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2018

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Articles 1111 - 1140 of 2925

Full-Text Articles in Computer Sciences

Matlab Simulation For Electrically Excited Synchronous Motors With Low Switching Frequency, Qingqing Yuan, Bin Song, Yang Na Jun 2018

Matlab Simulation For Electrically Excited Synchronous Motors With Low Switching Frequency, Qingqing Yuan, Bin Song, Yang Na

Journal of System Simulation

Abstract: Switch loss is one of the main energy consumption of the high power transmission system, while the low switching frequency approach is an effective way to improve above issues. However, it will result in a severe harmonic distortion and further affect the control performance. A selective harmonic elimination pulse width modulation (SHEPWM) strategy has been used to ensure the low energy consumption operation of a diode clamped three-level converter whose load is a high power electrically excited synchronous motors (EESM). For the SHEPWM's characteristics of specific harmonic elimination and harmonic energy moving on the high order, a simple high-pass …


Simulation And Optimization On Electrodynamic Repulsion Force Of Contact System In Circuit Breaker With Oil Dashpot, Yanhua Qiao, Xiuping Su, Tianying Dong Jun 2018

Simulation And Optimization On Electrodynamic Repulsion Force Of Contact System In Circuit Breaker With Oil Dashpot, Yanhua Qiao, Xiuping Su, Tianying Dong

Journal of System Simulation

Abstract: A 3D finite element model for contact system of circuit breaker with oil dashpot is established. Two electrodynamic repulsion forces, the Holm force between contacts and the Lorentz force between the conductor arms, are analyzed. The current density distribution, magnetic intensity distribution and the forces of the contact and contact arm are obtained. Compared with the theoretical value, it shows that it is feasible to use this method to solve electrodynamic repulsion force. The main factors that influence the Holm force are analyzed. The simulation results show the changes of Holm force with different surface contact coefficient, contact pressure …


Research And Simulation Of Roots-Type Power Machine Control System Based On Fuzzy Pid, Yan-Jun Xiao, Yonggeng Wang, Jing Ran, Feng Hua, Yongcong Li Jun 2018

Research And Simulation Of Roots-Type Power Machine Control System Based On Fuzzy Pid, Yan-Jun Xiao, Yonggeng Wang, Jing Ran, Feng Hua, Yongcong Li

Journal of System Simulation

Abstract: For utilizing the domestic low grade waste heat resources, a Roots-type steam engine is developed. To make the roots engine stably output electric energy, an efficient constant power control system needs to be designed. The controlled object characteristics of the roots engine are analyzed; the modeling of the control system is established; and on this basis the fuzzy control algorithm is introduced. The fuzzy adaptive PID controller for the roots power machine constant power output is designed and the related MATLAB simulation is carried out. The results show that the Roots type steam power machine with fuzzy adaptive PID …


Parallel Design And Load Balance Of Openmp Based Warfighting Simulation, Wang Xiao, Yaqi Liu, Yuben Tao Jun 2018

Parallel Design And Load Balance Of Openmp Based Warfighting Simulation, Wang Xiao, Yaqi Liu, Yuben Tao

Journal of System Simulation

Abstract: Parallel simulation is a main trend of large scale and high precision war fighting simulation (WS). However, currently there is no unified framework to design a parallel WS and no effective method to load balance of it. Based on the parallel agent theory, an OpenMP based parallel WS design framework (PWSF) is proposed. To solve the problem of the complex simulation load distribution resulted from the diversity of entities' models and the position independence of the interactions, a load balance method based on METIS multilevel graph partition tool is suggested. Based on the improved PHOLD test model, experiments on …


Modeling And Simulation Of Islanded System With Wind And Storage Power, Ye Peng, Yaoning Hu, Minghui Sun Jun 2018

Modeling And Simulation Of Islanded System With Wind And Storage Power, Ye Peng, Yaoning Hu, Minghui Sun

Journal of System Simulation

Abstract: With the consumption of primary energy and the severe environmental issues, the new energy power generation has been attracted much attention by scholars at home and abroad. As an important application form of new energy power generation, the operation of the islanded system with wind and storage power has a huge potential for future development. For the islanded system with wind and storage power, each mathematical model and the mathematical model of control system were established. In the electromagnetic transient simulation platform PSCAD, the corresponding electromagnetic transient simulation model was built based on the established mathematical model. The dynamic …


