1,721,147 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
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
Multi-epoch combination of high-contrast direct imaging observations for joint exoplanet detection and orbit estimation
No full textLa détection et la caractérisation d'exoplanètes par imagerie directe nécessitent d'atteindre des contrastes et des résolutions angulaires très élevés. Ces conditions ne sont rencontrées qu'en combinant (i) des instruments de pointe équipés de systèmes coronographiques et d'optique adaptative extrêmes, (ii) des stratégies d'observation optimales, comme l'imagerie différentielle, pour introduire une diversité entre les signaux des objets d'intérêts et celui de l'étoile, et (iii) des algorithmes de post-traitement dédiés à l'élimination des fuites stellaires résiduelles. Concernant le dernier point, des efforts considérables ont été entrepris au cours de la dernière décennie dans la conception d'algorithmes de post-traitement plus efficaces. L'ensemble des processus d'acquisition et de traitement de données permet actuellement de détecter des exoplanètes massives à des séparations angulaires supérieures à quelques dizaines d'unité astronomique. Les performances restent toutefois limitées à des séparations angulaires plus faibles en raison du manque de diversité induit par le traitement individuel de chaque époque d'observation. Au cours de cette thèse, j'ai développé un nouvel algorithme capable de combiner plusieurs observations de la même étoile et permettant d'additionner constructivement les faibles signaux des exoplanètes recherchées tout en tenant compte de leur mouvement orbital képlérien à travers les époques. L'algorithme développé, appelé PACOME, intègre une exploration des orbites plausibles des objets recherchés à un formalisme statistique de détection et d'estimation basé sur le maximum de vraisemblance et modélisant les corrélations présentes dans les données. Cette méthode permet notamment de dériver un critère de détection multiépoque fiable et interprétable en termes de probabilité de détection. En plus de sa capacité à capturer les très faibles signaux issus d'exoplanètes, PACOME fournit simultanément des estimations de leurs éléments orbitaux et des incertitudes associées. La méthode nécessitant d'explorer, d'échantillonner et d'optimiser sur des espaces multidimensionnels, des outils numériques spécifiques ont également été mis en œuvre. Ce travail a été testé et validé sur plusieurs jeux de données astrophysiques obtenus avec l'instrument VLT/SPHERE. En recourant à des simulations réalistes, PACOME s'est avéré capable de détecter des sources très faibles restant indétectables par les techniques monoépoques de post-traitement les plus avancées. Le gain en sensibilité de détection augmente optimalement selon la racine carrée du nombre d'époques, comme prévu théoriquement. PACOME a également été appliqué à plusieurs systèmes exoplanétaires emblématiques tels que HD 95086 ou HR 8799, permettant ainsi de redétecter toutes les sources connues avec des rapports signal sur bruit très élevés et d'en déduire fidèlement les orbites. Le développement de cette méthode est également motivé, à moyen terme, par l'arrivée des prochains télescopes de trente mètres qui permettront d'explorer les environnements stellaires internes où les niveaux de contraste typiques à atteindre nécessiteront de longs temps d'exposition. Ceux-ci ne pourront être obtenus qu'en combinant plusieurs observations effectuées à des jours, des semaines ou des mois d'intervalle et pour lesquelles le mouvement orbital des exoplanètes devra impérativement être compensé, faisant de PACOME une méthode de choix.Exoplanet detection and characterization via direct imaging require both high contrast and high angular resolution. These requirements can only be achieved by combining (i) cutting-edge instrumental facilities equipped with extreme adaptive optics and coronagraphic systems, (ii) optimized differential imaging to introduce a diversity between the signals of the sought-for objects and that of the star, and (iii) dedicated post-processing algorithms to further reduce the residual stellar leakages. With respect to the third point, substantial efforts have been undertaken over this last decade on the design of more efficient post-processing algorithms. The whole data collection and retrieval processes currently allow to detect massive exoplanets at angular separations greater than a few dozen of astronomical units. The performances remain upper-bounded at shorter angular separations due to the lack of diversity induced by the processing of each epoch of observation individually. During this thesis, I developed a new algorithm that is able to combine several observations of the same star by accounting for the Keplerian orbital motion across epochs of the sought-for exoplanets in order to constructively co-add their weak signals. The proposed algorithm, PACOME, integrates an exploration of the plausible orbits of the sought-for objects within an end-to-end maximum likelihood-based statistical detection and estimation formalism that explicitly models and accounts for the correlations in the data. In particular, the latter enables the derivation of a reliable multi-epoch detection criterion, interpretable in terms of probability of detection. In addition to capturing very weak signals from extrasolar planets, PACOME simultaneously provides estimates of their orbital elements and associated uncertainties. As the method requires exploring, sampling and optimizing over multidimensional spaces, specific numerical tools were implemented as well. This work was tested and validated on several astrophysical datasets obtained from the VLT/SPHERE instrument. Through realistic simulations, PACOME proved itself capable of detecting very faint sources remaining undetectable by the most advanced single-epoch post-processing methods. The gain in detection sensitivity scales optimally as high as the square root of the number of epochs, as theoretically expected. PACOME was also applied on several iconic exoplanetary systems such as HD 95086 or HR 8799, allowing all known sources to be re-detected with very high signal-to-noise ratios, and their orbits to be reliably inferred. The development of this method is also motivated, in the medium term, by the upcoming thirty-meter class telescopes, which will enable exploring the inner stellar environments where the typical contrast levels to reach will require long exposure times. These will only be achieved by combining several observations conducted days, weeks or months apart, for which the orbital motion of the exoplanets will have be compensated, hence making PACOME a method of choice
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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