1,721,097 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
Contribution to the Prediction of Abdominal Aortic Aneurysms (AAA) Rupture
No full textL'objectif de ce travail est de contribuer à une meilleure prédiction de la rupture des Anévrismes de l'Aorte Abdominale. Pour ce faire, des simulations par éléments finis ont été mises en oeuvre sur des anévrismes modèles dans des conditions proches de la réalité physiopathologique, i.e. en tenant compte de l'anisotropie de la paroi anévrismale, du caractère poreux du thrombus et des Interactions Fluide-Structure. Dans la première partie, une étude statique en l'absence du thrombus a permis de mettre en évidence l'influence de la géométrie de l'anévrisme et du comportement mécanique (isotrope ou anisotrope) de la paroi sur la distribution des contraintes, i.e. la rupture potentielle de l'anévrisme, ainsi que sur l'évolution du module de Peterson. Dans la seconde partie, une modélisation poro-hyperélastique du thrombus est proposée, en s'appuyant sur des données expérimentales de la littérature. La prise en compte de ce comportement et des Interactions Fluide-Structure montre que la pression intra-thrombus demeure du même ordre de grandeur que la pression intra-luminale, conformément à des mesures in vivo réalisées par ailleurs. Enfin, nous montrons que ceci n'est pas en contradiction avec une réduction du risque de rupture potentielle de l'anévrisme.The aim of this work is to contribute to a better prediction of the Abdominal Aortic Aneurysm rupture (AAA). For that purpose, finite elements simulations have been performed on idealized AAA models under physiopathological like conditions, by taking into account the aneurysmal wall anisotropy, the intra-luminal thrombus porosity and the Fluid-Structure Interactions. In the first part, the influence of the aneurysm geometry and its wall properties (isotropic or anisotropic hyperelasticity) on the wall stress distribution and the Peterson's modulus has been studied in a static analysis and without taking into account the thrombus. In the second part, based on the experimental results from the litterature, a porohyperelastic model has been proposed for the thrombus. By considering such behavior for the thrombus and the Fluid-Structure Interactions, we observe that the intra-thrombus pressure is the same order as the intra-luminal pressure, which is consistent with in vivo measurements. Our results show that despite this unchanged pressure, the maximum wall stress decreases leading to a decrease of the aneurysm potential rupture
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
Experimental characterization and multi-scale modeling of the transport of heat and mass in dry and wet snow
No full textL’objectif principal de la thèse est de décrire le transport de chaleur et de masse pour différentes conditions de métamorphoses de neige, depuis l’échelle des pores jusqu’à l’échelle d’une couche de neige.Les points importants de cette caractérisation sont l’identification des processus physiques importants des métamorphoses et des propriétés de la neige à fine échelle, et leur modélisation à l’échelle macroscopique.En premier lieu, les processus physiques à l’oeuvre dans la neige sèche soumise à la métamorphose d’équi-température sont observés à l’aide d’un modèle 3-D à champ de phase à l’échelle du grain. Les propriétés de microstructure et de transport sont analysées et une estimation du coefficient de condensation, un paramètre mal contraint qui décrit l’intensité des changements de phase, est estimé en comparant les simulations à des données expérimentales.En second lieu, les processus physiques de la neige sèche soumise à la métamorphose de gradient thermique sont explorés selon une approche expérimentale et théorique. Deux expériences en chambre froide sont réalisées pour suivre l’évolution de la microstructure de la neige sous gradient de température, ainsi que les champs de température et d’humidité dans la couche de neige. Ces observations ont mis en évidence deux processus à l’échelle des grains peu documentés jusqu’à présent : la formation d’hétérogénéités dans la couche de neige causées par la dépendance de la croissance des grains à la température et la formation d’une fine couche d’air à la base de la couche de neige causée par le transport vertical de vapeur.Pour modéliser les transport de chaleur et de masse sous gradient thermique à l’échelle de la couche de neige, la méthode de changement d’échelle d’homogénéisation a été appliquée. Elle permet de dériver depuis la fine échelle, les modèles macroscopiques équivalents en considérant pour la première fois la gamme complète des valeurs du coefficient de condensation. Les performances et les limites des modèles sont ensuite estimées en comparant les simulations aux deux expériences précédemment réalisées.Enfin, le transport de chaleur et de masse dans la neige humide a été étudié par une approche numérique et théorique. D’une part, les équations de la physique à fine échelle ont été réunies afin de proposer une homogénéisation pour un cas simple, incluant des paramètres effectifs spécifiques à la neige humide. D’autre part, de l’eau liquide a été numériquement introduite dans des images 3-D tomographiques de neige sèche à différents niveaux de saturation. Les courbes de rétention d’eau ont été analysées et les propriétés de transport effectives dans la neige humide ont finalement été estimées.The thesis focuses on describing heat and mass transport for various conditions of snow metamorphism, from the pore scale to the snow layer scale. The key points of this characterization are to identify the important physical processes of metamorphism and snow properties at the pore scale and to provide their modelings at the macroscopic scale.First, the processes of dry snow under equi-temperature metamorphism (ETM) are investigated using a 3-D phase-field model at the pore scale. Microstructural and transport properties are analyzed and an estimation of the condensation coefficient, a poorly constrained parameter that drives the intensity of phase change processes, is estimated by comparing the model to experimental data.Second, the processes of dry snow under temperature gradient metamorphism (TGM) are explored based on experimental and theoretical approaches. Two cold-room experiments were conducted to monitor the evolution of the snow microstructure under a temperature gradient as well as the temperature and humidity fields in the snow layer. Those observations highlighted two pore-scale processes, little documented until now, which are: the formation of a heterogeneous snow layer due to the dependency of grain growth on temperature, and the formation of an air gap at the base of the snow layer by vertical vapor flux.On the modeling side, to describe heat and mass transfer under TGM at the snow layer scale, the upscaling method of homogenization was applied. It enables the derivation of the equivalent macroscopic modelings from the physics at the pore scale, considering for the first time the full range of condensation coefficients. The performances and limitations of the obtained models were then evaluated by comparing the simulations to the latter experiments.Finally, heat and mass transfer in wet snow is investigated by numerical and theoretical approaches. The fine-scale physical equations were gathered to propose an homogenization for a simple case, involving effective properties specific to wet snow. Then, liquid water was numerically included in 3-D tomographic images of dry snow with different levels of saturation. Water retention curves were analyzed and the transport effective properties of wet snow were estimated. This numerical study comes along with a theoretical study of the pore-scale processes of wet snow metamorphism
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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