Mathematical Analysis
Mostrando 1-12 de 1187 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. Quimiometria III - Revisitando a análise exploratória dos dados multivariados
In this work, three methods for pattern recognition, used as exploratory data analysis, are revisited. A brief review of principal component analysis, PCA, an unsupervised method, is provided. Next, the Mahalanobis distance and the confidence ellipses usually drawn around the scores samples are discussed. Fisher’s canonical variate analysis (a supervised m
Química Nova. 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. Finite element computational development for thermo-mechanical analysis of plane steel structures exposed to fire
Abstract This article presents a numerical formulation based on finite element procedures for application in nonlinear thermo-mechanical analyses of steel planar structures under fire condition. The mechanical properties of structural elements degrade when subjected to high temperatures, resulting in significant reductions in strength and stiffness. Under th
REM - International Engineering Journal. Publicado em: 2022
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5. 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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6. Optimization Techniques and Mathematical Modeling Applied to Reluctance Motors
Abstract The present work aims at the application of different optimization strategies in the electromagnetic analysis of the Variable Reluctance Motor (VRM) through Finite Element (FE) simulation. Two case studies are investigated: the first one aims to optimize the geometry and electrical characteristics of windings of a single-phase VRM 6/6, minimizing co
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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7. Mathematical Modeling of the Film Influence on the Salting Time of Mozzarella Cheese in a Static and Dynamic System: Application of Artificial Neural Networks of the Multilayer Perceptron Type
The NaCl and KCl diffusion in the film formed on the cheese surface during salting was simulated by the finite element method. The time and salts concentration values on the cheese surface were determined, tabulated, and presented to the multilayer perceptron neural network (MLP) for the regression modeling. The samples were divided into 70, 15 and 15% for t
Journal of the Brazilian Chemical Society. Publicado em: 2022
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8. 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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9. Analysis of Self-Regulated Learning at Each Level of Mathematical Creative Thinking Skill
Resumo A maioria dos indivíduos entende o pensamento criativo matemático não apenas como um fator cognitivo, mas também como um fator afetivo. A aprendizagem autorregulada (SRL) é considerada um fator afetivo que influencia a capacidade de pensamento criativo matemático. O objetivo deste estudo é determinar o efeito do SRL na capacidade de pensamento
Bolema: Boletim de Educação Matemática. Publicado em: 2022
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10. 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
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11. SEWAGE PERFORMANCE OF A NEW TYPE OF FLAP FILTER
ABSTRACT The drainage performance of a mesh filter determines the water consumption degree of the filter and the efficiency of the next work cycle. Through analysis, we found that the influent flow rate and the sediment content of the influent were important influencing factors. This experiment focused on the drainage time, pressure difference, and cleanline
Eng. Agríc.. Publicado em: 2021-04
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12. Mathematical Analysis and Improvement of the Maximum Spatial Eigenfilter for Direction of Arrival Estimation
Abstract Maximum spatial eigenfiltering improves the accuracy of maximum likelihood direction-of-arrival estimators for closely-spaced signal sources but may interchangeably attenuate widely-spaced signal sources, producing a severe performance degradation. Although this behavior has been observed experimentally, it still lacks a mathematical explanation. In
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-03