1,720,963 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

    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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    Preparation and dielectric investigations of Ba0.60Sr0.40TiO3 ferroelectric ceramics with different degree of porosity, presenting

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    By introducing a controlled porosity into the ceramic systems, the properties can be improved and make the material proper for being used as high-frequency ultrasonic transducers or for tunable applications. The tailored porosity exposes special properties and characteristics of the materials, which might be completely different than their conventional dense equivalents. The aim of this study was to characterize (Ba,Sr)TiO3 ceramics with different porosity levels. Powders with the composition Ba0.60Sr0.40TiO3 (BST) were prepared following the mixed oxide method by solid-state reaction at a sintering temperature of 1450°C for 2h. The BST ceramics with various porosities have been prepared by addition of lamellar graphite in concentration of 10, 20 and 35%. The effect of addition of graphite on dielectric properties was investigated. We noticed that the increasing of the amount of graphite increases the graded porosity and leads to a low mechanical quality factor. The relative density of the obtained samples varies from values around 95% for the dense ceramic to 66% for porous ceramics. Graphite was burned out through the sintering process and this resulted in a modification of morphology, microstructure and pore density of the ceramic product. The porous samples produced with homogeneous or graded porosity show a strong difference of the dielectric properties and microstructure in comparison with the dense ceramic samples. The role of anisotropic porosity on the functional properties on the dielectric properties is discussed. Microstructural, morphological and dielectric investigations have been performed and data were compared with other literature studies. From SEM analysis it was found that with addition of graphite as pore forming the samples present a fracture mode transformation from intragranular fracture to an intergranular fracture and a decreasing of grain size of BST. Furthermore, as BST grain size becomes smaller, the volume of grain boundary increases and the crack prefers spreading along grain boundary to splitting the strengthened grain. The Impedance Spectroscopy analyse was performed in the temperature range of (21-200)°C and frequency of 20Hz–2MHz. The dielectric investigations have shown that the dielectric constant of the Ba0.60Sr0.40TiO3 (BST) ceramics with different degree of porosity, decrease and remains constant at higher frequency, indicating dielectric dispersion. The frequency dependence of the real and imaginary part of permittivity present a few characteristic relaxations which appear in the specific frequency ranges: (i) the increasing of the real and imaginary parts of permittivity at low frequencies below 100Hz for the compositions with x=10, 20 and 35% graphite is most probably associated to the thermally activated space charge effects (Maxwell–Wagner phenomena) and (ii) anomalies of the imaginary part of permittivity above 103Hz, for samples with x=10 and 20% porosity, which seems to be related to a Debye-type relaxation process. The dielectric properties of the investigated ceramics were characterized and correlated with their microstructure. From dielectric constant dependence with temperature, a shift of Curie temperature of ceramics was observed and possible reasons for these effects were interpreted. Acknowledgements: This work was financially supported by CNCS-UEFISCDI projects PNII-ID-PCE-2011-30745 and by ERASMUS placement programme between Univ. “Al. I. Cuza” Iasi & ISTEC-CNR Faenza, Italy. The collaboration in frame of the COST Action MP0904 is highly acknowledgements

    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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