Engineering Commons^™

Simulation On Global Demand Information Sharing Value In B2b Supply Chain, Dongbo Hu, Shen Yue, Rudan Heng, Binbin Zhang

Journal of System Simulation

Abstract: In B2B e-commerce environment, a multi-agent simulation model based on the supply chain with multi suppliers was established to study the incentive effects of the global demand information sharing on suppliers and the effects of different parameters on these incentive effects. The research results are as follows: Compared with the local demand information sharing, the global demand information sharing can bring significant incentive effect to the supplier. The global demand information sharing is more valuable with the number of selected suppliers getting closer to the number of alternative suppliers, and an optimal number of alternative suppliers do exist. Based …

Novel Power Control Algorithm For Cognitive Radio Network, Long Min, Juanjuan Lei

Journal of System Simulation

Abstract: For the problems of near-far effect, large path loss, and stability of algorithm, etc., in the cognitive radio, a new power control algorithm was proposed. Utility function was improved effectively, where punishment factors, such as, link quality and the interference capacity limit of the primary users (PUs) were considered. Signal-to-interference radio (SINR) of cognitive users (CUs) was controlled above the minimum threshold, and the interference value of the CUs was controlled below the capacity tolerance of PUs. The existence of Nash equilibrium was given. Simulation results show that the new algorithm has better stability; the loss of path …

Research On Feedback Compensation Control For Aircraft Electric Antiskid Brake System Based On Il, Gao Jie, Gao Bing, Jianying Liu

Journal of System Simulation

Abstract: Safety, efficiency and comfort of aircraft are all determined by antiskid braking system. Because of the problem of inadequate control in the anti-skid braking system, the nonlinear model of the aircraft electric braking system was built by the analysis of aircraft landing process, and the iterative learning algorithm was introduced for reciprocating characteristics of anti-skid control. The groups in different speeds and road conditions were trained using the PD type learning rate. The knowledge base on the relationship among the optimal slip ratio and velocity and road conditions was built. The feed-forward control knowledge system for identifying the different …

Survey Of Studies On Numerical Simulations Of Optical-Wave Propagation In Atmospheric Turbulence, Bin Ren, Chunyi Chen, Huamin Yang

Journal of System Simulation

Abstract: The complicated random behavior of atmospheric turbulence makes it difficult to verify the theories of optical-wave propagation in atmospheric turbulence by conducting experimental measurements. The parameters used in numerical simulations can be easily controlled; therefore numerical simulations have been used as another important tool to investigate the optical-wave propagation in atmospheric turbulence. Based on the existing literature, both the theoretical models and numerical generating methods for random phase screens of atmospheric turbulence are surveyed, and the spatial sampling constraints for numerical simulations of optical propagation in atmospheric turbulence were summarized. By comprehending the existing results, it has been pointed …

Genetic Algorithm For Solving Multi-Objective Dynamic Flexible Job Shop Scheduling, Wang Chun, Zhang Ming, Zhicheng Ji, Wang Yan

Journal of System Simulation

Abstract: To solve the scheduling problem of mold workshop in a toy factory with dynamic and flexible features, a mathematical model was established by introducing virtual operation and virtual working hours. Based on the strategies of periodic scheduling combined with dynamic event scheduling as well as the rolling window scheduling operation technology, dynamic scheduling was transformed into several continuous static scheduling windows, under which multi-objective genetic algorithm was used to solve the model. The priority of operation scheduling was given in different dynamic events. In addition, the encoding and anti-encoding of chromosome's operation sequence were made based on the proposed …

Fast Tree Modeling Method Based On Simple Freehand Sketch, Ma Ling, Xiaoping Liu, Xiaoping Liu

Journal of System Simulation

Abstract: Aiming at problems such as complicated process and professional knowledge requirements in tree modeling, a quick tree modeling method for non-experts was proposed, combining branch library with simple sketch to make non-experts create tree model quickly. The method preprocessed the sketch to eliminate noise and error points and identify the strokes, the trunk and branch were reconstructed, child three-dimensional profile was built through the two-dimensional canopy profile, under the constraint of the child profile, suitable branches from library and insert were extracted into the branches, consequently the whole tree model was completed. Experimental results show that this method …

Improved Particle Swarm Optimization Based On Lévy Flights, Rongyu Li, Wang Ying

Journal of System Simulation

Abstract: The particle swarm optimization (PSO) has some demerits, such as relapsing into local extremum, slow convergence velocity and low convergence precision in the late evolutionary. The Lévy particle swarm optimization (Lévy PSO) was proposed. In the particle position updating formula, Lévy PSO eliminated the impact of speed on the convergence rate, and used Levy flight to change the direction of particle positions movement to prevent particles getting into local optimum value, and then using greedy strategy to update the evaluation and choose the best solution to obtain the global optimum. The experimental results show that Lévy PSO can effectively …

Performance Modeling Of Cryptographic Service System Virtualization Based On Issm, Songhui Guo, Qingbao Li, Sun Lei, Xuerong Gong, Tianchi Yang

Journal of System Simulation

Abstract: The complicated architecture of cryptographic service system virtualization raised the difficulty of performance modeling. A performance modeling approach based on ISSMs was proposed. The approach divided the execution process into two stages, host preprocessing and arithmetic-module calculating, and built two sub-models based on queuing theory. On this basis, the effectiveness of this approach was verified. The results show that this method can analyze the impacts on system performance caused by task arrival rates, host and cryptographic card configurations quantitatively, and also be helpful for providing reasonable solutions to deploy virtualized cryptographic service system on cloud computing platforms.

