765 research outputs found

    Akivis Superalgebras and speciality

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    In this paper we define Akivis superalgebra and study enveloping superalgebras for this class of algebras, proving an analogous of the PBW Theorem. Lie and Malcev superalgebras are examples of Akivis superalgebras. For these particular superalgebras, we describe the connection between the classical enveloping superalgebras and the corresponding generalized concept defined in this work

    The students' point of view about quality of educational multimedia software

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    The study reported here is part of an international project supported by EU (PEDACTICE - Educational Multimedia in Compulsory School: From Pedagogical Assessment to Product Assessment) and had as main goal to know the opinion and the perception of the Portuguese students about criteria of quality of educational multimedia software. In order to obtain elements on the student`s point of view about educational multimedia software, we decided to interview small groups of pupils who are involved in the work with multimedia materials and than gather, organize and analyse the information got. The sample of interviewed pupils can be considered as representative of the Lisbon schools attended by teachers and pupils very much interested in multimedia materials which these students use not only as an aid to learning activities but also as a support to home and school work. As main results of the study we can refer: a) the confirmation of the success of computers and multimedia among the young Portuguese student population, being manifest either in their attitudes or in the diversity of their experiences, including the technical mastery of informas; b) the acknowledgment, by the students, of the role of the school and of those of their teachers who had till now led the process; c) an unexpected emphasis attached by the students, mainly by the older ones, to the use of computer as a resource for school work which, till now, was done without it; and d) the rare use of the computer for supporting tasks of creative or autonomous nature.European Comissio

    A inovação como aposta para o desenvolvimento turístico sustentável do litoral centro de Portugal

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    O turismo costeiro é a actividade turística mais relevante em Portugal. Este facto devese essencialmente à extensa e diversificada linha de costa e à amenidade do clima do nosso país. No entanto, o turismo que se tem vindo a praticar nas áreas costeiras portuguesas não responde às questões da sustentabilidade que cada vez mais estão na base da competitividade dos destinos turísticos. A garantia de sustentabilidade e a atracção pelo novo e pelo diferente são factores essenciais à capacidade de atracção e competitividade de um determinado território. O sector turístico não foge à regra. Como tal é necessário inverter o modelo massificado que caracteriza o turismo costeiro e inovar nas formas e nos modelos propostos. O Centro Litoral de Portugal é uma região com fortes potencialidades turísticas, mas que se encontram subaproveitadas ou incorrectamente geridas. Nota-se, cada vez mais, uma quebra significativa da procura pela falta de qualidade que é oferecida aos turistas. Para tornar estas áreas atractivas é urgente torná-las inovadoras, apostando nas suas singularidades e oferecendo o que os outros não conseguem oferecer, através da exploração sustentável dos recursos endógenos. Pretendemos com este trabalho compreender de que forma o conceito de regiões inovadoras pode potenciar o desenvolvimento do turismo sustentável no Litoral Centro de Portugal

    The inverse of a tridiagonal kk-Toeplitz matrix

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    An square matrix is kk-Toeplitz if its diagonals are periodic sequences of period kk. We find rational formulas for the determinant, the characteristic polynomial, and the elements of the inverse of a tridiagonal kk-Toeplitz matrix (in particular, of any tridiagonal matrix) over any commutative unital ring, using only elementary linear algebra.Comment: 15 page

    Some (Hopf) algebraic properties of circulant matrices

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    We study some (Hopf) algebraic properties of circulant matrices, inspired by the fact that the algebra of circulant n×nn\times n matrices is isomorphic to the group algebra of the cyclic group with nn elements. We introduce also a class of matrices that generalize both circulant and skew circulant matrices, and for which the eigenvalues and eigenvectors can be read directly from their entries.Comment: 12 page

    Mecanismos explicativos das falsas memórias no paradigma DRM

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    Neste artigo apresenta-se uma revisão da literatura sobre as principais teorias e mecanismos explicativos da ocorrência de falsas memórias no paradigma Deese-Roediger-McDermott (DRM). São também apresentados dados de artigos empíricos que suportam cada uma das teorias, e discutidas as suas implicações para a compreensão deste fenômeno. Historicamente, as primeiras explicações teóricas centravam-se no conceito de associação para explicar as intrusões em tarefas de memória. Mais tarde, o conceito de ativação assumiu grande relevância para explicar a ocorrência de memórias falsas no paradigma DRM. Contudo, o conceito de ativação revelou-se insufi ciente para explicar alguns resultados descritos por vários autores. Assim, junto com os mecanismos de ativação, as duas grandes teorias explicativas (teoria de ativação e monitoramento e teoria do traço difuso) consideram a existência de mecanismos de monitoramento ou controle. Os mecanismos de monitoramento permitem explicar a diminuição ou o desaparecimento das memórias falsas em algumas condições experimentais. Apesar de serem diferentes, as visões de ambas as teorias não são inconciliáveis e talvez sejam necessárias para a integral compreensão das falsas memórias no paradigma DRM. Assim, propõe-se a adoção de uma abordagem teórica que integre contributos das duas teoriasThis literature review explores the major theories and explanatory mechanisms in the occurrence of false memories in the Deese-Roediger-McDermott paradigm (DRM). This study presents data from empirical studies that support each of the theories and discusses their implications for understanding false memories. Historically, the fi rst theories explaining false memories focused on the concept of association in order to explain intrusions in memory tasks. Later on, the concept of activation received greater importance in explaining false memories in the DRM paradigm. However, activation by itself is insuffi cient to explain all the results described by several authors. Therefore, the two current major theories that explain false memories in the DRM paradigm (activation monitoring theory and fuzzy trace theory) consider the existence of monitoring or control mechanisms, together with activation mechanisms. These monitoring mechanisms, which operate in opposite direction to activation mechanisms, explain the decrease or disappearance of false memories under certain circumstances. Although different, activation monitoring and fuzzy trace theories have reconcilable perspectives and may be both necessary for a comprehensive understanding of false memories in the DRM paradigm. Thus, we propose the adoption of a theoretical approach that integrates contributionsfrom both theories
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