Application Of Finite Element Modification And Model Order Reduction In Temperature Control System, Xiaona Wang, Ye Ying, Qiyue Xu, Sebastian Marin, Michael Hohmann, Shuliang Ye Jun 2018

Application Of Finite Element Modification And Model Order Reduction In Temperature Control System, Xiaona Wang, Ye Ying, Qiyue Xu, Sebastian Marin, Michael Hohmann, Shuliang Ye

Journal of System Simulation

Abstract: A modification and model order reduction (MOR) method based on finite element model is proposed, which can be used in the design of simulation platform of furnace temperature control system. Based on the step response test of furnace behavior and the modification of finite element model's key parameters in ANSYS, the model reflecting the actual characteristics of furnace is obtained. Based on the software tool called mor4ansys using Krylo subspace reduction method, the state space model is obtained. The MATLAB/Simulink simulation platform based on state space model is built for more research work on furnace temperature control design. Based …


Optimal Deployment Of Distant Support Jamming Formation Based On Directional Crossover Genetic Algorithm, Jinliang Luo, Jiacai Jin, Wang Lei, Ding Feng Jun 2018

Optimal Deployment Of Distant Support Jamming Formation Based On Directional Crossover Genetic Algorithm, Jinliang Luo, Jiacai Jin, Wang Lei, Ding Feng

Journal of System Simulation

Abstract: Optimal deployment of distant support jamming formation is studied for improving penetration capability of air assault group in air offensive operation. The total detection threats of penetration route are chosen as the performance indicator, and the optimal deployment mode of distant support jamming formation is built. The closed region detection method is used to compute fitness value. The difficult problem of computing detection coverage of radar net under jamming condition is solved by using traditional geometry analytic method. A selective directional crossover genetic algorithm is designed to compute the optimal deployment mode. The simulation results show that the algorithm …


Modeling And Simulation Of Networked Control Systems Based On Improved Bp Network, Shifeng Li, Zhanzhi Qiu, Liping Fan, Lina Zhao Jun 2018

Modeling And Simulation Of Networked Control Systems Based On Improved Bp Network, Shifeng Li, Zhanzhi Qiu, Liping Fan, Lina Zhao

Journal of System Simulation

Abstract: In the circumstance where both the delay model and the controlled object model were unknown in networked control systems, a class of networked predictive control systems based on improved BP network were studied. For the problem of obtaining the hidden layer nodes number of BP network, a rapid calculation method was proposed. For the problem of avoiding local optimum of BP network, a hybrid learning method was proposed. A off-line BP network model was proposed for coping with the problem of the delay prediction based on the above algorithms. For the problem of the linear …


Algorithm For Tracking Position And Orientation Of Drug Delivery Capsules In Gastrointestinal Tract, Xudong Guo, Zhengping Lu, Qinfen Jiang, Shuyi Wang, Haipo Cui Jun 2018

Algorithm For Tracking Position And Orientation Of Drug Delivery Capsules In Gastrointestinal Tract, Xudong Guo, Zhengping Lu, Qinfen Jiang, Shuyi Wang, Haipo Cui

Journal of System Simulation

Abstract: To realize an accurate releasing by a drug-delivery capsule in the gastrointestinal tract, a method of magnetic vector detection with angle sensing has been presented to track the capsule in real time; and a prototype of the tracking system has been developed. Based on the fundamentals of spatial distribution of magnetic vector fields, a nonlinear model of tracking is established. An improved artificial bee colony algorithm is studied to solve the magnetic inverse problem. In the improved algorithm, a chaos operator is used to generate an initial population and a sort selection is used to prevent premature convergence. …


Design Of Mini Folding Electric Scooter Based On Relative Attitude Angle Control, Lijun Jiang, Zhanghong Wu, Shaohui Pan, Zhelin Li, Zhiyong Xiong, Yongqing Fu Jun 2018

Design Of Mini Folding Electric Scooter Based On Relative Attitude Angle Control, Lijun Jiang, Zhanghong Wu, Shaohui Pan, Zhelin Li, Zhiyong Xiong, Yongqing Fu

