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Numerical Analysis and Scientific Computing

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Articles 3991 - 4020 of 4163

Full-Text Articles in Artificial Intelligence and Robotics

Vibration Simulation And Damping Ratio Optimization Of Seat Suspension System For High-Speed Rail, Changcheng Zhou, Yuewei Yu, Leilei Zhao Jan 2019

Vibration Simulation And Damping Ratio Optimization Of Seat Suspension System For High-Speed Rail, Changcheng Zhou, Yuewei Yu, Leilei Zhao

Journal of System Simulation

Abstract: According to the 1/4 body-seat vertical vibration model of high-speed rail, an optimal design simulation model for damping ratio of seat suspension was established. An optimal design mathematical model for damping ratio of seat suspension was built with the optimal ride comfort as the target. Taking the track vertical irregularity as input and the seat suspension vertical stroke as constraint condition, an optimization design method for damping ratio of seat suspension based on track excitation was presented. With a practical example, the damping ratio was designed and validated by simulation. The results show that the damping ratio value …


Optimal Control And Simulation Of Hard Shoulder Running On Highways, Ruimin Li, Ye Zhen, Bin Li Jan 2019

Optimal Control And Simulation Of Hard Shoulder Running On Highways, Ruimin Li, Ye Zhen, Bin Li

Journal of System Simulation

Abstract: This paper summarizes the problems in the operation of hard shoulder running (HSR). A new algorithm for optimizing HSR on highways is proposed, which aims to minimize the total time spent (TTS) in the whole network. Based on the METANET model of highways, the algorithm utilizes genetic algorithm and sliding windows technique to forecast and optimize the operation of HSR under different constraint conditions and target functions. The strategy is tested on the I-80E highway in California. The experimental results show that when the change frequency of HSR is less than or equal to 14 during a sliding window …


Simulation Of Missile Head Cover Separation And Landing Locations, Tian Hao, Mu Zhou, Huitong Li, Zhao Yang Jan 2019

Simulation Of Missile Head Cover Separation And Landing Locations, Tian Hao, Mu Zhou, Huitong Li, Zhao Yang

Journal of System Simulation

Abstract: Some missiles use head cover to protect the internal equipment during the launching process. In order to prevent the head cover from damaging the people or equipment after separation, researchers need to predict the landing position range and take protective measures. This paper designs a separation scheme for a missile head cover separation based on solid propellant gas generator and solid rocket. In this study, we establish a dynamic simulation model of head cover separation and falling procedure. The simulation calculation of the head cover location range considering multiple factors using Monte-Carlo method is developed. And the motional …


Fast False Scene Jamming Algorithm For Sar-Gmti Based On Moving Jamming Station, Mingxing Fang, Daping Bi, Aiguo Shen Jan 2019

Fast False Scene Jamming Algorithm For Sar-Gmti Based On Moving Jamming Station, Mingxing Fang, Daping Bi, Aiguo Shen

Journal of System Simulation

Abstract: Traditional false scene jamming of SAR is invalid for SAR-GMTI system, which does not have the feature of moving targets, so a fast false scene jamming algorithm for SAR-GMTI based on moving jamming station is proposed. Through reasonable simplification of the traditional algorithm, the fast false scene jamming algorithm of matrix form is put forward. The method is proposed to take advantage of both fast false scene jamming algorithm and moving jamming station, so it can produce false scene jamming with real moving feature. It not only solves the real-time problem of traditional false scene jmming, but …


Research On Dynamic Framed Binary Tree Anti-Collision Algorithm For Rfid System, Xiaohong Zhang, Weihui Zhou Jan 2019

Research On Dynamic Framed Binary Tree Anti-Collision Algorithm For Rfid System, Xiaohong Zhang, Weihui Zhou

Journal of System Simulation

Abstract: Based on dynamic frame-slotted ALOHA algorithm and binary search tree algorithm, a dynamic framed binary tree (DFBT) anti-collision algorithm is presented to solve the problem of multi-tag collision in radio frequency identification (RFID). Vogt algorithm is adopted to estimate tags number, then the dynamic frame-slotted ALOHA (DFSA) algorithm is used to identify tags, and the unidentified tags are extracted and the highest collision bit is judged by readers. The highest collision tags are grouped by the collision bit within the binary search tree (BST) algorithm. Simulation results show that the DFBT algorithm can improve the identification efficiency and stability …


