WorldCat Identities

Université Paris-Sud Laboratoire de recherche en informatique

Overview
Works: 200 works in 209 publications in 3 languages and 392 library holdings
Genres: Conference papers and proceedings  Periodicals 
Roles: Other, Editor, Organizer of meeting, Originator
Publication Timeline
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Most widely held works by Université Paris-Sud
Proceedings by IEEE Computer Society( )

in English and held by 114 WorldCat member libraries worldwide

Proceedings by France) International Conference on Distributed Computing Systems (2Nd : 1981 : Paris( Book )

5 editions published in 1981 in English and held by 57 WorldCat member libraries worldwide

Modélisation et évaluation des systèmes informatiques : textes des exposés du Séminaire, janvier-décembre 1983 by SEMINAIRE SUR LA MODELISATION ET L'EVALUATION DES SYSTEMES INFORMATIQUES( Book )

2 editions published between 1980 and 1981 in French and English and held by 9 WorldCat member libraries worldwide

Rapport de recherche by Université Paris-Sud( )

in English and Undetermined and held by 7 WorldCat member libraries worldwide

INTERNATIONAL WORKSHOP ON PROGRAM CONSTRUCTION, CASTERA-VERDUZAN (GERS) SEPTEMBER 8-12, 1980 by International Workshop on Program Construction( Book )

1 edition published in 1980 in English and held by 4 WorldCat member libraries worldwide

INTERNATIONAL WORKSHOP ON PROGRAM CONSTRUCTION, CASTERA-VERDUZAN (GERS) SEPTEMBER 8-12, 1980 by International Workshop on Program Construction( Book )

1 edition published in 1980 in English and held by 3 WorldCat member libraries worldwide

Distributed computing systems( )

1 edition published in 1981 in English and held by 3 WorldCat member libraries worldwide

Apprentissage : comptes rendus by Journée française sur l'apprentissage( Book )

1 edition published in 1986 in French and held by 2 WorldCat member libraries worldwide

Interconnexion et routage efficaces pour des procédures de recherche décentralisées dans les systèmes pair-à-pair by Philippe Gauron( Book )

2 editions published between 2006 and 2010 in French and held by 2 WorldCat member libraries worldwide

Les systèmes pair-à-pair décentralisés mettent en relation un grand nombre d'utilisateurs pour mutualiser des ressources dans un environnement dynamique. Les applications de ces systèmes vont du partage de fichiers à la téléphonie par Internet, en passant par la décentralisation de services comme les DNS. Afin de limiter les ressources nécessaires, chaque recherche doit transmettre les messages rapidement et contrôler le nombre de messages dans le réseau. C'est pourquoi cette thèse s'intéresse au routage et à l'interconnexion nécessaire pour assurer ce routage. Dans la première partie, je présente un état de l'art des différents systèmes existants. J'y détaille la problématique générale et les caractéristiques des différentes classes de systèmes pair-à-pair. La seconde partie traite des réseaux à contenu adressable, qui permettent d'assurer un routage avec des bornes sur le nombre de sauts des requêtes et la charge par noeud. J'y expose d'abord les différents réseaux à contenu adressable existants. Je présente ensuite un nouveau protocole, D2B, dont je prouve en particulier qu'il améliore la charge par noeud tout en assurant un nombre de sauts et un degré faible. Je détaille enfin une liste d'optimisations applicables aux réseaux à contenu adressable en général, ou à D2B en particulier. Dans la troisième partie, je récapitule les principaux travaux qui tirent parti des communautés d'utilisateurs d'une part, et ceux qui exploitent la structure de loi de puissance de l'autre. Je présente ensuite ma seconde contribution, QRE, qui exploite efficacement à la fois ces deux caractéristiques des échanges: agrégats en communautés et loi de puissance
Distributed computing systems : proceedings by International conference on distributed computing systems( Book )

1 edition published in 1981 in Multiple languages and held by 2 WorldCat member libraries worldwide

Computations on Massive Data Sets : Streaming Algorithms and Two-party Communication by Christian Konrad( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

High Performance by Exploiting Information Locality through Reverse Computing by Mouad Bahi( )

1 edition published in 2011 in English and held by 1 WorldCat member library worldwide

