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2020

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Articles 6991 - 7020 of 10642

Full-Text Articles in Engineering

Focused Beam System Biaxial Material Characterization, Nicholas A. O'Gorman Mar 2020

Focused Beam System Biaxial Material Characterization, Nicholas A. O'Gorman

Theses and Dissertations

Electromagnetic material characterization is the process of determining the constitutive parameters (complex permittivity and permeability) of given a sample. Due to the large number of unknowns involved, multiple unique measurements are required for material property extraction. Many measurement methods, such as waveguides and striplines, possess a rigid internal structure that the sample being measured must adhere to. This rigidity limits these methods to samples that fit within the device and inhibits oblique sample orientations, limiting the number of independent measurements that can be obtained. A focus beam system, due to being an open system with greater freedom in sample size …

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Mc80: Quantifying Effect Of Fleet Health On Sortie Execution In F-16 Fleet, Kyle R. Gladney Mar 2020

Mc80: Quantifying Effect Of Fleet Health On Sortie Execution In F-16 Fleet, Kyle R. Gladney

Theses and Dissertations

By order of the Secretary of Defense, all of the US Air Force's F-16 units were tasked to improve their fleet health to a Mission Capability (MC) rate of 80 percent, as part of a Department of Defense-wide push to make its Critical Aviation Platforms, and the units that employ them, more ready and lethal. This study uses historical fleet health and sortie execution data captured from LIMS-EV (Weapon System Viewer, 2020) to create a multiple regression model that quantifies the value of increased fleet health, defined as either MC rate or Aircraft Availability (AA) rate, in terms of increasing …

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Resilient Aircraft Sustainment: Quantifying Resilience Through Asset And Capacity Allocation, Zachary B. Shannon Mar 2020

Resilient Aircraft Sustainment: Quantifying Resilience Through Asset And Capacity Allocation, Zachary B. Shannon

Theses and Dissertations

Decision makers lack a clear, generalizable method to quantify how additional investment in inventory and capacity equates to additional levels of resilience. This research facilitates a deeper understanding of the intricacies and complex interconnectedness of organizational supply chains by monetarily quantifying changes in network resilience. The developed Area under the Curve metric (AUC) is used to quantify the level of demand that each asset allocation can meet during a disruptive event. Due to its applicability across multiple domains, the USAF F-16 repair network in the Pacific theater (PACAF) is modeled utilizing discrete event simulation and used as the illustrating example. …

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Flight Characteristic Verification Of The Variable Camber Compliant Wing, Sharee B. Acosta Mar 2020

Flight Characteristic Verification Of The Variable Camber Compliant Wing, Sharee B. Acosta

Theses and Dissertations

Morphing wing technology gives aircraft the ability to change wing shape to control the aircraft and flight performance characteristics. AFIT, AFRL and USU Aero Lab have collaborated to design and test a variable camber compliant wing (VCCW) on a small unmanned aerial vehicle (UAV). Flight tests demonstrated the wing performance and provided data to refine a VCCW flight simulator. Work was completed with the USU AeroLab-generated MachUp and the actual flight data to improve the simulator to provide results close to those of the actual flight test. The research provides a tool to reduce time and cost for future flight …

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A Comparative Evaluation Of The Detection And Tracking Capability Between Novel Event-Based And Conventional Frame-Based Sensors, James P. Boettiger Mar 2020

A Comparative Evaluation Of The Detection And Tracking Capability Between Novel Event-Based And Conventional Frame-Based Sensors, James P. Boettiger

Theses and Dissertations

Traditional frame-based technology continues to suffer from motion blur, low dynamic range, speed limitations and high data storage requirements. Event-based sensors offer a potential solution to these challenges. This research centers around a comparative assessment of frame and event-based object detection and tracking. A basic frame-based algorithm is used to compare against two different event-based algorithms. First event-based pseudo-frames were parsed through standard frame-based algorithms and secondly, target tracks were constructed directly from filtered events. The findings show there is significant value in pursuing the technology further.

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One-Dimensional Multi-Frame Blind Deconvolution Using Astronomical Data For Spatially Separable Objects, Marc R. Brown Mar 2020

One-Dimensional Multi-Frame Blind Deconvolution Using Astronomical Data For Spatially Separable Objects, Marc R. Brown

Theses and Dissertations

Blind deconvolution is used to complete missions to detect adversary assets in space and to defend the nation's assets. A new algorithm was developed to perform blind deconvolution for objects that are spatially separable using multiple frames of data. This new one-dimensional approach uses the expectation-maximization algorithm to blindly deconvolve spatially separable objects. This object separation reduces the size of the object matrix from an NxN matrix to two singular vectors of length N. With limited knowledge of the object and point spread function the one-dimensional algorithm successfully deconvolved the objects in both simulated and laboratory data.

