Search results for "fonctions"
showing 10 items of 43 documents
An approach for influence estimatation in complex networks : application to the social network Twitter
2019
Influence in complex networks and in particular Twitter has become recently a hot research topic. Detecting most influential users leads to reach a large-scale information diffusion area at low cost, something very useful in marketing or political campaigns. In this thesis, we propose a new approach that considers the several relations between users in order to assess influence in complex networks such as Twitter. We model Twitter as a multiplex heterogeneous network where users, tweets and objects are represented by nodes, and links model the different relations between them (e.g., retweets, mentions, and replies).The multiplex PageRank is applied to data from two datasets in the political…
From resurgent functions to real resummation through combinatorial Hopf algebras
2014
Pas de résumé en anglais.
Writting practice for developp mind and language
2016
This thesis wanted to put on the opposite between established culture, transmitted by School, and private culture, the VAE candidates’ concerned by this research, as well as the author’s. This putting on the opposite is fed by a purpose: to show to what extent the individual and collective work of writing on practical, allows to articulate first the peculiarity of the subjects, the trajectories, the experiences, the situations and the activities, with the generalization of the institutional speech linked with the standardized procedures of the device VAE ? In a second time does this work of writing allows to build knowledges from the experience, object and source of development, and to make…
Contribution to variational analysis : stability of tangent and normal cones and convexity of Chebyshev sets
2014
The aim of this thesis is to study the following three problems: 1) We are concerned with the behavior of normal cones and subdifferentials with respect to two types of convergence of sets and functions: Mosco and Attouch-Wets convergences. Our analysis is devoted to proximal, Fréchet, and Mordukhovich limiting normal cones and subdifferentials. The results obtained can be seen as extensions of Attouch theorem to the context of non-convex functions on locally uniformly convex Banach space. 2) For a given bornology β on a Banach space X we are interested in the validity of the following "lim inf" formula (…).Here Tβ(C; x) and Tc(C; x) denote the β-tangent cone and the Clarke tangent cone to …
Algorithmic approaches to Siegel's fundamental domain
2017
Siegel determined a fundamental domain using the Minkowski reduction of quadratic forms. He gave all the details concerning this domain for genus 1. It is the determination of the Minkowski fundamental domain presented as the second condition and the maximal height condition, presented as the third condition, which prevents the exact determination of this domain for the general case. The latest results were obtained by Gottschling for the genus 2 in 1959. It has since remained unexplored and poorly understood, in particular the different regions of Minkowski reduction. In order to identify Siegel's fundamental domain for genus 3, we present some results concerning the third condition of thi…
Caractéristiques et fonctionnement des conseils d'administration français. Un état des lieux.
2004
International audience; Dans ce travail, nous décrivons les principales caractéristiques (taille des conseils, cumul des fonctions et indépendance des membres) de 97 conseils d'administration français en 2002 et leur fonctionnement (nombre de réunions et assiduité), ainsi que ceux des principaux comités spécialisés (comité d'audit, comité de rémunération, comité de nomination et comité stratégique). Nos résultats permettent de mettre en évidence une évolution très significative des conseils en France au cours des 20 dernières années, suite notamment à la publication des rapports Vienot (1995 et 1999) et Bouton (2002).
A categorization and executive functions approach of food rejection in young children
2021
Food neophobia and pickiness are two strong psychological obstacles to young children’s consumption of fruits and vegetables, which are necessary components of a diet that facilitates normal and healthy development. It is therefore of critical importance to investigate the cognitive underpinnings of these two kinds of food rejection to promote the adoption of healthy eating behaviors. Food acceptance and rejection appear to be partly conditioned by children’s knowledge of the food domain. Knowledge allows children to recognize a given food, categorize it, and make inference-based decisions on its properties and possible consequences of consumption. Underdeveloped knowledge may cause food st…
Les déterminants de la qualité des conseils d'administration français
2005
International audience; Dans cet article, nous vérifions si la "qualité" des conseils d'administration dépend de la structure de propriété et de la politique financière des grandes sociétés cotées en bourse, caractérisées par une séparation de la décision (control) et du contrôle (ownership). En nous basant sur la théorie de l'agence, nous considérons que les conseils sont de meilleure qualité lorsqu'ils comprennent une fraction élevée d'administrateurs indépendants et/ou lorsque les fonctions de direction générale et de présidence du conseil sont dissociées. Pour les 85 sociétés cotées en bourse de notre échantillon, nous confirmons notamment que la qualité des conseils croît avec la fract…
Deciphering Biotic Interactions and Their Role in Soil Microbial Community Assembly and Functions
2022
Microbial communities play a key role in ecosystem functioning as well as in plant, animal, and human welfare. Their assembly relies on different processes commonly referred to as abiotic and biotic filters. Despite the widespread emphasis on abiotic filters in terrestrial ecosystems, a growing body of evidence suggests that interactions between microorganisms play a critical role in community assembly. However, the contribution of these interactions to microbial community assembly and the factors influencing them have not been clearly established. In most cases, biotic interactions between microorganisms have been investigated based on cocultures of a handful of strains, completely overloo…
Control of photoassociation of atomic Bose-Einstein condensates by laser field configuration
2016
In this work we show that it is to perform an efficient adiabatic passage in a basic quadratic-nonlinear quantum two-state system describing weakly bound molecule formation in atomic Bose-Einstein condensates through photoassociation by laser fields. An efficient adiabatic transfer is also possible if the third-order nonlinearities describing the atom-atom, atom-molecule, and molecule-molecule elastic scattering are taken into account. The transfer is achieved by choosing a proper detuning derived by solving the inverse problem.We also show that one can perform a stimulated Raman exact tracking in a quadratic-nonlinear quantum three-state system.The irreversible losses from the intermediate…