The main resources for computation are time, space and energy. Reducing them is the main challenge in the field of processor performance.In this thesis, we are interested in a fourth factor which is information. Information has an important and direct impact on these three resources. We show how it contributes to performance optimization. Landauer has suggested that independently on the hardware where computation is run information erasure generates dissipated energy. This is a fundamental result of thermodynamics in physics. Therefore, under this hypothesis, only reversible computations where no information is ever lost, are likely to be thermodynamically adiabatic and do not dissipate power. Reversibility means that data can always be retrieved from any point of the program. Information may be carried not only by the data but also by the process and input data that generate it. When a computation is reversible, information can also be retrieved from other already computed data and reverse computation. Hence reversible computing improves information locality.This thesis develops these ideas in two directions. In the first part, we address the issue of making a computation DAG (directed acyclic graph) reversible in terms of spatial complexity. We define energetic garbage as the additional number of registers needed for the reversible computation with respect to the original computation. We propose a reversible register allocator and we show empirically that the garbage size is never more than 50% of the DAG size. In the second part, we apply this approach to the trade-off between recomputing (direct or reverse) and storage in the context of supercomputers such as the recent vector and parallel coprocessors, graphical processing units (GPUs), IBM Cell processor, etc., where the gap between processor cycle time and memory access time is increasing. We show that recomputing in general and reverse computing in particular helps reduce register requirements and memory pressure. This approach of reverse rematerialization also contributes to the increase of instruction-level parallelism (Cell) and thread-level parallelism in multicore processors with shared register/memory file (GPU). On the latter architecture, the number of registers required by the kernel limits the number of running threads and affects performance. Reverse rematerialization generates additional instructions but their cost can be hidden by the parallelism gain. Experiments on the highly memory demanding Lattice QCD simulation code on Nvidia GPU show a performance gain up to 11%
Adaptation automatique et semi-automatique des optimisations de programmes by Lénaïc Bagnères( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Les compilateurs offrent un excellent compromis entre le temps de développement et les performances de l'application. Actuellement l'efficacité de leurs optimisations reste limitée lorsque les architectures cibles sont des multi-cœurs ou si les applications demandent des calculs intensifs. Il est difficile de prendre en compte les nombreuses configurations existantes et les nombreux paramètres inconnus à la compilation et donc disponibles uniquement pendant l'exécution. En se basant sur les techniques de compilation polyédrique, nous proposons deux solutions complémentaires pour contribuer au traitement de ces problèmes. Dans une première partie, nous présentons une technique automatique à la fois statique et dynamique permettant d'optimiser les boucles des programmes en utilisant les possibilités offertes par l'auto-tuning dynamique. Cette solution entièrement automatique explore de nombreuses versions et sélectionne les plus pertinentes à la compilation. Le choix de la version à exécuter se fait dynamiquement avec un faible surcoût grâce à la génération de versions interchangeables: un ensemble de transformations autorisant le passage d'une version à une autre du programme tout en faisant du calcul utile. Dans une seconde partie, nous offrons à l'utilisateur une nouvelle façon d'interagir avec le compilateur polyédrique. Afin de comprendre et de modifier les transformations faites par l'optimiseur, nous traduisons depuis la représentation polyédrique utilisée en interne n'importe quelle transformation de boucles impactant l'ordonnancement des itérations en une séquence de transformations syntaxiques équivalente. Celle-ci est compréhensible et modifiable par les programmeurs. En offrant la possibilité au développeur d'examiner, modifier, améliorer, rejouer et de construire des optimisations complexes avec ces outils de compilation semi-automatiques, nous ouvrons une boîte noire du compilateur: celle de la plateforme de compilation polyédrique
Strengthening the heart of an SMT-solver : Design and implementation of efficient decision procedures by Mohamed Iguernelala( )

1 edition published in 2013 in English and held by 1 WorldCat member library worldwide