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. …

Research On Natural Gas Explosion Rules For Cuboid Obstacles In Offshore Oil Platform, Pengcheng Wang, Yuqing Sun

Journal of System Simulation

Abstract: Quantities and blockage ratios of equipment on the platform has a great effect on the peak overpressure and temperature. The loss caused by explosion can be reduced to the minimum through the reasonable distribution of equipment, and the finite element method has been widely used in the simulation of gas cloud explosion. Offshore oil platform models with different cuboid obstacles were established by the finite element method and cuboid obstacles were distributed in 15 different situations. Mathematical relationships between overpressure and cuboid obstacles' quantities and blockage ratios were obtained. The results show that with the increase of quantities and …

Research On Picking Robot Vision Localization Based On Semi-Physical Simulation, Keyin Chen, Xiangjun Zou, Hongxing Peng, Haiying Liang, Yuanchuang Hu

Journal of System Simulation

Abstract: Aiming at the problems of accuracy and stability of the vision localization based on physical picking robot, which were easy to make mistakes, long cycle, and not easy to be carried out indoors, a picking robot vision localization method based on the semi-physical simulation technology was proposed combining with the robot vision localization mechanism and robot kinematics. This method adopted the virtual picking robot to instead of the physical robot, and studied the vision localization of the fruit target in the virtual simulated environment, which was as the vision localization based on semi-physical simulation. The test results show that: …

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 …

Improved Threshold Function Simulation Research In Vibration Signal Denoising, Hongxing Sun, Zhang Yang

Journal of System Simulation

Abstract: Filtering noise component of mechanical vibration signal effectively can observe the characteristics of vibration signal more clearly. So based on the wavelet threshold de-noising method, a new improved threshold function was proposed. The coefficient of wavelet transform mechanical vibration signals were estimated by the threshold selection method based on kurtosis value. Not only new threshold function conforms to the distribution characteristics of the vibration signal, but also new threshold function is continuous in the threshold point. And the new threshold function overcomes the inherent deviation which traditional threshold function brings. The research of noise reduction on the simulation signal …

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 …

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 …

Simulation And Analysis Of Ultra High Frequency Induction Heating Circuit Based On Current Source, Mangyuan Ma, Xinchun Shi, Wang Hui, Jianhui Meng

Journal of System Simulation

Abstract: The operating frequency range, operating mode and output power are determined by the circuit. A suitable circuit is very important for induction heating power supply. On the basis of Class-E and Boost Chopper circuit, a new current source was analyzed with parallel resonant load circuit by energy conservation law and Fourier decomposition, which derived mathematical relation among the parameters and provided application theory. This circuit was studied by using Matlab/Simulink with variable parameters, which obtained the operating waves with different parameters and values. Comparing the operating waves with the theoretical analysis, the simulation results are completely consistent with the …

Modeling Method Of Air Command And Security Work Process Service Oriented, Yongliang Luo, Yuanhui Qin

Journal of System Simulation

Abstract: A modeling method of air command and security work process service oriented was proposed combined with the typical process equipment air command and support building requirements. Air command and process characteristics was analyzed systematically. On this basis, a complex process modeling method was proposed. From the concept of process meta-model, process formalized description mechanism was studied. A prototype flow modeling tool was developed, and the rationality of the proposed method was analyzed combined with the application example.

Sensing, Computing, And Communications For Energy Harvesting Iots: A Survey, Dong Ma, Guohao Lan, Mahbub Hassan, Wen Hu, Sajal K. Das

Research Collection School Of Computing and Information Systems

With the growing number of deployments of Internet of Things (IoT) infrastructure for a wide variety of applications, the battery maintenance has become a major limitation for the sustainability of such infrastructure. To overcome this problem, energy harvesting offers a viable alternative to autonomously power IoT devices, resulting in a number of battery-less energy harvesting IoTs (or EH-IoTs) appearing in the market in recent years. Standards activities are also underway, which involve wireless protocol design suitable for EH-IoTs as well as testing procedures for various energy harvesting methods. Despite the early commercial and standards activities, IoT sensing, computing and communications …

Efficient Hardware Implementations Of Bio-Inspired Networks, Anakha Vasanthakumaribabu

