Numerical Analysis and Scientific Computing Commons^™

Research Of Strategy To Restrain Surplus Force Of Aircraft Rudder Electro-Hydraulic Loading System, Xiaolin Liu, Chunting Wang

Journal of System Simulation

Abstract: For the problem that is caused by surplus torque of aircraft rudder electro-hydraulic loading system is not easy to inhibit, compound controller structure function and control strategy were proposed that combined rubber-metal buffer spring, the displacement of steering gear and speed feed forward of aircraft rudder and the output force feedback use single neuron PID based on dynamic RBF neural network on-line identification. Ant clustering algorithm was used to optimize the dynamic RBF neural network to identify the object online to obtain Jacobian information, then use the single neuron PID controller complete control parameters online self-tuning control. The …

Optimization Design And Simulation Of Washout Algorithm For Flight Simulator, Wang Hui, Daoyang Zhu, Xiaojing Fu

Journal of System Simulation

Abstract: The key of the fidelity of flight simulators lies in the merits of the washout algorithm; the classical washout algorithm has been widely applied owing to its convenient parameter adjustment as well as rapid feedback and execution speed. However, the classical washout algorithm still exists some certain defects in its structure design, which will cause exaggerated phase retardation error and false cues thus resulting in the deterioration in dynamic fidelity of flight simulators. According to vestibular perception system, the structure redesign of the classical washout algorithm was carried out, using the compensation theory to reduce its phase retardation and …

Force/Position Control For Dual-Arm Space Robot Capturing Object, Qiuhuang Dong, Chen Li, Haiyun Li, Zhiyong Chen

Journal of System Simulation

Abstract: The dynamics control and simulation of dual-arm space robot capture object was studied. The dynamics model of space robot was derived by the second Lagrange equation, for the object capture process, the impact influence on space robot base and arm was calculated by momentum theory. For the space robot and object close-chain system after capturing, a force/position coordinate control algorithm was designed to control the system motion and object clamp force; the stability, reliability and safety of capture process would be ensured by the control algorithm. The simulation result based on the dynamics model and control algorithm was carried …

Research On Modeling And Control For Fuel-Steam Pressure Of Super Critical Power Unit, Junjie Gu, Zhang Yan, Jianyong Chen, Wang Peng, Wensheng Yu

Journal of System Simulation

Abstract: The main steam pressure is an important parameter which characterizes the energy supply and demand of supercritical boiler and steam turbine, which is affected largely by the mount of fuel. At present, most fuel coal of thermal power plant is complex, calorific value fluctuates, resulting in the frequent fluctuation of the main steam pressure, seriously affecting the safe operation of the unit. A fuel — main steam pressure ADRC closed loop feedback control loop was designed in the fuel control system, the spontaneous disturbance of coal-fired thermal value was estimated by ESO, which was then real time compensated in …

Study On Pulverizing System Simulation Model Of 300mw Lignite Oxygen-Enriched Combustion Boiler, Jianqiang Gao, Shaodong Sun

Journal of System Simulation

Abstract: The simulation model of the pulverizing system of a 300 MW lignite oxygen-enriched combustion boiler was developed. And the dynamic and static simulation experiments were completed, the experiments included lignite surface moisture content variation, disturbance of feeder norm speed, flue gas inlet temperature and flow rate etc. The results show that, the model is able to correctly simulate the dynamic process of the system. Moisture reduction has a larger impact on the pulverizing system operating parameters. The mill outlet temperature gets a significant rise, especially when it is less than 30%. When the feeder norm speed or flow rate …

Thermal Power Plants Main Steam Temperature System Control Based On Implicit Pigpc, Zhongda Tian, Shujiang Li, Yanhong Wang

Journal of System Simulation

Abstract: Aiming at the large inertial time-delay characteristic of main steam temperature control system on the thermal power plants, a control method based on Implicit PI-based generalized predictive controller (GPC) was proposed. The implicit PIGPC algorithm with PI structure was proposed based on implicit GPC, implicit PI-based GPC combined the advantages of PI control and implicit GPC, the feedback structure of PI and prediction function of GPC was combined. The predictive control algorithm with PI structure was obtained through a new objective function, the performance of controller was improved. At the same time, the stability of the compensation algorithm was …

Key Technology Of Fully Immersive Virtual Experience Cabin, Baojiang Du, Zha Liang, Lin Ling

Journal of System Simulation

Abstract: The structure of simulated experience cabin for fire safety education was introduced and the design and implementation methods of a virtual fire escape system for fire safety education were proposed, and specifically the specific implementation and optimization of virtual fire scenario, the conjunction method of double virtual interactive platforms and the simplification of model and the method of communication between the virtual scenes and the PLC control hardware devices were discusses. Fire safety education oriented virtual fire escape skills training system was achieved, which was applied in the teaching and experience room for fire safety training. Application results show …

