Biclustermd: An R Package For Biclustering With Missing Values,
2019
Iowa State University
Biclustermd: An R Package For Biclustering With Missing Values, John Reisner, Hieu Pham, Sigurdur Olafsson, Stephen Vardeman, Jing Li
The R Journal
Biclustering is a statistical learning technique that attempts to find homogeneous partitions of rows and columns of a data matrix. For example, movie ratings might be biclustered to group both raters and movies. biclust is a current R package allowing users to implement a variety of biclustering algorithms. However, its algorithms do not allow the data matrix to have missing values. We provide a new R package, biclustermd, which allows users to perform biclustering on numeric data even in the presence of missing values.
Modeling Regimes With Extremes: The Bayesdfa Package For Identifying And Forecasting Common Trends And Anomalies In Multivariate Time-Series Data,
2019
National Oceanic and Atmospheric Administration
Modeling Regimes With Extremes: The Bayesdfa Package For Identifying And Forecasting Common Trends And Anomalies In Multivariate Time-Series Data, Eric J. Ward, Sean C. Anderson, Luis A. Damiano, Mary E. Hunsicker, Michael A. Litzow
The R Journal
The bayesdfa package provides a flexible Bayesian modeling framework for applying dynamic factor analysis (DFA) to multivariate time-series data as a dimension reduction tool. The core estimation is done with the Stan probabilistic programming language. In addition to being one of the few Bayesian implementations of DFA, novel features of this model include (1) optionally modeling latent process deviations as drawn from a Student-t distribution to better model extremes, and (2) optionally including autoregressive and moving-average components in the latent trends. Besides estimation, we provide a series of plotting functions to visualize trends, loadings, and model predicted values. A secondary …
Coxed: An R Package For Computing Duration-Based Quantities From The Cox Proportional Hazards Model,
2019
University of Virginia
Coxed: An R Package For Computing Duration-Based Quantities From The Cox Proportional Hazards Model, Jonathan Kropko, Jeffrey J. Harden
The R Journal
The Cox proportional hazards model is one of the most frequently used estimators in duration (survival) analysis. Because it is estimated using only the observed durations’ rank ordering, typical quantities of interest used to communicate results of the Cox model come from the hazard function (e.g., hazard ratios or percentage changes in the hazard rate). These quantities are substantively vague and difficult for many audiences of research to understand. We introduce a suite of methods in the R package coxed to address these problems. The package allows researchers to calculate duration-based quantities from Cox model results, such as the expected …
Sentiment Analysis, Quantification, And Shift Detection,
2019
University of Arkansas, Fayetteville
Sentiment Analysis, Quantification, And Shift Detection, Kevin Labille
Graduate Theses and Dissertations
This dissertation focuses on event detection within streams of Tweets based on sentiment quantification. Sentiment quantification extends sentiment analysis, the analysis of the sentiment of individual documents, to analyze the sentiment of an aggregated collection of documents. Although the former has been widely researched, the latter has drawn less attention but offers greater potential to enhance current business intelligence systems. Indeed, knowing the proportion of positive and negative Tweets is much more valuable than knowing which individual Tweets are positive or negative. We also extend our sentiment quantification research to analyze the evolution of sentiment over time to automatically detect …
Contrasting Geometric Variations Of Mathematical Models Of Self-Assembling Systems,
2019
University of Arkansas, Fayetteville
Contrasting Geometric Variations Of Mathematical Models Of Self-Assembling Systems, Michael Sharp
Graduate Theses and Dissertations
Self-assembly is the process by which complex systems are formed and behave due to the interactions of relatively simple units. In this thesis, we explore multiple augmentations of well known models of self-assembly to gain a better understanding of the roles that geometry and space play in their dynamics. We begin in the abstract Tile Assembly Model (aTAM) with some examples and a brief survey of previous results to provide a foundation. We then introduce the Geometric Thermodynamic Binding Network model, a model that focuses on the thermodynamic stability of its systems while utilizing geometrically rigid components (dissimilar to other …
Tracking Political Events In Social Media: A Case Study Of Hong Kong Protests,
2019
Singapore Management University
Tracking Political Events In Social Media: A Case Study Of Hong Kong Protests, Haodi Qi, Hanyu Jiang, Wende Bu, Chengzi Zhang, Kyong Jin Shim
Research Collection School Of Computing and Information Systems
In this study, we analyze social conversations about Hong Kong Protests, a series of events that were widely seen and debated in social media in 2019. Our system collects data from Twitter and Reddit using their APIs. It performs sentiment analysis, and the analysis results show changes in public sentiment around major events. Social network analysis reveals influencers - users that are in the center of social conversations. Our interactive Tableau dashboard allows the user to easily monitor live social conversations about Hong Kong protests.
