1,721,349 research outputs found
Cepheid radii and the CORS method revisited
No full textWe have refined the CORS method, introduced in 1980 for the computation of the cepheid radii, in order to extend its applicability to recent and extensive sets of observations. The refinement is based on the computation, from observational data only, of one of the terms of the solving equation, previously based only on precise calibrations of photometric colours. A limited number of assumptions, generally accepted in the literature, is used.\par New radii are computed for about 70 cepheids, and the resulting P-R relation is discussed
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
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
Predicted properties of RR lyrae stars in the sloan digital sky survey photometric system
Full text linkThe luminosities and effective temperatures, as well as the whole bolometric light curves of non-linear convective RR Lyrae models with 0.0001 <= Z <= 0.006, are transformed into the Sloan Digital Sky Survey (SDSS) photometric system. The obtained ugriz light curves, mean magnitudes and colours, pulsation amplitudes and colour-colour loops are shown and analytical relations connecting pulsational to intrinsic stellar parameters, similar to the ones currently used in the Johnson-Cousins filters, are derived. Finally, the behaviour in the colour-colour planes is compared with available observations in the literature and possible systematic uncertainties affecting this comparison are discussed
Cepheid radii and the CORS method revisited
No full textWe have rened the CORS method, introduced in 1980 for the computation of the cepheid radii, in order to extend
its applicability to recent and extensive sets of observations.
The renement is based on the computation, from observational data only, of one of the terms of the solving equation, previously based only on precise calibrations of photometric colors. A limited number of assumptions, generally accepted in the literature, is used.
New radii are computed for about 70 cepheids, and the resulting P-R relation is discussed
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