synthesis operation,the membership evaluation weighted average deviation is used to obtain the comprehensive evaluation vector,and then the …

Reliability Evaluation Method For Reuse Model Of Complex Simulation System, Ziheng Ye, Fuzhen Zhang, Yaoqin Zhu, Weiqing Li

Journal of System Simulation

Abstract: Model reuse can enhance the flexibility and scalability of simulation applications,and is necessary in the construction of complex simulation systems.Assessing credibility in multi-model combination simulation is the basic question of whether the model can be effectively reused.Aiming at the two simulation model reuse,in different application environments of physical model-oriented and numerical settlement-oriented,the credibility evaluation method for simulation reuse models based on bias propagation is proposed,and the respective modeling methods and evaluation methods are introduced in detail. Taking UAV as an example,the comparison result with the classic credibility evaluation method shows that the method can reduce the difficulty of …

Prediction Of Epidemic Transmission And Evaluation Of Prevention And Control Measures Based On Artificial Society, Bin Chen, Yang Mei, Chuan Ai, Ma Liang, Zhengqiu Zhu, Hailiang Chen, Mengna Zhu, Xu Wei

Journal of System Simulation

Abstract: The COVID-19 has been controlled under the strict measures,but how to normalize it deserves in-depth study.The COVID-19 transmission model and the human contact network are established separately based on SEIR model and the artificial social scenario.With the support of the multi-agent computational experiment method,a large sample calculation experiment was performed on the Tianhe supercomputer to simulate the epidemic transmission in typical areas such as communities,schools,and workplaces in artificial cities,and to predict and evaluate the risk of epidemic spread after resumption of work and school.The results show that epidemic prevention and control must be prepared for a …

A Survey On Underwater Bionic Electric Perception, Guangming Xie, Junzheng Zheng, Wang Chen

Journal of System Simulation

Abstract: Sensing and detection technologies for underwater robots in complex underwater environments have been urgently needed.Weakly electric fields-based underwater bionic electric perception is a promising technical route.A kind of fish in nature,called weakly electric fish,can perceive their surrounding environment and other creatures through the varied electric field generated by themselves.Inspired by the electric fish,researchers have focused on the principle and methods of underwater perception based on weakly electric fields and the applications for intelligent underwater robots.The biological mechanism of weakly electric fish,the modeling and perception theory of underwater electric field,the underwater electric perception technology,and their applications are reviewed,and the …

An Online Evaluation Framework Of Complex Simulation System Based On Acceptability Criteria, Zhenglin Sun, Weiqiang Yuan, Weiqing Li

Journal of System Simulation

Abstract: An online simulation evaluation method based on Acceptability Criteria (AC) for the lag of current complex simulation systems is proposed.A qualitative and quantitative AC to index mapping model is used to establish an evaluation index system.Based on index sets and evaluation functions,a seven-tuple model of a simulation process finite automaton is proposed,and a mapping of the simulation process to automata and a data-driven state transfer mechanism are given.Based on the above results,an online evaluation tool is designed and the effectiveness is verified through a case.The result that the method can effectively solve lag in the evaluation …

Human-Computer Interaction Speech Emotion Recognition Based On Random Forest And Convolution Feature Learning, Wang Jing, Hongyan Liu, Fangfang Liu, Qingqing Wang

Journal of System Simulation

Abstract: Focus on the different speech features of different types of people in the automatic speech emotion recognition of emotional robots,a random forest for speech emotion recognition is proposed,and a preliminary simulation experiment of emotional social robot system based on convolution feature learning is carried out.The results show that the emotional robot can track in real time,the seven basic emotions of excitement,anger,sadness,happiness,surprise,fear and neutrality.By using non personalized speech emotion features,the original personalized speech emotion features are supplemented,and the general emotion and special emotion are extracted.For emotional robot,using these indicators has a certain application prospect in the simulation experiment …

One Turbulent Modeling Method Based On Environmental Forecast Data, Dawei Fan, Jiahui Tong

Journal of System Simulation

Abstract: Based on the existing natural environment model of aircraft simulation test,the method of conversion and processing for environmental prediction data is studied.Based on the random wave theory,the mathematical model of turbulent wind is established,and the simulation modeling method is studied.Based on Davenport spectrum,a turbulent wind model based on environmental prediction data is established and is introduced into the mathematical simulation experiment of a type of aircraft to obtain the influence of wind turbulent on the flight state of the aircraft.The experimental results show that the gust turbulence has a greater impact on the aircraft's angle of …

Stereo Camera Calibration Based On Multiple Fitness Full-Parameter Autonomous Mutation Particle Swarm, Guiyang Zhang, Muyao Xue, Zijian Zhu, Huo Ju

Journal of System Simulation

Abstract: The acquisition of target parameters based on visual measurement provides reliable data support for performance analysis and evaluation of simulation system.The precision of measurement results is determined by the accuracy of camera calibration.A calibration method based on full parameter autonomous mutation particle swarm optimization is proposed.Traditional calibration method is utilized to obtain the initial internal parameters.The fast and global calibration algorithm based on particle swarm optimization is achieved by inertial coefficient contraction adjustment,global factor learning adjustment strategy based on particle distance,multi-adaptation function and the independent variation law.The experimental results show that the proposed method can improve the …

Establishment And Development Of Simulation-Based Aero Engine Acquisition On, Caiyun Liang, Hongxin Li, Yanfeng Sui, Luan Xu, Shi Feng

