建模与仿真(英文)最新文献_第4页

Numerical Model Research on Rotational Performance of Beam-Column High-Strength Bolt Extension End-Plate Connection Node 梁柱高强螺栓端板连接节点转动性能的数值模型研究

建模与仿真(英文) Pub Date : 2021-05-21 DOI: 10.4236/ojmsi.2021.93015

Xiao Lang

引用次数: 0

A Comparison of Deterministic and Stochastic Susceptible-Infected-Susceptible (SIS) and Susceptible-Infected-Recovered (SIR) Models 确定性和随机易感-感染-易感(SIS)和易感-感染-恢复(SIR)模型的比较

建模与仿真(英文) Pub Date : 2021-05-21 DOI: 10.4236/ojmsi.2021.93016

A. Moujahid, F. Vadillo

{"title":"A Comparison of Deterministic and Stochastic Susceptible-Infected-Susceptible (SIS) and Susceptible-Infected-Recovered (SIR) Models","authors":"A. Moujahid, F. Vadillo","doi":"10.4236/ojmsi.2021.93016","DOIUrl":"https://doi.org/10.4236/ojmsi.2021.93016","url":null,"abstract":"In this paper we build and analyze two stochastic epidemic models with \u0000death. The model assumes that only susceptible individuals (S) can get infected (I) and may die \u0000from this disease or a recovered individual becomes susceptible again (SIS \u0000model) or completely immune (SIR Model) for the remainder of the study period. \u0000Moreover, it is assumed there are no births, deaths, immigration or emigration \u0000during the study period; the community is said to be closed. In these infection \u0000disease models, there are two central questions: first it is the disease \u0000extinction or not and the second studies the time elapsed for such extinction, \u0000this paper will deal with this second question because the first answer \u0000corresponds to the basic reproduction number defined in the bibliography. More \u0000concretely, we study the mean-extinction of the diseases and the technique used \u0000here first builds the backward Kolmogorov differential equation and then solves \u0000it numerically using finite element method with FreeFem++. Our contribution and \u0000novelty are the following: however the reproduction number effectively concludes the \u0000extinction or not of the disease, it does not help to know its extinction times \u0000because example with the same reproduction numbers has very different time. \u0000Moreover, the SIS model is slower, a result that is not surprising, but this \u0000difference seems to increase in the stochastic models with respect to the \u0000deterministic ones, it is reasonable to assume some uncertainly.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43471854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Probabilistic Modelling of COVID-19 Dynamic in the Context of Madagascar 马达加斯加地区COVID-19动态概率建模

建模与仿真(英文) Pub Date : 2021-05-21 DOI: 10.4236/OJMSI.2021.93014

Angelo Raherinirina, Tsilefa Stefana Fandresena, A. R. Hajalalaina, H. Rabetafika, R. Rakotoarivelo, Fontaine Rafamatanantsoa

{"title":"Probabilistic Modelling of COVID-19 Dynamic in the Context of Madagascar","authors":"Angelo Raherinirina, Tsilefa Stefana Fandresena, A. R. Hajalalaina, H. Rabetafika, R. Rakotoarivelo, Fontaine Rafamatanantsoa","doi":"10.4236/OJMSI.2021.93014","DOIUrl":"https://doi.org/10.4236/OJMSI.2021.93014","url":null,"abstract":"We propose a probabilistic approach to modelling the propagation of the \u0000coronavirus disease 2019 (COVID-19) in Madagascar, with all its specificities. \u0000With the strategy of the Malagasy state, which consists of isolating all \u0000suspected cases and hospitalized confirmed case, we get an epidemic model with \u0000seven compartments: susceptible (S), Exposed (E), Infected (I), Asymptomatic \u0000(A), Hospitalized (H), Cured (C) and Death (D). In addition to the classical \u0000deterministic models used in epidemiology, the stochastic model offers a \u0000natural representation of the evolution of the COVID-19 epidemic. We inferred the models with the official data provided by the COVID-19 \u0000Command Center (CCO) of Madagascar, between March and August 2020. The basic \u0000reproduction number R0 and the other parameters were estimated \u0000with a Bayesian approach. We developed an algorithm that allows having a \u0000temporal estimate of this number with confidence intervals. The estimated \u0000values are slightly lower than the international references. Generally, we were \u0000able to obtain a simple but effective model to describe the spread of the \u0000disease.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48302466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

