Operations Research, Systems Engineering and Industrial Engineering Commons^™

Modeling And Analysis Of Trust Attack Based On Object-Oriented Petri Net, Guangqiu Huang, Bai Lu

Journal of System Simulation

Abstract: On the basis of trust attack graph, the object-oriented trust attack Petri net model was put forward, the dynamic model described the attack behaviors among components of trust entity object. By introducing the object Petri net, the trust attack relations between trust entity objects and components were shown in the Petri net, simulating the collaborative work between the components. According to the new trust relation reconstruction rules, a trust attack path inference algorithm was proposed to make the attacker knowing the changes of harmfulness when attacking the components, thus the attacker could decide the attack direction. The maximal …

Simulation Of Three-Region Commutation Torque Ripple Reduction For Brushless Dc Motor, Junjie Zhu, Haoran Liu

Journal of System Simulation

Abstract: Aiming at brushless DC motor torque ripple during commutation section, new three-step three phases PWM method was proposed based on voltage balance principle, improving existing two phase PWM suppression method and suitable for all speed section. In this new method, the principle of non-commutation phase voltage and the neutral point voltage variation was researched. Voltage difference was remained the same by three-step PWM control strategy before and after commutation in order to suppression current ripple. Comparing with existing current slope research method, this new method is with a series of advantages: simple parameters, computing, and sampling circuit design. …

Study On Visual Function Of Human Computer Interaction In Parachuting Simulator, Han Liang, Gong Xuan, Jiangyun Wang, Yanghua Du

Journal of System Simulation

Abstract: The parachuting training system consists of software and hardware, to simulate the parachute training through head mounted display and operating equipment, combined with system modeling, kinematic computation, visual display and expert evaluation. Principle methods of head mounted display with human-computer interactive function and exploitation of Vega Prime inventive exploration on the information collection of viewpoint are conducted. It provides a real time training environment through the configuration of environmental effects, scene control, collision detection and driving information.

Observer-Based Integral Backstepping Control For Permanent Magnet Synchronous Motor, Yonghong Lan, Liangliang Wang, Caixue Chen

Journal of System Simulation

Abstract: For the speed tracking control problem of Permanent Magnet Synchronous Motor (PMSM), an observer-based back-stepping speed tracking control method was presented. To reconstruct the motor speed and stator axis current, a full order Luenberger observer for PMSM was constructed. By using Lyapunov stability theory, the linear matrix inequality (LMI) based design method of observer was obtained. Through the design of the virtual control input that include the reconstruction variables, using back-stepping control strategy and integrating with tracking errors, the controller of the closed-loop system was proposed. The obtained controller can achieve high precision speed tracking. The …

Stability Of Electrically Conducting Fluid Flow In Channel Under Magnetic Field, Dong Shuai, Lishuai Liu, Xuemin Ye

Journal of System Simulation

Abstract: The stability of conducting fluid flow in a channel under a vertical magnetic field was simulated by non-normal modal stability analysis. The perfect conductivity assumption of the channel wall was employed in the model, and its effect on the stability problem was considered. The results show that when the Hartmann number Ha is larger than 9, the two opposite Hartmann boundary layers are essentially independent of each other; however, when the Hartmann number Ha is smaller than 9, there are still residual interactions between the two opposite Hartmann boundary layers, which has influences on the stability of the flow. …

Interaction Of Particle-Particle And Particle-Bubble In Water:Molecular Dynamics Simulation, Qingqun Luo, Jieming Yang

Journal of System Simulation

Abstract: Graphene and a bulk of gas were used to represent a part of particle and a part of bubble, respectively, and their interactions in liquid water with dissolved gas were simulated. Changes of the structural phase diagram, the gas density, and the potential of mean force were analyzed. The results show that the interactions of particle-particle and particle-bubble are both related to the nanobubble bridges therein. The forming processes of nanobubble bridges were shown in details. The range of nanobubble bridges and the energy change of the system were quantitatively calculated.

