Conformal anomalies on Einstein spaces with Boundary

The anomalous rescaling for antisymmetric tensor fields, including gauge bosons, and Dirac fermions on Einstein spaces with boundary has been prone to errors and these are corrected here. The explicit calculations lead to some interesting identities that indicate a deeper underlying structure.Comment: 8 pages, NCL94-TP10, (ReVTeX

MREPSA : modelo de recomendação de estratégias pedagógicas baseado em aspectos socioafetivos do aluno em ambiente virtual de aprendizagem

Esta pesquisa investiga como construir um modelo de recomendação que integra estratégias pedagógicas a partir dos aspectos socioafetivos do aluno em Ambiente Virtual de Aprendizagem (AVA). Considerando que os aspectos afetivos e sociais vivenciados pelo sujeito interferem sobre seu desenvolvimento cognitivo, é relevante que o docente acompanhe as alterações comportamentais de cada aluno em sala de aula e, especialmente, no AVA. Neste contexto, a mediação do professor através de estratégias pedagógicas (EP) personalizadas adequadas à situação socioafetiva do estudante é significativa e pode contribuir em prol do aprendizado. Estratégias pedagógicas são ações planejadas para atingir aos objetivos pretendidos na formação do alunado. O presente estudo foi realizado em uma abordagem qualitativa e quantitativa do tipo estudo de casos múltiplos. O público-alvo da investigação são professores de ensino superior que utilizaram o AVA ROODA - Rede cOOperativa De Aprendizagem como plataforma para o desenvolvimento de suas atividades de ensino. Neste escopo, a pesquisa foi desenvolvida em cinco etapas, a saber: 1) Realização de estudo teórico sobre as temáticas de Sistemas de Recomendação, Socioafetividade, segundo a epistemologia genética de Piaget, Traços de Personalidade e Estratégias Pedagógicas, visando ao embasamento teórico nas respectivas e a identificação de trabalhos correlatos. 2) Construção do Modelo de Recomendação de Estratégias Pedagógicas a partir do perfil socioafetivo do aluno em ambiente virtual de aprendizagem. 3) Implementação das definições do MREPSA em um sistema de recomendação no AVA de aplicação. 4) Avaliação do Modelo no AVA de aplicação. 5) Análise dos resultados. A coleta de dados foi realizada mediante a aplicação de questionário cujas respostas foram examinadas segundo a metodologia de Análise de Conteúdo. Nesta perspectiva, foram estabelecidas três categorias de análise: Categoria I – A efetividade do MREPSA como modelo de recomendação, Categoria II – A qualidade do MREPSA como modelo de recomendação e Categoria III – A pertinência das recomendações ofertadas a partir do MREPSA. Os resultados apresentados apontam que as recomendações fornecidas são pertinentes com os estados socioafetivos dos estudantes. Ressaltam, ainda, que as sugestões são adequadas e úteis como ferramenta de apoio ao professor. Desse modo, as EP auxiliam a compreender a situação em que o aluno se encontra, ao mesmo tempo que provêm sugestões de ação pedagógica em resposta ao momento que este está passando. Com isso, vislumbra-se que o modelo pode servir de base para o desenvolvimento de novas abordagens de recomendação baseadas em aspectos socioafetivos, as quais podem contribuir para que os docentes possam dar uma atenção mais personalizada às necessidades afetivas e sociais de seus alunos em Ambientes Virtuais de Aprendizagem, em especial, na Educação a Distância.This research investigates how to build a recommendation model that integrates pedagogical strategies based on the student's socio-affective aspects in the Virtual Learning Environment (VLE). Considering that the affective and social aspects experienced by the subject interfere with his cognitive development, it is relevant that the teacher accompanies the behavioral changes of each student in the classroom and, especially, in the VLE. In this context, the mediation of the teacher through personalized pedagogical strategies (EP) tailored to the student's socio-affective situation is significant and can contribute to learning. Pedagogical strategies are actions designed to achieve the intended educational objectives. The present study was carried out using a qualitative and quantitative approach, such as multiple case studies. The target audience of the investigation are higher education teachers who used the VLE ROODA as a platform for the development of their teaching activities. In this scope, the research was developed in five stages, namely: 1) Carrying out a theoretical study on the themes of Recommendation Systems, Socio-affectivity, according to Piaget's genetic epistemology, Personality Traits and Pedagogical Strategies, aiming at the theoretical foundation in the respective and the identification of related works. 2) Construction of the Pedagogical Strategies Recommendation Model based on the student's socio-affective profile in a virtual learning environment. 3) Implementation of MREPSA definitions in a recommendation system in the application AVA. 4) Evaluation of the Model in the VLE. 5) Analysis of the results. Data collection was performed by applying a questionnaire whose answers were examined according to the Content Analysis methodology. In this perspective, three categories of analysis were established: Category I - The effectiveness of MREPSA as a recommendation model, Category II - The quality of MREPSA as a recommendation model and Category III - The relevance of the recommendations offered from MREPSA. The results presented show that the recommendations provided are relevant to the students' socio-affective states. They also emphasize that the suggestions are adequate and useful as a tool to support the teacher. In this way, the EPs help to understand the situation in which the student is, while providing suggestions for pedagogical action in response to the moment he is going through. Thus, it is envisaged that the model can serve as a basis for the development of new recommendation approaches based on socio-affective aspects, which can contribute so that teachers can give a more personalized attention to the affective and social needs of their students in the Virtual Learning Environment, especially in Distance Education