Journal of System Simulation

Abstract: To help people move conveniently after getting off the public transport in the city, anew mini electric scooter design is proposed. This new scooter uses a smart mobile phone to receive driving intention and owns more efficient, convenient and space-saving folding pattern. A kinematics model of scooter is set up and discussed. A control strategy based on the relative attitude angle, an attitude sensor data consolidation approach based on the complementary filter, a solution to the Euler angle jumping and an estimate method to the wrong operation are proposed. The design is made into a prototype based on …


Dynamic Blind Source Separation Method Of Bearing Fault Diagnosis Based On Ga-Aw-Pso, Tianqi Zhang, Baoze Ma, Xingzi Qiang, Shengrong Quan Jun 2018

Dynamic Blind Source Separation Method Of Bearing Fault Diagnosis Based On Ga-Aw-Pso, Tianqi Zhang, Baoze Ma, Xingzi Qiang, Shengrong Quan

Journal of System Simulation

Abstract: The adaptive particle swarm optimization based on genetic mechanism (GA-AW-PSO) is proposed, aiming at blind source separation for dynamic hybrid bearing signals. The negentropy of separated signal is regarded as an objective function. The inertia weight is adjusted adaptively to reduce the invalid iterations according to the fitness difference. The introduction of genetic mechanism can increase diversity and is helpful for dynamic signal processing. The parameterized representation of orthogonal matrices can reduce the complexity of the algorithm. The simulation results show that the proposed method is superior to traditional blind source separation for the dynamic mechanical hybrid analog signal. …


Online Synthesis Incremental Data Streams Classification Algorithm, Sanmin Liu, Yuxia Liu Jun 2018

Online Synthesis Incremental Data Streams Classification Algorithm, Sanmin Liu, Yuxia Liu

Journal of System Simulation

Abstract: Online learning is the effective way to solve the sample's non-recurrence in data streams classification, and how to deal with the problem of sample deficiency is the critical point for improving online learning efficiency. According to the mean square error decomposition theory of the model's parameter estimation and the idea of cluster, the new samples are constructed by linear synthesis with the class center and the sample, which can improve the distribution information of sample and reduce the lower bound of parameter value. The online incremental learning is executed and the class center point is continuously updated. Through theory …


Train Energy Saving Operation Based On Simulated Annealing Algorithm, Liu Wei, Jiaxuan Xu, Peipei Wang, Ruilong Liu, Jingkun Tang Jun 2018

Train Energy Saving Operation Based On Simulated Annealing Algorithm, Liu Wei, Jiaxuan Xu, Peipei Wang, Ruilong Liu, Jingkun Tang

Journal of System Simulation

Abstract: For the timing and energy saving algorithm of urban railway, the train operation iterative process was analyzed by dividing the operation intervals to meet the requirements of the subway trains timing energy saving operation. The differentiation was adopted to establish the train operation iterative model, and as a result the timing energy saving problem was transformed into the solution of train output using coefficient sequence. An optimization solving method based on simulated annealing algorithm was proposed and the algorithm was implemented using MFC program. Three intervals of Shanghai Metro Line 3 were selected and the solution of the train …


Event-Triggered Non-Fragile H∞ State Estimation For Fuzzy Time-Delay Neural Networks, Yanqin Wang, Weijian Ren Jun 2018

Event-Triggered Non-Fragile H∞ State Estimation For Fuzzy Time-Delay Neural Networks, Yanqin Wang, Weijian Ren

Journal of System Simulation

Abstract: For a class of fuzzy neural networks with randomly occurring time-varying delays and randomly data packet loss, an event-triggered non-fragile H∞ state estimator is designed. The event-triggered condition is introduced to determine whether the signal is transmitted or not, so as to reduce the occupation rate of network resource. Random variables of Gaussian distribution and the multiplicative gain uncertainties are adopted to construct the non-fragile state estimator with randomly occurring gain variations. By constructing Lyapunov function, and via stochastic computation and linear matrix inequality technique, the sufficient conditions for the existence of non-fragile estimators are obtained, which guarantee …


Emergency Condition Selection Based On Tcp-Nets, Weihong Liu, Zheng Xiao, Cheng Chen, Li Qiao Jun 2018

