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Individual-Level Modelling Of Infectious Disease Data: Epiilm, Vineetha Warriyar, Waleed Almutiry, Rob Deardon 2020 University of Calgary

Individual-Level Modelling Of Infectious Disease Data: Epiilm, Vineetha Warriyar, Waleed Almutiry, Rob Deardon

The R Journal

In this article we introduce the R package EpiILM, which provides tools for simulation from, and inference for, discrete-time individual-level models of infectious disease transmission proposed by Deardon et al. (2010). The inference is set in a Bayesian framework and is carried out via Metropolis Hastings Markov chain Monte Carlo (MCMC). For its fast implementation, key functions are coded in Fortran. Both spatial and contact network models are implemented in the package and can be set in either susceptible-infected (SI) or susceptible-infected-removed (SIR) compartmental frameworks. Use of the package is demonstrated through examples involving both simulated and real data.


Conference Report: Why R? 2019, Michał Burdukiewicz, Filip Pietluch, Jarosław Chilimoniuk, Katarzyna Sidorczuk, Dominik Rafacz, Leon Eyrich Jessen, Stefan Rödiger, Marcin Kosiński, Piotr Wójcik 2020 Warsaw University of Technology

Conference Report: Why R? 2019, Michał Burdukiewicz, Filip Pietluch, Jarosław Chilimoniuk, Katarzyna Sidorczuk, Dominik Rafacz, Leon Eyrich Jessen, Stefan Rödiger, Marcin Kosiński, Piotr Wójcik

The R Journal

WhyR?conferences have been the hallmark of the Why R? Foundation (whyr.pl). Our goal has been to establish a series of international R-related events in Poland. After three years, weare happy to announce that our main event, the Why R? conference, has become one of the largest annual R conferences in Central Europe.


Difnlr: Generalized Logistic Regression Models For Dif And Ddf Detection, Adéla Hladká, Patrícia Martinková 2020 Institute of Computer Science of the Czech Academy of Sciences, Charles University

Difnlr: Generalized Logistic Regression Models For Dif And Ddf Detection, Adéla Hladká, Patrícia Martinková

The R Journal

Differential item functioning (DIF) and differential distractor functioning (DDF) are impor tant topics in psychometrics, pointing to potential unfairness in items with respect to minorities or different social groups. Various methods have been proposed to detect these issues. The difNLR R package extends DIF methods currently provided in other packages by offering approaches based on generalized logistic regression models that account for possible guessing or inattention, and by pro viding methods to detect DIF and DDF among ordinal and nominal data. In the current paper, we describe implementation of the main functions of the difNLR package, from data generation, through …


Survboost: An R Package For High-Dimensional Variable Selection In The Stratified Proportional Hazards Model Via Gradient Boosting, Emily Morris, Kevin He, Yanming Li, Yi Li, Jian Kang 2020 University of Michigan

Survboost: An R Package For High-Dimensional Variable Selection In The Stratified Proportional Hazards Model Via Gradient Boosting, Emily Morris, Kevin He, Yanming Li, Yi Li, Jian Kang

The R Journal

High-dimensional variable selection in the proportional hazards (PH) model has many successful applications in different areas. In practice, data may involve confounding variables that do not satisfy the PH assumption, in which case the stratified proportional hazards (SPH) model can be adopted to control the confounding effects by stratification without directly modeling the confounding effects. However, there is a lack of computationally efficient statistical software for high-dimensional variable selection in the SPH model. In this work an R package, SurvBoost, is developed to implement the gradient boosting algorithm for fitting the SPH model with high-dimensional covariate variables. Simulation studies …


Copulacenr: Copula Based Regression Models For Bivariate Censored Data In R, Tao Sun, Ying Ding 2020 Renmin University of China, University of Pittsburgh

Copulacenr: Copula Based Regression Models For Bivariate Censored Data In R, Tao Sun, Ying Ding

The R Journal

Bivariate time-to-event data frequently arise in research areas such as clinical trials and epidemiological studies, where the occurrence of two events are correlated. In many cases, the exact event times are unknown due to censoring. The copula model is a popular approach for modeling correlated bivariate censored data, in which the two marginal distributions and the between margin dependence are modeled separately. This article presents the R package CopulaCenR, which is designed for modeling and testing bivariate data under right or (general) interval censoring in a regression setting. It provides a variety of Archimedean copula functions including a flexible two-parameter …


Sortedeffects: Sorted Causal Effects In R, Schuowen Chen, Victor Chernozhukov, Iván Fernández-Val, Ye Luo 2020 Boston University

Sortedeffects: Sorted Causal Effects In R, Schuowen Chen, Victor Chernozhukov, Iván Fernández-Val, Ye Luo

