1,720,987 research outputs found

    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

    Multi-angle color prediction of glossy anodized titanium samples through the determination of the oxide layer structural parameters

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    The purpose of the present study is to predict the whole chromatic path traveled by the colors of glossy anodized titanium samples in every specular geometry. It is based on measurements of the samples’ reflectance spectra in a limited number of specular geometries, which allow us to obtain the oxide layer structural parameters (thickness, refractive index), which are then put into an optical model to predict the samples’ reflectance spectra in every specular geometry. A good color prediction performance is obtained, with an average 1E94 color distance over all samples and geometries of 1.9. The oxide layer structural parameters are also in good agreement with refractive index values extracted from the literature and thicknesses measured on electron microscopy images of sample sections

    Determination of oxidized metals' oxide layer thickness from local extrema of reflectance spectra: Theoretical basis and application to anodized titanium

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    The present paper concerns the oxide layer thickness determination of oxidized metals in the case where an optical interference phenomenon occurs due to multiple reflections inside the oxide layer. The paper focuses on anodized titanium but can be extended to the layer thickness determination of any material composed of a non-absorbing layer over an absorbing substrate. It establishes theoretical formulae to compute the oxide layer thickness from the positions of the local extrema of the material reflectance spectra. In contrast with many publications these formulae take into account the air/oxide and oxide/metal interfaces' electromagnetic phase-shift. They make also the distinction between TE-, TM- and non-polarized light and are valid for all incidence angles. By applying these formulae to simulated reflectance spectra with known oxide thicknesses, we show that neglecting the interface phase-shift is not appropriate for determining the oxide thickness of samples with thin oxide thicknesses, with for example a relative error on the thickness higher than 85% for a 20 nm thick layer for normally incident light. When the interface phase-shift is taken into account this relative error goes down to 3%. Nevertheless the light polarization has to be carefully selected for incidence angles close to the Brewster angle of the air/oxide interface. This paper shows also that the relative error on the oxide thickness determination is relatively well correlated with the relative standard deviation characterizing the discrepancy of the oxide thickness values obtained from different positions of extrema. The typical behavior with polarization and incidence angle of this standard deviation predicted by the theoretical study is in good agreement with the experimental behavior observed for anodized titanium samples

    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

    Dispelling the Myths Behind First-author Citation Counts

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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
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