Emergency Condition Selection Based On Tcp-Nets, Weihong Liu, Zheng Xiao, Cheng Chen, Li Qiao

Journal of System Simulation

Abstract: The representative or relative important emergency conditions need to be selected for making well-directed emergency plans. The quantitative method is normally used to select emergency conditions, but it requires users to specify the weight of every attribute, which does not conform to the users' habit. A qualitative method for emergency condition selection is put forward which includes two steps: for the first step, TCP-nets is adopted to describe users' requirements; and for the second step, the most important emergency conditions are selected based on TCP-nets. The effectiveness of the method is proved, and the efficiency is verified by experiments …


Cooperative Target Recognition With Multiple Features Judgment, Guopeng Sun, Xiangyang Hao, Zhenjie Zhang, Pengrui Yan Jun 2018

Cooperative Target Recognition With Multiple Features Judgment, Guopeng Sun, Xiangyang Hao, Zhenjie Zhang, Pengrui Yan

Journal of System Simulation

Abstract: For solving cooperative target recognition problem in visual navigation, a fast and accurate algorithm based on progressive judgment of multiple features is proposed. The image is processed and judged by multiple features including image contours, Hu moment invariants and FAST corners. The non-target areas are eliminated and the real targets are obtained. In the process, algorithm is improved and some accelerated strategies are adopted to meet real-time requirements. Experiments show that the proposed algorithm can identify cooperative target robustly and adaptively with different distances, different angles and environment disturbance.


Test Data Compression Scheme For Fast Search Best Rational Approximate Fraction, Haifeng Wu, Wenfa Zhan, Yifei Cheng Jun 2018

Test Data Compression Scheme For Fast Search Best Rational Approximate Fraction, Haifeng Wu, Wenfa Zhan, Yifei Cheng

Journal of System Simulation

Abstract: Rapid growth of test data volume becomes a major factor for test time and manufacturing cost increasing. To reduce test data volume, a code-based compression scheme with fast search best rational approximate fraction is presented. The run-length data is converted into floating point numbers; and the equal best rational approximate fractions of floating point numbers is searched quickly; the appearing law of run-length data in the form of integer numerator and integer denominator is stored instead of storing run-length data directly. This scheme is compatible with traditional code-based methods. It also has simple compression and decompression protocol, good compression …


Route Planning For Vessel Based On Dynamic Complexity Map, Zhe Du, Yuanqiao Wen, Huang Liang, Chunhui Zhou, Changshi Xiao Jun 2018

Route Planning For Vessel Based On Dynamic Complexity Map, Zhe Du, Yuanqiao Wen, Huang Liang, Chunhui Zhou, Changshi Xiao

Journal of System Simulation

Abstract: Aiming at multiple mobile objects in complex navigation environment, a route planning method based on the dynamic complexity map is proposed. According to the theory of complexity measurement, a dynamic complexity map is established. By taking advantage of the idea of A * algorithm, the complexity value is taken as an actual cost and the Euclidean Distance from current point to the target is taken as a heuristic costs. Considering the ship dimensions, the channel boundary constraint function is added. The experimental results show that on the premises of satisfying the constraint of ship dimensions, the planned route …


Effect Of Interfacial Curvature On Drag Reduction Of Superhydrophobic Microchannels, Chunxi Li, Zhang Shuo, Xuemin Ye Jun 2018

Effect Of Interfacial Curvature On Drag Reduction Of Superhydrophobic Microchannels, Chunxi Li, Zhang Shuo, Xuemin Ye

Journal of System Simulation

Abstract: The two-dimensional fluid flow in superhydrophobic microchannels with transverse grooves was numerically simulated with Fluent to investigate the impact of the liquid-gas interface curvature on the effective slip behavior in the laminar regime. The effects of shear-free fraction, normalized periodic cell length and Reynolds number on the normalized slip length and pressure drop reduction are also examined. The results show that as protrusion angle increases, the normalized slip length and pressure drop reduction exhibit with single-hump variations. When θ=θopt, increments in the normalized slip length and pressure drop reduction tend to be greater as shear-free …


Imu Single-Axis Rotation Method And Error Analysis Of Modulation Inertial Navigation System, Sun Wei, Ruibao Li, Zhang Yuan, Yang Dan Jun 2018