The R Journal

Chernozhukov et al. (2018) proposed the sorted effect method for nonlinear regression models. This method consists of reporting percentiles of the partial effects, the sorted effects, in addition to the average effect commonly used to summarize the heterogeneity in the partial effects. They also propose to use the sorted effects to carry out classification analysis where the observational units are classified as most and least affected if their partial effect are above or below some tail sorted effects. The R package SortedEffects implements the estimation and inference methods therein and provides tools to visualize the results. This vignette serves as …


Simulation Analysis On Ballistic Deflection Of Projectile Obliquely Penetrating Into Concrete, Jianfeng Xue, Peihui Shen, Xiaoming Wang 2020 ZNDY Ministerial Key Laboratory, Nanjing University of Science and Technology, Nanjing 210094, China;

Simulation Analysis On Ballistic Deflection Of Projectile Obliquely Penetrating Into Concrete, Jianfeng Xue, Peihui Shen, Xiaoming Wang

Journal of System Simulation

Abstract: In order to study the trajectory deflection law of projectiles obliquely penetrating into concrete targets, based on the theory of rigid body kinematics and cavity expansion, the penetration motion differential equations of ogive-nosed projectile were established. The variation rules of trajectory offset and invasion depth were given in different initial conditions through the programming calculation and numerical simulation by MATALB and ANSYS-LYNA software. The calculation results agree well with experimental data. The results show that the influence of penetration depth and deflection angle increase with the oblique angle increasing. The influence of ballistic deflection decreases with the …


Multi-Rate Simulation Based On Explicit-Implicit Hybrid Integration, Bingda Zhang, Chen Ming, Wang Xiao, Lanyu Wang 2020 Key Laboratory of Smart Grid of Ministry of Education, Tianjin University, Tianjin 300072, China;

Multi-Rate Simulation Based On Explicit-Implicit Hybrid Integration, Bingda Zhang, Chen Ming, Wang Xiao, Lanyu Wang

Journal of System Simulation

Abstract: A multi-rate simulation method based on explicit-implicit hybrid integration algorithm for the grid-connected photovoltaic system which included power electronic devices with a variety of switching frequency was put forward. Inductances and capacitances were used to divide the grid-connected photovoltaic system into subsystems. A multi-rate interface was put forward to satisfy the request of real time. The stability criterion of the multi-rate simulation algorithm was put forward. FPGA was used as a platform to build the digital grid-connected photovoltaic system. The hardware in loop test for DC/DC and DC/AC converter controllers was conducted on this platform to verify the accuracy …


Reachable Set Modeling Approach For Autonomous Vehicle's Dynamic Conflict Control, Cao Kai, Xiufang Liu, Yang Xu, Shen Peng 2020 School of Traffic & Vehicle Engineering, Shandong University of Technology, Zibo 255049, China;

Reachable Set Modeling Approach For Autonomous Vehicle's Dynamic Conflict Control, Cao Kai, Xiufang Liu, Yang Xu, Shen Peng

Journal of System Simulation

Abstract: Aiming at the problem of active safety control modeling for autonomous vehicles, a combined method using the formal modeling and the dynamic non-cooperative game theory was proposed for discussing a control strategy of trajectory tracking and collision avoidance under dynamic conflict condition between autonomous vehicles. And it was proposed to divide the system control into three modes: trajectory tracking, collision avoidance and switching between trajectory tracking and collision avoidance. Taking into account the complexity as a hybrid systems and the existence of the trajectory tracking error for autonomous vehicle, a modeling approach based on reachable set was proposed for …


Weighted Online Estimation Of Soc Based On Adaptive Battery Model, Haohao Sun, Tinglong Pan, Dinghui Wu 2020 Engineering Research Center of Internet of Things Technology Applications Ministry of Education, Jiangnan University, Wuxi 214122, China;

Weighted Online Estimation Of Soc Based On Adaptive Battery Model, Haohao Sun, Tinglong Pan, Dinghui Wu

Journal of System Simulation

Abstract: Aiming at the problem that the traditional lithium battery model has poor adaptive ability in SOC estimation and the local estimation accuracy of the single SOC estimation algorithm is low, online identification of model parameters with Multi-Innovation Stochastic Gradient algorithm and method of weighted online estimation of SOC was proposed. The results of lithium-ion battery model parameters online identification updated in real time, realizing lithium-ion battery model adaptive. Aiming at the estimation of SOC, a method of weighted online estimation method based on the PI (proportion and integral) regulator's OCV combined with Ah (an integral method) was proposed. Weights …


Multi-Variable Modeling Research For Main-Steam Temperature Of Power Station Boiler Based On Improved Differential Evolution Algorithm, Li Qin, Zhang Hao, Daogang Peng, Yibo Guo, Nianlong Wang, Yuzhen Sun 2020 1. College of Electronics and Information Engineering, Tongji University, Shanghai 201804, China;;2. College of Automation Engineering, Shanghai University of Electric Power Shanghai Key Laboratory of Power Station Automation Technology, Shanghai 200090, China;;