Smooth Transition Method Over Entire Speed Range Of Switched Reluctance Motor, Diansheng Sun Jan 2019

Smooth Transition Method Over Entire Speed Range Of Switched Reluctance Motor, Diansheng Sun

Journal of System Simulation

Abstract: In order to smoothly switch different control modes of switched reluctance motor under the condition of low speed and high speed, a novel scheme using function fitting method to control turn-on angle, turn-off angle and phase current chopping is proposed. The active disturbance rejection speed control system is structured for switched reluctance motor in order to restrain all kinds of disturbance and improve the dynamic performance. Simulation results indicate that the principle of the method is correct and the turn-on angle, turn-off angle and phase current chopping is coordinated to realize the smooth switching of different control modes with …


Formation Mechanism And Simulation Analysis Of Railgun Armature Electromagnetic Transition, Zhiheng Wang, Wan Mei, Xiaojiang Li Jan 2019

Formation Mechanism And Simulation Analysis Of Railgun Armature Electromagnetic Transition, Zhiheng Wang, Wan Mei, Xiaojiang Li

Journal of System Simulation

Abstract: Armature transition of railgun causes rails erosion and change of launching parameters, which is one of the key problems restricting the performance of railgun. The formation mechanism of armature transition at the down-slope of driving current is analyzed. The armature transition estimation model and electromagnetic parameters calculation model are given. The formation process of armature transition at the down-slope of driving current is simulated by AYNSYS Workbench. The current and magnetic field distribution are simulated, so as the armature deformation caused by the armature electromagnetic force. The effect of current dropping rate on armature transition is analyzed. The …


Modified Fractional Order Sliding Model Control For Dc Speed Regulating System, Zhicheng Zhao, Zhitao Zhao, Jinggang Zhang, Xianjiao Zhao Jan 2019

Modified Fractional Order Sliding Model Control For Dc Speed Regulating System, Zhicheng Zhao, Zhitao Zhao, Jinggang Zhang, Xianjiao Zhao

Journal of System Simulation

Abstract: An improved fractional order sliding model control (FOSMC) is proposed for DC speed regulating system to eliminate static error easily caused by disturbance in sliding model control. Second order mathematical model is established through taking the derivative of first-order mathematical model of DC speed regulating system. The theory of fractional calculus is introduced to the switching function of sliding mode, and fractional sliding model is designed combining exponential reaching law and second order mathematical model. The control signal of voltage can be obtained through taking output of the controller and integrator in series. Stability analysis of the system is …


A Mppt Control Method Of Wind Turbines With Nonsingular And Fast Terminal Sliding Mode, Dazhong Li, Wu Feng Jan 2019

A Mppt Control Method Of Wind Turbines With Nonsingular And Fast Terminal Sliding Mode, Dazhong Li, Wu Feng

Journal of System Simulation

Abstract: In order to improve the energy capture efficiency of doubly-fed induction generator (DFIG), a control method is designed based on direct speed control (DSC) to achieve maximum power point tracking (MPPT). An effective wind speed estimator based on high-degree cubature Kalman filter (HCKF) and Newton-Raphson method (NR) is proposed for solving the difficulty in obtaining effective wind speed using traditional control strategy. A speed controller based on nonsingular fast terminal sliding mode surface is designed to obtain a faster speed response for the speed loop. The numerical simulation research of the 2.4MW wind turbine under rapidly variable wind …


Relevance Analysis Of Deicing Parameters And Deicing Efficiency Of Aircraft Ground, Bin Chen, Liwen Wang Jan 2019

Relevance Analysis Of Deicing Parameters And Deicing Efficiency Of Aircraft Ground, Bin Chen, Liwen Wang

Journal of System Simulation

Abstract: Aircraft ground freezing could lead to potential danger and delay for flight. To alleviate these problems, the main method is to use the deicing fluids to clean ice or snow on the aircraft body, which lacks of reference of the deicing fluids parameters and efficiency. To study the effect of the deicing fluids parameters on the aircraft deicing efficiency, the deicing mechanism is analyzed.The black box mathematical model of the deicing process is generalized abstractly. The deicing process is divided into two subprocesses to establish the deicing model.The relevance between the deicing fluids parameters and deicing efficiency is studied …