A Way Of Integrated Navigation Fault Detection Of Near Space Hypersonic Cruising Aircraft, Hailin Li, Bin Zhang, Dewei Wu, Lu Hu

Journal of System Simulation

Abstract: The doppler shift is augmented, that causes acquisition and tracking of GNSS losing, error of CNS's ray propagation also causes the problem of celestial body tracking when aircraft is hypersonically flighting. A way of INS/GNSS/CNS integrated navigation fault detection of the hypersonic cruising aircraft based on the residual chi-square-Fuzzy ARTMAP (Adaptive Resonance Theory Map) fast neural networks was proposed. The fault diagnostic elements of INS/GNSS/CNS integrated navigation system of the hypersonic cruising aircraft were given; the detection function formula of residual chi-square test and Fuzzy ARTMAP fast neural networks arithmetic was deduced; the realizing way was studied. The …

Forecasting Of Short-Term Power Load Of Secrpso-Svm Based On Data-Driven, Hairong Sun, Bixia Xie, Tian Yao, Zhuoqun Li

Journal of System Simulation

Abstract: For the parameter selection of support vector machine in modeling, a particle swarm optimization algorithm based on second-order oscillation and repulsion factor was proposed to optimize the parameter of SVM. The algorithm employed the nonlinear decreasing weight to balance the global and local search ability. Second-order oscillation factor could maintain the population diversity. The repulsion factor was introduced to make the swarm even distribution in search space, which could avoid local optimum. For the complex characteristics of nonlinearity, time-varying and multifactorial of electric power load, a support vector machine forecasting model based on data was proposed, and the influence …

Ect Image Reconstruction Algorithm Based On Generalized Regularization, Ma Min, Guo Qi, Chaoqi Yan

Journal of System Simulation

Abstract: Aiming at the numerical instability caused by the singular value decomposition algorithm and the over-smooth caused by the Tiknonov regularization in the image reconstruction of electrical capacitance tomography (ECT) system, a more generalized regularization algorithm was proposed. The penalty phase of the regularized objective function was modified by the positive definite matrix so that it could reconstruct the image with non smooth information, In the process of solving the objective function, the diagonal weight matrix was introduced, and the data items based on l₂-norm were improved. By comparing the image quality, the relative error of the image …

Goods Consumed During Transit In Split Delivery Vehicle Routing Problems: Modeling And Solution, Wenzhe Yang, Di Wang, Wei Pang, Ah-Hwee Tan, You Zhou

Research Collection School Of Computing and Information Systems

This article presents the modeling and solution of an extended type of split delivery vehicle routing problem (SDVRP). In SDVRP, the demands of customers need to be met by efficiently routing a given number of capacitated vehicles, wherein each customer may be served multiple times by more than one vehicle. Furthermore, in many real-world scenarios, consumption of vehicles en route is the same as the goods being delivered to customers, such as food, water and fuel in rescue or replenishment missions in harsh environments. Moreover, the consumption may also be in virtual forms, such as time spent in constrained tasks. …

A Retrial Queueing Model With Thresholds And Phase Type Retrial Times, Srinivas R. Chakravarthy

Industrial & Manufacturing Engineering Publications

There is an extensive literature on retrial queueing models. While a majority of the literature on retrial queueing models focuses on the retrial times to be exponentially distributed (so as to keep the state space to be of a reasonable size), a few papers deal with nonexponential retrial times but with some additional restrictions such as constant retrial rate, only the customer at the head of the retrial queue will attempt to capture a free server, 2-state phase type distribution, and finite retrial orbit. Generally, the retrial queueing models are analyzed as level-dependent queues and hence one has to use …

Identification Of Patterns And Disruptions In Ambient Sensor Data From Private Homes, Yan Wang

USF Tampa Graduate Theses and Dissertations

The world’s population is rapidly aging and the increasing demand for home and health care services from this aging population brings unprecedented challenges to the economy and society. Ambient-assisted smart homes, residences equipped with ambient sensors to monitor the resident’s daily activities in a continuous and unobtrusive way, present great potential to manage the growing care service needs of this older population segment, and enable them to age-in-place.

Despite growing research, using ambient sensor data from private homes to monitor daily activities, health and wellness still faces significant challenges. To study ambient sensor data from private homes where annotated data …

Waiting-Time Paradox In 1922, Naoki Masuda, Takayuki Hiraoka

Northeast Journal of Complex Systems (NEJCS)

We present an English translation and discussion of an essay that a Japanese physicist, Torahiko Terada, wrote in 1922. In the essay, he described the waiting-time paradox, also called the bus paradox, which is a known mathematical phenomenon in queuing theory, stochastic processes, and modern temporal network analysis. He also observed and analyzed data on Tokyo City trams to verify the relevance of the waiting-time paradox to busy passengers in Tokyo at the time. This essay seems to be one of the earliest documentations of the waiting-time paradox in a sufficiently scientific manner.