This thesis tackles the problem of automatically proving the validity of mathematical formulas generated by program verification tools. In particular, it focuses on Satisfiability Modulo Theories (SMT): a young research topic that has seen great advances during the last decade. The solvers of this family have various applications in hardware design, program verification, model checking, etc.SMT solvers offer a good compromise between expressiveness and efficiency. They rely on a tight cooperation between a SAT solver and a combination of decision procedures for specific theories, such as the free theory of equality with uninterpreted symbols, linear arithmetic over integers and rationals, or the theory of arrays.This thesis aims at improving the efficiency and the expressiveness of the Alt-Ergo SMT solver. For that, we designed a new decision procedure for the theory of linear integer arithmetic. This procedure is inspired by Fourier-Motzkin's method, but it uses a rational simplex to perform computations in practice. We have also designed a new combination framework, capable of reasoning in the union of the free theory of equality, the AC theory of associative and commutativesymbols, and an arbitrary signature-disjoint Shostak theory. This framework is a modular and non-intrusive extension of the ground AC completion procedure with the given Shostak theory. In addition, we have extended Alt-Ergo with existing decision procedures to integrate additional interesting theories, such as the theory of enumerated data types and the theory of arrays. Finally, we have explored preprocessing techniques for formulas simplification as well as the enhancement of Alt-Ergo's SAT solver
Distributed computing systems( )

1 edition published in 1981 in English and held by 1 WorldCat member library worldwide

Alignement pratique de structure-séquence d'ARN avec pseudonœuds by Wei Wang( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

Aligner des macromolécules telles que des protéines, des ADN et des ARN afin de révéler ou exploiter, leur homologie fonctionnelle est un défi classique en bioinformatique, qui offre de nombreuses applications, notamment dans la modélisation de structures et l'annotation des génomes. Un certain nombre d'algorithmes et d'outils ont été proposés pour le problème d'alignement structure-séquence d'ARN. Cependant, en ce qui concerne les ARN complexes, comportant des pseudo-noeuds, des interactions multiples et des paires de bases non canoniques, de tels outils sont rarement utilisés dans la pratique, en partie à cause de leurs grandes exigences de calcul, et de leur incapacité à supporter des types généraux de structures. Récemment, Rinaudo et al. ont donné un algorithme paramétré général pour la comparaison structure-séquence d'ARN, qui est capable de prendre en entrée n'importe quel type de structures comportant des pseudo-noeuds. L'algorithme paramétré est un algorithme de programmation dynamique basée sur la décomposition arborescente. Nous avons développé plusieurs variantes et extensions de cet algorithme. Afin de l'accélérer sans perte sensible de précision, nous avons introduit une approche de programmation dynamique par bandes. De plus, trois algorithmes ont été développés pour obtenir des alignements sous-optimaux. De plus, nous introduisons dans ce contexte la notion de MEA (Maximum-expected Structure-Alignment) pour calculer un alignement avec la précision maximale attendue sur un ensemble d'alignements. Tous ces algorithmes ont été implémentés dans un logiciel nommé LiCoRNA (aLignment of Complex RNAs). Les performances de LiCoRNA ont été évaluées d'abord sur l'alignement des graines des familles de de la base de données RFAM qui comportent des pseudo-noeuds. Comparé aux autres algorithmes de l'état de l'art, LiCoRNA obtient généralement des résultats équivalents ou meilleurs que ses concurrents. Grâce à la grande précision démontrée par LiCoRNA, nous montrons que cet outil peut être utilisé pour améliorer les alignements de certaines familles de RFAM qui comportent des pseudo-noeuds
Méthodes adaptatives pour les applications d'accès à l'information centrées sur l'utilisateur by Paul Lagrée( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