A Novel Algorithm For Improving Fairness Between Uplink And Downlink Flows In Heterogeneous Network, Peiyu Li, Zheqing Li, Wang Hui, Xia Qian Jan 2019

A Novel Algorithm For Improving Fairness Between Uplink And Downlink Flows In Heterogeneous Network, Peiyu Li, Zheqing Li, Wang Hui, Xia Qian

Journal of System Simulation

Abstract: In order to improve the fairness between uplink and downlink flows in AP optimization, a novel algorithm called FOUD(fairness over uplink and downlink) is proposed.Considering the influence of the attempt limit and the bit error rate of wireless, the FOUD algorithm modeling of AP and wireless stations is studied separately by using two-dimensional Markov chain, which derives the probability of data sending under the condition of different bit error rate and different number of uplink and downlink flows. Simulation results show that FOUD can improve the fairness of the uplink and downlink bandwidth as well as the …


Frequency Domain Analysis Of Common Configuration Semi-Submersible Drilling Platform Based On System Simulation, Chen Bo, Zhiyong Yu, Lü Yong, Xiaojian Li Jan 2019

Frequency Domain Analysis Of Common Configuration Semi-Submersible Drilling Platform Based On System Simulation, Chen Bo, Zhiyong Yu, Lü Yong, Xiaojian Li

Journal of System Simulation

Abstract: To analysis of 4 semi-submersible drilling platform hydrodynamic performance providing a comprehensive guidance for system selection. The 1:1 3D wet surface model is established by ANSYS and numerical simulation is carried out based on the dynamic analysis software AQWA. Simulation results show that longitudinal waves impact the surge, heaving and pitching motion a lot, beam seas have large effects on the sway, heave, roll motion vertical heave response increases significantly, as will as surge, sway, heave damping coefficient of vector direction and the added mass coefficient of algebraic. We can not only increase the number of columns to …


A Method Of Finding The Shortest Path Of Dynamic Networks, Lunwen Wang, Zhang Ling Jan 2019

A Method Of Finding The Shortest Path Of Dynamic Networks, Lunwen Wang, Zhang Ling

Journal of System Simulation

Abstract: We analyze the research status of finding the shortest path of dynamic networks, analyze the complexity of getting the shortest path, study the relationship between the structure of the dynamic networks and finding the shortest path of the dynamic networks. It is proved that dynamic networks defined by velocity automatically meet weak FIFO’s condition. The networks whose passing function of any side is not decreasing function equals dynamic networks which use velocity. The sufficient condition of directly using Dijkstra algorithm to get the shortest path is that the networks must meet weak FIFO’s condition. How to build a …


Fuzzy Sliding Backstepping Mode Control For Flight Simulator Servo Based On Friction And Disturbance Compensation, Huibo Liu, Shanglei Liu Jan 2019

Fuzzy Sliding Backstepping Mode Control For Flight Simulator Servo Based On Friction And Disturbance Compensation, Huibo Liu, Shanglei Liu

Journal of System Simulation

Abstract: Considering friction, modeling errors and other uncertainties of flight simulator servo system, a compensation strategy which combines model-based friction compensation with nonlinear disturbance observer compensation was proposed. First, the friction is modeled , whose parameters are identified by using genetic algorithm, and using the identified model to compensate. Second, using a nonlinear disturbance observer to estimate the modeling errors, friction less-compensation or over-compensation and other uncertainties, and using this observed value to compensate. The system adopted sliding backstepping controller to ensure the stabilization of the system. Finally, the fuzzy algorithm is adopted to adjust the switching gain of sliding …


Preliminary Study Of Modeling And Simulation Technology Oriented To Neo-Type Artificial Intelligent Systems, Libo Hu, Xudong Chai, Zhang Lin, Li Tan, Duzheng Qing, Tingyu Lin, Liu Yang Jan 2019