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System Methodology Of Digital Transformation In Military Manufacturing Industry, Daolin Yu, Wenhai Zhu, Qing Xiao, Guoqiang Shi Mar 2020

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 …

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Wind Power Generation Hardware-In-Loop Simulation System Based On Rapid Control Prototype Technology, Aihua Wu, Buhui Zhao, Jingfeng Mao, Haiqun Shen, Xudong Zhang Mar 2020

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 …

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Emergency Evacuation Simulation For Dense Passenger Flow In A Rail Transit Transfer Station, Xu Hui, Tian Cheng, Wang Yong Mar 2020

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 …

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2020 Engineering State Summer Camp Canceled Due To Coronavirus, Usu College Of Engineering Mar 2020

2020 Engineering State Summer Camp Canceled Due To Coronavirus, Usu College Of Engineering

College of Engineering News

News Release—March 25, 2020— In response to the growing concerns about COVID-19, the College of Engineering at Utah State University is canceling its 2020 Engineering State youth summer camp.

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Spatial Structure Optimization Of Natural Forest Based On Bee Colony-Particle Swarm Algorithm, Dongsheng Qing, Xiaofang Zhang, Jianjun Li, Guo Rui, Qiaoling Deng Mar 2020

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 …

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An Estimation Of Distribution Algorithm Based On Multiple Elites Sampling And Individuals Differential Search, Yu Fei, Ruifeng Wu, Wei Bo, Yinglong Zhang, Xuewen Xia Mar 2020

An Estimation Of Distribution Algorithm Based On Multiple Elites Sampling And Individuals Differential Search, Yu Fei, Ruifeng Wu, Wei Bo, Yinglong Zhang, Xuewen Xia

Journal of System Simulation

Abstract: An estimation distribution algorithm based on the multiple elites sampling and the individuals differential search (EDA-M/D) is proposed. In EDA-M/D, the elites carry out the sampling to generate the offspring independently and enhance the exploration. Meanwhile, the variance of the population distributionis selected to control the sampling radius. Thus, the target of the population can be gradually transited from exploration to exploitation. If the elite population stagnates, the nonentities will choose the mean value of the elites distribution μ and the population historical best solution as the two exemplars to execute a differential search operator, and then help the …

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Multi-Uav 3d Formation Path Planning Based On Improved Artificial Potential Field, Haiyun Chen, Huazhou Chen, Liu Qiang Mar 2020

Multi-Uav 3d Formation Path Planning Based On Improved Artificial Potential Field, Haiyun Chen, Huazhou Chen, Liu Qiang

Journal of System Simulation

Abstract: Focusing on the GNRON (goal nonreachable with obstacles nearby), the local minima and chattering of the traditional artificial potential field method, the potential field functions are improved and analyzed to guarantee the goal is the global minimum. In the dynamic potential field, a mechanism of judging whether to fall into local minima is introduced, a method of “moving along the orientation of 90° of goal direction” is used to jump out of the local minima, and the path planning of multi-UAV formation, the synergistic obstacle avoidance and collision prevention are achieved. The path is optimized by applying the regression …

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Simulation Analysis On Flexible Track Drilling Machine Based On Adams, Yanchao Zhang, Ting Wang, Danlong Song Mar 2020

Simulation Analysis On Flexible Track Drilling Machine Based On Adams, Yanchao Zhang, Ting Wang, Danlong Song

Journal of System Simulation

Abstract: The three-dimensional model of the flexible track drilling machine is designed by the virtual prototyping technology. The model is imported into ADAMS (Automatic Dynamic Analysis of Mechanical Systems) software to carry out the kinematics and dynamic simulation analysis of its virtual prototype, and the rationality and feasibility of the system design are evaluated. Through the comparative analysis, the reasonable driving velocity and acceleration parameters of the hole making system are given. According to the analysis of the dynamic characteristics of the systems, the asymmetric driving problems in the system are found and the corresponding improvement scheme is put forward. …

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Speech Control Scheme Design And Simulation For Uav Based On Hmm And Rnn, Zhou Nan, Jianliang Ai Mar 2020