Punctuation Prediction For Vietnamese Texts Using Conditional Random Fields,
2019
Singapore Management University
Punctuation Prediction For Vietnamese Texts Using Conditional Random Fields, Hong Quang Pham, Binh T. Nguyen, Nguyen Viet Cuong
Research Collection School Of Computing and Information Systems
We investigate the punctuation prediction for the Vietnamese language. This problem is crucial as it can be used to add suitable punctuation marks to machine-transcribed speeches, which usually do not have such information. Similar to previous works for English and Chinese languages, we formulate this task as a sequence labeling problem. After that, we apply the conditional random field model for solving the problem and propose a set of appropriate features that are useful for prediction. Moreover, we build two corpora from Vietnamese online news and movie subtitles and perform extensive experiments on these data. Finally, we ask four volunteers …
Robust And Self-Synchronous Steganography For Voice-Over-Ip Based On Ldpc Codes,
2019
PLA Information and Technology University, Zhengzhou 450001, China;
Robust And Self-Synchronous Steganography For Voice-Over-Ip Based On Ldpc Codes, Zhanzhan Gao, Guangming Tang, Haitao Song
Journal of System Simulation
Abstract: VoIP (Voice over IP) is a kind of voice communication technology based on UDP/IP protocols, so packet loss will inevitably happen when the channel environment deteriorates. Besides that, stego VoIP data flows are real-time and have no head or tail, which pose more challenges to accurately extract the secret messages. This paper proposes a robust and self-synchronous VoIP steganography method, which solves the above two problems under the premise of maintaining good imperceptibility. In this method, low density parity check (LDPC) codes are introduced to preprocess the secret data, and the encoded data are embedded into voice …
No-Collision Curling Trajectory Simulation System,
2019
1. Shenyang Sport University, Shenyang 110102, China;;3. School of Computer Science, Beijing University of Posts and Telecommunications, Beijing 100876, China;
No-Collision Curling Trajectory Simulation System, Tian Yu, Xu Ming
Journal of System Simulation
Abstract: In just a few decades, China’s curling accomplished splendid work. But it’s scientific research falling behind a lot. Applying computer simulation technology in sports training can effectively help the athletes to understand the problems that exist in the training. When curling stone slides on the ice, it can be regarded as two-dimensional motion of rigid body, which can be decomposed into two parts: translation of the center of mass and rotation of a fixed axis around the center of mass. Using computer simulation technology to simulate the curling trajectory, and with the help of this system, the athletes can …
Locally Weighted Learning Control For Dynamic Restricted Manipulators,
2019
1. School of Electrical and Information Engineering, Jiangsu University, Zhenjiang 212013, China; ;
Locally Weighted Learning Control For Dynamic Restricted Manipulators, Wang Gang, Tairen Sun, Shengpei Ding
Journal of System Simulation
Abstract: This paper proposes a locally weighted learning control law for a manipulator with state and input constraints and modeling uncertainties. By visualizing the control input as an extended state, the control problem is converted into control design for a state-constraint uncertain nonlinear system. Barrier Lyapunov functions are introduced into a backstepping procedure and a locally weighted learning control is designed, which ensures the exponential convergence of the barrier functions to a small neighborhood of zero and then guarantees satisfaction of system constraints and the tracking error convergence. The control feasibility and effectiveness is validated by theoretical analysis and …
Simulation Analysis Of Vehicle Electromagnetic Environment Under Excitation Of Vhf Antenna,
2019
College of Communication Engineering, Jilin University, Changchun 130022, China;