Metamodelagem MOF e sua aplicação para modelagem de sistemas imunológicos artificiais

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.Este trabalho versa sobre metamodelagem com o Meta-Object Facility (MOF), linguagem padrão para metamodelagem proposta pelo Object Management Group (OMG), e sua aplicação na concepção de um metamodelo para um Sistema Imunológico Artificial (SIA). O MOF é uma linguagem abstrata, tecnologicamente neutra, utilizada para a criação de metamodelos expansíveis, portáveis, interoperáveis e independentes de plataforma. Seus metamodelos viabilizam à transformação automática de modelos para diferentes plataformas de desenvolvimento, o que acelera o processo de desenvolvimento de softwares ao mesmo tempo em que reduz custos. Seus conceitos foram aplicados na criação de um metamodelo para um Sistema Imunológico Artificial, abordagem freqüentemente utilizada em pesquisas em segurança computacional em redes de computadores. O metamodelo gerado é genérico, o que torna-o aplicável não somente na concepção de sistemas de detecção de intrusão em redes de computadores mas, também, em outros nos quais os princípios definidos para um sistema imunológico artificial se faça adequada

Affective and social aspects in distance education : the interdisciplinarity in focus

This article presents an analysis of the possible contributions of the affective and social aspects to the development of pedagogical practices in the modality of Distance Education. The interactions of students in a Virtual Learning Environment (VLE) were observed and identified based on the use of specific instruments of affective and social analysis. The aim is to assist the teacher in the development of his pedagogical practices carried out through an VLE. The methodology used was the qualitative developed in a discipline at a public university in the south of Brazil in 2018. Twelve undergraduate students from different undergraduate courses participated in the study. The data were extracted from the Social Map and Affective Map tools available in ROODA VLE, used in the discipline. These tools enable a mapping of the student's affective and social profile, from the productions and interactions of the students in the VLE. The results point to the relevance of the support that the information provided by the maps can provide to the teacher. In this sense, they contribute to the decision of pedagogical practices, since they can corroborate the strategies adopted by the teacher or they can base the (re)orientation of the proposed activities in order to meet the affective and social demands of each student. The data obtained provided, in addition to a more in-depth discussion on the subject, the development of new resources as a system of recommendation of pedagogical strategies based on the social and affective aspects of the student