Dissertations

The human brain, with its massive computational capability and power efficiency in small form factor, continues to inspire the ultimate goal of building machines that can perform tasks without being explicitly programmed. In an effort to mimic the natural information processing paradigms observed in the brain, several neural network generations have been proposed over the years. Among the neural networks inspired by biology, second-generation Artificial or Deep Neural Networks (ANNs/DNNs) use memoryless neuron models and have shown unprecedented success surpassing humans in a wide variety of tasks. Unlike ANNs, third-generation Spiking Neural Networks (SNNs) closely mimic biological neurons by operating …

Model-Based Deep Siamese Autoencoder For Clustering Single Cell Rna-Seq Data, Zixia Meng

Theses

In the biological field, the smallest unit of organisms in most biological systems is the single cell, and the classification of cells is an everlasting problem. A central task for analysis of single-cell RNA-seq data is to identify and characterize novel cell types. Currently, there are several classical methods, such as K-means algorithm, spectral clustering, and Gaussian Mixture Models (GMMs), which are widely used to cluster the cells. Furthermore, typical dimensional reduction methods such as PCA, t-SNE, and ZIDA have been introduced to overcome “the curse of dimensionality”. A more recent method scDeepCluster has demonstrated improved and promising performances in …

Evaluating Driving Performance Of A Novel Behavior Planning Model On Connected Autonomous Vehicles, Keyur Shah

Honors Scholar Theses

Many current algorithms and approaches in autonomous driving attempt to solve the "trajectory generation" or "trajectory following” problems: given a target behavior (e.g. stay in the current lane at the speed limit or change lane), what trajectory should the vehicle follow, and what inputs should the driving agent apply to the throttle and brake to achieve this trajectory? In this work, we instead focus on the “behavior planning” problem—specifically, should an autonomous vehicle change lane or keep lane given the current state of the system?

In addition, current theory mainly focuses on single-vehicle systems, where vehicles do not communicate with …

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 …

Design And Implementation Of Reconfigurable Video Array Processor Test Platform, Jiang Lin, Feilong He, Shan Rui, Wang Shuai, Haoyue Wu, Wu Xin

Journal of System Simulation

Abstract: Aiming at the design requirements of the reconfigurable video array processor and the problem of traditional method testing the video codec system with slow speed, low precision and poor observability. A Qt-based user interface is developed, and a hardware-software co-testing platform based on FPGA is designed and implemented. The platform realizes the data transmission and image reproduction based on the software simulation on the PC side, and the parallel mapping of the video encoding and decoding algorithms based on the reconfigurable video array processor on the FPGA side. The experiment results show that the data can be transmitted correctly …

Force/Position Hybrid Control Method For Surface Parts Polishing Robot, Yufeng Ding, Xinpu Min

Journal of System Simulation

Abstract: A force/position hybrid control method for polishing the complex surface with an industrial robot is put forward. The method can achieve the stable force control and precise position control to ensure the consistency of the material removal rate at different normal vectors. After the trajectory of the normal vector is planned in CAD software, the force signal feedback from the sensor and the PI controller in the normal vector direction are combined,and the robot end tool corrects the motion trajectory in the vector direction of the surface to indirectly control the contact force between the tool and the surface. …

Simulation And Analysis Of Kinematic Parameters Of Vehicle Offset And Rear-End Collision Accident, Wenhui Zhang, Yongmin Su, Shurui Sun

Journal of System Simulation

Abstract: In order to deeply study the motion behavior of vehicles in the rear-end collision, a vehicle rear end collision accident model is established in the PC-Crash simulation environment. Considering with the relative velocity, offset, speed of the rear-end vehicle and wheel angle, the acceleration, yaw angle and yaw rate of the vehicle are obtained. The research results show that when the bias degree is 20%, the yaw angles of the rear-end vehicle and rear tracked vehicle is the biggest, and is easy to induce the secondary accidents such as rollover and fixtures crash. The larger the relative …

Research On Dynamic Editable Method For Combat Simulation Model Combination, Wu Wei

Journal of System Simulation

Abstract: Focus on the low flexibility, interactivity and maneuverability of the combat simulation system, a dynamic editing method for the simulation model combination is proposed. This method is based on the technology of dynamic design of model combination, dynamic editing of simulation model combination and visual programming, which using the Interface-oriented and face-cut design in the model design to realize the flexible and high efficient combat modeling and simulation. A military ship model is designed as the experimental case, in which the feasibility and effectiveness of the proposed method are discussed and verified. The experiment results demonstrate that the method …

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 …

Simulation On A Car-Following Strategy For Adaptive Cruise Control System, Zhiqiang Zhai, Jinliang Xu, Yuan Hao, Yongming Zhou, Longfei Zhao, Shiqian Wang

Journal of System Simulation

Abstract: A car-following strategy based on the variable distance is proposed to improve the applicability of the ACC (Adaptive cruise control) system. The curvature radius of centroid trajectory of the host vehicle is computed by the kinetic model based on the unscented Kalman filter. In order to identify the car-following object, a vehicle tracking model is presented according to the relative kinetic states between the front vehicle and the host vehicle. The ACC system adjust the velocity of the host vehicle to control the safe distance between the host vehicle and the object vehicle. A complex condition with the lane-changing …