Imu Single-Axis Rotation Method And Error Analysis Of Modulation Inertial Navigation System, Sun Wei, Ruibao Li, Zhang Yuan, Yang Dan

Journal of System Simulation

Abstract: Aiming at the problem that inertial device bias has an influence on the improvement of system precision, a single axis error modulation scheme whose sensitive axis is misalignment with rotation axis which can continuously rotate in clockwise and counterclockwise is proposed. Based on the same level precision of inertial components in IMU, the IMU is installed on rotation mechanism with non-coincidence. The symmetric part of inertial device deviation can be compensated by the positive and negative cancellation of the device deviation in the rotation axis direction and the rotation modulation in the vertical plane of the rotary axis. The …


A Machine Learning Framework To Classify Mosquito Species From Smart-Phone Images, Mona Minakshi Jun 2018

A Machine Learning Framework To Classify Mosquito Species From Smart-Phone Images, Mona Minakshi

USF Tampa Graduate Theses and Dissertations

Mosquito borne diseases have been a constant scourge across the globe resulting in numerous diseases with debilitating consequences, and also death. To derive trends on population of mosquitoes in an area, trained personnel lay traps, and after collecting trapped specimens, they spend hours under a microscope to inspect each specimen for identifying the actual species and logging it. This is vital, because multiple species of mosquitoes can reside in any area, and the vectors that some of them carry are not the same ones carried by others. The species identification process is naturally laborious, and imposes severe cognitive burden, since …


An Exploration Of Linear Classifiers For Unsupervised Spiking Neural Networks With Event-Driven Data, Wesley Chavez Jun 2018

An Exploration Of Linear Classifiers For Unsupervised Spiking Neural Networks With Event-Driven Data, Wesley Chavez

Dissertations and Theses

Object recognition in video has seen giant strides in accuracy improvements in the last few years, a testament to the computational capacity of deep convolutional neural networks. However, this computational capacity of software-based neural networks coincides with high power consumption compared to that of some spiking neural networks (SNNs), up to 300,000 times more energy per synaptic event in IBM's TrueNorth chip, for example. SNNs are also well-suited to exploit the precise timing of event-driven image sensors, which transmit asynchronous "events" only when the luminance of a pixel changes above or below a threshold value. The combination of event-based imagers …


Bounding Box Improvement With Reinforcement Learning, Andrew Lewis Cleland Jun 2018

Bounding Box Improvement With Reinforcement Learning, Andrew Lewis Cleland

Dissertations and Theses

In this thesis, I explore a reinforcement learning technique for improving bounding box localizations of objects in images. The model takes as input a bounding box already known to overlap an object and aims to improve the fit of the box through a series of transformations that shift the location of the box by translation, or change its size or aspect ratio. Over the course of these actions, the model adapts to new information extracted from the image. This active localization approach contrasts with existing bounding-box regression methods, which extract information from the image only once. I implement, train, and …


Improving Performance Of Iterative Methods By Lossy Checkponting, Dingwen Tao, Sheng Di, Xin Liang, Zizhong Chen, Franck Cappello Jun 2018

Improving Performance Of Iterative Methods By Lossy Checkponting, Dingwen Tao, Sheng Di, Xin Liang, Zizhong Chen, Franck Cappello

Computer Science Faculty Research & Creative Works

Iterative methods are commonly used approaches to solve large, sparse linear systems, which are fundamental operations for many modern scientific simulations. When the large-scale iterative methods are running with a large number of ranks in parallel, they have to checkpoint the dynamic variables periodically in case of unavoidable fail-stop errors, requiring fast I/O systems and large storage space. To this end, significantly reducing the checkpointing overhead is critical to improving the overall performance of iterative methods. Our contribution is fourfold. (1) We propose a novel lossy checkpointing scheme that can significantly improve the checkpointing performance of iterative methods by leveraging …


Deep Learning For Link Prediction In Dynamic Networks Using Weak Estimators, Carter Chiu, Justin Zhan Jun 2018

Deep Learning For Link Prediction In Dynamic Networks Using Weak Estimators, Carter Chiu, Justin Zhan

