Trends in Computational and Applied Mathematics最新文献

Análise de Resíduos para o Modelo Logístico Generalizado Dependente do Tempo 随时间变化的广义 Logistic 模型残差分析

Trends in Computational and Applied Mathematics Pub Date : 2023-11-27 DOI: 10.5540/tcam.2023.024.04.00635

L. F. Oliveira, L. S. Santos, L. Fabio, P. H. Ferreira, J. M. Carrasco

引用次数: 0

Fuzzy Divergence for Lung Radiography Image Enhancement 用于肺部放射成像图像增强的模糊发散法

Trends in Computational and Applied Mathematics Pub Date : 2023-11-27 DOI: 10.5540/tcam.2023.024.04.00699

W. P. Sousa, C. C. P. Cruz, R. Lanzillotti, W. P. Sousa

引用次数: 0

Números de Stirling do Primeiro Tipo e as Relações de Girard 第一类斯特林数与吉拉德的关系

Trends in Computational and Applied Mathematics Pub Date : 2023-11-27 DOI: 10.5540/tcam.2023.024.04.00745

G. F. Pinheiro, I. M. Craveiro, E. Macena

引用次数: 0

Evaluating the Interplay between Transmissibility and Virulence of SARS-CoV-2 by Mathematical Modeling 通过数学建模评估 SARS-CoV-2 传播性和毒性之间的相互作用

Trends in Computational and Applied Mathematics Pub Date : 2023-11-27 DOI: 10.5540/tcam.2023.024.04.00595

L. P. L. Junior, H. Yang, B. Spira, A. C. Yang, Hyun Mo

{"title":"Evaluating the Interplay between Transmissibility and Virulence of SARS-CoV-2 by Mathematical Modeling","authors":"L. P. L. Junior, H. Yang, B. Spira, A. C. Yang, Hyun Mo","doi":"10.5540/tcam.2023.024.04.00595","DOIUrl":"https://doi.org/10.5540/tcam.2023.024.04.00595","url":null,"abstract":"During the first months of 2020 SARS-CoV-2 spread to all continents, virtually reaching all countries. In the subsequent months, new variants emerged in different regions of the world. A mathematical model based on the Covid-19 natural history encompassing the age-dependent fatality was applied to evaluate SARS-CoV-2 transmissibility and virulence. Transmissibility was assessed by calculating the basic reproduction number R0 and virulence by counting the proportion of severe Covid-19 cases and deaths. The model parameters were adjusted against the data observed in the state of São Paulo, Brazil, considering two different levels of virulence. The severe Covid-19 cases and deaths were three times higher and R0 was 25% lower when the more virulent SARS-CoV-2 variant was compared to the less virulent variant. However, under the high-virulence scenario the number of transmitting individuals is 25% lower, mainly due to the isolation of symptomatic individuals. The corollary that transmission increases in the low virulence scenario is also true. The estimated parameters, using data from São Paulo up to May 13, 2020, showed that the Covid-19 epidemic predicted with low virulence SARS-CoV-2 transmission matched the observed data just before the beginning of the relaxation, which occurred by mid-June 2020. The assessment of the interplay between transmissibility can be applied to explain in somehow the appearance of gamma and omicron variants of concern in São Paulo.","PeriodicalId":291172,"journal":{"name":"Trends in Computational and Applied Mathematics","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139230092","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: 0

A Multiobjective Optimization Application to Control the Aedes Aegypti Mosquito using a Two-Dimensional Diffusion-Reaction Model 利用二维扩散-反应模型控制埃及伊蚊的多目标优化应用

Trends in Computational and Applied Mathematics Pub Date : 2023-11-27 DOI: 10.5540/tcam.2023.024.04.00779

J. S. Lima, A. S. V. Vasconcelos, R. Cardoso, J. S. Lima

{"title":"A Multiobjective Optimization Application to Control the Aedes Aegypti Mosquito using a Two-Dimensional Diffusion-Reaction Model","authors":"J. S. Lima, A. S. V. Vasconcelos, R. Cardoso, J. S. Lima","doi":"10.5540/tcam.2023.024.04.00779","DOIUrl":"https://doi.org/10.5540/tcam.2023.024.04.00779","url":null,"abstract":"Aedes aegypti is the main vector of multiple diseases, such as dengue, yellow fever, Zika, and chikungunya. Diseases associated with mosquitoes have been growing in recent years, with more than one-third of the world population at risk. Control techniques have been studied to prevent the spread of the Aedes aegypti, such that new formula and how to use adulticides and larvicides, among others. This paper proposes a novel approach in the field of partial differential equations and optimization. We consider a two-dimensional diffusion-reaction model that describes the interaction between aquatic and adult female stages spreading across a domain with parameters dependent on rainfall and temperature. We also formulate a mono-objective and multiobjective optimization problem to minimize the Aedes aegypti populations and the control, considering the application of adulticides and larvicides, using actual data from the city of Lavras/Brazil. The operator splitting technique is used to solve the diffusion-reaction system, coupling finite difference and the fourth-order Runge-Kutta method and optimal solutions were searched by using the Real-Biased Genetic Algorithm and Non-dominated Sorting Genetic Algorithm -II. Numerical results show significant reduction of the Aedes aegypti population.","PeriodicalId":291172,"journal":{"name":"Trends in Computational and Applied Mathematics","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139232270","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: 0