Undefined socio-affective scenarios in a virtual learning environment a view from learning analytics

There is a growing number of virtual courses being offered by Brazilian educational institutions, requiring the development of technological resources and research to assist in the teaching and learning processes in Distance Education (DE). The analysis of the students’ socio-affective profiles in Virtual Learning Environments (VLE) enables possibilities to develop methodologies and/or resources to better understand them. The Social Map (SM) and Affective Map (AM), both features of the Cooperative Learning Network (ROODA in Portuguese), provide inferences and graphic presentations of students’ socioaffective profiles. Thus, this article aims to identify students with Undefined Socio-affective Scenarios in a VLE, based on Learning Analytics (LA). LA is defined as the measurement, collection, and analysis of data. This qualitative and quantitative research approach was carried out based on 10 case studies. The target audience was divided between 77 undergraduate students, 29 graduate students, 27 elderly people, and 86 professors who participated in teaching activities at a Brazilian public university. Data collected from the SM and AM were extracted in order to identify the relationship between these two aspects. The result was 18 Socio-affective Scenarios using LA and the identification of 108 Pedagogical Strategies to contribute to the analysis of students’ learning profiles

Ferramenta de recomendação de estratégias pedagógicas em um ambiente virtual de aprendizagem

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How the Change in Horizon Area Drives Black Hole Evaporation

We rephrase the derivation of black hole radiation so as to take into account, at the level of transition amplitudes, the change of the geometry induced by the emission process. This enlarged description reveals that the dynamical variables which govern the emission are the horizon area and its conjugate time variable. Their conjugation is established through the boundary term at the horizon which must be added to the canonical action of general relativity in order to obtain a well defined action principle when the area varies. These coordinates have already been used by Teitelboim and collaborators to compute the partition function of a black hole. We use them to show that the probability to emit a particle is given by $e^{- \Delta A/4}$ where $\Delta A$ is the decrease in horizon area induced by the emission. This expression improves Hawking result which is governed by a temperature (given by the surface gravity) in that the specific heat of the black hole is no longer neglected. The present derivation of quantum black hole radiation is based on the same principles which are used to derive the first law of classical black hole thermodynamics. Moreover it also applies to quantum processes associated with cosmological or acceleration horizons. These two results indicate that not only black holes but all event horizons possess an entropy which governs processes according to quantum statistical thermodynamics.Comment: 26 pages latex, extensively revised version of gr-qc/9801043. Definitive version to be published in Nucl. Phys.

The gauge invariant effective potential: equilibrium and non-equilibrium aspects

We propose a gauge invariant formulation of the effective potential in terms of a gauge invariant order parameter, for the Abelian Higgs model. The one-loop contribution at zero and finite temperature is computed explicitly, and the leading terms in the high temperature expansion are obtained. The result is contrasted to the effective potential obtained in several covariant gauge-fixing schemes, and the gauge invariant quantities that can be reliably extracted from these are identified. It is pointed out that the gauge invariant effective potential in the one-loop approximation is complex for {\em all values} of the order parameter between the maximum and the minimum of the tree level potential, both at zero and non-zero temperature. The imaginary part is related to long-wavelength instabilities towards phase separation. We study the real-time dynamics of initial states in the spinodal region, and relate the imaginary part of the effective potential to the growth rate of equal-time gauge invariant correlation functions in these states. We conjecture that the spinodal instabilities may play a role in non-equilibrium processes {\em inside} the nucleating bubbles if the transition is first order.Comment: 27 pages revtex 3.0, no figures; one reference adde

Self-forces in the Spacetime of Multiple Cosmic Strings

We calculate the electromagnetic self-force on a stationary linear distribution of four-current in the spacetime of multiple cosmic strings. It is shown that if the current is infinitely thin and stretched along a line which is parallel to the strings the problem admits an explicit solution.Comment: This paper has been produced in Latex format and has 18 page