Engineering Commons^™

Brief Technical Analysis Of Malicious Cyber Attacks In Power System, Yan Ru, Minrui Fei, Dajun Du

Journal of System Simulation

Abstract: The power system is responsible for providing electric power to the society. Whether its operation is safe and reliable or not is directly related to the economic livelihood and national security. The malicious cyber-attacks happening on power systems in recent years were summarized, the attack methods used in malicious attack were enumerated, and the complexity and diversity of attack methods were analyzed. The vulnerability of the power system at present was pointed putting forward the corresponding measures to ensure the safe and stable operation of power system. Experimental simulation is designed to analyze the attack methods. The future research …

Two-Dimensional Parameter Estimation Of Near Field Sources Based On Propagator Method, Caifeng Liang, Pan Jing, Liu Ying, Li Xu

Journal of System Simulation

Abstract: A new method based on fourth-order cumulant and propagator method for the joint estimation of the range and DOA of spatial near-field sources is presented. The fourth-order cumulant matrix is constructed using the received uniform linear array data, the received signal noise subspace is estimated by propagator method; the range and DOA of spatial near-field sources are gotten through the spectrum peak search method after the MUSIC spectrum function construction. Compared with the traditional MUSIC algorithm, the presented algorithm with the propagator method directly estimates the least squares solution of the noise subspace, rather than conventional orthogonal solution of …

Accuracy Of New Lattice Monte Carlo Simulation Algorithm Of Biased Diffusion Model, Zhengxiong Wu, Guo Gang, Duan Hong

Journal of System Simulation

Abstract: It is already proved that the traditional fixed time step lattice Monte Carlo (LMC) algorithm can reproduce both the mean and the variance of the particle displacement exactly. However, there is always a non-zero skewness when there is a drift. To further improve the accuracy, a new LMC algorithm of biased diffusion model with five transition probabilities has been devised, which indeed reproduces the first three moments exactly. The valid scope of lattice step and time step can be determined numerically once the drift and the diffusivity are given. A new measurement is introduced to study the accuracy characteristics …

A Cnn Based Cognitive Method To Battlefields Encompassing Situation With Insufficient Samples, Zhu Feng, Xiaofeng Hu, Xiaoyuan He, Yisi Kong, Yang Lu

Journal of System Simulation

Abstract: To research the issue of how to grasp the commander's cognitive experience successfully and effectively facing to battlefields sight map, Convolution Neural Network (CNN) as a kind of the typical algorithm in deep learning can provide the key ways. However, CNN needs the enough samples for running. These samples are hardly to achieve for the time being. Aimed at these problems, some exploring researches were carried out. The issues of battlefields encompassing situation cognition met generally in the warfare and lacking enough samples were discussed. On the basis of analyzing the image characteristics of battlefields encompassing situation and the …

Simulation Of Cooperative Behavior Contagion In Small World Network, Shilong Wang

Journal of System Simulation

Abstract: Under small world network structure, this research constructed a contagion model of cooperative behavior based on behavioral characteristics such as homogeneity gathering, two degrees of separation, influence paradox, attenuation nature, etc. and used Netlogo platform to run the simulation. The results indicate the contagion of cooperative behavior has hysteresis, emergent and progressive properties; the average path length constrains the contagion completion; the strong ties are prone to spread cooperative behavior; the distribution level of node degree of network significantly impacts the contagion time. The discoveries afford guidance for enhancing cooperation performance in small groups, by adjusting relationship …

Dynamic Evolvement And Emergence Modeling For Distributed Operational Systems Capability, Yinghui Yang, Jianhua Li, Mingli Nan, Chen Qiang, Jifang Wen

Journal of System Simulation

Abstract: Aiming at dynamic characteristic of battlefield environment, particularity of operational systems, function heterogeneity and nonlinear effect of operational units, a new dynamic evolvement and emergence modeling method for distributed operational systems capability was proposed. Operational systems super-network model composing of unit layer and network & system layer was built based on super-network theory, and relationship between two layers was analyzed. Concepts of unit capability, network & system capability, systematic capability and fire procedure link were defined. Unit to capability mapping relationship and capability to capability relationship were researched respectively. Affects of unit self-effect, units' inter-effect, network promotion and battlefield …

Robust Control Of Free-Floating Two-Flexible-Link Space Manipulator Based On Observer, Xiaoyan Yu, Chen Li