Computer Science Faculty Research

Link prediction is the task of evaluating the probability that an edge exists in a network, and it has useful applications in many domains. Traditional approaches rely on measuring the similarity between two nodes in a static context. Recent research has focused on extending link prediction to a dynamic setting, predicting the creation and destruction of links in networks that evolve over time. Though a difficult task, the employment of deep learning techniques have shown to make notable improvements to the accuracy of predictions. To this end, we propose the novel application of weak estimators in addition to the utilization …


Design, Development And Testing An Academic Repository, Kevin M. Handeli, Stefan Robila Jun 2018

Design, Development And Testing An Academic Repository, Kevin M. Handeli, Stefan Robila

Department of Computer Science Faculty Scholarship and Creative Works

Technological advances, established best web development practices, and modern design of the 21st century have provided students, professors, researchers, etc., quasi-effortless access to academic documents encompassed within cleaner user interface and a higher level of usability. Access to and rigorous management of research publication and products is also mandated by funding agencies. Given these characteristics, we have developed an academic repository to maintain the student projects in a typical academic department. A repository of this nature is comprised of two major components: the database and the user interface. The key focus is to provide secure access to research materials (e.g. …


Message From The Program Chairs - Volume 1, Jiannong Cao, Stelvio Cimato, Yasuo Okabe, Sahra Sedighsarvestani Jun 2018

Message From The Program Chairs - Volume 1, Jiannong Cao, Stelvio Cimato, Yasuo Okabe, Sahra Sedighsarvestani

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.


Similarity Based Large Scale Malware Analysis: Techniques And Implications, Yuping Li Jun 2018

Similarity Based Large Scale Malware Analysis: Techniques And Implications, Yuping Li

USF Tampa Graduate Theses and Dissertations

Malware analysis and detection continues to be one of the central battlefields for cybersecurity industry. For the desktop malware domain, we observed multiple significant ransomware attacks in the past several years, e.g., it was estimated that in 2017 the WannaCry ransomware attack affected more than 200,000 computers across 150 countries with hundreds of millions damages. Similarly, we witnessed the increased impacts of Android malware on global individuals due to the popular smartphone and IoT devices worldwide. In this dissertation, we describe similarity comparison based novel techniques that can be applied to achieve large scale desktop and Android malware analysis, and …


Tkse: Trustworthy Keyword Search Over Encrypted Data With Two-Side Verifiability Via Blockchain, Yinghui Zhang, Robert H. Deng, Jiangang Shu, Kan Yang, Dong Zheng Jun 2018

Tkse: Trustworthy Keyword Search Over Encrypted Data With Two-Side Verifiability Via Blockchain, Yinghui Zhang, Robert H. Deng, Jiangang Shu, Kan Yang, Dong Zheng

Research Collection School Of Computing and Information Systems

As a very attractive computing paradigm, cloud computing makes it possible for resource-constrained users to enjoy cost-effective and flexible resources of diversity. Considering the untrustworthiness of cloud servers and the data privacy of users, it is necessary to encrypt the data before outsourcing it to the cloud. However, the form of encrypted storage also poses a series of problems, such as: How can users search over the outsourced data? How to realize user-side verifiability of search results to resist malicious cloud servers? How to enable server-side verifiability of outsourced data to check malicious data owners? How to achieve payment fairness …


An Integrated Approach For Effective Injection Vulnerability Analysis Of Web Applications Through Security Slicing And Hybrid Constraint Solving, Julian Thome, Lwin Khin Shar, Domenico Bianculli, Lionel Briand Jun 2018

An Integrated Approach For Effective Injection Vulnerability Analysis Of Web Applications Through Security Slicing And Hybrid Constraint Solving, Julian Thome, Lwin Khin Shar, Domenico Bianculli, Lionel Briand

Research Collection School Of Computing and Information Systems

Malicious users can attack Web applications by exploiting injection vulnerabilities in the source code. This work addresses the challenge of detecting injection vulnerabilities in the server-side code of Java Web applications in a scalable and effective way. We propose an integrated approach that seamlessly combines security slicing with hybrid constraint solving; the latter orchestrates automata-based solving with meta-heuristic search. We use static analysis to extract minimal program slices relevant to security from Web programs and to generate attack conditions. We then apply hybrid constraint solving to determine the satisfiability of attack conditions and thus detect vulnerabilities. The experimental results, using …