1,720,958 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
La evolución de la secuencia de Hubble
No full textEl presente artículo tiene como objetivo hacer una introducción de los resultados recientemente publicados por Delgado-Serrano et al. (2010). En dicho trabajo se realiza, por primera vez, un estudio comparativo de galaxias próximas y lejanas
La evolución de la secuencia de Hubble
No full textEl presente artículo tiene como objetivo hacer una introducción de los resultados recientemente publicados por Delgado-Serrano et al. (2010). En dicho trabajo se realiza, por primera vez, un estudio comparativo de galaxias próximas y lejanas
L évolution de la séquence de Hubble : morpho-cinématique des galaxies distantes
Get PDFThe main objective of my thesis was to provide us, for the first time, with a reliable wiev of the distant Hubble sequence, and its evolution over the past 6 Gyr. To achieve this goal, we have created a new morphological classification method which (1) includes all the available observational data, (2) can be easily reproduced, and (3) presents a negligible subjectivity. This method allows us to study homogeneously the morphology of local and distant galaxies, and has the main advantage of presenting a good correlation between the morphological type and dynamical state of each galaxy. The first step has been to study the evolution of galaxies using the IMAGES survey. This survey allowed us to establish the kinematic state of distant galaxies, to study the chemical evolution of galaxies over the past 8 Gyr, and to test important dynamical relations such as the Tully-Fisher relation. The information gained from kinematics is, indeed, crucial to guarantee a robust understanding of the different physical processes leading to the present day Hubble sequence. Using Integral Field Spectroscopy, which provides a complete kinematic diagnosis, we have been able to test our new morphological classification against the kinematic state of each galaxy. We found that the morpho-kinematic correlation is much better using our classification than other morphological classifications. Applying our classification to a representative sample of galaxies at z ∼ 0.6, we found that 4/5 of spiral galaxies are rotating disks, while more than 4/5 peculiar galaxies are not in a dynamical equilibrium. Appliyng our morphological classifications to a repesentative sample of both local and distant galaxies, having equivalent observational data, we obtained a Hubble sequence both in the local and distant Universe. We found that spiral galaxies were 5/2 times less adundant in the past, which is compensated exactly by the strong decrease by a factor 5 of peculiar galaxies, while the fractional number of elliptical and lenticular galaxies remains constant. It strongly suggests that more than half of the present-day spirals had peliculiar morphologies, 6 Gyr ago. Finally, I present further studies concerning the history of individual galaxies at z < 1, combining kinematic and morphological observations. I also present the first ever-estimated distant baryonic Tully-Fisher relation, which does not appear to evolve over the past 6 Gyr. In the coming years, our morphological classification and these studies will be extended to galaxies at z >> 1, thanks to the future ELTs.L'objectif principal de ma thèse était de fournir, pour la première fois, une vision fiable de la séquence de Hubble distante, et de son évolution au cours des dernières 6 milliards d'années. Pour atteindre cet objectif, nous avons construit une nouvelle classification morphologique qui (1) prend en compte toutes les données observationnelles disponibles, (2) peut être facilement reproduite, et (3) présente une subjectivité négligeable. Cette méthode peut être appliquée à l'étude morphologique des galaxies locales et distantes, et son principal avantage est de présenter une bonne corrélation entre le type morphologique et l'état dynamique de chaque galaxie. La première étape a été d'étudier l'évolution des galaxies grâce au relevé IMAGES. Ce relevé nous a permis d'établir l'état cinématique des galaxies lointaines, d'étudier leur évolution chimique depuis 8 milliards d'années, et de tester des relations dynamiques importantes telles que celle de Tully-Fisher. La cinématique est, en effet, une information cruciale nécessaire pour garantir une compréhension solide des différents processus physiques conduisant à la séquence de Hubble actuelle. En utilisant la spectroscopie intégrale de champ, qui fournnit un diagnostic cinématique complet, nous avons été en mesure de tester notre méthode de classification morphologique en fonction de l'état cinématique de chaque galaxie. En utilisant notre classification, nous avons trouvé une corrélation morpho-cinématique bien meilleur qu'avec d'autres classifications. En appliquant notre classification à un échantillon représentatif de galaxies à z ∼ 0.6, nous avons constaté que 4/5 galaxies spirales sont des disques en rotation, tandis que plus de 4/5 des galaxies particulières ne sont pas en équilibre dynamique. En appliquant notre classification morphologique à deux échantillons réprésentatifs de galaxies locales et distants, disposant des données observationnelles équivalentes, nous avons obtenu une séquence de Hubble dans l'Univers local et dans l'Univers distant. Nous avons trouvé que les galaxies spirales étaient 5/2 fois moins abondantes dans le passé, ce qui est compensé exactement par la forte diminution, par un facteur 5, des galaxies particulières, alors que la fraction de galaxies elliptiques et lenticulaires reste constante. Ce résultat suggère fortement que plus de la moitié des spirales d'aujourd'hui avait des morphologies particulières, 6 milliards d'années auparavant. Enfin, je présente de nouvelles études concernant l'histoire de galaxies individuelles à z < 1, en combinant des observations morphologiques et cinématiques. Je présente aussi la première étude concernant la relation Tully-Fisher baryonique lointaine, qui montre une absence d'évolution depuis 6 milliards d'années. Dans les années à venir, notre classification morphologique et ces études seront étendues aux galaxies à z >> 1, grâce aux futurs ELTs
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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