Computer Sciences Commons^™

Rtds Simulation Of Quasi-Proportional Resonant Control Of Statcom Under High Voltage, Zhang Yang, Xiaopin Yang

Journal of System Simulation

Abstract: ±100 MVar high voltage static synchronous compensator (STATCOM) device is used for high voltage DC transmission which needs higher reliability. Faster response for its control system to deal with metal ground fault and other situations is required. Direct Current Control (DCC) can be used for these situations. Quasi- Proportional Resonant (quasi-PR) controller under DCC was studied and its parameters settings were discussed. The calculation methods of key parameters such as K_p and K_r were explained by mathematical deduction process. The STATCOM under higher voltage in Yunnan-Guangxi Funing transaction station was taken as an example for the calculation …

Simulation Of Adaptive Dangerous Weather Warning Method Based On Airborne Weather Radar, Wang Lei, Xingang Liu, Wei Ming

Journal of System Simulation

Abstract: A kind of suitable airborne weather radar algorithm for different seasons, latitude and longitude and underlying surface in China was proposed. A simulation model of airborne weather radar for detecting strong storm weather based on the ground-based weather radar data was established. The improved algorithm of region segmentation and TITAN were used to identify strong storms and their characteristic parameters. China was divided into 16 climate characteristic regions (including East China Sea and South China Sea) per the latitude and longitude. The threshold of strong hail storm radar echo characteristic parameters in these areas was obtained, and the dangerous …

Meteorological Service Federate Design And Realization Based On Hla, Yintian Liu, Xiaodong Wang, Zaikui Wang

Journal of System Simulation

Abstract: To increase flight safety and flight experience under special weather phenomena, the diversity and typical cases of special weather conditions should be considered in flight simulation training, the dynamic and successive meteorological data should be studied, and the insufficient of meteorological services should be overcome by comparing with the traditional flight simulator. The meteorological service with the generation model of multiple size of template library for typical special weather, the dynamical deduction model of meteorological data, and the interpolation calculation model of meteorological grid-point data were proposed. The meteorological service federate based on High Level Architecture (HLA) was established. …

Weld Trajectory Measurement Based On Stripe Type Laser Sensor, Li Lin, Weijie Chen, Yanbiao Zou

Journal of System Simulation

Abstract: Teaching and playback are usually used on welding robot to weld a part. To make sure the implementation of this mode, it is needed to locate the part using artificial sport welding in the front process, which could cause location error and make the actual track deviate from the teaching track. A welding track offline detection device using stripe type laser sensor was proposed for solving the problem. The laser sensor was mounted at the end of the robot. The robot moved along the weld trajectory before welding. The information of the weld track section was gotten and the …

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 …

Self-Trained Deep Ordinal Regression For End-To-End Video Anomaly Detection, Guansong Pang, Cheng Yan, Chunhua Shen, Anton Van Den Hengel, Xiao Bai

Research Collection School Of Computing and Information Systems

Depression is among the most prevalent mental disorders, affecting millions of people of all ages globally. Machine learning techniques have shown effective in enabling automated detection and prediction of depression for early intervention and treatment. However, they are challenged by the relative scarcity of instances of depression in the data. In this work we introduce a novel deep multi-task recurrent neural network to tackle this challenge, in which depression classification is jointly optimized with two auxiliary tasks, namely one-class metric learning and anomaly ranking. The auxiliary tasks introduce an inductive bias that improves the classification model’s generalizability on small depression …

Learning Transferable Deep Convolutional Neural Networks For The Classification Of Bacterial Virulence Factors, Dandan Zheng, Guansong Pang, Bo Liu, Lihong Chen, Jian Yang

Research Collection School Of Computing and Information Systems

Motivation: Identification of virulence factors (VFs) is critical to the elucidation of bacterial pathogenesis and prevention of related infectious diseases. Current computational methods for VF prediction focus on binary classification or involve only several class(es) of VFs with sufficient samples. However, thousands of VF classes are present in real-world scenarios, and many of them only have a very limited number of samples available.Results: We first construct a large VF dataset, covering 3446 VF classes with 160 495 sequences, and then propose deep convolutional neural network models for VF classification. We show that (i) for common VF classes with sufficient samples, …

Transfer Learning: Bridging The Gap Between Deep Learning And Domain-Specific Text Mining, Chaoran Cheng

Dissertations

Inspired by the success of deep learning techniques in Natural Language Processing (NLP), this dissertation tackles the domain-specific text mining problems for which the generic deep learning approaches would fail. More specifically, the domain-specific problems are: (1) success prediction in crowdfunding, (2) variants identification in biomedical literature, and (3) text data augmentation for domains with low-resources.

In the first part, transfer learning in a multimodal perspective is utilized to facilitate solving the project success prediction on the crowdfunding application. Even though the information in a project profile can be of different modalities such as text, images, and metadata, most existing …

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 …

Analysis Of Gameplay Strategies In Hearthstone: A Data Science Approach, Connor W. Watson

Theses

In recent years, games have been a popular test bed for AI research, and the presence of Collectible Card Games (CCGs) in that space is still increasing. One such CCG for both competitive/casual play and AI research is Hearthstone, a two-player adversarial game where players seeks to implement one of several gameplay strategies to defeat their opponent and decrease all of their Health points to zero. Although some open source simulators exist, some of their methodologies for simulated agents create opponents with a relatively low skill level. Using evolutionary algorithms, this thesis seeks to evolve agents with a higher skill …

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 …