1,721,034 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
On the characterization and detection of vortices
No full textExisting vortex detection algorithms were searched, compared, criticized and coded in python modules. Some of them were further developed, improved and tested in numerical solutions of helicopter configurations. The best performing scheme was a modified algorithm based on the velocity gradient tensor's properties. Vortex core lines were thus extracted and a set of automatized tools was created to compute vortex defining parameters, namely the radius and the circulation strength, showing their evolution with the wake age.Outgoin
On the characterization and detection of vortices
No full textExisting vortex detection algorithms were searched, compared, criticized and coded in python modules. Some of them were further developed, improved and tested in numerical solutions of helicopter configurations. The best performing scheme was a modified algorithm based on the velocity gradient tensor's properties. Vortex core lines were thus extracted and a set of automatized tools was created to compute vortex defining parameters, namely the radius and the circulation strength, showing their evolution with the wake age.Outgoin
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
Experimental study of a gaseous mixing zone induced by the Richtmyer-Meshkov instability with a periodic and weakly diffuse initial interface
No full textLe travail de thèse présenté dans ce manuscrit propose une analyse expérimentale du dé-veloppement spatio-temporel d’une zone de mélange (air/hélium) initiée par instabilité deRichtmyer-Meshkov (IRM). Cette étude s’appuie sur la mise en oeuvre d’un tube à chocspositionné verticalement et sur le développement d’un nouveau protocole expérimental associéà un système innovant de génération de l’interface initiale entre les deux espèces gazeuses enprésence. Ce système est basé sur un dispositif d’obturation/ouverture composé d’un rideau rigiderétractable et d’une série volets mobiles. La caractérisation de l’interface initiale et de l’évolutionspatio-temporelle de la zone de mélange ainsi obtenue est effectuée en exploitant les résultats dedifférentes techniques de mesures telles que la visualisation strioscopique (Schlieren) résolue entemps, la tomoscopie plan laser (TPL) et la Vélocimétrie par Imagerie de Particules (PIV). Enpremier lieu, différentes campagnes de mesures visant à caractériser l’interface initiale ont permisde quantifier la répétabilité du système et de démontrer ses capacités à générer une interfacepériodique faiblement diffuse. Dans un second temps, une étude du mélange gazeux obtenu pourun jeu de paramètres expérimentaux donné, est proposée. L’analyse s’intéresse en particulieraux mécanismes d’initiation et de transition a la turbulence de la zone de mélange produite parl’IRM. L’interaction entre cette zone de mélange en cours de développement et le choc réfléchisur l’extrémité supérieure du tube (phénomène de rechoc) est également étudiée dans l’optique deconfirmer la transition turbulente de la zone de mélange.This work proposes an experimental analysis of the spatio-temporal development of an air/heliummixing zone promoted by the Richtmyer-Meshkov instability (RMI). This study relies on the useof a vertical shock tube and on the development of a new experimental protocol associated with aninnovative device for the generation of an initial interface between two gazeous species. This deviceconsists a rigid retractable curtain and of a series of rotating shutters. The characterization ofthis initial interface and the spatio-temporal evolution of the RMI-induced mixing zone is carriedout by exploiting the results of various experimental methods such as time resolved Schlierenvisualizations, planar laser mie scattering and Particle Image Velocimetry (PIV). In a first step,various measurement campaigns have made it possible to quantify the repeatability of the newdevice and to demonstrate its ability to generate a periodic, weakly diffused interface. In a secondstep, a study of the gaseous mixing for a given set of experimental parameters is proposed. Theanalysis focuses on the understanding of the underlying mechanisms driving the gaseous interfaceformation and the transition to turbulence of the RMI-induced mixing. The interaction betweenthis mixing zone and the reflected shock from the upper end of the tube (re-shock phenomenon)is also studied in order to confirm the turbulent transition of the mixing zone
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
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
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