Research Of Vibration Control On Nonlinear Rotor System With Fuzzy-Pid, Liu Jun, Zhenwang Liu, Jianen Chen, Liangfu Wang

Journal of System Simulation

Abstract: In order to overcome the problems which are the model of the nonlinear restoring force and the nonlinear vibration control, the vibration control of the nonlinear rotor system and the processing the nonlinear restoring force were accomplished based on the electromagnetic actuator using the FUZZY-PID controller with the fitness function of the variable width and variable geometric shapes. Using the Jeffcott rotor model with the nonlinearities of the forces of the bearing and the electromagnetic actuator, the simulations of the vibration control on the rotor system were performed. Through comparing with the control methods of the traditional PID and …

Simulation And Evaluation Of Facility Layout In Environment With Complexity For Manufacturing System, Ailin Yu, Qingxin Chen, Mao Ning

Journal of System Simulation

Abstract: To research the performance for manufacturing system of equipment with different layout of facility, a method of simulation and evaluation in the environment with complexity of manufacturing system was proposed. Three kinds of typical layout of facility were concluded and abstract by the enterprise facts. The evaluation system was established in the environment with complexity of manufacturing system. The construction method of the entropy models were described emphatically. Simulation models were developed based on the production and process model. The layouts were analyzed and evaluated by the data of the evaluation system from simulation experiments.

Optimal Design Of High Power Medium Frequency Transformer Based On Channel Lightweight Requirement, Fangcheng Lü, Yunxiang Guo, Li Peng

Journal of System Simulation

Abstract: The analytical calculation method for winding loss and core loss of high power medium frequency transformer was analyzed, and the optimal design process was established. A 300 kW medium frequency transformer for lightweight application of electric locomotive was designed optimally by the method of free parameters scanning. Through the establishment of evaluation parameters equation, the best scheme considered both the total loss and transformer weight. On this basis, the winding loss and core loss for six groups of design scheme were verified by finite element simulation in 2D eddy current field and transient field of Ansoft Maxwell respectively. Through …

Steering Dynamics Simulation Analysis Of Replaceable Triangular Track Of Skidder, Xiaowen Ge, Jiejian Hou, Lihai Wang

Journal of System Simulation

Abstract: In order to design a kind of high efficiency and low cost multifunctional skidder suitable for forest conditions of China, the replaceable triangular track was applied to skidder and the virtual prototype of triangular track skidder and road models were built based on the theoretical analysis by Solidworks and RecurDyn Software. Simulation analysis regarding the effects of pre-tension, turning angle, road conditions, loading and skidding on skidder's turning performance was made. Research results show that the pre-tension of 19.2 kN (40% of the vehicle weight) is much proper for turning. The larger turning angle is, the easier skidder turned, …

Ari: The Automated R Instructor, Sean Kross, Jeffrey T. Leek, John Muschelli

The R Journal

We present the ari package for automatically generating technology-focused educational videos. The goal of the package is to create reproducible videos, with the ability to change and update video content seamlessly. We present several examples of generating videos including using R Markdown slide decks, PowerPoint slides, or simple images as source material. We also discuss how ari can help instructors reach new audiences through programmatically translating materials into other languages.

The R Journal (June 2020) 12(1): Complete Issue, The R Foundation

The R Journal

Editorial, Michael J. Kane

Contributed Research Articles

gk: An R Package for the g-and-k and Generalised g-and-h Distributions, Dennis Prangle

NlinTS: An R Package for Causality Detection in Time Series, Youssef Hmamouche

Mapping Smoothed Spatial Effect Estimates from Individual-Level Data: MapGAM, Lu Bai, Daniel L. Gillen, Scott M. Bartell, and Verónica M. Vieira

mudfold: An R Package for Nonparametric IRT Modelling of Unfolding Processes, Spyros E. Balafas, Wim P. Krijnen, Wendy J. Post, and Ernst C. Wit

tsmp: An R Package for Time Series with Matrix Profile, Francisco Bischoff and Pedro Pereira Rodrigues

Individual-Level Modelling of Infectious Disease Data: EpiILM, …

Modeling And Analysis Of Trust Attack Based On Object-Oriented Petri Net, Guangqiu Huang, Bai Lu

