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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
Modélisation de la tenue en fatigue d'assemblages métalliques par une approche locale
No full textNowadays, two important challenges to be addressed in fatigue prediction deal with multiaxiality and random loads, especially when both effects are combined. This is particularly true in assembled aircraft structures where many nonlinear phenomena interact (non-linearity of the behavior of material, contact with friction, behavior of the screw ...). The aim of this thesis is to develop a robust fatigue life prediction approach for estimating the fatigue life of bolted metallic assemblies subjected to a variety of multiaxial loading conditions. It consists in predicting the fatigue life of assembled parts using a local approach based on explicit modeling of the fastener and induced forces. For this purpose, a major experimental campaign has been undertaken with experiments of increasing complexity ranging from uniaxial characterization specimens, to complex multiaxially loaded assemblies by means of a biaxial (tension/compression) experimental device. At the same time, a numerical finite element analysis was carried out to model representative industrial assemblies as faithfully as possible, taking into account all observed non-linearities (geometric, induced by the contact problem, secondary bending, notching, material...). The dialog between experimental results and numerical simulations has allowed us to test and validate the fatigue damage model developed, as well as to improve our understanding of crack initiation mechanisms in bolted metal assemblies subjected to multiaxial loading.De nos jours, deux défis importants à relever en matière de prédiction de la tenue fatigue concernent la multiaxialité et les sollicitations aléatoires, en particulier lorsque ces deux effets sont combinés. Ceci est particulièrement vrai dans les structures aéronautiques assemblées où de nombreux phénomènes non-linéaires interagissent (non-linéarité du comportement du matériau, contact avec frottement, comportement de la fixation...). L'objectif de cette thèse est de proposer une démarche de prédiction de tenue en fatigue robuste, afin d'estimer la durée de vie en fatigue d'assemblages métalliques boulonnés soumis à des conditions de sollicitations multiaxiales variées. Il s'agit d'estimer la durée de vie de pièces assemblées par une approche locale reposant sur une modélisation explicite de la fixation et des efforts induits. À cette fin, une campagne expérimentale majeure a été entreprise avec des essais de complexité croissante allant d'éprouvettes de caractérisation uniaxiale, à des assemblages complexes chargés multiaxialement au moyen d'un dispositif expérimental biaxial. Parallèlement, une analyse numérique par éléments finis a été réalisée pour modéliser aussi fidèlement que possible des assemblages industriels représentatifs, en tenant compte de toutes les non-linéarités observées (géométriques, induites par le problème de contact, la flexion secondaire, l'entaille, le matériau ...). Le dialogue entre les résultats expérimentaux et les simulations numériques a permis de tester et de valider le modèle d'endommagement de fatigue développé, ainsi que de mieux comprendre les mécanismes d'amorçages de fissures dans les assemblages métalliques boulonnés soumis à des chargements multiaxiaux
Fatigue modeling of metallic assemblies using a local approach
No full textDe nos jours, deux défis importants à relever en matière de prédiction de la tenue fatigue concernent la multiaxialité et les sollicitations aléatoires, en particulier lorsque ces deux effets sont combinés. Ceci est particulièrement vrai dans les structures aéronautiques assemblées où de nombreux phénomènes non-linéaires interagissent (non-linéarité du comportement du matériau, contact avec frottement, comportement de la fixation...). L'objectif de cette thèse est de proposer une démarche de prédiction de tenue en fatigue robuste, afin d'estimer la durée de vie en fatigue d'assemblages métalliques boulonnés soumis à des conditions de sollicitations multiaxiales variées. Il s'agit d'estimer la durée de vie de pièces assemblées par une approche locale reposant sur une modélisation explicite de la fixation et des efforts induits. À cette fin, une campagne expérimentale majeure a été entreprise avec des essais de complexité croissante allant d'éprouvettes de caractérisation uniaxiale, à des assemblages complexes chargés multiaxialement au moyen d'un dispositif expérimental biaxial. Parallèlement, une analyse numérique par éléments finis a été réalisée pour modéliser aussi fidèlement que possible des assemblages industriels représentatifs, en tenant compte de toutes les non-linéarités observées (géométriques, induites par le problème de contact, la flexion secondaire, l'entaille, le matériau ...). Le dialogue entre les résultats expérimentaux et les simulations numériques a permis de tester et de valider le modèle d'endommagement de fatigue développé, ainsi que de mieux comprendre les