Speech Control Scheme Design And Simulation For Uav Based On Hmm And Rnn, Zhou Nan, Jianliang Ai

Journal of System Simulation

Abstract: In order to simplify the operation and avoid the misoperation of UAVs, Based on Hidden Markov Model and Recurrent Neural Networks, a speech control scheme for UAVs is designed. In this scheme, HMM is used to train and recognize the speech command samples of UAVs. HMM is used to pick out the error commands, RNN is used to train the sets of UAVs commands, and the next command based on the training result is predicted. It is determined whether to execute or not by calculating the correlation between commands recognized by HMM and predicted by RNN. The simulation results …

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Model Of Initial Spare Parts Configuration And Ordering Policy Optimization Based On Inventory State, Songshi Shao, Minzhi Ruan, Zhihua Zhang Mar 2020

Model Of Initial Spare Parts Configuration And Ordering Policy Optimization Based On Inventory State, Songshi Shao, Minzhi Ruan, Zhihua Zhang

Journal of System Simulation

Abstract: Rational planning of spare parts configuration project is an effective approach to improve the equipment availability and reduce the life cycle cost (LCC). First of all, the spare parts demand rate forecast model is constructed. According to the systemic analysis method, the spare parts support effectiveness evaluation targets system is built, and then, the initial spare parts configuration optimization method is researched. Aim to the consumption for partial repairable spare parts, the expected backorders function of the approximate Laplace demand distribution is given. Combining the (s-1, s) and (R, Q) inventory policy, the ordering model is established under the …

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Analysis Of Aeroengine Vibration Signal, Pi Jun, Jiaze Chang, Guangcai Liu Mar 2020

Analysis Of Aeroengine Vibration Signal, Pi Jun, Jiaze Chang, Guangcai Liu

Journal of System Simulation

Abstract: Aiming at the analysis of the vibration characteristics of aeroengine rotor, an improved blind source separation algorithm based on cumulant independent component analysis (ICA) is proposed. The new algorithm is used to separate the rotor vibration signal and identify the rotor fault types. The effectiveness of this algorithm is verified by the aeroengine rotor vibration signal simulation. Comparing with the existing algorithms based on second-order cumulants and high-order cumulants, the new method improves the performance index and the signal similarity coefficient. This algorithm is used to separate the vibration signal collected by the engine rotor platform and the rotor …

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Research On Building Mechanism Model Simulation In Energy-Saving Control, Bai Yang, Decheng Yuan, Li Ling Mar 2020

Research On Building Mechanism Model Simulation In Energy-Saving Control, Bai Yang, Decheng Yuan, Li Ling

Journal of System Simulation

Abstract: In the existing building system, the energy consumption is huge, the control system is complex, and the electricity cost is high. In order to reduce the cost of electricity, the mechanism model of the building is established for simulation. The accuracy of the model is verified by simulation to confirm the model applicability to the building system. Comparing the constant electricity price with the time-varying electricity price, the system under the model predictive control can response to the price change of electricity with time and can achieve the cost control and energy-saving.

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Knowledge Infused Learning (K-Il): Towards Deep Incorporation Of Knowledge In Deep Learning, Ugur Kursuncu, Manas Gaur, Amit Sheth Mar 2020

Knowledge Infused Learning (K-Il): Towards Deep Incorporation Of Knowledge In Deep Learning, Ugur Kursuncu, Manas Gaur, Amit Sheth

Publications

Learning the underlying patterns in data goes beyondinstance-based generalization to external knowledge repre-sented in structured graphs or networks. Deep learning thatprimarily constitutes neural computing stream in AI hasshown significant advances in probabilistically learning la-tent patterns using a multi-layered network of computationalnodes (i.e., neurons/hidden units). Structured knowledge thatunderlies symbolic computing approaches and often supportsreasoning, has also seen significant growth in recent years,in the form of broad-based (e.g., DBPedia, Yago) and do-main, industry or application specific knowledge graphs. Acommon substrate with careful integration of the two willraise opportunities to develop neuro-symbolic learning ap-proaches for AI, where conceptual and probabilistic repre-sentations are combined. …

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Research On Evolution Model Of Online Public Opinion Based On Temporal Network, Li Feng, Wei Ying Mar 2020

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 …

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Performance Balanced Opportunistic Routing And Simulation Analysis Based On Cooperative Game, Huahong Ma, Honghai Wu, Guoqiang Zheng, Baofeng Ji Mar 2020

