1,721,151 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Nancy dos Santos Casagrande, A implantação da Língua Portuguesa no Brasil do século XVI: Um percurso historiográfico
Full text linkEs una reseña de la obra: Nancy dos Santos Casagrande, A implantação da Língua Portuguesa no Brasil do século XVI: Um percurso historiográfico, São Paulo, Editora PUC-SP, 2005, 225 pp.It is a review of the work: Nancy dos Santos Casagrande, A implantação da Língua Portuguesa no Brasil do século XVI: Um percurso historiográfico, São Paulo, Editora PUC-SP, 2005, 225 pp.É uma revisão do trabalho: Nancy dos Santos Casagrande, A implantação da Língua Portuguesa no Brasil do século XVI: Um percurso historiográfico, São Paulo, Editora PUC-SP, 2005, 225 pp
On the effect of steel substrate alloying elements on the in-situ formation of intermediate thermal diffusion barrier layers
No full textThe aim of this work was to evaluate the feasibility of a hot-dipping aluminizing process, for the simultaneous production of an iron aluminide coating, a protective alumina topcoat layer and an intermediate thermal diffusion barrier layer, at the aluminide coating/steel substrate interface, the latter being thought in order to limit the detrimental depletion of Al content in the coating layer as a consequence of its inward diffusion towards the substrate. Indeed, the steel substrates were opportunely selected for their high weight percentages of alloying elements (namely Ni, Cr, Mn and Co) potentially able to diffuse from the substrate and react with the inward diffusing Al at the temperatures employed in the coating preparation, thus forming transition metal aluminides able to stop Al depletion, thus potentially prolong the lifetime of iron aluminide coatings in service. The effective in-situ growth of this intermetallic thermal diffusion layer was found to be strictly dependent on several factors, including the enthalpy of formation of the alloying-element aluminides, together with the atomic percentages of the selected alloying element in the steel substrate as well as its diffusion rate. The obtained results, can be considered an important contribution to the selection criteria of iron aluminides-coated steel substrates, to be employed in burdensome scenarios at high temperatures
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
Fifty years of Shannon information theory in assessing the accuracy and agreement of diagnostic tests
Full text linkSince 1948, Shannon theoretic methods for modeling information have found a wide range of applications in several areas where information plays a key role, which goes well beyond the original scopes for which they have been conceived, namely data compression and error correction over a noisy channel. Among other uses, these methods have been applied in the broad field of medical diagnostics since the 1970s, to quantify diagnostic information, to evaluate diagnostic test performance, but also to be used as technical tools in image processing and registration. This review illustrates the main contributions in assessing the accuracy of diagnostic tests and the agreement between raters, focusing on diagnostic test performance measurements and paired agreement evaluation. This work also presents a recent unified, coherent, and hopefully, final information-theoretical approach to deal with the flows of information involved among the patient, the diagnostic test performed to appraise the state of disease, and the raters who are checking the test results. The approach is assessed by considering two case studies: the first one is related to evaluating extra-prostatic cancers; the second concerns the quality of rapid tests for COVID-19 detection
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