Numerical Analysis and Scientific Computing Commons^™

Hardware-In-The-Loop Simulation Method For Laser Active Imaging Guidance, Zhang Qing, Yijie Li

Journal of System Simulation

Abstract: The system of laser active imaging guidance hardware-in-the-loop simulation is a significant system for testing and validating the capability of laser active imaging guidance and control, it also means a lot in practical applications. The composition of guidance and control system for the laser active imaging aerocraft is analyzed, and the purpose and test flow for the hardware-in-the-loop simulation system are introduced. The integrated project for laser active imaging guidance hardware-in-the-loop simulation system is designed. The functions and elements for the crucial simulation equipment of laser active imaging echo simulator are analyzed; the elements of model composition and …

Improved Dv-Hop Localization Scheme Based On The Best Path Matching Strategy, Qinqin Shi, Xu Qiang, Jianping Zhang

Journal of System Simulation

Abstract: Improvement strategies are provided in view of the fact that the original DV-Hop (Distance, Vector-Hop) method has great error in distance estimation due to the network anisotropy in practical applications and the sensitivity of its location derivation algorithm to the range error. In the distance estimation step, a strategy of computing path similarity parameter is proposed to find out the most similar beacon-beacon path to beacon-node path; in the position calculation step, a modified PSO (Particle Swarm Optimization) algorithm is added after the initial position of an unknown node being derived using Lateration algorithm. Simulation shows that compared with …

Traffic Dynamic Regulation And Control Technology In The Central Area Of Nanning City, Yiman Du, Hongfan Su, Jianping Wu, Chen Yu, Huang Lin, Longfei Liu

Journal of System Simulation

Abstract: As the transportation develops rapidly, the traffic burden increases in downtown areas, especially in the areas of convention center, government building, and business & financial center, which exacerbates traffic congestion nearby. Conventional traffic control measures taken include stagger shifts, congestion charging, and tail number limit. Interests of multi aspects are involved in these measures, which has broad effect. The traffic managers now begin to ameliorate traffic burden by technical methods. A feedback-gate control based regional traffic volume control method was proposed and a microscopic simulation was adopted. This reasearch aims to ameliorate traffic pressure and balance traffic flow through …

Satellite Formation Keeping And Its Stability Analysis Based On Artificial Potential Field Method, Shengqing Yang, Wenyu Ye, Yubin He, Yabin Wan

Journal of System Simulation

Abstract: In this paper, a control method of satellite formation keeping is investigated based on artificial potential field. Since the N-body problem doesn’t have analytical solutions, a leader-follower formation is proposed as a restricted N-body problem. The stable structure has infinite possible pairs of coordinates in the inertial frame, therefore the Jacobian matrix of the corresponding error dynamic system at the equilibrium point is unsolvable. By introducing a transformation of coordinates from inertial frame to a specific reference frame, the stability analysis of error dynamic system is only related to the structure of formation. By the reduction of error …

Structure Optimization Analysis Of Distillation Kettle Based On Elastic-Plastic Mechanics, Xiaodong Hu, Liu Ning, Xiangsong Qi, Jianpeng Wang

Journal of System Simulation

Abstract: Based on the analysis of structural strength by elastic mechanics, there is a large stress singularity due to the discontinuity of the equipment structure, which makes the calculation result not consistent with the actual stress of the equipment. According to the actual design and structure of a distillation reactor, based on the theory of elastic-plastic mechanics, through modeling, meshing, loading and constraint analysis, the stress distribution of distillation kettle is analyzed; and the wall thickness and stiffener structure are optimized. The results show that the calculation results are reliable and the design of wall thickness is smaller than the …

Overview Of Image Segmentation And Registration For Spine Biological Modeling, Juping Gu, Tianyu Cheng, Hua Liang, Jianping Wang, Zhao Jian, Cao Yong

Journal of System Simulation

Abstract: The prevalence of common spinal fractures is high in this day. Spinal image segmentation and registration are the key step and prerequisite of target recognition, biomechanical modeling and finite element analysis. They are also the key technology of noninvasive surgery navigation. Aiming at the problems of spinal image processing, the classical medical image segmentation and registration algorithm is introduced. It also analyzes the defects and prospects of the future development trend of spine image processing. The research results have certain significance for further understanding of spinal medical image processing and promoting the development of rehabilitation therapy for spinal fractures.