Aplicações Estáveis entre Superfícies Fechadas 封闭表面之间的稳定应用

Trends in Computational and Applied Mathematics Pub Date : 2023-11-27 DOI: 10.5540/tcam.2023.024.04.00659

C. Mendes de Jesus

引用次数: 0

Urban Pollutant Dispersion on a Turbulent Fluid Model 城市污染物在湍流模型上的扩散

Trends in Computational and Applied Mathematics Pub Date : 2023-11-27 DOI: 10.5540/tcam.2023.024.04.00617

V. A. Silva, E. G. Zaze, P. A. Bastos, P. A. Bastos, F. P. Devecchi, M. B. Kolicheski

{"title":"Urban Pollutant Dispersion on a Turbulent Fluid Model","authors":"V. A. Silva, E. G. Zaze, P. A. Bastos, P. A. Bastos, F. P. Devecchi, M. B. Kolicheski","doi":"10.5540/tcam.2023.024.04.00617","DOIUrl":"https://doi.org/10.5540/tcam.2023.024.04.00617","url":null,"abstract":"In 2019, more than 90% of the world’s population was living in places where pollutantconcentrations exceeded the air-quality guidelines. Anthropogenic activity has been the main cause of climate change in the last 20 years, especially in urban centres where industrial activities and motorized traffic mainly occur. This article presents a study of air pollutant dispersion by computational fluid dynamics modelling using OpenFOAM for urban street canyon simulations. The aim of this study was to investigate the influence of vegetation on natural ventilation, dispersion and CO2 mitigation. The behavior of pollutants was modeled by the Reynolds-averaged Navier–Stokes equations (RANS) and the k−ε fluid turbulence model. The results indicate that aerodynamic effects are more important at lower pollutant wind velocities, as they reduce turbulent dispersion and allow a higher reduction in the concentration of air pollutants. In addition, the direction of the wind, relative to the main axis of the street, had a significant impact on the results found. In general, in the presence of trees, perpendicular winds can lead to higher concentration of pollutants, while parallel winds allow improve air quality, considerably reducing those pollutant concentrations.","PeriodicalId":291172,"journal":{"name":"Trends in Computational and Applied Mathematics","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139233967","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: 0

Some Special Integer Partitions Generated by a Family of Functions 由函数族生成的一些特殊整数分区

Trends in Computational and Applied Mathematics Pub Date : 2023-11-27 DOI: 10.5540/tcam.2023.024.04.00717

M. L. Matte

引用次数: 0

Resultados Numéricos do Método de Elementos Analíticos em Aglomerados de Inomogeneidades 非均质团中分析元素法的数值结果

Trends in Computational and Applied Mathematics Pub Date : 2023-11-27 DOI: 10.5540/tcam.2023.024.04.00759

J. M. Santos, H. C. Jhúnior, A. Firmiano, E. Wendland

引用次数: 0

Mathematical Modeling and Georeferenced Forecasting for the COVID-19 at the State of RS, Brazil 巴西RS州2019冠状病毒病的数学建模和地理参考预测

Trends in Computational and Applied Mathematics Pub Date : 2023-07-20 DOI: 10.5540/tcam.2023.024.03.00487

J. C. Marques, A. Cezaro, D. L. Alves, P. V. A. B. L. ˆOA, Matheus Lazo, D. Sales, Joice Chaves

{"title":"Mathematical Modeling and Georeferenced Forecasting for the COVID-19 at the State of RS, Brazil","authors":"J. C. Marques, A. Cezaro, D. L. Alves, P. V. A. B. L. ˆOA, Matheus Lazo, D. Sales, Joice Chaves","doi":"10.5540/tcam.2023.024.03.00487","DOIUrl":"https://doi.org/10.5540/tcam.2023.024.03.00487","url":null,"abstract":"In this contribution, we present a predictive tool developed to help in the management of the evolution of the COVID-19 pandemic situation in Rio Grande do Sul (RS) - Brazil. This tool is the result of georeferenced data analysis, mathematical modeling, and parameter calibration for the dynamics of a SIR-type model defined on a spatial structure that allows distinct subpopulations to interact, similar to the controlled distancing (A_l for l = 1, ···, 21) groupings proposed by the RS government and public health authorities. The predictive analysis, updated biweekly, provides three distinct scenarios per month (milder, average, and severe) and is made available as WebSIGs (Geographic Information System - GIS). The forecast of the average scenario for each Al group is the result of a simulation of the proposed SIRtype dynamics with calibrated parameters derived from an augmented Lagrangian maximum a posteriori estimation and data on the number of infected cases made available by the RS Health Secretariat. The milder and severe scenarios are obtained from the average scenario, with changes in the contagion rates of each Al group. When compared to the number of infections reported in each Al group, the modeling predictions for a biweekly time window (the first two weeks) were quite satisfactory, with errors ranging from 0% to 5.13%, gradually increasing over time. Therefore, we suggest a biweekly re-calibration of the parameters and corresponding forecasts as a wise strategy.","PeriodicalId":291172,"journal":{"name":"Trends in Computational and Applied Mathematics","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121645140","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: 0