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    Délégation et hiérarchie

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    Delegation and hierarchy Three reasons are given in agency models to justify the choice of a three-level hierarchy as the organization's internal structure : communication costs, double moral hazard and contract incompleteness. In this paper, we suggest another explanation. We show, in a simple model, that a three-level hierarchy is the optimal internal structure when the different tasks of the agency strongly overlap.Délégation et hiérarchie Cet article se propose d'apporter une explication à l'introduction d'un niveau intermédiaire dans une relation principal-agent. Les trois arguments qui sont principalement avancés dans les modèles d'agence pour expliquer le choix d'une hié­rarchie à trois échelons comme structure interne d'organisation sont le coût de la communication, la présence de double risque moral et le caractère incomplet des contrats. Nous proposons une autre justification dans cet article. Nous montrons, dans le cadre d'un modèle simple, qu'une hiérarchie à trois échelons est une structure interne optimale lorsque les activités de l'agence sont fortement imbriquées.Vafaï Kouroche, Anvar Shebli. Délégation et hiérarchie. In: Revue économique, volume 49, n°5, 1998. pp. 1199-1225

    METHODOLOGIE DE DEVELOPPEMENT ET DE MODELISATION UML DES SYSTEMES D'ACQUISITION ET DE TRAITEMENT EN TEMPS REEL POUR LES EXPERIENCES DE PHYSIQUE DES HAUTES ENERGIES

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    Jury : Reza ANSARI (président), Jean-Marc GEIB (rapporteur), François TERRIER (directeur), Sylvain TISSERANT (rapporteur), Bertrand VALLAGEThe increasing complexity of the real-time data acquisition and processing systems (TDAQ : the so-called Trigger and Data AcQuisition systems) in high energy physics calls for an appropriate evolution of development tools. This work is about the interplay between in principle specifications of TDAQ systems and their actual design and realization on a concrete hardware and software platform. The basis of our work is to define a methodology for the development of TDAQ systems that meets the specific demands for the development of such systems. The result is the detailed specification of a “methodological framework” based on the Unified Modeling Language (UML) and designed to manage a development process. The use of this UML-based methodological framework progressively leads to the setting up of a “home-made” framework, i.e. a development tool that comprises reusable components and generic architectural elements adapted to TDAQ systems. The main parts of this dissertation are sections II to IV. Section II is devoted to the characterization and evolution of TDAQ systems. In section III, we review the main technologies that are relevant to our problematic, namely software reuse techniques such as design patterns and frameworks, especially concerning the real-time and embedded systems domain. Our original conceptual contribution is presented in section IV, where we give a detailed, formalized and example-driven specification of our development model. Our final conclusions are presented in section V, where we present the MORDICUS project devoted to a concrete realization of our UML methodological framework, and the deep affinities between our work and the emerging “Model Driven Architecture” (MDA) paradigm developed by the Object Management Group.La complexité croissante des systèmes d'acquisition et de traitement en temps réel (TDAQ) pour les expériences de physique des hautes énergies appelle à une évolution ad hoc des outils de développement. Dans cet ouvrage, nous traitons de l'articulation entre la spécification de principe des systèmes TDAQ et leur conception/réalisation sur une plateforme matérielle et logicielle concrète. Notre travail repose sur la définition d'une méthodologie de développement des systèmes TDAQ qui réponde aux problématiques de développements particulières à ces systèmes. Il en résulte la spécification détaillée d'un « canevas méthodologique » basé sur le langage UML, destiné à encadrer un processus de développement. L'usage de ce canevas méthodologique UML doit permettre la mise en place progressive d'un canevas « maison », c'est-à-dire un atelier de développement comprenant des composants réutilisables et des éléments d'architecture génériques adaptés aux applications TDAQ. L'ouvrage s'articule autour de 4 sections principales. La section II est dévolue à la caractérisation et à l'évolution des systèmes TDAQ. En section III, nous nous intéressons aux technologies pertinentes pour notre problématique, notamment les techniques de réutilisation logicielle telles les motifs récurrents (design patterns) et les canevas (frameworks), avec une orientation en faveur des domaines du temps réel et de l'embarqué. Notre apport conceptuel spécifique est exposé en section IV, où nous procédons notamment à la spécification détaillée, formalisée et exemples à l'appui, de notre modèle de développement. Enfin, nous terminons notre propos en section V en évoquant le projet de R&D MORDICUS de mise en œuvre concrète de notre canevas méthodologique UML, ainsi que les développements récents de l'OMG (Object Management Group) sur l'architecture orientée modèles (Model Driven Architecture), particulièrement en résonance avec notre travail