Journal of System Simulation

Abstract: The joint motion robust control and optimal flexible vibration control of a free-floating two-flexible-link space manipulator based on linear observers was discussed. The dynamic model of a free-floating space manipulator with two flexible links was established by the momentum conservation and the Lagrange equations. Based on singular perturbation approach and choosing appropriate local coordinate frame, a slow subsystem and a flexible-link fast subsystem were obtained. The corresponding controllers were proposed for the two subsystems, which was the linear observer based robust slow subsystem controller and the linear observer based flexible link fast subsystem optimal controller. Numerical simulation demonstrates …

Research On Force Compliance Of The Hydraulic Control System In Major-Motion Mechanism For Manipulator, Geqiang Li, Jingwei Zhang, Yuesong Li, Bin Zhou, Shuye Ma

Journal of System Simulation

Abstract: The force compliance method of the hydraulic control system in major-motion mechanism was proposed during the forging process. Taking the major-motion mechanism of the forging manipulator as the target, the inverse kinematics model of major-motion mechanism was established, and the dynamic model of hydraulic control system was built. Through taking the pressure as the controlled variable, the model of the lifting hydraulic control system was obtained by using the co-simulation technology. Based on the principle of the horizontal buffering system, the model of the buffering hydraulic system which was made up of the buffering cylinder and the accumulator …

In-Cylinder Flow Analysis And Verification Of Opposed-Piston Two-Stroke Engine, Fukang Ma, Changlu Zhao, Zhenfeng Zhao, Wang Hao, Yu Xia, Cao Yan, Jiqing Zhang

Journal of System Simulation

Abstract: The effects of flat piston uniform scavenging chamber, flat piston non-uniform scavenging chamber and pit piston non-uniform scavenging chamber on the in-cylinder flow were analyzed. Uniflow scavenging zero-dimensional model was used to qualitative analysis in-cylinder flow organizational process and influence rule for opposed-piston two-stroke engine. Results show that uniform scavenging chamber can organize swirl and increase scavenging efficiency and non-uniform scavenging chamber can organize tumble and increase turbulent kinetic energy. Scheme 3 is favorable to organize tumble and maintain the in-cylinder turbulence intensity, which is increased by 150 percent.

Dfig Grid Connection Simulation Method Used For Transient Analysis Of Black-Start, Liqing Liu, Zengqiang Mi, Du Ping, Yuliang Wan, Yuan He

Journal of System Simulation

Abstract: Establishing a grid connection model of doubly-fed induction generator based wind turbine (DFIG) could be useful in the research and verification of black-start strategy in isolated power grid containing wind power. A DFIG grid connection simulation method based on Simulink was proposed. Through analyzing the operation characteristics of doubly-fed induction generator in no-load and grid-connected conditions, its dual-operation simulation model was established. According to the grid-connection theory of DFIG, the established doubly-fed induction generator model was combined with wind turbine, converter and other built-in modules, and the DFIG grid connection model was built with its control system added. …

Research On Intelligent Hauling Speed Regulation System Based On Shearer's Reliability, Xunan Liu, Lijua Zhao, Dongmin Gai, Zhangyu Du, Liangying Hao

Journal of System Simulation

Abstract: Under the mine, Shearer's hauling speed affected the shearer's efficiency and reliability. Taking MG32570*2/325-BWD shearer as research object, from shearer's reliability, by using Simulink, the intelligent speed regulation system was established, based on shearer key parts' reliability. The building & simulation of hauling motor load torque block and recommended optimum hauling speed generation block which was fitted by neural network was solved. The simulation results show that: this system can achieve the recommended speed, which is traced by hauling speed rapidly and accurately. When consistent coefficient and cutting depth are 2.85 and 0.58m, the hauling motor's maximum speed is …

Eigen-Value Combination Approach For Speech Enhancement, Huijuan Lu, Yaqing Liu, Yanqiu Liu, Guan Wei

Journal of System Simulation

Abstract: In order to further suppress noise, a kind of speech enhancement algorithm based on Eigen-value merge was proposed. Eigen-values combination was used to improve the speech quality on the basis of the classic embedded pre-whitening subspace methods. The study shows that, after decomposing the covariance matrix of speech signals with noise, the larger Eigen-value component mainly includes speech information, and the smaller Eigen-value component mainly contains noise. Sorted by Eigen-values from small to big, the adjacent large Eigen-value component replaces with small Eigen-value component, which can effectively suppress noise and improve the quality of speech. Compared with other speech …