Journal of System Simulation

Abstract: Follow the increasing demand of aircraft for aero engine‘s capabilities and because of the increase of engine‘s own technical difficulty,the risks,cycles and costs of the engine development is rising,and the high demand of traditional acquisition model is urgently needed.The idea of digitalized aero engine acquisition is presented,which starts from joint analysis,applies multi-dimensional scaling technology,carries out integrated simulation based on the models of each dimension of virtual prototype,and realizes the evaluation of technical scheme.The mapping relationship among technical solutions,schedules and costs etc.are established,and a basic framework for simulation based acquisition of engines is constructed by using the work …

Automatic Discovery Method Of Dynamic Job Shop Dispatching Rules Based On Hyper-Heuristic Genetic Programming, Suyu Zhang, Wang Yan, Zhicheng Ji

Journal of System Simulation

Abstract: The dynamic job shop has the uncertainty of resource state and the randomness of tasks,so it is difficult to find the common dispatching rules applicable to a variety of complex production scenarios.A method for automatic discovery of dynamic shop dispatching rules based on Hyper-Heuristic genetic programming is proposed,with makespan and average weighted tardiness as the optimization goals,is improved by using the automatic discovery of machine sequencing rules and the dynamic adaptability of workshop scheduling under different production scenarios.Through the semantic analysis of dispatching rules,the function of terminators on different optimization objectives is analyzed.The experiment result shows that …

Longitudinal Partitioning Waveform Relaxation Methods For The Analysis Of Transmission Line Circuits, Tarik Menkad

Electronic Thesis and Dissertation Repository

Three research projects are presented in this manuscript. Projects one and two describe two waveform relaxation algorithms (WR) with longitudinal partitioning for the time-domain analysis of transmission line circuits. Project three presents theoretical results about the convergence of WR for chains of general circuits.

The first WR algorithm uses a assignment-partition procedure that relies on inserting external series combinations of positive and negative resistances into the circuit to control the speed of convergence of the algorithm. The convergence of the subsequent WR method is examined, and fast convergence is cast as a generic optimization problem in the frequency-domain. An automatic …

Static And Dynamical Properties Of Multiferroics, Sayed Omid Sayedaghaee

Graduate Theses and Dissertations

Since the silicon industrial revolution in the 1950s, a lot of effort was dedicated to the research and development activities focused on material and solid-state sciences. As a result, several cutting-edge technologies are emerging including the applications of functional materials in the design and enhancement of novel devices such as sensors, highly capable data storage media, actuators, transducers, and several other types of electronic tools. In the last two decades, a class of functional materials known as multiferroics has captured significant attention because of providing a huge potential for new designs due to possessing multiple ferroic order parameters at the …

Optimal Collaborative Path Planning For Unmanned Surface Vehicles Carried By A Parent Boat Along A Planned Route, Ari Carisza Graha Prasetia, I-Lin Wang, Aldy Gunawan

Research Collection School Of Computing and Information Systems

In this paper, an effective mechanism using a fleet of unmanned surface vehicles (USVs) carried by a parent boat (PB) is proposed to complete search or scientific tasks over multiple target water areas within a shorter time . Specifically, multiple USVs can be launched from the PB to conduct such operations simultaneously, and each USV can return to the PB for battery recharging or swapping and data collection in order to continue missions in a more extended range. The PB itself follows a planned route with a flexible schedule taking into consideration locational constraints or collision avoidance in a real-world …

Optimal Scheduling And Decision Making Method For Dynamic Flexible Job Shop, Wang Yan, Ding Yu

Journal of System Simulation

Abstract: For multi-objective dynamic flexible job-shop scheduling, an improved multi-objective differential evolution algorithm is proposed. The adaptive cross-mutation operator is introduced into the differential evolution algorithm to improve its global search capability. The fast non-dominated sorting method based on immunological principles is introduced to improve the quality of the solution set in the selection and sorting. An improved TOPSIS-G1-EVM comprehensive decision-making method is proposed. The comprehensive weight of G1-EVM is calculated by Nash equilibrium theory. The comprehensive weight and TOPSIS evaluation system are combined to evaluate each dispatching scheme. The experimental results show that the optimal scheduling algorithm is superior …

Research On Configurable Simulation Integration Technology For Equipment Software, Yuanyuan Wang, Yuxin Duan, Guangzhao Song

Journal of System Simulation

Abstract: The problems of the traditional distributed digital simulation system are analyzed. The method of constructing the digital simulation system based on the equipment software is studied. The configurable simulation integration middleware is designed. The overall structure of the configurable middleware is designed and the design ideas of each module are briefly summarized. An example of a digital simulation system with networked transformation of equipment shows that the middleware can be effectively and flexibly configured and can provide support for constructing digital simulation system with software, which can be promoted and used in other simulation systems.

Effect Of New Titanium Alloy On Biomechanical Behavior Of Dental Implant, Jiwu Zhang, Qiguo Rong

Journal of System Simulation

Abstract: Titanium alloy materials have excellent mechanical properties, chemical stability and biocompatibility, and have become the main raw materials for implants. However, the biomechanical compatibility of medical titanium alloys still needs to be improved in order to meet the long-term safety and functionality of patient's clinical treatment requirement. New medical titanium alloy materials with high strength and low modulus play an important role in reducing the loosening and shedding of implants caused by stress shielding. The effects of new medical titanium alloy materials and traditional medical titanium alloy materials on implant structure and stress distribution of jaw are compared and …