    Méthodologie de développement et de modélisation UML des systèmes d'acquisition et de traitement en temps réel pour les expériences de physique des hautes énergies

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    La complexité croissante des systèmes d'acquisition et de traitement en temps réel (TDAQ) pour les expériences de physique des hautes énergies appelle à une évolution ad hoc des outils de développement. Dans cet ouvrage, nous traitons de l'articulation entre la spécification de principe des systèmes TDAQ et leur conception/réalisation sur une plateforme matérielle et logicielle concrète. Notre travail repose sur la définition d'une méthodologie de développement des systèmes TDAQ qui réponde aux problématiques de développement particulières à ces systèmes. Il en résulte la spécification détaillée d'un "canevas méthodologique" basé sur le langage UML, destiné à encadrer un processus de développement. L'usage de ce canevas méthodologique UML doit permettre la mise en place progressive d'un canevas " maison ", c'est-à-dire un atelier de développement comprenant des composants réutilisables et des éléments d'architecture génériques adaptés aux applications TDAQ. L'ouvrage s'articule autour de 4 sections principales. La section II est dévolue à la caractérisation et à l'évolution des systèmes TDAQ. En section III, nous nous intéressons aux technologies pertinentes pour notre problématique, notamment les techniques de réutilisation logicielle telles les motifs récurrents (design patterns) et les canevas (frameworks), avec une orientation en faveur des domaines du temps réel et de l'embarqué. Notre apport conceptuel spécifique est exposé en section IV, où nous procédons notamment à la spécification détaillée, formalisée et exemples à l'appui, de notre modèle de développement. Enfin, nous terminons notre propos en section V en évoquant le projet de R&D MORDICUS de mise en œuvre concrète de notre canevas méthodologique UML, ainsi que les développements récents de l'OMG (Object Management Group) sur l'architecture orientée modèles (Model Driven Architecture), particulièrement en résonance avec notre travail.The increasing complexity of the real-time data acquisition and processing systems (TDAQ : the so-called Trigger and Data AcQuisition systems) in high energy physics calls for an appropriate evolution of development tools. This work is about the interplay between in principle specifications of TDAQ systems and their actual design and realization on a concrete hardware and software platform. The basis of our work is to define a methodology for the development of TDAQ systems that meets the specific demands for the development of such systems. The result is the detailed specification of a "methodological framewor" based on the Unified Modeling Language (UML) and designed to manage a development process. The use of this UML-based methodological framework progressively leads to the setting up of a "home-made" framework, i.e. a development tool that comprises reusable components and generic architectural elements adapted to TDAQ systems. The main parts of this dissertation are sections II to IV. Section II is devoted to the characterization and evolution of TDAQ systems. In section III, we review the main technologies that are relevant to our problematic, namely software reuse techniques such as design patterns and frameworks, especially concerning the real-time and embedded systems domain. Our original conceptual contribution is presented in section IV, where we give a detailed, formalized and example- driven specification of our development model. Our final conclusions are presented in section V, where we present the MORDICUS project devoted to a concrete realization of our UML methodological framework, and the deep affinities between our work and the emerging "Model Driven Architecture" (MDA) paradigm developed by the Object Management Group.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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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