Gm-Cphd Filter With State-Dependent Clutter, Lili Ma, Xiaoshan Qin, Jinguang Chen

Journal of System Simulation

Abstract: For many sensors the clutters observed are easier to concentrate in the area around targets, namely the state-dependent clutter, which is different from the known clutter distribution in traditional filtering algorithms. So, the accuracy the real-time performance and of traditional multi-target tracking will be greatly degraded. To solve this problem, a kind of GM-CPHD filter with state-dependent clutter was proposed. The relationship between clutter and state was modeled. The clutter intensity was recalculated according to the distribution of clutter in the whole surveillance area and applied to update process; at the same time, in order to reduce the time …

Research On Static Behavior Of Xx-Joints Based On Ansys, Pan Ying, Linxiao Qin

Journal of System Simulation

Abstract: Nonlinear finite element analysis was used in the ultimate bearing capacity on planar XX-joints by ANSYS software. The stress distributions of the joints were demonstrated, the main failure modes of the joints were determined, and the influences of some fundamental geometric parameters on the ultimate strength were the research points. The results show β (diameter ratio of the branch to the chord), θ (axial angle of the chord and the branch), γ (the ratio of the diameter of the chord to the thickness of the walls of the chord) are the main …

Research Of Impact Point Accuracy Of One-Dimensional Trajectory Correction Projectile Based On Monte Carlo, Xiaoyun Lei, Zhian Zhang

Journal of System Simulation

Abstract: After the one-dimensional trajectory correction projectile out of the muzzle, various disturbance factors caused the impact point dispersion. Monte Carlo method was utilized on the shooting accuracy analysis. Based on the practical test datasets, three major factors were determined, namely, time delay of opening-damper mechanism, error of drag coefficient and measurement error of target. As to the disturbances, function randn was used for the analysis of the three major factors on the flat of Matlab. According to error distribution of the factors, the probability distribution and dispersion of the impact point were obtained. The maximum and minimum ranges of …

Potato Storage Temperature Prediction Control Based On Pso And Esns, Junxia Liu, Xinrong Xiong, Hu Bing

Journal of System Simulation

Abstract: According to the current situation of potato storage and serious waste of raw materials and human resources of potato processing enterprises, combined with temperature data characteristics of potato storage from Xinjiang Great Russell Agricultural Science and Technology Development LTD., and control effect of the conventional control methods which is not ideal, a new temperature predictive control method was proposed, which rolled to optimize the input control variable by using particle swarm optimization algorithm and get the actual output values, use ESNs to forecast the temperature in the storage, the system was corrected by deviation between forecasting output and actual …

Improving Microbiological Safety Of Low Moisture Food Products Using Radio Frequency And Ethylene Oxide, Long Chen

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Recent foodborne illness outbreaks in US associated with consumption of low-moisture foods (LMF) have heightened concerns of their microbial safety. Salmonella is a pathogen of major concern in LMF due to its ability to persist in low water activity (a_w) environments. The disadvantages of existing decontamination technologies for LMF call for novel and efficient intervention technologies. Radio frequency (RF) and ethylene oxide (EtO) were evaluated in this dissertation for improving microbial food safety and quality of LMF. Cumin seeds and inshell hazelnuts were selected as model foods.

It took < 2 min of stationary RF heating to achieve > 5 log reductions of Salmonella in cumin seeds without …

Real Time Design Space Exploration Of Static And Vibratory Structural Responses In Turbomachinery Through Surrogate Modeling With Principal Components, Spencer Reese Bunnell

Theses and Dissertations

Design space exploration (DSE) is used to improve and understand engineering designs. Such designs must meet objectives and structural requirements. Design improvement is non-trivial and requires new DSE methods. Turbomachinery manufacturers must continue to improve existing engines to keep up with global demand. Two challenges of turbomachinery DSE are: the time required to evaluate designs, and knowing which designs to evaluate. This research addressed these challenges by developing novel surrogate and principal component analysis (PCA) based DSE methods. Node and PCA-based surrogates were created to allow faster DSE of turbomachinery blades. The surrogates provided static stress estimation within 10% error. …