Traffic Patterns For Intelligent Vehicles In The Intersection, Wang Jian, Feng Qi, Xiaowei Hu

Journal of System Simulation

Abstract: With the applications of GPS/DR/MM integrated positioning technology and vehicle infrastructure integration technology, three traffic patterns with which intelligent vehicles go through the intersection are put forward. These three traffic patterns include signal lights adaptive traffic pattern, vehicle self-organizing traffic pattern and vehicle infrastructure integration traffic pattern. They can reduce vehicle delay, avoid traffic conflicts, decrease the probability of traffic accidents, improve traffic efficiency and realize the barrier-free accessibility of intelligent vehicles to the intersection. According to the parameters such as vehicles arrival rate, critical velocity and the average vehicle spacing, a clearance movement model and a circular path …

Design And Research On Simulation Model Of Limestone-Wet Flue Gas Desulfurization Absorption Tower, Zhang Yue, Han Pu, Zhang Xiang

Journal of System Simulation

Abstract: The mass transfer and chemical reaction processes of wet flue gas desulfurization (FGD) are very complex. It is helpful to improve the operation level of desulfurization site by studying the internal mechanism and establishing a high precision mechanism model. The absorption tower is divided into some regions, and the modeling targets in different regions are determined. The sulfur dioxide absorption region is divided into different heights of the "cell" by the slurry droplet falling distance and exposure time. According to the motion characteristics and mass transfer process, the desulfurization efficiency and pressure drop are calculated, and the absorption efficiency …

Modeling And Simulation Of Car-Following On Expressway, Yuhan Jia, Jianping Wu, Yiman Du, Mingyu Liu

Journal of System Simulation

Abstract: Aiming at the high-speed following phenomenon on expressways, an improved car-following model is developed in the paper considering variable safety headway distance. The new model is calibrated and validated by the data collected using an instrumented vehicle in Beijing. Stability analysis of the new model is investigated using the control theory method. The numerical simulations are implemented and the result shows good consistency with theoretical study. The new model is integrated into the traffic simulation system of FLOWSIM. Experiment results show that the improved OV model based FLOWSIM can outperform the original system on some specific conditions.

Evaluation Method Of Imminent Battle Situation In Air Combat, Huimin Cao, Anxiang Huang, Lei Xiang

Journal of System Simulation

Abstract: In the state of air combat, the situation change rapidly. Quick and accurate assessment of the current situation and making decisions is the key to the victory of air combat and the preservation of own strength. Based on the specialty of the modern air battle and pelagic operation, this article adds the political factor, the pilot individual actual combat ability, and the formation cooperative tactical task to fight against the single constraint into the evaluation index system. This makes the evaluation more reasonable and comprehensive and closer to the actual combat, so as to provide more accurate basis for …

3d Flight Trajectory Simulation Generator Based On Track Constraints, Shuguang Sun, Cheng Peng

Journal of System Simulation

Abstract: The airborne navigation equipment needs accurate flight trajectory data to test its performance. According to the requirements of the Beidou receivers, considering the constraint of trajectory and flight performance, a flight trajectory generator is designed using iteration like method. The flight trajectory generator can generate the whole trajectory data and the flight parameters of the aircraft based on the actual flight procedures, and display the data and parameters in real time. The whole flight trajectory simulation data from Beijing International Capital Airport to Guangzhou Baiyun International Airport is generated. The result shows that the flight trajectory generator can generate …

Modular Design Method Of Integrated Avionics Simulation System, Mingbo Zhao, Pan Long, Longwei Jiang, Wang Gang, Guangxing Zhao

Journal of System Simulation

Abstract: In the past, there were some problems in the software design for the flight simulation avionics system such as the decentralized structure and the low degree of modularization. Aiming at these problems, a hierarchical, modular integrated avionics system is constructed. The logic part dispersed in each function module is independent to form the integrated logic module. Each task function module and its sub module are responsible for the calculation of the relevant task function algorithm. Modular design is carried out in a deeper level. By dataflow analysis, each module in this design has strong cohesion and weak coupling and …