mécanismes d'amorçages de fissures dans les assemblages métalliques boulonnés soumis à des chargements multiaxiaux.Nowadays, two important challenges to be addressed in fatigue prediction deal with multiaxiality and random loads, especially when both effects are combined. This is particularly true in assembled aircraft structures where many nonlinear phenomena interact (non-linearity of the behavior of material, contact with friction, behavior of the screw ...). The aim of this thesis is to develop a robust fatigue life prediction approach for estimating the fatigue life of bolted metallic assemblies subjected to a variety of multiaxial loading conditions. It consists in predicting the fatigue life of assembled parts using a local approach based on explicit modeling of the fastener and induced forces. For this purpose, a major experimental campaign has been undertaken with experiments of increasing complexity ranging from uniaxial characterization specimens, to complex multiaxially loaded assemblies by means of a biaxial (tension/compression) experimental device. At the same time, a numerical finite element analysis was carried out to model representative industrial assemblies as faithfully as possible, taking into account all observed non-linearities (geometric, induced by the contact problem, secondary bending, notching, material...). The dialog between experimental results and numerical simulations has allowed us to test and validate the fatigue damage model developed, as well as to improve our understanding of crack initiation mechanisms in bolted metal assemblies subjected to multiaxial loading
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
Modélisation de la tenue en fatigue d'assemblages métalliques par une approche locale
No full textNowadays, two important challenges to be addressed in fatigue prediction deal with multiaxiality and random loads, especially when both effects are combined. This is particularly true in assembled aircraft structures where many nonlinear phenomena interact (non-linearity of the behavior of material, contact with friction, behavior of the screw ...). The aim of this thesis is to develop a robust fatigue life prediction approach for estimating the fatigue life of bolted metallic assemblies subjected to a variety of multiaxial loading conditions. It consists in predicting the fatigue life of assembled parts using a local approach based on explicit modeling of the fastener and induced forces. For this purpose, a major experimental campaign has been undertaken with experiments of increasing complexity ranging from uniaxial characterization specimens, to complex multiaxially loaded assemblies by means of a biaxial (tension/compression) experimental device. At the same time, a numerical finite element analysis was carried out to model representative industrial assemblies as faithfully as possible, taking into account all observed non-linearities (geometric, induced by the contact problem, secondary bending, notching, material...). The dialog between experimental results and numerical simulations has allowed us to test and validate the fatigue damage model developed, as well as to improve our understanding of crack initiation mechanisms in bolted metal assemblies subjected to multiaxial loading.De nos jours, deux défis importants à relever en matière de prédiction de la tenue fatigue concernent la multiaxialité et les sollicitations aléatoires, en particulier lorsque ces deux effets sont combinés. Ceci est particulièrement vrai dans les structures aéronautiques assemblées où de nombreux phénomènes non-linéaires interagissent (non-linéarité du comportement du matériau, contact avec frottement, comportement de la fixation...). L'objectif de cette thèse est de proposer une démarche de prédiction de tenue en fatigue robuste, afin d'estimer la durée de vie en fatigue d'assemblages métalliques boulonnés soumis à des conditions de sollicitations multiaxiales variées. Il s'agit d'estimer la durée de vie de pièces assemblées par une approche locale reposant sur une modélisation explicite de la fixation et des efforts induits. À cette fin, une campagne expérimentale majeure a été entreprise avec des essais de complexité croissante allant d'éprouvettes de caractérisation uniaxiale, à des assemblages complexes chargés multiaxialement au moyen d'un dispositif expérimental biaxial. Parallèlement, une analyse numérique par éléments finis a été réalisée pour modéliser aussi fidèlement que possible des assemblages industriels représentatifs, en tenant compte de toutes les non-linéarités observées (géométriques, induites par le problème de contact, la flexion secondaire, l'entaille, le matériau ...). Le dialogue entre les résultats expérimentaux et les simulations numériques a permis de tester et de valider le modèle d'endommagement de fatigue développé, ainsi que de mieux comprendre les mécanismes d'amorçages de fissures dans les assemblages métalliques boulonnés soumis à des chargements multiaxiaux
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
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