When users interact on modern Web systems, they let numerous footprints which we propose to exploit in order to develop better applications for information access. We study a family of techniques centered on users, which take advantage of the many types of feedback to adapt and improve services provided to users. We focus on applications like recommendation and influencer marketing in which users generate discrete feedback (e.g. clicks, "likes", reposts, etc.) that we incorporate in our algorithms in order to deliver strongly contextualized services. The first part of this dissertation is dedicated to an approach for as-you-type search on social media. The problem consists in retrieving a set of k search results in a social-aware environment under the constraint that the query may be incomplete (e.g., if the last term is a prefix). Every time the user updates his / her query, the system updates the set of search results accordingly. We adopt a "network-aware" interpretation of information relevance, by which information produced by users who are closer to the user issuing a request is considered more relevant. Then, we study a generic version of influence maximization, in which we want to maximize the influence of marketing or information campaigns by adaptively selecting "spread seeds" from a small subset of the population. Influencer marketing is a straightforward application of this, in which the focus of a campaign is placed on precise key individuals who are typically able to reach millions of consumers. This represents an unprecedented tool for online marketing that we propose to improve using an adaptive approach. Notably, our approach makes no assumptions on the underlying diffusion model and no diffusion network is needed. Finally, we propose to address the well-known cold start problem faced by recommender systems with an adaptive approach. If no information is available regarding the user appreciation of an item, the recommender system needs to gather feedback (e.g., clicks) so as to estimate the value of the item. However, in order to minimize "bad" recommendations, a well-designed system should not collect feedback carelessly. We introduce a dynamic algorithm that aims to intelligently achieve the balance between "bad" and "good" recommendations
Optimization of the number of copies in a distributed data base by Université Paris-Sud( Book )

1 edition published in 1979 in English and held by 1 WorldCat member library worldwide

Théorie des représentations combinatoire de tours de monoïdes : Application à la catégorification et aux fonctions de parking by Aladin Virmaux( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

This thesis is focused on combinatorical representation theory of finite monoids within the field of algebraic combinatorics. A monoid M is a finite set endowed with a multiplication and a neutralelement. A representation of M is a morphism from M into the monoid of matrices M_n(ck) where ck is a field; in this work it will typically bereferred to as ck = CC. The results obtained in the last decades allows us to use representation theory of groups, and combinatorics on preorders in order to explore representation theory of finite monoides. In 1996, Krob and Thibon proved that the induction and restriction rules of irreducible and projective representations of the tower of 0-Hecke monoids endows its ring of caracters with a Hopf algebra structure, isomorph to thenon-commutative symmetric functions Hopf algebra ncsf. This gives a categorification of ncsf, which is an interpretation of the non-commutative symmetruc functions in the language of representation theory. This extends a theorem of Frobenius endowing the character ring of symmetric groups to theHopf algebra of symmetric functions. Since then a natural problem is to categorify other Hopf algebras -- for instance the Planar Binary Tree algebra of Loday and Ronco -- by a tower of algebras. Guessing such a tower of algebra is a difficult problem in general. In this thesis we restrict ourselves to towers of monoids in order to have a better control on its representations. This is quite natural as on one hand, this setup covers both previous fundamental examples, whereas ncsf cannot be categorified in the restricted set of tower of group algebras. In the first part of this work, we start with some results about representation theory of towers of monoids. We then focus on categorification with towers of semilatices, for example the tower of permutohedrons. We categorify the algebra, and cogebra structure of fqsym, but not the full Hopf algebra structure with its dual. We then make a comprehensive search in order to categorify pbt with a tower of monoids. We show that under natural hypothesis, there exists no tower of monoids satisfying the categorification axioms. Finally we show that in some sense, the tower of 0-Hecke monoids isthe simplest tower categorifying ncsf. The second part of this work deals with parking functions, applying results from the first part. We first study the representation theory of non decreasing parking functions. We then present a joint work with Jean-Baptiste Priez on ageneralization of parking functions from Pitman and Stanley. To obtain enumeration formulas, we use a variant of the species theory which was more efficient in our case. We used an action of H_n(0) instead of the symmetric group and use the Krob-Thibon theorem to lift the character of this action into the Hopf algebra of non-commutative symmetric functions
 
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Alternative Names
Centre national de la recherche scientifique

Centre national de la recherche scientifique France Equipe de recherche associée 0452

L.R.I.

L.R.I. (Université Paris-Sud. Laboratoire de recherche en informatique)

Laboratoire de recherche en informatique (Orsay)

Laboratory of Research in Computer Science

LRI

LRI (Laboratoire de recherche en informatique ; Orsay)

LRI (Université Paris-Sud. Laboratoire de recherche en informatique)

UMR 8623

UMR8623

Unité mixte de recherche 8623

Université de Paris-Sud, Laboratoire de recherche en informatique

Université de Paris XI Laboratoire de Recherche en Informatique

Université Paris-Sud Laboratoire de Recherche en Informatique

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