Gesture Recognition Method Based On Multi-Feature Fusion, Yuanming Wang, Zhang Jun, Yuanhui Qin, Xiujuan Chai

Journal of System Simulation

Abstract: Aiming at the specific application requirements of command gesture for flight deck, a gesture recognition method based on multi-feature fusion is proposed. The 3D trajectory feature vector and hand sparse representation are established from two aspects of the trajectory and posture based on the visual information collected by depth camera. On the one hand, the gesture is recognized through normalization resampling and alignment based on the trajectory feature. On the other hand, the gesture is recognized through sparse representation alignment based on the HOG feature. The recognition results are fused effectively. The experimental results indicate that our …

Cs04all: Machine Learning Module, Hunter R. Johnson

Open Educational Resources

These are materials that may be used in a CS0 course as a light introduction to machine learning.

The materials are mostly Jupyter notebooks which contain a combination of labwork and lecture notes. There are notebooks on Classification, An Introduction to Numpy, and An Introduction to Pandas.

There are also two assessments that could be assigned to students. One is an essay assignment in which students are asked to read and respond to an article on machine bias. The other is a lab-like exercise in which students use pandas and numpy to extract useful information about subway ridership in NYC. …

Stock Market Prediction Analysis By Incorporating Social And News Opinion And Sentiment, Zhaoxia Wang, Seng-Beng Ho, Zhiping Lin

Research Collection School Of Computing and Information Systems

The price of the stocks is an important indicator for a company and many factors can affect their values. Different events may affect public sentiments and emotions differently, which may have an effect on the trend of stock market prices. Because of dependency on various factors, the stock prices are not static, but are instead dynamic, highly noisy and nonlinear time series data. Due to its great learning capability for solving the nonlinear time series prediction problems, machine learning has been applied to this research area. Learning-based methods for stock price prediction are very popular and a lot of enhanced …

Vistanet: Visual Aspect Attention Network For Multimodal Sentiment Analysis, Quoc Tuan Truong, Hady Wirawan Lauw

Research Collection School Of Computing and Information Systems

Detecting the sentiment expressed by a document is a key task for many applications, e.g., modeling user preferences, monitoring consumer behaviors, assessing product quality. Traditionally, the sentiment analysis task primarily relies on textual content. Fueled by the rise of mobile phones that are often the only cameras on hand, documents on the Web (e.g., reviews, blog posts, tweets) are increasingly multimodal in nature, with photos in addition to textual content. A question arises whether the visual component could be useful for sentiment analysis as well. In this work, we propose Visual Aspect Attention Network or VistaNet, leveraging both textual and …

Adaptive Cost-Sensitive Online Classification, Peilin Zhao, Yifan Zhang, Min Wu, Steven C. H. Hoi, Mingkui Tan, Junzhou Huang

Research Collection School Of Computing and Information Systems

Cost-Sensitive Online Classification has drawn extensive attention in recent years, where the main approach is to directly online optimize two well-known cost-sensitive metrics: (i) weighted sum of sensitivity and specificity; (ii) weighted misclassification cost. However, previous existing methods only considered first-order information of data stream. It is insufficient in practice, since many recent studies have proved that incorporating second-order information enhances the prediction performance of classification models. Thus, we propose a family of cost-sensitive online classification algorithms with adaptive regularization in this paper. We theoretically analyze the proposed algorithms and empirically validate their effectiveness and properties in extensive experiments. Then, …

Cryptocurrency Mining On Mobile As An Alternative Monetization Approach, Nguyen Phan Sinh Huynh, Kenny Choo, Rajesh Krishna Balan, Youngki Lee

Research Collection School Of Computing and Information Systems

Can cryptocurrency mining (crypto-mining) be a practical ad-free monetization approach for mobile app developers? We conducted a lab experiment and a user study with 228 real Android users to investigate different aspects of mobile crypto-mining. In particular, we show that mobile devices have computational resources to spare and that these can be utilized for crypto-mining with minimal impact on the mobile user experience. We also examined the profitability of mobile crypto-mining and its stability as compared to mobile advertising. In many cases, the profit of mining can exceed mobile advertising's. Most importantly, our study shows that the majority (72%) of …

