1,721,002 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Reconciling the emission mechanism discrepancy in Mira's tail and its evolution in an interface with shear
Get PDFGalaxy Evolution Explorer observations of the Mira AB binary system revealed a surrounding structure that has been successfully hydrodynamically interpreted as a bow shock and tail of ram-pressure-stripped material. Even the narrow tail, initially difficult to model, has been understood to be the effect of the passage of Mira from a warm neutral medium into a hot, low-density medium, postulated to be the Local Bubble. However, no model to date has explained the observed kink and associated general curvature of the tail. We test the hypothesis that before entering the Local Bubble, Mira was traveling through a shear flow with approximately 1/3 Mira's own velocity at an angle of 30° to Mira's proper motion. The hypothesis reproduces the kinked nature of Mira's tail and predicts recompression and reheating of the tail material to the same or greater levels of density and temperature predicted in the shock. This provides a heat source for the FUV emission, allowing for an extended lifetime of the FUV emission in line with other estimates of the age of the tail. The uniqueness of Mira's situation implies that the chances of observing other FUV tails behind asymptotic giant branch stars are highly unlikely.dium into a hot, low-density medium, postulated to be the Local Bubble. However, no model to date has explained the observed kink and asso- ciated general curvature of the tail. We test the hypothesis that before entering the Local Bubble, Mira was travelling through a shear ow with approximately 1/3 Mira's own velocity at an angle of 30 to Mira's proper motion. The hypothesis reproduces the kinked nature of Mira's tail and predicts recompression and reheating of the tail material to the same or greater levels of density and temperature predicted in the shock. This provides a heat source for the FUV emission, allowing for an extended lifetime of the FUV emission in line with other estimates of the age of the tail. The uniqueness of Mira's situation implies that the chances of observing other FUV tails behind AGB stars is highly unlikely
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe 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
Rebrightening of Planetary Nebulae Through Interaction with the Interstellar Medium
Get PDFThe interaction of planetary nebulae (PNe) with the interstellar medium (ISM) as they move through it is now acknowledged to be a major shaping effect not just for ancient and large PNe, but also for relatively young PNe with high-speed central stars. The most common effect is a rebrightening as the PN shell interacts with a pre-existing bow-shock structure formed during the previous evolutionary phase of the central star. In this review we consider this rebrightening in detail for the first time and discuss its origins, highlighting some observed examples. We go on to discuss the AGB progenitor stars, reviewing the evidence for bow-shock structures, and consider the progeny of rebrightened PNe — strongly disrupted objects which bear very little resemblance to typical PNe. Sh 2-68 is inferred to be perhaps the only documented case so far of such a PN
Wonderful Mira.
Get PDFSince being named 'wonderful' in the seventeenth century for its peculiar brightness variability, Mira A has been the subject of extensive research and become the prototype for a whole class of 'Mira' variable stars. The primary star in a binary system, Mira A is reaching the end of its life and currently undergoing an extended period of enhanced mass loss. Recent observations have revealed a surrounding arc-like structure and a stream of material stretching 12 light years away in opposition to the arc. In this article, I review recent modelling of this cometary appearance as a bow shock with an accompanying tail of material ram pressure stripped from the head of the bow shock, place Mira in an evolutionary context, predict its future with reference to the similar star R Hya and planetary nebula Sh 2-188, and speculate some avenues of research both on Mira itself and on other 'Mira-like' stars with bow shocks and tails. I also discuss the implications of this discovery for our own star, the Sun
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