Preliminary Study Of Modeling And Simulation Technology Oriented To Neo-Type Artificial Intelligent Systems, Libo Hu, Xudong Chai, Zhang Lin, Li Tan, Duzheng Qing, Tingyu Lin, Liu Yang

Journal of System Simulation

Abstract: A brief interpretation of the rapidly developing “New Internet+ Big Data+ Artificial Intelligence+” era is given in the paperand the essence and the architectureof neo-type artificial intelligence systems are explained. The meaning of neo-type artificial intelligence system oriented modelling and simulation technology is proposed and the new challenges they are facing are discussed. The research contents and preliminaryresults on neo-type artificial intelligence system oriented modelling and simulation technology are given, which includeneo-type artificial intelligence system oriented modelling/secondary modelling, intelligent simulation computer, smart cloud simulation and intelligent simulation hardware/software supporting system technology, and intelligent simulation system application engineering technology. Several …


Android Application For Mnist Handwritten Digits Classification, Mina Gabriel Jan 2019

Android Application For Mnist Handwritten Digits Classification, Mina Gabriel

Project Topics and Ideas

Use Neural Network architecture to classify MNIST handwritten digits dataset, student/s should implement a phone application (Android) to demonstrate their work, application will then be published to the app store for other students and CISC faculty members for evaluation and feedback.


Transdimensional Transformation Based Markov Chain Monte Carlo, Moumita Das, Sourabh Bhattacharya Jan 2019

Transdimensional Transformation Based Markov Chain Monte Carlo, Moumita Das, Sourabh Bhattacharya

Journal Articles

Variable dimensional problems, where not only the parameters, but also the number of parameters are random variables, pose serious challenge to Bayesians. Although in principle the Reversible Jump Markov Chain Monte Carlo (RJMCMC) methodology is a response to such challenges, the dimension-hopping strategies need not be always convenient for practical implementation, particularly because efficient “move-types” having reasonable acceptance rates are often difficult to devise. In this article, we propose and develop a novel and general dimension-hopping MCMC methodology that can update all the parameters as well as the number of parameters simultaneously using simple deterministic transformations of some low-dimensional (often …


Classification Of Stars From Redshifted Stellar Spectra Utilizing Machine Learning, Michael J. Brice Jan 2019

Classification Of Stars From Redshifted Stellar Spectra Utilizing Machine Learning, Michael J. Brice

All Master's Theses

The classification of stellar spectra is a fundamental task in stellar astrophysics. There have been many explorations into the automated classification of stellar spectra but few that involve the Sloan Digital Sky Survey (SDSS). Stellar spectra from the SDSS are applied to standard classification methods such as K-Nearest Neighbors, Random Forest, and Support Vector Machine to automatically classify the spectra. Stellar spectra are high dimensional data and the dimensionality is reduced using standard Feature Selection methods such as Chi-Squared and Fisher score and with domain-specific astronomical knowledge because classifiers work in low dimensional space. These methods are utilized to classify …


Snap Scholar: The User Experience Of Engaging With Academic Research Through A Tappable Stories Medium, Ieva Burk Jan 2019

Snap Scholar: The User Experience Of Engaging With Academic Research Through A Tappable Stories Medium, Ieva Burk

CMC Senior Theses

With the shift to learn and consume information through our mobile devices, most academic research is still only presented in long-form text. The Stanford Scholar Initiative has explored the segment of content creation and consumption of academic research through video. However, there has been another popular shift in presenting information from various social media platforms and media outlets in the past few years. Snapchat and Instagram have introduced the concept of tappable “Stories” that have gained popularity in the realm of content consumption.

To accelerate the growth of the creation of these research talks, I propose an alternative to video: …


Distributed Multi-Label Learning On Apache Spark, Jorge Gonzalez Lopez Jan 2019

Distributed Multi-Label Learning On Apache Spark, Jorge Gonzalez Lopez

Theses and Dissertations

This thesis proposes a series of multi-label learning algorithms for classification and feature selection implemented on the Apache Spark distributed computing model. Five approaches for determining the optimal architecture to speed up multi-label learning methods are presented. These approaches range from local parallelization using threads to distributed computing using independent or shared memory spaces. It is shown that the optimal approach performs hundreds of times faster than the baseline method. Three distributed multi-label k nearest neighbors methods built on top of the Spark architecture are proposed: an exact iterative method that computes pair-wise distances, an approximate tree-based method that indexes …