Multi-Variable Modeling Research For Main-Steam Temperature Of Power Station Boiler Based On Improved Differential Evolution Algorithm, Li Qin, Zhang Hao, Daogang Peng, Yibo Guo, Nianlong Wang, Yuzhen Sun

Journal of System Simulation

Abstract: By analyzing the factors which affected the main-steam temperature, a multi-variable model was introduced to overcome the bad result of single variable cascade control. An improved differential evolution algorithm was proposed including mutation strategies random selection, crossover ratio and mutation ratio adaptive adjustment, which was used for closed-loop identification of main-steam multi-variable transfer function model. The principle and method how to obtain valid identification data from power plant distributed control system history database was introduced, and the data from some 1 000 MW coal-fired power plant was used to identify and verify the main-steam temperature multi-variable model, …


Study On Visual Function Of Human Computer Interaction In Parachuting Simulator, Han Liang, Gong Xuan, Jiangyun Wang, Yanghua Du 2020 1. School of Automation Science and Electrical Engineering, Beihang University, Beijing 100191, China;;

Study On Visual Function Of Human Computer Interaction In Parachuting Simulator, Han Liang, Gong Xuan, Jiangyun Wang, Yanghua Du

Journal of System Simulation

Abstract: The parachuting training system consists of software and hardware, to simulate the parachute training through head mounted display and operating equipment, combined with system modeling, kinematic computation, visual display and expert evaluation. Principle methods of head mounted display with human-computer interactive function and exploitation of Vega Prime inventive exploration on the information collection of viewpoint are conducted. It provides a real time training environment through the configuration of environmental effects, scene control, collision detection and driving information.


Stability Of Electrically Conducting Fluid Flow In Channel Under Magnetic Field, Dong Shuai, Lishuai Liu, Xuemin Ye 2020 School of Energy Power and Mechanical Engineering, North China Electric Power University, Baoding 071003, China;

Stability Of Electrically Conducting Fluid Flow In Channel Under Magnetic Field, Dong Shuai, Lishuai Liu, Xuemin Ye

Journal of System Simulation

Abstract: The stability of conducting fluid flow in a channel under a vertical magnetic field was simulated by non-normal modal stability analysis. The perfect conductivity assumption of the channel wall was employed in the model, and its effect on the stability problem was considered. The results show that when the Hartmann number Ha is larger than 9, the two opposite Hartmann boundary layers are essentially independent of each other; however, when the Hartmann number Ha is smaller than 9, there are still residual interactions between the two opposite Hartmann boundary layers, which has influences on the stability of the flow. …


Research On Wavelength Routing Algorithm Based On Multi-Service In Satellite Optical Networks, Qingli Liu, Junfei Yao, Zhiguo Liu 2020 1. Communication and Network Laboratory (Dalian University), Dalian 116622, China;;2. School of Information Engineering, Dalian University, Dalian 116622, China;

Research On Wavelength Routing Algorithm Based On Multi-Service In Satellite Optical Networks, Qingli Liu, Junfei Yao, Zhiguo Liu

Journal of System Simulation

Abstract: An optical wavelength routing algorithm for satellite networks based on multi-service was proposed, in order to solve the problem of low utilization rate of wavelengths, slow convergence and low efficiency of satellite optical networks. In this algorithm, it divided the area of the satellite network and updated the link in the area to improve the convergence speed of algorithm. Different services were assigned different wavelength sets to satisfy requirement of different service. According to the initial link weight, which included wavelength remain number and transmission delay, it changed link weight dynamically to achieve network load balancing and rational use …


Performance Analysis On Multiuser Untrusted Amplify-And-Forward Relay Networks, Deng Dan, Zhou Wen 2020 1. Guangzhou Panyu Polytechnic, Guangzhou 511483, China;;

Performance Analysis On Multiuser Untrusted Amplify-And-Forward Relay Networks, Deng Dan, Zhou Wen

Journal of System Simulation

Abstract: The effect of the untrusted relaying node was investigated on the secrecy outage probability (SOP) of amplify-and-forward (AF) relay networks in the presence of direct links and multiple users. In the considered system, the best user was selected according a certain criterion. It transmitted signals to the destination node with the aid of the untrusted relaying node. To reduce the useful information leakage, three selection criteria were proposed based on the channel state information of the direct and/or relaying link. The closed-form analytical SOP and the corresponding asymptotic expressions were derived. Computer simulation was conducted to validate the theoretical …


Forecasting Of Short-Term Power Load Of Secrpso-Svm Based On Data-Driven, Hairong Sun, Bixia Xie, Tian Yao, Zhuoqun Li 2020 1. School of Control and Computer Engineering, North China Electric Power University, Baoding 071003, China;;

