1,720,962 research outputs found
Problema de fronteira livre com ativação gradiente e singularidades oscilatórias
No full textThis thesis provides an in-depth analysis of two distinct categories of free boundary problems,
which are fundamental in understanding complex systems governed by differential equations.
In the first segment of the study, we delve into the realm of highly degenerate elliptic equations.
This part focuses on a model characterized by a nonlinear diffusion process, which becomes the
driving force in areas where the gradient exceeds a specific threshold. This investigation not only
sheds light on the behavior of these solutions but also explores the convergence points with other
emerging research trends, thereby enriching the discourse in this field.
The second part of the thesis transitions into an exploration of free boundary variational models,
particularly those marked by oscillatory singularities. This segment is pivotal in addressing
problems where the oscillatory nature results in a spectrum of free boundary geometries. Through
meticulous research, we conduct an extensive analysis and establish a novel monotonicity formula.
This formula is instrumental in considering the variable aspects of these models. Significantly,
we demonstrate that when the singular power varies in a 1,+ fashion, then the free boundary is
locally a 1, surface, up to a negligible set of Hausdorff co-dimension at least 2.
This thesis aims to contribute substantially to the field of mathematical analysis and differential
equations, offering novel perspectives and methodologies in the study of free boundary problems.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESEsta tese oferece uma análise aprofundada de duas categorias distintas de problemas de fronteira
livre, fundamentais para a compreensão de sistemas complexos regidos por equações diferenciais.
No primeiro segmento do estudo, mergulhamos no âmbito das equações elípticas altamente
degeneradas. Esta parte foca em um modelo caracterizado por um processo de difusão não
linear, que se torna a força motriz em áreas onde o gradiente excede um limiar específico. Esta
investigação não apenas ilumina o comportamento dessas soluções, mas também explora os
pontos de convergência com outras tendências emergentes de pesquisa, enriquecendo assim o
discurso neste campo.
A segunda parte da tese transita para a exploração de modelos variacionais de fronteira livre,
particularmente aqueles marcados por singularidades oscilatórias. Este segmento é fundamental
para abordar problemas em que a natureza oscilatória resulta em um espectro de geometrias
de fronteira livre. Por meio de uma pesquisa meticulosa, conduzimos uma análise extensiva e
estabelecemos uma nova fórmula de monotonicidade. Esta fórmula é instrumental para considerar
os aspectos variáveis desses modelos. De forma significativa, demonstramos que, quando o
poder singular varia de acordo com um padrão 1,+ , então a fronteira livre se manifesta
localmente como uma superfície 1,, exceto por um conjunto negligenciável, caracterizado por
uma co-dimensão de Hausdorff de pelo menos 2.
Esta tese tem como objetivo contribuir substancialmente para o campo da análise matemática e
equações diferenciais, oferecendo perspectivas e metodologias novas no estudo de problemas de
fronteira livre
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Teoria de regularidade para soluções de equações elípticas não-locais
Full text linkIn this dissertation, our goal is to present a brief introduction to the regularity theory for solution of Nonlocal Elliptic equations. The work is divided in three chapters where we discuss three big papers from Caffarelli and Silvestre. The ideia is to present the Nonlocal version of the existing theory to Uniformly Elliptic operators and we bring important results like an ABP estimate, a comparison principle, Ca and C 1,a Hölder estimates, regularity results by approximation and a version of the Evans-Krylov theorem for solutions of an Integro-Differential equation for which the associated operator is concave.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESNesta dissertação, nosso objetivo é apresentar uma breve introdução à Teoria de Regularidade
para soluções de equações Elípticas Não-Locais. O trabalho está dividido em três capítulos
onde dissertamos sobre três grandes artigos de Caffarelli e Silvestre. A ideia é apresentar a
versão Não-Local da teoria existente para operadores Uniformemente Elípticos e traz importantes
resultados como uma estimativa ABP, um princípio de comparação, estimativas Hölder Ca e C1,a, resultados de regularidade por aproximação e uma versão do teorema de Evans-Krylov
para soluções de uma equação Íntegro-Diferencial cujo operador associado é côncavo.São Cristóvã
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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