Automatic Slide Generation For Scientific Papers, Athar Sefid, Jian Wu, Prasenjit Mitra, C. Lee Giles Jan 2019

Automatic Slide Generation For Scientific Papers, Athar Sefid, Jian Wu, Prasenjit Mitra, C. Lee Giles

Computer Science Faculty Publications

We describe our approach for automatically generating presentation slides for scientific papers using deep neural networks. Such slides can help authors have a starting point for their slide generation process. Extractive summarization techniques are applied to rank and select important sentences from the original document. Previous work identified important sentences based only on a limited number of features that were extracted from the position and structure of sentences in the paper. Our method extends previous work by (1) extracting a more comprehensive list of surface features, (2) considering semantic or meaning of the sentence, and (3) using context around the …


The D&D Sorting Hat: Predicting Dungeons And Dragons Characters From Textual Backstories, Joseph C. Macinnes Jan 2019

The D&D Sorting Hat: Predicting Dungeons And Dragons Characters From Textual Backstories, Joseph C. Macinnes

Senior Independent Study Theses

Dungeons and Dragons is a tabletop roleplaying game which focuses heavily on character interaction and creating narratives. The current state of the game's character creation process often bogs down new players in decisions related to game mechanics, not a character's identity and personality. This independent study investigates the use of machine learning and natural language processing to make these decisions for a player based on their character's backstory - the textual biography or description of a character. The study presents a collection of existing characters and uses these examples to create a family of models capable of predicting a character's …


Template-Based Math Word Problem Solvers With Recursive Neural Networks, Lei Wang, Dongxiang Zhang, Jipeng Zhang, Xing Xu, Lianli Gao, Bing Tian Dai, Heng Tao Shen Jan 2019

Template-Based Math Word Problem Solvers With Recursive Neural Networks, Lei Wang, Dongxiang Zhang, Jipeng Zhang, Xing Xu, Lianli Gao, Bing Tian Dai, Heng Tao Shen

Research Collection School Of Computing and Information Systems

The design of automatic solvers to arithmetic math word problems has attracted considerable attention in recent years and a large number of datasets and methods have been published. Among them, Math23K is the largest data corpus that is very helpful to evaluate the generality and robustness of a proposed solution. The best performer in Math23K is a seq2seq model based on LSTM to generate the math expression. However, the model suffers from performance degradation in large space of target expressions. In this paper, we propose a template-based solution based on recursive neural network for math expression construction. More specifically, we …


Feasible Form Parameter Design Of Complex Ship Hull Form Geometry, Thomas L. Mcculloch Dec 2018

Feasible Form Parameter Design Of Complex Ship Hull Form Geometry, Thomas L. Mcculloch

LSU New Orleans Theses and Dissertations

This thesis introduces a new methodology for robust form parameter design of complex hull form geometry via constraint programming, automatic differentiation, interval arithmetic, and truncated hierarchical B- splines. To date, there has been no clearly stated methodology for assuring consistency of general (equality and inequality) constraints across an entire geometric form parameter ship hull design space. In contrast, the method to be given here can be used to produce guaranteed narrowing of the design space, such that infeasible portions are eliminated. Furthermore, we can guarantee that any set of form parameters generated by our method will be self consistent. It …


Automatic Identification Of Animals In The Wild: A Comparative Study Between C-Capsule Networks And Deep Convolutional Neural Networks., Joel Kamdem Teto, Ying Xie Nov 2018

Automatic Identification Of Animals In The Wild: A Comparative Study Between C-Capsule Networks And Deep Convolutional Neural Networks., Joel Kamdem Teto, Ying Xie

Master of Science in Computer Science Theses

The evolution of machine learning and computer vision in technology has driven a lot of

improvements and innovation into several domains. We see it being applied for credit decisions, insurance quotes, malware detection, fraud detection, email composition, and any other area having enough information to allow the machine to learn patterns. Over the years the number of sensors, cameras, and cognitive pieces of equipment placed in the wilderness has been growing exponentially. However, the resources (human) to leverage these data into something meaningful are not improving at the same rate. For instance, a team of scientist volunteers took 8.4 years, …


