1,720,996 research outputs found
Claude Lobry, un mathématicien militant
Full text linkInternational audienceWe show in this communication, that Claude Lobry has always been contributing to mathematics and simultaneously promoting actions to develop a certain idea of acting in mathematicsOn montre ici que Claude Lobry, ne peut s’empêcher de faire à la fois des mathématiques et de développer des actions pour promouvoir une certaine façon de faire des mathématiques
Avant Propos
Full text linkInternational audienceLes amis de Claude Lobry ont organisé du 10 au 14 septembre 2007 à l’université Gaston Berger de Saint Louis une conférence en son honneur. Les apports scientifiques de Claude Lobry ont été non seulement multiformes et pluridisciplinaires, mais il a souvent été un précurseur dans nombre d’activités. Cette conférence s’est tenue en Afrique, à la demande des mathématiciens africains, en raison de l’activité particulière de Claude Lobry pour le développement des mathématiques en Afrique depuis sa prise de fonction comme Directeur du CIMPA en 1995 jusqu’à nos jours. Son livre « Les mathématiques : une nécessité pour le développement » est un vibrant plaidoyer pour le développement des mathématiques en Afriqu
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
Approche structurelle des systèmes, de la géométrie à la théorie des graphes
No full textInternational audienceIn this work, which was presented at the conference in honor of Claude Lobry, we focus on a structural approach of systems which was the mainstream of our research. The modeling ability of this approach and the power of the associated graph tools are enlightened. As an illustration we consider the disturbance decoupling problem by measurement feedback and solve this problem using geometric and graph techniquesDans ce travail présenté au colloque scientifique organisé en l’honneur de Claude Lobry nous nous focalisons sur une approche structurelle des systèmes qui a été le fil conducteur de beaucoup de nos travaux. Les capacités de modélisation de cette approche et la puissance de l’outil graphique associé sont mises en lumière. A titre d’illustration on considère le problème de rejet de perturbations par retour de mesure en utilisant des outils géométriques et graphiques
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
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
Ockham’s razor: Deriving cyclic evolutions from viability and inertia constraints
No full textInternational audienceThis article deals with a theme to which Claude Lobry has been interested for a long time: what is the nature of mathematics motivated by biological sciences? It starts by presenting the subjective opinions of its author, illustrated by the simplest application one can think of: demonstrating that it is possible to produce cyclic evolutions on the simple basis of viability and inertia constraints, without using periodic differential equations. It is not impossible that this approach is foreign to an explanation of biological clocks (or economic cycles) in another field.Cet article traite d’un thème auquel Claude Lobry s’est longtemps intéressé : quelle est la nature des mathématiques motivées par les sciences biologiques ? Il commence par exposer les opinions subjectives de l’auteur, illustrées pas une application des plus simples démontrant qu’il est possible de produire des évolutions cycliques à partir de simples hypothèses (contraintes de viabilité et d’inertie) pour produire des évolutions cycliques, sans faire appel aux équations différentielles périodiques. Il n’est pas impossible que ce point de vue soit étranger à une explication du fonctionnement des horloges biologiques (ou des cycles économiques dans un autre domaine)
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