1,720,955 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
Etude et contrôle d'un écoulement turbulent décollé au moyen d'un jet balayant : application aux véhicules terrestres et aériens
No full textThis thesis investigates the experimental study of a sweeping jet and its application for controlling turbulent separated flows. Turbulent separations, a common phenomenon in many industrial applications, are known to degrade aerodynamic performances. Over the past decades, active flow control has emerged as a promising solution due to its adaptability to varying flow conditions. However, identifying an energy-efficient actuator capable of effectively managing flow separation remains a significant research challenge. In the first part of this study, a sweeping jet geometry is developed and characterised through hot-wire measurements. Results demonstrate that the proposed sweeping jet achieves high outlet jet velocities (up to 330 m/s) and frequencies (up to 2200 Hz), aligning well with the requirements for active flow control. The second part focuses on applying the characterised sweeping jet to control a canonical turbulent separation over a 25° sloped ramp. Wall pressure measurements, hot-wire anemometry, and PIV techniques are employed to assess the effects of the sweeping jet on aerodynamic performances and turbulent separation. Findings reveal that actuation angles of 30° and 45° significantly improve aerodynamic performance in the canonical ramp case. Despite these advancements, a comprehensive understanding of how the sweeping jet affects the separated shear layer remains elusive. The final section of this thesis addresses this gap by examining the control's influence on entrainment mechanisms that drive shear layer recovery. PIV measurements indicate that the sweeping jet enhances mass and momentum entrainment at the TNTI, energising the separated shear layer and mitigating or eliminating turbulent separation.Cette thèse porte sur l'étude expérimentale d'un jet balayant et de son application dans le cas du contrôle des écoulements turbulents décollés. Les décollements turbulents, un phénomène courant dans de nombreuses applications industrielles, sont connus pour dégrader les performances aérodynamiques. Au cours des dernières décennies, le contrôle actif des écoulements s'est imposé comme une solution prometteuse en raison de sa capacité à s'adapter aux conditions variables de l'écoulement contrôlé. Cependant, l'identification d'un actionneur énergétiquement économe capable de contrôler efficacement les décollements reste un défi de recherche important. Dans la première partie de cette étude, une géométrie de jet balayant est développée et caractérisée à l'aide de mesures par fil chaud. Les résultats montrent que le jet balayant proposé atteint des vitesses de jet de sortie élevées (jusqu'à 330 m/s) et des fréquences élevées (jusqu'à 2200 Hz), répondant ainsi aux exigences du contrôle actif. La deuxième partie se concentre sur l'application du jet balayant au contrôle d'un décollement turbulent sur une rampe inclinée à 25°. Des mesures de pression pariétale, de fil chaud et de vélocimétrie par image de particules (PIV) sont utilisées pour évaluer les effets du jet balayant sur les performances aérodynamiques et le décollement turbulent. Les résultats montrent que pour des angles d'actionnement de 30° et 45°, le jet balayant améliore significativement les performances aérodynamiques dans le cas canonique de la rampe. Malgré ces avancées, une compréhension complète de l'impact du jet oscillant sur la couche de cisaillement séparée fait encore défaut. La dernière partie de cette thèse aborde cette lacune en examinant l'influence du contrôle sur les mécanismes d'entraînement qui régissent le recollement de la couche de cisaillement. Les mesures PIV indiquent que le jet balayant augmente l'entraînement de masse et de quantité de mouvement à l'interface turbulente/non turbulente (TNTI), énergisant ainsi la couche de cisaillement décollée et atténuant ou supprimant la séparation turbulente
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
Etude et contrôle d'un écoulement turbulent décollé au moyen d'un jet balayant : application aux véhicules terrestres et aériens
No full textThis thesis investigates the experimental study of a sweeping jet and its application for controlling turbulent separated flows. Turbulent separations, a common phenomenon in many industrial applications, are known to degrade aerodynamic performances. Over the past decades, active flow control has emerged as a promising solution due to its adaptability to varying flow conditions. However, identifying an energy-efficient actuator capable of effectively managing flow separation remains a significant research challenge. In the first part of this study, a sweeping jet geometry is developed and characterised through hot-wire measurements. Results demonstrate that the proposed sweeping jet achieves high outlet jet velocities (up to 330 m/s) and frequencies (up to 2200 Hz), aligning well with the requirements for active flow control. The second part focuses on applying the characterised sweeping jet to control a canonical turbulent separation over a 25° sloped ramp. Wall pressure measurements, hot-wire anemometry, and PIV techniques are employed to assess the effects of the sweeping jet on aerodynamic performances and turbulent separation. Findings reveal that actuation angles of 30° and 45° significantly improve aerodynamic performance in the canonical ramp case. Despite these advancements, a comprehensive understanding of how the sweeping jet affects the separated shear layer remains elusive. The final section of this thesis addresses this gap by examining the control's influence on entrainment mechanisms that drive shear layer recovery. PIV measurements indicate that the sweeping jet enhances mass and momentum entrainment at the TNTI, energising the separated shear layer and mitigating or eliminating turbulent separation.Cette thèse porte sur l'étude expérimentale d'un jet balayant et de son application dans le cas du contrôle des écoulements turbulents décollés. Les décollements turbulents, un phénomène courant dans de nombreuses applications industrielles, sont connus pour dégrader les performances aérodynamiques. Au cours des dernières décennies, le contrôle actif des écoulements s'est imposé comme une solution prometteuse en raison de sa capacité à s'adapter aux conditions variables de l'écoulement contrôlé. Cependant, l'identification d'un actionneur énergétiquement économe capable de contrôler efficacement les décollements reste un défi de recherche important. Dans la première partie de cette étude, une géométrie de jet balayant est développée et caractérisée à l'aide de mesures par fil chaud. Les résultats montrent que le jet balayant proposé atteint des vitesses de jet de sortie élevées (jusqu'à 330 m/s) et des fréquences élevées (jusqu'à 2200 Hz), répondant ainsi aux exigences du contrôle actif. La deuxième partie se concentre sur l'application du jet balayant au contrôle d'un décollement turbulent sur une rampe inclinée à 25°. Des mesures de pression pariétale, de fil chaud et de vélocimétrie par image de particules (PIV) sont utilisées pour évaluer les effets du jet balayant sur les performances aérodynamiques et le décollement turbulent. Les résultats montrent que pour des angles d'actionnement de 30° et 45°, le jet balayant améliore significativement les performances aérodynamiques dans le cas canonique de la rampe. Malgré ces avancées, une compréhension complète de l'impact du jet oscillant sur la couche de cisaillement séparée fait encore défaut. La dernière partie de cette thèse aborde cette lacune en examinant l'influence du contrôle sur les mécanismes d'entraînement qui régissent le recollement de la couche de cisaillement. Les mesures PIV indiquent que le jet balayant augmente l'entraînement de masse et de quantité de mouvement à l'interface turbulente/non turbulente (TNTI), énergisant ainsi la couche de cisaillement décollée et atténuant ou supprimant la séparation turbulente
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
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
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