Multi-Resolution Analysis Of Large Molecular Structures And Interactions, Kasra Manavi Nov 2018

Multi-Resolution Analysis Of Large Molecular Structures And Interactions, Kasra Manavi

Computer Science ETDs

Simulation of large molecular structures and their interactions has become a major component of modern biomolecular research. Methods to simulate these type of molecules span a wide array of resolutions, from all atom molecular dynamics to model interaction energetics to systems of linear equations to evaluate population kinetics. In recent years, there has been an acceleration of molecular structural information production, primarily from x-ray crystallography and electron microscopy. This data has provided modelers the ability to produce better representations of these molecular structures. The purpose of this research is to take advantage of this information to develop multi-resolution models for …


A Multi-Task Approach To Incremental Dialogue State Tracking, Anh Duong Trinh, Robert J. Ross, John D. Kelleher Nov 2018

A Multi-Task Approach To Incremental Dialogue State Tracking, Anh Duong Trinh, Robert J. Ross, John D. Kelleher

Conference papers

Incrementality is a fundamental feature of language in real world use. To this point, however, the vast majority of work in automated dialogue processing has focused on language as turn based. In this paper we explore the challenge of incremental dialogue state tracking through the development and analysis of a multi-task approach to incremental dialogue state tracking. We present the design of our incremental dialogue state tracker in detail and provide evaluation against the well known Dialogue State Tracking Challenge 2 (DSTC2) dataset. In addition to a standard evaluation of the tracker, we also provide an analysis of the Incrementality …


Enhancing 3d Visual Odometry With Single-Camera Stereo Omnidirectional Systems, Carlos A. Jaramillo Sep 2018

Enhancing 3d Visual Odometry With Single-Camera Stereo Omnidirectional Systems, Carlos A. Jaramillo

Dissertations, Theses, and Capstone Projects

We explore low-cost solutions for efficiently improving the 3D pose estimation problem of a single camera moving in an unfamiliar environment. The visual odometry (VO) task -- as it is called when using computer vision to estimate egomotion -- is of particular interest to mobile robots as well as humans with visual impairments. The payload capacity of small robots like micro-aerial vehicles (drones) requires the use of portable perception equipment, which is constrained by size, weight, energy consumption, and processing power. Using a single camera as the passive sensor for the VO task satisfies these requirements, and it motivates the …


Investigating Dataset Distinctiveness, Andrew Ulmer, Kent W. Gauen, Yung-Hsiang Lu, Zohar R. Kapach, Daniel P. Merrick Aug 2018

Investigating Dataset Distinctiveness, Andrew Ulmer, Kent W. Gauen, Yung-Hsiang Lu, Zohar R. Kapach, Daniel P. Merrick

The Summer Undergraduate Research Fellowship (SURF) Symposium

Just as a human might struggle to interpret another human’s handwriting, a computer vision program might fail when asked to perform one task in two different domains. To be more specific, visualize a self-driving car as a human driver who had only ever driven on clear, sunny days, during daylight hours. This driver – the self-driving car – would inevitably face a significant challenge when asked to drive when it is violently raining or foggy during the night, putting the safety of its passengers in danger. An extensive understanding of the data we use to teach computer vision models – …


Online Spatio-Temporal Matching In Stochastic And Dynamic Domains, Meghna Lowalekar, Pradeep Varakantham, Patrick Jaillet Aug 2018

Online Spatio-Temporal Matching In Stochastic And Dynamic Domains, Meghna Lowalekar, Pradeep Varakantham, Patrick Jaillet

Research Collection School Of Computing and Information Systems

Online spatio-temporal matching of servers/services to customers is a problem that arises at a large scale in many domains associated with shared transportation (e.g., taxis, ride sharing, super shuttles, etc.) and delivery services (e.g., food, equipment, clothing, home fuel, etc.). A key characteristic of these problems is that the matching of servers/services to customers in one stage has a direct impact on the matching in the next stage. For instance, it is efficient for taxis to pick up customers closer to the drop off point of the customer from the first stage of matching. Traditionally, greedy/myopic approaches have been adopted …