Journal of System Simulation

Abstract: On the basis of trust attack graph, the object-oriented trust attack Petri net model was put forward, the dynamic model described the attack behaviors among components of trust entity object. By introducing the object Petri net, the trust attack relations between trust entity objects and components were shown in the Petri net, simulating the collaborative work between the components. According to the new trust relation reconstruction rules, a trust attack path inference algorithm was proposed to make the attacker knowing the changes of harmfulness when attacking the components, thus the attacker could decide the attack direction. The maximal …

Study On Secrecy Capacity Of Wireless Sensor Networks Based On Amplify-And-Forward Compressed Sensing Scheme, Jianlan Guo, Yuqiang Chen, Yijun Liu

Journal of System Simulation

Abstract: Due to the limitation of wireless sensor nodes on computation, power energy and storage space, the security issue has become a prevalent concern in the wireless communication. A deep insight on the secrecy capacity of wireless sensor network based on the Amplify-and-Forward (AF) compressed sensing scheme was offered providing a corresponding calculable capacity threshold. Moreover, a feasible algorithm based on augmented Lagrange method for the reconstruction of communication signals was proposed. Furthermore, the impact of the secrecy capacity was discussed to various numbers of active sensor nodes, relay nodes and eavesdropper nodes. Simulation results demonstrate the validity of the …

Provenance Of R’S Gradient Optimizers, John C. Nash

The R Journal

Gradient optimization methods (function minimizers) are well-represented in both the base and package universe of R (R Core Team, 2019). However, some of the methods and the codes developed from them were published before standards for hardware and software were established, in particular the IEEE arithmetic (IEEE, 1985). There have been cases of unexpected behaviour or outright errors, and these are the focus of the histoRicalg project. A summary history of some of the tools in R for gradient optimization methods is presented to give perspective on such methods and the occasions where they could be used effectively.

S, R, And Data Science, John M. Chambers

The R Journal

Data science is increasingly important and challenging. It requires computational tools and programming environments that handle big data and difficult computations, while supporting creative, high-quality analysis. The R language and related software play a major role in computing for data science. R is featured in most programs for training in the field. R packages provide tools for a wide range of purposes and users. The description of a new technique, particularly from research in statistics, is frequently accompanied by an R package, greatly increasing the usefulness of the description.

The history of R makes clear its connection to data science. …

The Rockerverse: Packages And Applications For Containerisation With R, Daniel Nüst, Dirk Eddelbuettel, Dom Bennett, Robrecht Cannoodt, Dav Clark, Gergely Daróczi, Mark Edmondson, Colin Fay, Ellis Hughes, Lars Kjeldgaard, Sean Lopp, Ben Marwick, Heather Nolis, Jacqueline Nolis, Hong Ooi, Kathik Ram, Noam Ross, Lori Shepard, Péter Sólymos, Tyson Lee Swetnam, Nitesh Turaga, Charlotte Van Petegem, Jason Williams, Craig Willis, Nan Xiao

The R Journal

The Rocker Project provides widely used Docker images for R across different application scenarios. This article surveys downstream projects that build upon the Rocker Project images and presents the current state of R packages for managing Docker images and controlling containers. These use cases cover diverse topics such as package development, reproducible research, collaborative work, cloud-based data processing, and production deployment of services. The variety of applications demonstrates the power of the Rocker Project specifically and containerisation in general. Across the diverse ways to use containers, we identified common themes: reproducible environments, scalability and efficiency, and portability across clouds. We …

Linear Fractional Stable Motion With The Rlfsm R Package, Stepan Mazur, Dmitry Otryakhin

The R Journal

Linear fractional stable motion is a type of a stochastic integral driven by symmetric alpha-stable Lévy motion. The integral could be considered as a non-Gaussian analogue of the fractional Brownian motion. The present paper discusses R package rlfsm created for numerical procedures with the linear fractional stable motion. It is a set of tools for simulation of these processes as well as performing statistical inference and simulation studies on them. We introduce: tools that we developed to work with that type of motions as well as methods and ideas underlying them. Also we perform numerical experiments to show finite-sample behavior …

Bayesmallows: An R Package For The Bayesian Mallows Model, Øystein Sørensen, Marta Crispino, Qinghua Liu, Valeria Vitelli

The R Journal

BayesMallows is an R package for analyzing preference data in the form of rankings with the Mallows rank model, and its finite mixture extension, in a Bayesian framework. The model is grounded on the idea that the probability density of an observed ranking decreases exponentially with the distance to the location parameter. It is the first Bayesian implementation that allows wide choices of distances, and it works well with a large amount of items to be ranked. BayesMallows handles non-standard data: partial rankings and pairwise comparisons, even in cases including non-transitive preference patterns. The Bayesian paradigm allows coherent quantification of …