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    An algorithm for localization of cylinders by reflection mode scattered field

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    The problem of localizing perfectly electrical conducting cylinders of arbitrary radius is dealt with in a two dimensional geometry. A reflection mode multi-frequency multi-bistatic configuration is considered, and a linear inversion algorithm based on the truncated singular values decomposition is proposed. The algorithm is validated against simulated data, and the effect of errors in the knowledge of the cylinders' radius is discussed

    Assessment of an inverse algorithm for cylinders localization

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    We examine how an algorithm for localizing cylinders of arbitrary known radius is affected by errors in the radius knowledge. Reflection mode multi-frequency multi-bistatic configuration is considered. The problem is first examined in far zone, where analytical results can be found. Then, numerical results for the near zone case are provided and a procedure to estimate the cylinder's radius, if it is not known, is introduced. The expected behavior is tested against simulated and experimental data for both perfectly electrical conducting and dielectric cylinders embedded into a lossless homogeneous background. Numerical results of localization of objects embedded into a lossy half space are also shown

    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
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