Mathematical Model
Mostrando 1-12 de 1806 artigos, teses e dissertações.
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1. A Mathematical Model for Accessing Dengue Hemorrhagic Fever in Infants
ABSTRACT A mathematical model was developed to describe the dynamics of the primary infection of dengue virus in infants who were born to a mother immune to some serotype of the dengue virus. The model is given by a system of nonlinear ordinary differential equations with time-dependent variables for the number of dengue virus antibodies of the infant transf
Trends in Computational and Applied Mathematics. Publicado em: 2022
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2. FUZZY MODELING OF SALINITY EFFECTS ON PUMPKIN (Cucurbita pepo) DEVELOPMENT
ABSTRACT The low quality of the water currently used for irrigation purposes harms the quality of the products and can lead to a reduction in production. Thus, the objective of this work was to verify the effect of saline water in irrigation water, on biometric variables of pumpkin crop using a system based on fuzzy rules. The agronomic experimental part of
Engenharia Agrícola. Publicado em: 2022
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3. A Model of Social Distancing for Interacting Age-Distributed Multi-Populations: An Analysis of Students’ In-Person Return to Schools
ABSTRACT Because of the current scenario of the SARS-CoV-2 (COVID-19) pandemic in Brazil, whose vaccination campaign is in its initial stage, government authorities have pointed towards the complete reopening of the economy. And recently, for the in-personal return of classroom teaching in schools. Given the family relationship, one of the questions that rem
Trends in Computational and Applied Mathematics. Publicado em: 2022
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4. Comparative Study of Some Numerical Schemes for a Fractional Order Model of HIV Infection Treatment
ABSTRACT A fractional order mathematical model that already exists in the literature, was considered. This model was established to study the effects of medicinal treatment in people infected with the human immunodeficiency virus (HIV). The importance of this study is that the model evaluates, among other parameters, the density of healthy and HIV-infected C
Trends in Computational and Applied Mathematics. Publicado em: 2022
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5. Steel desulfurization on RH degasser: physical and mathematical modeling
Abstract Due to the high-quality steel demand, especially for ultra-low Sulfur steel, RH desulfurization has been practiced. Based on this, mathematical and physical modeling have been applied to study steel desulfurization by reagent addition in the RH degasser vacuum chamber. The main result of cold modeling, using water and oil emulating steel and slag, r
REM - International Engineering Journal. Publicado em: 2022
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6. Numerical Simulations of the SEIR Epidemiological Model with Population Heterogeneity to Assess the Efficiency of Social Isolation in Controlling COVID-19 in Brazil
ABSTRACT On 30 January 2020, the World Health Organization (WHO) officially declared the epidemic of Coronavirus (COVID-19), which is a highly contagious virus that has been causing deaths worldwide. Early treatment was proven to be inefficient and social isolation became the main factor inhibiting the disease, before vaccination. In this article, we evaluat
Trends in Computational and Applied Mathematics. Publicado em: 2022
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7. Determination of Electric and Magnetic Field Calculation Uncertainty in the Vicinity of Overhead Transmission Lines
Abstract This paper presents a new approach for uncertainty determination of the electric field intensity and magnetic flux density calculation in the vicinity of overhead transmission lines. The proposed method is based on the law of propagation of uncertainty as defined in the Guide to the expression of Uncertainty in Measurement. A mathematical model is d
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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8. Fuzzy Boundary for Beams Vibrations in Vehicles
ABSTRACT This work aims to study the transversal motion of a car’s chassis, modeled by a beam and supported at its ends by two sets of spring-damper elements. A finite differences method is utilized along with Robin boundary conditions to solve the mathematical modeling. The constants of the boundary conditions are modeled by a fuzzy parameter obtained thr
Trends in Computational and Applied Mathematics. Publicado em: 2022
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9. A Nodal-iterative Technique for Criticality Calculations in Multigroup Neutron Diffusion Models
ABSTRACT In this work, a nodal and iterative technique to evaluate the effective multiplication factor as well as the neutron flux, in multigroup diffusion problems, is presented. An iterative scheme, similar to the source iteration method, is implemented to decouple the system of differential equations which is the fundamental mathematical model. Then, anal
Trends in Computational and Applied Mathematics. Publicado em: 2022
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10. CONSTRUCTION OF A MATHEMATICAL MODEL BASED ON A GENETIC ALGORITHM FOR AN APTITUDE PROGRAM IN HIGH SCHOOL STUDENT OPTIMIZATION
RESUMO Introdução: O algoritmo genético é um dos mais importantes modelos matemáticos teóricos para simulação de desenvolvimento biológico. É amplamente utilizado em muitos campos, tais como engenharia, medicina e economia. Objetivo: Utilizar o algoritmo genético como base de um modelo matemático para otimização no programa de aptidão nos es
Revista Brasileira de Medicina do Esporte. Publicado em: 2022
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11. THERMODYNAMIC PROPERTIES OF WHITE BEAN GRAINS FOR DIFFERENT EQUILIBRIUM WATER CONTENTS
ABSTRACT In drying processes and in the storage of agricultural products, the study of thermodynamic properties is indispensable in the search for solutions to issues of stability and optimization of the conditions of agro-industrial processes. The aim of this work was to determine hygroscopic equilibrium isotherms and study the thermodynamic properties of w
Eng. Agríc.. Publicado em: 2021-05
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12. FUZZY MODELING OF THE EFFECTS OF DIFFERENT IRRIGATION DEPTH IN RADISH CROP. PART II: BIOMETRIC VARIABLES ANALYSIS
ABSTRACT In order to estimate the response of biometric variables in different irrigation depths in radish crop, as well as their relations in the development of the crop, a fuzzy mathematical analysis was carried out from irrigation with depths of different percentages of the crop evapotranspiration (ETc), using Gaussian pertinence functions for the input v
Eng. Agríc.. Publicado em: 2021-05