Copper Electrodeposition From Deep Eutectic Solvents —Voltammetric Studies Providing Insights Into The Role Of Substrate: Platinum Vs Glassy Carbon, Rohan Akolkar

Faculty Scholarship

We report on the effect of the substrate on electrochemical deposition of Cu from deep eutectic solvent ethaline. We investigated the polarization behavior during electrodeposition of Cu on Pt and glassy carbon (GC) from both Cu2+ and Cu+ containing ethaline using cyclic voltammetry (CV). Formation of bulk Cu deposits on both substrates underwent nucleation and growth processes; however, the nucleation was considerably sluggish on GC compared to Pt. While experiments in Cu+ solutions indicated that coalescence of Cu islands on Pt is a slow process and that its surface may not be fully covered by Cu, such determination of Cu …

Recent Shrinkage And Fragmentation Of Bluegrass Landscape In Kentucky, Bo Tao, Yanjun Yang, Jia Yang, S. Ray Smith, James F. Fox, Alex C. Ruane, Jinze Liu, Wei Ren

Plant and Soil Sciences Faculty Publications

The Bluegrass Region is an area in north-central Kentucky with unique natural and cultural significance, which possesses some of the most fertile soils in the world. Over recent decades, land use and land cover changes have threatened the protection of the unique natural, scenic, and historic resources in this region. In this study, we applied a fragmentation model and a set of landscape metrics together with the satellite-derived USDA Cropland Data Layer to examine the shrinkage and fragmentation of grassland in the Bluegrass Region, Kentucky during 2008–2018. Our results showed that recent land use change across the Bluegrass Region is …

Electrochemical Sensors Enhanced By Convection And By 3d Arrays Of Vertically Aligned Carbon Nanotubes, Benjamin James Brownlee

Theses and Dissertations

Early and accessible diagnostics are important elements to reducing the negative side-effects of untreated disease. One key advancement in diagnostic monitoring is through the development of highly sensitive sensors that have the capability to detect lower concentrations, while still remaining accessible for point-of-care use. This dissertation characterizes electrochemical sensing platforms that are enhanced by convection and by 3D electrodes made from high surface area, vertically aligned carbon nanotubes (VACNTs). Free-standing VACNTs were patterned into microchannel arrays for flow-through amperometric sensing. Convective mass transfer enhancement was shown to improve sensor performance in amperometric sensing through the use of high surface area …

Robust Real-Time Model Predictive Control For High Degree Of Freedom Soft Robots, Phillip Edmond Hyatt

Theses and Dissertations

This dissertation is focused on the modeling and robust model-based control of high degree-of-freedom (DoF) systems. While most of the contributions are applicable to any difficult-to-model system, this dissertation focuses specifically on applications to large-scale soft robots because their many joints and pressures constitute a high-DoF system and their inherit softness makes them difficult to model accurately. First a joint-angle estimation and kinematic calibration method for soft robots is developed which is shown to decrease the pose prediction error at the end of a 1.5 m robot arm by about 85\%. A novel dynamic modelling approach which can be evaluated …

Gaussian-Awareness Deep Learning For Block-Level Compressive Video Sensing, Yifei Pei

Computer Science and Engineering Master's Theses

Compressive sensing (CS) is a signal processing framework that effectively recovers a signal from a small number of samples. Traditional compressed sensing algorithms, such as basis pursuit (BP) and orthogonal matching pursuit (OMP) have several drawbacks, such as low reconstruction performance at small compressed sensing rates and high time complexity. Recently, researchers focus on deep learning to get compressive sensing matrix and reconstruction operations collectively. However, they failed to consider sparsity in their neural networks to compressive sensing recovery; thus, the reconstruction performances are still unsatisfied. In this thesis, we use 2D-discrete cosine transform and 2D-discrete wavelet transform to impose …

Attention Mechanism In Battlefield Situation Awareness, Yisi Kong, Xiaofeng Hu, Zhu Feng, Jiuyang Tao

Journal of System Simulation

Abstract: Battlefield situation awareness (BSA) is the basis of C2 and decision making. Research on BSA can clarify the mechanism and lay the foundation for designing intelligent model and algorithm to assist commanders with situation awareness. Taking attention mechanism as the point, the relevant discussion in psychology was summarized, a framework of the attention mechanism in BSA was put forth, and its application in operational target value assessment was explored.