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. …

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Parallel Computing Of Multi-Agent System In Spatially-Explicit Modeling And Simulation, Hongchun Qu, Xianhui Yao, Yin Li Mar 2020

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 …

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Visualization Of Tropical Cyclones Based On Digital Earth, Shuoben Bi, Yucheng Gong, Mingyue Lu, Zhou Hao, Tang Zhi Mar 2020

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 …

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Maritime Radar Terrain Echo Simulation Based On Dem And Sar, Yongfeng Suo, Shenhua Yang, Guoquan Chen, Zhuqiang Xiang Mar 2020

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 …

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Learning In The Machine: To Share Or Not To Share?, Jordan Ott, Erik Linstead, Nicholas Lahaye, Pierre Baldi Mar 2020

Learning In The Machine: To Share Or Not To Share?, Jordan Ott, Erik Linstead, Nicholas Lahaye, Pierre Baldi

Engineering Faculty Articles and Research

Weight-sharing is one of the pillars behind Convolutional Neural Networks and their successes. However, in physical neural systems such as the brain, weight-sharing is implausible. This discrepancy raises the fundamental question of whether weight-sharing is necessary. If so, to which degree of precision? If not, what are the alternatives? The goal of this study is to investigate these questions, primarily through simulations where the weight-sharing assumption is relaxed. Taking inspiration from neural circuitry, we explore the use of Free Convolutional Networks and neurons with variable connection patterns. Using Free Convolutional Networks, we show that while weight-sharing is a pragmatic optimization …

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Research On Emergency Risk Decision Simulation Based On Multi-Agent And Prospect Theory, Wang Jian, Chenqi Situ, Shengqiang Yuan Mar 2020

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 …

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Rapid Simulation And Volume Rendering Of Electromagnetic Environment Based On Geographic Coordinate System, Yuguo Wu, Beibei Han Mar 2020

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 …

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Research Of Link Acquisition Technology For Virtual-Reality Network, Liu Yuan, Xingbing Feng, Xiaofeng Wang, Zhaohong Deng Mar 2020

Research Of Link Acquisition Technology For Virtual-Reality Network, Liu Yuan, Xingbing Feng, Xiaofeng Wang, Zhaohong Deng

Journal of System Simulation

Abstract: Network simulation is an important foundation for the cyberspace shooting range, where the data acquisition and evaluation for the emulation network is its key link. Based on the emulation network formed by OpenStack, a distributed link data acquisition system for the diversified emulation links is constructed. The paper studies the collaborative acquisition technology and the efficient link data acquisition technology of 3 kinds of links, such as the virtual link in the host, the virtual link between the host and the virtual-reality link, and the evaluation technology based on the link data. Experiments show that the proposed method improves …

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Anti-Dead-Zone Control For Two Flexible Links Space Robot With Integration Of Motion And Vibration, Xiaoqin Huang, Chen Li Mar 2020

Anti-Dead-Zone Control For Two Flexible Links Space Robot With Integration Of Motion And Vibration, Xiaoqin Huang, Chen Li

Journal of System Simulation

Abstract: The angle tracking and flexible vibration suppression integrated control for the two flexible links free-floating space robot with joint torque output dead-zone and external disturbance are discussed. The hybrid trajectory concept with rigid motion and flexible mode is introduced, and an adaptive control scheme of the integral sliding mode neural network based on the integration of motion and vibration is proposed. In case the slope and boundary of dead-zone is uncertain and the upper kind of the optimal approximation error is unknown, the compensation term of the scheme can eliminate the effect, and ensures the robustness of the rigid …

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A Game Cheating Detection System Based On Petri Nets, Zheng Hong, Ye Cheng, Wenxuan Deng, Pan Li Mar 2020

A Game Cheating Detection System Based On Petri Nets, Zheng Hong, Ye Cheng, Wenxuan Deng, Pan Li

Journal of System Simulation

Abstract: Game cheating endangers the normal cyber game seriously. The bottlenecks of the anti-cheating technology are the low efficiency and its too much dependence on the signature matching. Not relying on the signature matching, a highly efficient game cheating detection system is proposed, which models by process trees. This can save the storage space without affecting the detection results. The system is tested with the cheating softwares on the popular cyber game and the fusion efficiency of the update model is evaluated. The results show that the storage space reduction rate can reach about 60%, which means effectiveness and feasibility …

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