Numerical Analysis and Scientific Computing Commons^™

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 …

Towards The Automatic Evolution Of Workload Models In Large-Scale Astronomical Data Management, Huajin Wang, Wan Meng, Han Rui, Ren Wei, Haiming Zhang, Jianhui Li

Journal of System Simulation

Abstract: The benchmark's guiding role in system selection/optimization requires its workload model has the ability to: Run on various systems of the target application scenario (be portable); Reflect the typical tasks' characteristics and data access patterns (be representative). The emerging systems and tasks in large-scale astronomical data management field have led workload models constructed by existing methods to be prone to lose portability and representativeness. An automatic evolutionary workload modeling method has been proposed: Abstract operations are used to keep the workload model’s portability; Automatic workload log analytics are used to keep the workload model’s representativeness. The feasibility of this …

Analysis Of Lane Changing Conflict Based On Tta In Expressway Weaving Area, Wang Bao, Linjie Gao, Zhicai Juan

Journal of System Simulation

Abstract: The study of lane changing behavior in expressway weaving area is of great significance to the analysis of the traffic flow conflict and driving behavior characteristics. In this paper, a lane changing conflict model was established and trajectory extraction software was used to extract and calculate TTA (time to avoidance) and TTC (time to collision). We got 336 TTAs and 233 TTCs and 4 grades of the lane changing conflict level were built by using statistical method. We came up with the proposed lane changing speed and some traffic management strategies. The study will help to …

Direct Parameter Identification Method For Steam Turbine And Its Governing System, Jingliang Zhong, Xiaolong Gou, Tongtian Deng

Journal of System Simulation

Abstract: Since most of the traditional parameter identification methods used in the steam turbine and its governing system have the shortages of poor fitness, complicated identification process and long period, a novel identification method based on least square theory, called direct identification method, is proposed in this paper. Parameter to be identified can be obtained quickly and accurately through direct identification method if the identification process is transferred to solve nonlinear equation which represents the minimal error between simulated data and measured data. The identification results show that during identification process the proposed method has high identification efficiency, accurate identification …

Research On Conceptual Model For Trainer Embedded Training System, Jierong Tian, Zhang Li, Han Liang, Cunhu Shi

Journal of System Simulation

Abstract: Embedded training is an effective way to solve the problem of pilot tactical training, and represents a new technique trend in military training. Aiming at the requirements of trainer embedded training, the visual conceptual model that includes case model, static model and dynamic model for trainer embedded training system is constructed by unified modeling language (UML). Based on the conceptual model and the trainer characteristics, with the consideration of the reality and the future development, the structure model of embedded training system is designed referring to foreign architecture of embedded training system. The bus communication of embedded training …

Damage Simulation Of A Certain Type Of Armored Equipment Based On Finite Element Analysis, Junqing Huang, Tuan Wang, Guanghui Li, Fan Rui

Journal of System Simulation

Abstract: Based on the finite element numerical simulation method, the damage simulation of a certain type of armored equipment was studied. The numerical simulation model of ammo power was established. Based on 3D modeling technology, the vulnerability model of the armored equipment in the component level with high-resolution was established. The spatial relation model of projectile and target was established based on the interaction analysis of projectile and target. According to the characteristic of ammo damage element, combined with the damage criterion of armored equipment component, the damage condition of the component and the damage grade of the armored equipment …

Analysis And Optimization For Combat Capability Based On Sequential Simulation Experiment, Chenyan Kong, Zhu Jing, Jiao Song, Shaojie Mao

Journal of System Simulation

Abstract: To deal with the optimization of combat capability, the sequential simulation experiment method was proposed. The simulation evaluation method with precision constraint was used to control the simulation running times. The sensitivity analysis experiment was carried out to identify the important factors affecting the combat capability. The relation model between the important factors and combat capability was constructed via regression analysis experiment. To get the combat capability improvement as large as possible with the price as small as possible, the optimization was used. In the application example, the air-defense combat capability was improved by the method.

Modeling And Simulation For Automobile Connecting Rod Production Line Based On System Dynamics, Li Han, Wenhui Fan, Feng Yuan, Mengni Zhu, Shengxiao Zhang

Journal of System Simulation

Abstract: In the production line system, it is of much significance to assign operation to workstations in order to balance the manufacturing workload and increase productivity under the given constraint conditions. Based on System Dynamics theory, this paper builds a simulation model of a connecting rod production line in an automobile component company. With this model, the paper analyses the balancing rate and influential factors. Then some preliminary optimization is made to improve the production line performance.

Modeling And Simulation Of Connecting Rod Production Line, Yuanyuan Yan, Wenhui Fan, Feng Yuan

Journal of System Simulation

Abstract: Discrete event system simulation method is widely applied to solve various problems, and line balancing problem is also one of them. In this paper, we use discrete event system simulation method to solve line balancing problem. Connecting rod production line is modeled by using DES. A production line model is built and simulated in AnyLogic, the bottleneck process and the problems to be optimized are analyzed. A small program in MATLAB is used to optimize the production line, and find the optimal solution. Simulate again.

Design Of Simulation Platform For Space Operation Mission, Yuan Jing, Jianpin Yuan, Mingming Wang, Wang Fei, Zhang Chi

Journal of System Simulation

Abstract: The design of simulation platform for space mission operations is investigated. The platform has the advantages of high generality and extensibility, being easy to build up new task. FMI (Functional Mockup Interface) standard is adopted to achieve integration of multisource models, and Python scripts are used to realize the task schedule. Unity3D is adopted to implement the visual display system which could display space manipulation process with high fidelity 3D virtual scenes. Configuration tool is developed to map the 3D objects in visual scene with simulation physical variables for complex space control mechanism, which greatly improves the …

Restrain Boundary Effect Of Emd Based On Least Square Fitting, Zhenpeng He, Zhiqi Zhu, Haichao Xie, Yawen Wang, Zongqiang Li, He Rui, Chaoping Du, Jinlan Li

Journal of System Simulation

Abstract: To improve the accuracy of mechanical fault diagnosis, it’s meaningful to do research on the boundary effect of EMD. In this article, least squares linear method is applied to extend local extremum points at the end of a data series, which judges that whether the maximum value is within the wave fluctuation range of the original signal maximum points, whether the minimum value is within the wave fluctuation range of the original signal minimum points. It compares the extended extreme points and endpoint values, so the best signal endpoint is obtained. By calculating the value of similarity coefficient and …

Simulation Research On Post-Earthquake Road Network Repair Schedule Under Dynamic Traffic Flows, Shuanglin Li, Bin Zheng

Journal of System Simulation

Abstract: It is critical to repair the road network immediately to improve the emergency efficiency after earthquake. A mathematics model for post-earthquake road network repair scheduling under dynamic traffic flows (PRNRSDTF) is created and a hybrid genetic algorithm is provided to maximum the cumulative utilities. Finally, in the context of Wenchuan earthquake, a numerical example is abstract from Jingyang district of Deyang City to verify the reliability and validity of the proposed model and algorithm. The normal road network repair scheduling model without considering dynamical traffic flows is taken as a comparison. The results show that the PRNRSDTF model …