Partially Observable Multi-Sensor Sequential Change Detection: A Combinatorial Multi-Armed Bandit Approach, Chen Zhang, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

This paper explores machine learning to address a problem of Partially Observable Multi-sensor Sequential Change Detection (POMSCD), where only a subset of sensors can be observed to monitor a target system for change-point detection at each online learning round. In contrast to traditional Multisensor Sequential Change Detection tasks where all the sensors are observable, POMSCD is much more challenging because the learner not only needs to detect on-the-fly whether a change occurs based on partially observed multi-sensor data streams, but also needs to cleverly choose a subset of informative sensors to be observed in the next learning round, in order …

Discrete Social Recommendation, Chenghao Liu, Xin Wang, Tao Lu, Wenwu Zhu, Jianling Sun, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

Social recommendation, which aims at improving the performance of traditional recommender systems by considering social information, has attracted broad range of interests. As one of the most widely used methods, matrix factorization typically uses continuous vectors to represent user/item latent features. However, the large volume of user/item latent features results in expensive storage and computation cost, particularly on terminal user devices where the computation resource to operate model is very limited. Thus when taking extra social information into account, precisely extracting K most relevant items for a given user from massive candidates tends to consume even more time and memory, …

Robust Estimation Of Similarity Transformation For Visual Object Tracking, Yang Li, Jianke Zhu, Steven C. H. Hoi, Wenjie Song, Zhefeng Wang, Hantang Liu

Research Collection School Of Computing and Information Systems

Most of existing correlation filter-based tracking approaches only estimate simple axis-aligned bounding boxes, and very few of them is capable of recovering the underlying similarity transformation. To tackle this challenging problem, in this paper, we propose a new correlation filter-based tracker with a novel robust estimation of similarity transformation on the large displacements. In order to efficiently search in such a large 4-DoF space in real-time, we formulate the problem into two 2-DoF sub-problems and apply an efficient Block Coordinates Descent solver to optimize the estimation result. Specifically, we employ an efficient phase correlation scheme to deal with both scale …

Evolutionary Trends In The Collaborative Review Process Of A Large Software System, Subhajit Datta, Poulami Sarkar

Research Collection School Of Computing and Information Systems

In this paper, we study the evolutionary trends in the collaborative review process of a large open source software system. As expected, the number of reviews, the number of reviews commented on, as well as the number of reviewers, and the interactions between them show increasing trends over time. But unexpectedly, levels of clustering between developers in their interaction networks show a decreasing trend, even as connections between them increase. In the context of our study, clustering is an indicator of developer collaboration, whereas connection points to how intensely developers work together. Thus the trends we observe can inform how …

Extending Set Functors To Generalised Metric Spaces, Adriana Balan, Alexander Kurz, Jiří Velebil

Mathematics, Physics, and Computer Science Faculty Articles and Research

For a commutative quantale V, the category V-cat can be perceived as a category of generalised metric spaces and non-expanding maps. We show that any type constructor T (formalised as an endofunctor on sets) can be extended in a canonical way to a type constructor T_V on V-cat. The proof yields methods of explicitly calculating the extension in concrete examples, which cover well-known notions such as the Pompeiu-Hausdorff metric as well as new ones.

Conceptually, this allows us to to solve the same recursive domain equation X ≅ TX in different categories (such as sets and metric spaces) and …

An Evaluation Of Training Size Impact On Validation Accuracy For Optimized Convolutional Neural Networks, Jostein Barry-Straume, Adam Tschannen, Daniel W. Engels, Edward Fine

SMU Data Science Review

In this paper, we present an evaluation of training size impact on validation accuracy for an optimized Convolutional Neural Network (CNN). CNNs are currently the state-of-the-art architecture for object classification tasks. We used Amazon’s machine learning ecosystem to train and test 648 models to find the optimal hyperparameters with which to apply a CNN towards the Fashion-MNIST (Mixed National Institute of Standards and Technology) dataset. We were able to realize a validation accuracy of 90% by using only 40% of the original data. We found that hidden layers appear to have had zero impact on validation accuracy, whereas the neural …