A New Mathematical Modeling of the COVID-19 Pandemic Including the Vaccination Campaign 包括疫苗接种运动在内的新型COVID-19大流行数学模型

建模与仿真(英文) Pub Date : 2021-05-21 DOI: 10.4236/ojmsi.2021.93020

M. Yavuz, Fatma Özlem Coşar, Fatma Günay, F. Özdemi̇r

{"title":"A New Mathematical Modeling of the COVID-19 Pandemic Including the Vaccination Campaign","authors":"M. Yavuz, Fatma Özlem Coşar, Fatma Günay, F. Özdemi̇r","doi":"10.4236/ojmsi.2021.93020","DOIUrl":"https://doi.org/10.4236/ojmsi.2021.93020","url":null,"abstract":"In a short time, many illustrative studies have been \u0000conducted on the mathematical modeling and analysis of COVID-19. There are not \u0000enough studies taking into account the vaccine campaign among these studies. In \u0000this context, a mathematical model is developed to reveal the effects of \u0000vaccine treatment, which has been performed recently, on COVID-19 in this \u0000study. In the proposed model, as well as the vaccinated individuals, a \u0000five-dimensional compartment system including the susceptible, infected, \u0000exposed and recovered population is constructed. Moreover, besides the \u0000positivity, existence and uniqueness of the solution, biologically feasible \u0000region are provided. The basic reproduction number known as expected secondary infection which means \u0000that expected infection among the susceptible populations caused by this \u0000infection is evaluated. In the numerical simulations, the parameter values \u0000taken from the literature and estimated are used to perform the solutions of \u0000the proposed model. Fourth-order Runge-Kutta numerical scheme is applied to \u0000obtain the results.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47472910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 47

Mathematical Model and Non-Pharmaceutical Control of the Coronavirus 2019 Disease in Madagascar 马达加斯加2019冠状病毒病的数学模型和非药物控制

建模与仿真(英文) Pub Date : 2021-05-21 DOI: 10.4236/ojmsi.2021.93017

Angelo Raherinirina, Fontaine Rafamatanantsoa, Tsilefa Stefana Fandresena, R. Rakotoarivelo

{"title":"Mathematical Model and Non-Pharmaceutical Control of the Coronavirus 2019 Disease in Madagascar","authors":"Angelo Raherinirina, Fontaine Rafamatanantsoa, Tsilefa Stefana Fandresena, R. Rakotoarivelo","doi":"10.4236/ojmsi.2021.93017","DOIUrl":"https://doi.org/10.4236/ojmsi.2021.93017","url":null,"abstract":"For Madagascar, with the uncertainty over vaccines against the novel \u0000coronavirus 2019 and its variants, non-pharmaceutical approach is widely used. \u0000Our objective is to propose a mathematical control model which will serve as a \u0000tool to help decision-makers in the strategy to be implemented to better face \u0000the pandemic. By separating asymptomatic cases which are often not reported and symptomatic \u0000who are hospitalized after tests; we develop a mathematical model of the \u0000propagation of covid-19 in Madagascar, by integrating control strategies. We \u0000study the stability of the model by expressing the basic reproduction number \u0000using the next-generation matrix. Simulation with different parameters shows \u0000the effects of non-pharmaceutical measures on the speed of the disease spread. \u0000By integrating a control parameter linked to compliance with barrier measures \u0000in the virus propagation equation, we were able to show the impacts of the \u0000implementation of social distancing measures on the basic reproduction number. \u0000The strict application of social distancing measures and total confinement is unfavorable for economic situation even if they allow the contamination to be \u0000reduced quickly. Without any restrictions, the disease spreads at high speed \u0000and the peak is reached fairly quickly. In this condition, hospitals are \u0000overwhelmed and the death rate increases rapidly. With 50% respect for \u0000non-pharmaceutical strategies such as rapid detection and isolation of positive \u0000cases and barrier gestures; the basic reproduction number R0 can go down from 3 to 1.7. The pressures on the economic and social \u0000situation are rather viable. It is the most suitable for the Malagasy health \u0000system. The results proposed are a way to control the spread of the disease and \u0000limit its devastation in a country like Madagascar.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48307666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Research on Vertical Bearing Capacity of Pile Foundation under Wave Scouring 波浪冲刷作用下桩基竖向承载力研究