Simulation Analysis Of Vehicle Electromagnetic Environment Under Excitation Of Vhf Antenna, Xiaoying Sun, Hanqing Wang, Jinpeng Yang, Zhao Yu
Journal of System Simulation
Abstract: Aiming at the issue of distribution regularity of field strength in vehicle cab under excitation of vehicle-borne high-power VHF antenna, a method of numerical simulation combining with extreme value theory to predict maximum field strength is proposed, which minimizes sample collecting difficulty and fitting deviation. CST simulation software is applied to get field strength sample in vehicle cab, and generalized extreme value (GEV) is used to fitting entire field strength distribution. peak over threshold (POT) model based on Generalized Pareto distribution is used to research high field strength value sample statistical characteristics. Resultsshow that under antenna excitation of 92.5 …
Ti-A* Based Multi-Robot Dynamic Planning And Coordination Method,
2019
1.School of Mechanical Engineering, Hefei University of Technology, Hefei 230009, China; ;
Ti-A* Based Multi-Robot Dynamic Planning And Coordination Method, Zhao Ping, Xinyu Lei, Bozhi Chen, Jiaoyun Yang
Journal of System Simulation
Abstract: Multiple robots path planning problem in dynamic environment is one of the significant and basic problems of cluster robot perception and coordination. The planning problem is decomposed into two modules: the path planning and the conflict coordination. By introducing time-cost function, the Time Integrated A* algorithm (TI-A*) is introduced. Variable speed is employed simultaneously to coordinate the motion and hereby to avoid the deadlock and conflict. By adjusting the timing when the coordination phase is involved, two different coordination TI-A* algorithms are presented, including the speed-changing algorithm and path-changing algorithm. The two algorithms are compared and the respective …
Integrated Simulation Optimization Of Hard Shoulder Running Combined With Speed Harmonization,
2019
1. Institute of Transportation Engineering, Tsinghua University, Beijing 100084, China;;2. Chinese National traffic management engineering and technology research center, Beijing 100084, China;;
Integrated Simulation Optimization Of Hard Shoulder Running Combined With Speed Harmonization, Ruimin Li, Ye Zhen, Bin Li
Journal of System Simulation
Abstract: We have a study on hard shoulder running (HSR) combined with speed harmonization. The breakdown events were screened out during the study period from massive detector data. The impact of hard shoulder volume on breakdown probabilities was analyzed. The nonparametric breakdown probabilities distribution model and logistic regression model were put forward based on highway mainline traffic volume, hard shoulder volume and ramp volume from the study case which was divided into three factors-basic segment, on-ramp merging segment and off-ramp diverging segment. The speed harmonization and HSR were optimized through reducing the traffic breakdown probabilities of a congested traffic network. …
Simulation Estimation On Directional Green-Wave Traffic Control In Nanning City,
2019
1. Smart-city Research Center of Hangzhou Dianzi University, Hangzhou 310012, China;;2. Department of Civil Engineering Tsinghua University, Beijing 100084, China;;
Simulation Estimation On Directional Green-Wave Traffic Control In Nanning City, Yiman Du, Hongfan Su, Chen Yu, Longfei Liu, Jianping Wu
Journal of System Simulation
Abstract: Due to the noticeable development of Nanning city, traffic congestion has become a serious problem, especially during the peak hours along the Binhu road. The development of Nanning city is restricted by the imbalance distribution of traffic flow. In order to ease the overload burden of traffic along the Binhu road during the peak hours, the current problems are analyzed and some solutions with directional green-wave traffic control are proposed. Traffic microscopic simulation software is used to estimate the improvement between before and after implementations of the solutions.