Improving Vix Futures Forecasts Using Machine Learning Methods, James Hosker, Slobodan Djurdjevic, Hieu Nguyen, Robert Slater

SMU Data Science Review

The problem of forecasting market volatility is a difficult task for most fund managers. Volatility forecasts are used for risk management, alpha (risk) trading, and the reduction of trading friction. Improving the forecasts of future market volatility assists fund managers in adding or reducing risk in their portfolios as well as in increasing hedges to protect their portfolios in anticipation of a market sell-off event. Our analysis compares three existing financial models that forecast future market volatility using the Chicago Board Options Exchange Volatility Index (VIX) to six machine/deep learning supervised regression methods. This analysis determines which models provide best …

Application Of Virtual Reality In Rehabilitation Of Special Populations, Tingting Liu, Liu Zhen, Ping'an Qian, Rongrong Xuan, Wang Jin, Yanjie Chai

Journal of System Simulation

Abstract: With the continuous development of urbanization and the trend of population aging, the number of people who need physical and mental rehabilitation continues to increase. Using information technology to assist the rehabilitation process has the important practical significance. The existing studies about the application of virtual reality (VR) technology in the rehabilitation, psychological problems and children with autism for stroke are reviewed. A framework for the intelligent rehabilitation system is proposed. Virtual agent, the technology of somatosensory and voice recognition are advised to be used. Based on the proposed framework, a prototype rehabilitation game for autism and an upper …

A Review Of Rare Event Simulation, Liping Wang, Wenhui Fan

Journal of System Simulation

Abstract: Rare-event has a great significance for its lower probability of occurrence and greater harmfulness, the traditional Monte Carlo method is difficult to analyze it effectively. Rare-event simulation technique which is developed quickly and applied in many areas can sample the rare-event effectively with variance reduction methods and can estimate the occurrence probability of rare-event. The research status of rare-event simulation technique is summarized firstly; the principles, problems and progress of the main methods are analyzed and concluded secondly; after that the application fields of the technique are elaborated and summarized; the future development tendency of rare event simulation technique …

Integrated Modeling For Time Delay Stability Analysis In Gcps, Jianbo Jiang, Li Peng, Aimin Miao, Cao Min, Songhai Zhang, Tan Lei, Kerun Li

Journal of System Simulation

Abstract: According to the separation problems of physical and cyber modeling in time delay stability analysis for grid cyber-physical system (GCPS), an integrated modeling method is presented and proved by single machine infinite bus system (SMIBS). The time delay and stability of GCPS are analyzed and discussed, and the physical and cyber models of SMIBS are established respectively. The dynamic linking library by EA and VS based on information model (CIM) are generated, and the united simulation platform is achieved by MATLAB. The results of the simulation show that the unified structure of information flow …

Parameter Estimation Of Lfmcw Signals Based On Improved Sm Method, Jiang Li, Junni Zhou, Runling Yang, Liu Li

Journal of System Simulation

Abstract: The parameter estimation of linear frequency modulation continuous wave (LFMCW) signal is a research hotspot in electronic reconnaissance systems. In this paper, the time frequency distribution feature of LFMCW signals is studied first. Based on the improved S-method (SM), an algorithm for parameter estimation of LFMCW signals is proposed. It uses short-time Fourier transform (STFT) to calculate the SM with adaptive window width, which can suppress the crossterm interferences and improve the time-frequency resolution. Theoretical analysis and simulation experiment results demonstrate the validity of the proposed algorithm under low SNR.

Research On Method Of Battlefield Situation Representation Based On Multiplex Information Cell, Xiying Huang, Dinghai Zhao, Shao Wei

Journal of System Simulation

Abstract: We adopt the grid-space method to represent the battlefield as discrete cell model. And we construct the multiplex information cell (MIC) using the situation-meta’s information such as position, states collection, indexed by position. The positions of MICs correspond to the battlefield’s positions. Both of them can be represented as stack or data array. This method gives a way to build the whole mapping relationship between data structure which the computer can understand and the battle factors such as position and state of situation-meta. When the position or state of the situation-meta changes, the computer can redraw the view according …