1,720,998 research outputs found

    Caracterização espectral multitemporal dos cereais de estação fria em imagens de satélite com média resolução espacial.

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    A fim de avaliar os padrões de resposta de áreas cultivadas com cereais de estação fria destinados para pastagens e para produção de grãos em imagens de satélite, foram analisados perfis temporais de índice de vegetação por diferença normalizada (NDVI), adquiridos em 29 áreas cultivadas com trigo e azevém anual, nos Estados do Rio Grande do Sul e Paraná. Para cada área foi informada a espécie cultivada (trigo ou azevém anual) e a coordenada do ponto central da área adquirido por meio do Global Positioning System (GPS). Foram usadas as imagens do sensor MODIS (Moderate Resolution Imaging Spectroradiometer), com resolução espacial de 250 metros, sobre cada área monitorada, de onde os valores de NDVI foram extraídos. Os perfis temporais de NDVI mostraram que os cultivos de produção de grãos têm um comportamento espectral típico de cultivos agrícolas, enquanto que, nas áreas cultivadas para a produção de pastagem, não foi observado esse mesmo padrão. As diferenças nos padrões temporais observadas se devem a modificações que o pastoreio impõe na fenologia e na morfologia dessas plantas.</jats:p

    Researching grasslands for complex production systems: an example with silvopastoralism.

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    There is a well established consensus that the main challenges addressing the future of agriculture in today?s world are the increasing human population and food consumption

    A integração lavoura-pecuária no contexto dos campos sul-brasileiros: a visão da Embrapa Pecuária Sul.

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    Equipe: Danilo Menezes Sant'Anna, Marcelo Pilon, Naylor Bastiani Perez, Vinícius do Nascimento Lampert

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    Variations on the Author

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    “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

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    We 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
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