Multi-Agent Modeling And Simulation On China's Marine Energy Channel Security,
2019
College of Economics and Management, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
Multi-Agent Modeling And Simulation On China's Marine Energy Channel Security, Yongchen Guo, Shen Yang
Journal of System Simulation
Abstract: Security factors influencing China's offshore energy channel are analyzed, and the actual situation of China's oil import and transportation is described. Based on multi-agent modeling and simulation method, and starting at the micro level, the energy transport process is simulated and a multi-agent model of China's offshore energy channel (middle east lines) is built; and the simulation program on the NetLogo platform is conducted. The results show that the quantity of China’s VLCC is far from enough; the security impact of tropical cyclones is more serious than that of pirates; the increase proportion of carrier’s quantity is usually lower …
Simulation Of Gas-Liquid Mixing Flow In A Stirred Tank With Inverted Umbrella-Type Surface Aerator,
2019
Institute of Water Conservancy and Hydraulic Engineering, Xi'an University of Technology, Xi'an 710048, China;
Simulation Of Gas-Liquid Mixing Flow In A Stirred Tank With Inverted Umbrella-Type Surface Aerator, Wenli Wei, Weili Lou, Panpan Li, Yuling Liu
Journal of System Simulation
Abstract: The way of computational fluid dynamics with k-ε turbulence model as well as multiple reference frame method was used to simulate the hydraulic characteristics of gas-liquid mixing flow in a stirred tank installed with an inverted umbrella-type surface aerator. The inverted umbrella aerator consists of eight blades, and rotates at 5.23rad/s. The main purpose of this simulation is to study the distributions of air volume fraction and characteristics of mixing flow. The simulation results show that the distribution of the mixing flow is symmetrical; the change rules of the gas distribution at different positions along the axis direction are …
Parameter Matching Optimization Of Pure Electric Vehicle Based On Firefly Algorithm,
2019
1. College of Electrical and Information Engineering, Hunan University, Changsha 410082, China; ;
Parameter Matching Optimization Of Pure Electric Vehicle Based On Firefly Algorithm, Li Yan, Yigang He
Journal of System Simulation
Abstract: According to the design requirements and technical index of pure electric vehicle, the parameters of motor and battery related to power and economic performance are selected based on the computing results. Based on ADVISOR, a vehicle model of pure electric vehicle is established in MATLAB environment with the corresponding parameters validating the simulation results. On this basis, the multi-objective function is established, which includes the power performance, economic performance and cost price. This function is optimized by the firefly algorithm, which makes the dynamic parameters, the dynamic performance and economy performance of pure electric vehicle be improved significantly and …
Colored Petri Net Based Modeling On Warship Command And Control Information Flow,
2019
Department of Information Security, Wuhan 430033, China;
Colored Petri Net Based Modeling On Warship Command And Control Information Flow, Xueguang Zhou, Weidong Lü, Zhimin Yuan
Journal of System Simulation
Abstract: Aiming at the current problems of the complexity, influence of human factors, reusability and others, this paper built a warship command and control (C2) information flow model and obtained the warship C2 model with command and feedback information flow. This paper also defined standard information flow and position structure, and solved the reusing issue. The authenticity of information flow guaranteed the objectivity of this model, which met the demands of different kinds of vessels, and promoted the compactness and fitness between C2 system and warship reality on the model level.
Identification And Prediction Of Room Temperature Delay Neural Network Model For Vav Air Conditioning,
2019
Dalian University of Technology, Dalian 116024, China;
Identification And Prediction Of Room Temperature Delay Neural Network Model For Vav Air Conditioning, Xiuming Li, Jili Zhang, Tianyi Zhao, Tingting Chen
Journal of System Simulation
Abstract: Aiming at the problem of mathematical description for dynamic response characteristic of indoor temperature time-delay system, the fundamental principle of neural network model identification is introduced in regulation process of variable air volume (VAV) air conditioning system. Considering the model structure of Elman neural network, this paper presents an optimal selection algorithm for layer delay coefficient in order to determine delay time between indoor temperature and regulation parameters; and a multiple-step prediction model of indoor temperature time-delay system based on Elman neural network is built. The effectiveness of the proposed method is validated through the simulation experiment.
Design Of Adaptive Predictive Controller For Superheated Steam Temperature Control,
2019
1.Shanghai University of Electric Power Automation Engineering Academy, Shanghai 200082, China; ;
2.Shanghai Key Laboratory of Power Station Automation Technology, Shanghai 200082, China;
Design Of Adaptive Predictive Controller For Superheated Steam Temperature Control, Qian Hong, Yuqing Feng
Journal of System Simulation
Abstract: An adaptive model predictive controller for overheating steam temperature control of thermal power plants is designed, which is based on the control object with large delay, large inertia, nonlinearity and strong time-varying properties. Through the on-line identification and control of different models, compared with predictive controllers in a general model, in terms of adjusting the superheat steam temperature, the adjusting time can be shortened drastically, the overshoot can be reduced or even eliminated, and the dynamic performance is improved greatly when applying in adaptive model predictive controller. The results show that the adaptive model predictive controller, because of its …