建模与仿真(英文) Pub Date : 2021-04-15 DOI: 10.4236/OJMSI.2021.92008

Xinyue Wang

引用次数: 1

Mathematical Modelling of the COVID-19 Epidemic in Northern Ireland in 2020 2020年北爱尔兰COVID-19流行的数学模型

建模与仿真(英文) Pub Date : 2021-04-09 DOI: 10.4236/OJMSI.2021.92006

P. Hall, G. Kiss, Tilmann E. Kuhn, S. Moutari, E. Patterson, Emily R. Smith

引用次数: 0

DecPDEVS: New Simulation Algorithms to Improve Message Handling in PDEVS DecPDEVS:改进PDEVS中消息处理的新仿真算法

建模与仿真(英文) Pub Date : 2021-04-09 DOI: 10.4236/OJMSI.2021.92012

P. Bisgambiglia, P. Bisgambiglia

引用次数: 1

Worker’s Helmet Recognition and Identity Recognition Based on Deep Learning 基于深度学习的工人头盔识别与身份识别

建模与仿真(英文) Pub Date : 2021-04-09 DOI: 10.4236/OJMSI.2021.92009

Jie Wang, Guangzu Zhu, Shiqi Wu, Chunshan Luo

{"title":"Worker’s Helmet Recognition and Identity Recognition Based on Deep Learning","authors":"Jie Wang, Guangzu Zhu, Shiqi Wu, Chunshan Luo","doi":"10.4236/OJMSI.2021.92009","DOIUrl":"https://doi.org/10.4236/OJMSI.2021.92009","url":null,"abstract":"For decades, safety has been a concern for the construction \u0000industry. Helmet detection caught the attention of machine learning, but the \u0000problem of identity recognition has been ignored in previous studies, which \u0000brings trouble to the subsequent safety education of workers. Although, many \u0000scholars have devoted themselves to the study of person re-identification which \u0000neglected safety detection. The study of this paper mainly proposes a method \u0000based on deep learning, which is different from the previous study of helmet \u0000detection and human identity recognition and \u0000can carry out helmet detection and identity recognition for construction \u0000workers. This paper proposes a computer vision-based worker identity \u0000recognition and helmet recognition method. We collected 3000 real-name channel \u0000images and constructed a neural network based on the You Only Look Once (YOLO) v3 model to extract the \u0000features of the construction worker’s face and helmet, respectively. \u0000Experiments show that the method has a high recognition accuracy rate, fast \u0000recognition speed, accurate recognition of workers and helmet detection, and \u0000solves the problem of poor supervision of real-name channels.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47708908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

A Short Review on Computational Hydraulics in the context of Water Resources Engineering 水利工程背景下的计算水力学简评

建模与仿真(英文) Pub Date : 2021-02-24 DOI: 10.31224/osf.io/t4bne

S. Sarker

{"title":"A Short Review on Computational Hydraulics in the context of Water Resources Engineering","authors":"S. Sarker","doi":"10.31224/osf.io/t4bne","DOIUrl":"https://doi.org/10.31224/osf.io/t4bne","url":null,"abstract":"The term hydraulics concerned with the conveyance of water that can consist of very simple processes to complex physical processes, such as flow in open rivers, flow in pipes, flow of nutrients/sediments, flow of ground water to sea waves. The study of hydraulics is primarily a mixture of theory and experiments. Computational hydraulics is very helpful in-order to quantify and predict flow nature and behavior. Mathematical model is backbone of the computational hydraulics that consist simple to complex mathematical equations with linear and/or non-linear terms and ordinary or partial differential equations. Analytical solution of this mathematical equations is not feasible in the majority of cases. In this consequences, mathematical models are solved using different numerical techniques and associated schemes. In this manuscript we will review hydraulic principles along with their mathematical equations. Then we will learn some commonly used numerical technique to solve different types of differential equations related to the hydraulics. Among them the Finite Difference Method (FDM), Finite Element Method (FEM) and Finite Volume Method (FVM) will be discussed along with their use in real-life applications in the context of water resources engineering.","PeriodicalId":56990,"journal":{"name":"建模与仿真(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44861945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16