Forecasting Of Short-Term Power Load Of Secrpso-Svm Based On Data-Driven, Hairong Sun, Bixia Xie, Tian Yao, Zhuoqun Li

Journal of System Simulation

Abstract: For the parameter selection of support vector machine in modeling, a particle swarm optimization algorithm based on second-order oscillation and repulsion factor was proposed to optimize the parameter of SVM. The algorithm employed the nonlinear decreasing weight to balance the global and local search ability. Second-order oscillation factor could maintain the population diversity. The repulsion factor was introduced to make the swarm even distribution in search space, which could avoid local optimum. For the complex characteristics of nonlinearity, time-varying and multifactorial of electric power load, a support vector machine forecasting model based on data was proposed, and the influence …


Modeling And Simulation Of Mooring Force Prediction Based On Improved Ga-Bp Network, Shifeng Li, Zhanzhi Qiu 2020 1. Mechanical Engineering Inst, Dalian Jiaotong University, Dalian 116028, China;;

Modeling And Simulation Of Mooring Force Prediction Based On Improved Ga-Bp Network, Shifeng Li, Zhanzhi Qiu

Journal of System Simulation

Abstract: According to the mooring security and early warning control requirement of the large open sea terminal, a ship mooring force prediction model based on genetic algorithm and BP network was studied. Environmental dynamic factors were considered and a model structure was determined by a weight statistics method; the learning method was improved by individual parent information and contemporary individual local gradient information; according to the improved model, a ship mooring force prediction method of the open sea terminal was proposed. The simulation results show that the performance of the prediction model has improved in the iteration number, …


Intensity Analysis And Fatigue Life Simulation For Connecting Bolt Of Shearer Machine Body, Zhiyong Hao, Yaolong Lei, Mao Jun, Yuan Zhi 2020 1. Mechanical Engineering College of Liaoning Technical University, Fuxin 123000, China;;

Intensity Analysis And Fatigue Life Simulation For Connecting Bolt Of Shearer Machine Body, Zhiyong Hao, Yaolong Lei, Mao Jun, Yuan Zhi

Journal of System Simulation

Abstract: To obtain the cutting load spectrum of themachine body connecting bolt, the method of merging unknown quantities and multi calculation combined with the test experiments of shear mechanical properties was used to solve the overdetermined equations of shearer left haulage unit spatial mechanical model The cutting load spectrum of the machine body connecting bolt was taken to run PSD analysis, and the rainflow counting method was used to script the load spectrum. The frequency domain characteristics and time domain continuation characteristics were therefore obtained. The static analysis and fatigue life simulation analysis combined with the bolt load …


Application Of Weighted Dynamic Svdd In Nonlinear Process Monitoring, Yanhong Xie, Chengao Sun, Li Yuan 2020 1. Department of Science Shenyang University of Chemical Technology, Shenyang 110142, China;;

Application Of Weighted Dynamic Svdd In Nonlinear Process Monitoring, Yanhong Xie, Chengao Sun, Li Yuan

Journal of System Simulation

Abstract: Due to the complexity of the chemical process, the data are often characterized by dynamics and correlation between sequences. Traditional support vector data description (SVDD) methods are difficult to guarantee real-time monitoring online. A Weighted-Dynamic-SVDD (WDSVDD) method was proposed to monitor fault in real time online. The dynamic method was introduced, and the correlation between the data was considered. The weighted information was used to highlight the useful information. The model was established by using SVDD method, and the online real-time fault monitoring was realized. The method not only overcomes the adverse effect of non-Gaussian and nonlinearity, but …


Research On One-Cycle Controlled Bi-Directional Dc-Dc Converter Based On Switch Capacitor Network, Chen Lei, Tinglong Pan, Yanxia Shen, Dinghui Wu, Zhicheng Ji 2020 Institute of Electrical Automation, College of Internet of Things Engineering, Jiangnan University, Wuxi 214122, China;

Research On One-Cycle Controlled Bi-Directional Dc-Dc Converter Based On Switch Capacitor Network, Chen Lei, Tinglong Pan, Yanxia Shen, Dinghui Wu, Zhicheng Ji

Journal of System Simulation

Abstract: According to the switch capacitor network working characteristics of discharging in series, charging in parallel, a high ratio bidirectional DC-DC converter based on switch capacitor network was proposed. In order to improve the converter's ability of resist input voltage disturbance and dynamic response speed, an improved method was focused on which combined the advantage of one-cycle control and the output voltage feedback compensation control, which could realize inhibition the input voltage perturbation in one cycle and improve the converter's resistance ability of load disturbance. The operating principle and control characteristics of the new converter were analyzed. The improved one-cycle …


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