Maintenance Isn’T Just About Grease, Jim Burgin

Operations Management Presentations

Document maintenance is becoming a bit of a challenge. Slowly, but surely, business leaders are realizing that maintenance isn’t just a “necessary evil” but a competitive advantage that can help differentiate their company from others in the same industry. Maintenance is a broad concept, and this webinar is just to get you thinking about maintenance in a different way. Because of the “necessary evil” concept, professional maintenance resources are rare.

Maintenance costs real money. Depending on the size of the operation, labor, contractors, and material costs can be significant. While that seems like a lot of money, consider the costs …

A Data-Driven Framework For Decision Making Under Uncertainty: Integrating Markov Decision Processes, Hidden Markov Models And Predictive Modeling, Hossein Kamalzadeh

Operations Research and Engineering Management Theses and Dissertations

The problem of decision making under uncertainty can be broken down into two parts. First, how do we learn about the world? This involves the problem of modeling the system and its uncertainty. Secondly, given what we currently know about the world, how should we decide what to do, taking into account uncertainty of future events and observations that may change our conclusions. Many systems evolve over time and often the next state of the system is not known with certainty, often modeled as a probability distribution over system states. Dealing with such systems especially when we can make a …

Design And Research On Semi-Physical Simulation Test System Of Aero Engine, Jingfeng Shen, Chulei Li, Dianliang Wu, Jiaxin Zhang

Journal of System Simulation

Abstract: Aiming at the high danger and difficulty of the operation in the aero-engine test, a semi-physical simulation test system that integrates the functions of the test-run operation training, process analysis, simulation of the typical engine performance fault is proposed. Based on the fast response, accurate calculation and high human operation simulation of the engine digital model, the key problems of the research and implementation, such as the structural design of the distributed semi-physical simulation system, visualization of the calculation model of the engine subsystem and real-time visualization of the aero-engine test data displaying in the three-dimensional cave automatic …

Simulation Of Human Body Temperature Distribution Based On New Solution For Heat Conduction Differential Equation, Sina Dang, Hongjun Xue, Xiaoyan Zhang, Chengwen Zhong, Caiyong Tao

Journal of System Simulation

Abstract: In the traditional rectangular coordinate system, the human body characteristics can not match the differential equation. This leads to the low accuracy of the simulation results. Based on the geometric characteristics of the elliptic cylinder, the differential equation of the heat conduction is transformed from the rectangular coordinate system to the elliptic one, and the finite volume method of the alternating direction full implicit scheme pair is adopted. The improved heat conduction differential equation is applied to the simulation of the human body temperature. The simulation results, compared with the calculated values of the traditional differential equation …

A New Interactive Simulation Method For Virtual Tape Measurement, Dongjin Huang, Chenfeng Jiang, Xianglong Wang, Linhui Gu

Journal of System Simulation

Abstract: The virtual tape measurement is an extremely important process in the industrial training systems, and the fidelity of the measurement depends on the stability of the grasp and the accuracy of the tape measure. Combined with the virtual hand, a new interactive simulation method for the virtual tape measurement is proposed and applied to the wind-driven generator alignment training simulation system. The fusion of the geometric rules and physical rules improves the grasping judgment method, and the quaternion adjusts the grasp gesture. Based on the 3D algorithm, the tape width uneven is solved by optimizing the vertex setting to …

Modeling Analysis And Prediction On Ncp Epidemic Transmission, Huaxiong Sheng, Wu Lin, Changliang Xiao

Journal of System Simulation

Abstract: The modeling analysis on the NCP (Novel Coronavirus Pneumonia) epidemic transmission before and after the closure of Wuhan is presented. On the basis of preprocessing the epidemic data, the classical SIR model and differential recurrence method are used to analyze and forecast the epidemic situation in the stage of control. The theoretical value and measured value fits well. In the stage of free transmission, the logistic model is used to compare and analyze the epidemic data five days in advance or later with the actual data to show the importance of taking the epidemic prevention measures in time. The …

Research On Failure Modes Analysis Based On Weighted Evidence Theory, Lulu Shao, Jihong Han, Niu Kan, Xiaohu Liu, Shao Fang

Journal of System Simulation

Abstract: Aiming at the risk priority numbers of different failure modes being equal and the criticality of the fault modes changing greatly due to the tiny change of the risk parameters, a method of the failure modes analysis based on the weighted evidence theory is proposed from the perspective of the methodology of dealing with the uncertainty problem. The method qualifies the epistemic uncertainty existing in the expert evaluation of the risk parameters into the basic belief assignment and expert attribute weight respectively, and the information propagation and processing of the epistemic uncertainty is solved, and the ordered arrangement …