Adaptive Mutative Scale Chaos Particles Swarm Optimization Based On Logistic Mapping, Yanyang Zeng, Yunxia Feng, Wentao Zhao

Journal of System Simulation

Abstract: To overcome the shortcomings of Particle Swarm Optimization (PSO), an Adaptive Mutative Scale Chaos Particles Swarm Optimization (ACPSO) based on Logistic Mapping was proposed. The chaos method was used to initialize the particles. The adjustment method of the inertia weight depended on the particle's fitness; it could avoid premature convergence for the particles. When the particles fell into the local optimum, mutative scale chaos optimization strategy was adopted to adjust the optimal particles. To test the effectiveness of the algorithm, three representative algorithms were compared with. The results show that the algorithm has high convergence speed and high precision.

Target Combination Selection Optimization Method Of Joint Operations Based On Fuzzy Genetic Algorithm, Suike Li, Jianhua Xiang, Haijun Wang, Mingzhi Zhang, Li Yi

Journal of System Simulation

Abstract: Under the condition of informatization, it is necessary to use intelligent model and optimization method to realize the cooperation and fusion of multi arms combat firepower. Aiming at the problem of target decision-making and firepower allocation in joint operations, the fuzzy multi-objective programming model was constructed to achieve the overall goal of achieving the maximum and the best firepower as a dual goal. In the model solving algorithm, the possibility theory was used to transform the fuzzy number, the model was transformed into the multi-objective programming model in the deterministic form. In order to improve the efficiency of …

Motion Reconstruction And Simulation Using Sparse Inertial Sensors, Lijun Cui, Tianyu Huang, Feng Feng, Zhang Jie, Yang Kai, Liu Dong

Journal of System Simulation

Abstract: A method was proposed to reconstruct high-dimensional full-body motion sequences from low-dimensional control data collected by sparse inertial sensors. The approach solved the mapping problem from low dimension to high dimension. A numerical similarity- geometrical similarity-time continuity model was setup to ensure the reconstructed motion candidates in numerical-logical similarity. The gap between angle and angular acceleration was eliminated by acceleration reconstruction. An energy function was introduced to optimize the reconstructed results which guaranteed the accuracy. The analysis and comparison experiments show that the proposed method can reconstruct nature and credible motions in real-time and can be applied …

Business Process Modeling Algorithm Based On Ontology Language, Huang Ying, Kangshun Li, Li Wei, Keqing He

Journal of System Simulation

Abstract: In the view of problem in lack of information sharing mechanisms at the semantic level among processes, a business process modeling algorithm based on ontology language using concept hierarchy as background knowledge was proposed. The business process modeling by traditional business process languages can be transferred to ontology language (OWL) description so as to realize the semantic sharing of business process. The approach has two main advantages compared with traditional methods: (1) accelerating the building process, minimizing the conversion cost; (2) background knowledge guides the extraction of knowledge resided in database. As a way of validating the approach, part …

Measurement Error Correction Model Of Tof Depth Camera, Le Wang, Luo Yu, Haikuan Wang, Minru Fei

Journal of System Simulation

Abstract: 3D data intuitively reflects the full view of the target or scene. Time of Flight (ToF) camera is a range imaging sensor that can provide 3D geometric information of targets immediately, thus it is widely applied in the robot positioning and navigation, 3D reconstruction and other aspects etc. Due to the operational principle of the camera itself, there are variety measurement errors of the source data obtained by ToF, resulting in image distortion. The measurement errors in the imaging process of ToF camera were analyzed and summarized, and the cubic spline interpolation method combined with look-up table was proposed …

Modeling Of Spectrum Sensing Energy Consumption In Cognitive Radio Networks, Ziru Cui, Peng Yi

Journal of System Simulation

Abstract: In cognitive radio networks, the energy consumption in the process of spectrum sensing is the hot spot of research. A unified framework for modeling based on Poisson process was developed which could be used even under interference limited to count the energy consumption, thereby obtaining a spectrum sensing energy consumption. Spectrum sensing energy as the function of the number of secondary users in cognitive radio networks, their spatial density and the number of hops, could be modelled as a truncated gamma distribution. This model is used to statistically analyze cognitive users' energy consumption in the process of spectrum sensing …