Download or read book Optimisation du placement de t ches dans les syst mes distribu s et de l allocation de ressources pour les communications multipoints written by Moaiz Ben Dhaou and published by . This book was released on 2003 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les problèmes d'optimisation combinatoire consistent à déterminer une solution optimale parmi un ensemble généralement très grand de solutions possibles. Ce type de problèmes se pose de manière cruciale dans de très nombreux domaines. Dans notre thèse, nous avons étudié des problèmes d'optimisation issus des systèmes distribués et des réseaux de télécommunications. Comme les problèmes considérés sont NP-difficiles, il est très peu probable qu'ils puissent être résolus de manière optimale à l'aide d'un algorithme polynomial. Nous avons exploré d'un côté les aspects théoriques, en déterminant les variantes admettant des algorithmes polynomiaux pour les résoudre soit de manière exacte soit de manière approchée, et les aspects pratiques en développant des heuristiques efficaces. Nous avons d'abord étudié un problème de placement de tâches - de type min/max -dont l'objectif est de placer les tâches composant une application sur les différents processeurs d'une architecture parallèle de façon à minimiser le temps total d'exécution de l'application. Nous avons proposé des schémas d'approximation polynomiaux pour résoudre certaines variantes. Nous avons aussi présenté plusieurs heuristiques nouvelles pour résoudre le problème général ainsi que des méthodes de calcul de bornes inférieures. Le deuxième problème considéré est issu du domaine des télécommunications. Il s'agit d'un problème d'allocation de ressources pour des communications multipoints. Cette problématique, relativement récente, est née de la nécessité d'exploiter au mieux les nouvelles applications telles la visioconférence, le travail de groupe, ou les jeux en réseau par exemple. Nous avons étudié deux problèmes.

Download or read book Applications of Combinatorial Optimization Volume 3 written by Vangelis Th. Paschos and published by John Wiley & Sons. This book was released on 2013-02-07 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combinatorial optimization is a multidisciplinary scientific area, lying in the interface of three major scientific domains: mathematics, theoretical computer science and management. The three volumes of the Combinatorial Optimization series aims to cover a wide range of topics in this area. These topics also deal with fundamental notions and approaches as with several classical applications of combinatorial optimization. “Applications of Combinatorial Optimization” is presenting a certain number among the most common and well-known applications of Combinatorial Optimization.

Download or read book Applications of Combinatorial Optimization written by Vangelis Th. Paschos and published by John Wiley & Sons. This book was released on 2014-08-08 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combinatorial optimization is a multidisciplinary scientific area, lying in the interface of three major scientific domains: mathematics, theoretical computer science and management. The three volumes of the Combinatorial Optimization series aim to cover a wide range of topics in this area. These topics also deal with fundamental notions and approaches as with several classical applications of combinatorial optimization. Concepts of Combinatorial Optimization, is divided into three parts: - On the complexity of combinatorial optimization problems, presenting basics about worst-case and randomized complexity; - Classical solution methods, presenting the two most-known methods for solving hard combinatorial optimization problems, that are Branch-and-Bound and Dynamic Programming; - Elements from mathematical programming, presenting fundamentals from mathematical programming based methods that are in the heart of Operations Research since the origins of this field.

Download or read book GESTION DE L ALLOCATION DES RESSOURCES AUX OBJETS DANS LES SYSTEMES REPARTIS UNE APPROCHE MULTICRITERE INTEGRANT LES COMMUNICATIONS written by PASCAL.. CHATONNAY and published by . This book was released on 1998 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'APPARITION DES SYSTEMES REPARTIS A OBJETS (SRO) POSE DE NOUVELLES QUESTIONS DANS LE DOMAINE DE L'EQUILIBRAGE DE CHARGE. QUELLES SONT LES DIFFERENCES MAJEURES, DU POINT DE VUE DE L'ALLOCATION DE RESSOURCES, ENTRE LES SYSTEMES A BASE DE PROCESSUS ET LES SRO ? LES OBJETS NE REALISENT UNE TACHE QUE PAR COOPERATION, COMMENT GERER CETTE INTERDEPENDANCE ? NOUS PROPOSONS D'APPORTER DES ELEMENTS DE REPONSES A CES QUESTIONS. NOUS ETUDIONS ET METTONS EN OEUVRE UNE STRATEGIE D'OPTIMISATION DE L'ALLOCATION DES RESSOURCES DANS UN SRO, SUR UN RESEAU LOCAL DE STATIONS DE TRAVAIL, DANS LE BUT D'OPTIMISER L'EXECUTION DES APPLICATIONS. NOUS PROPOSONS DE REALISER UN PLACEMENT DES CONSTITUANTS DES APPLICATIONS VIA UN PROCESSUS MULTICRITERE. CE PROCESSUS AGREGE DES INFORMATIONS CONCERNANT TROIS DIMENSIONS DE L'EXECUTION : - LA CHARGE DES SITES, DETERMINEE PAR L'OBSERVATION DES FILS D'EXECUTION LOCAUX A CHAQUE SITE. CE CRITERE EST DECRIT PAR L'ENSEMBLE DE LA COMMUNAUTE COMME PRIMORDIAL DANS LA RECHERCHE D'UNE OPTIMISATION. - LES DEPENDANCES ENTRE OBJETS INDUITES PAR LES CHEMINS D'INVOCATIONS VIA L'OBSERVATION DES COMMUNICATION ENTRE OBJETS. - DES CONTRAINTES ASSOCIEES A LA SEMANTIQUE DES APPLICATIONS. CES CONTRAINTES PERMETTENT DE PALLIEES A L'ANTAGONISME DES DEUX PRECEDENTS CRITERES. L'OBSERVATION DES COMMUNICATIONS EST REALISEE VIA UN MODELE PERMETTANT DE NOUS ABSTRAIRE DES EPIPHENOMENES ET PROPOSANT UNE PREDICTION DES TENDANCES DU SYSTEME. NOUS AVONS MIS EN OEUVRE NOTRE SOLUTION DANS LE SYSTEME REPARTI A OBJETS COOL V2. L'OBJECTIF DE CETTE IMPLEMENTATION EST LA VALIDATION DE L'APPROCHE RELATIONNELLE (PRISE EN COMPTE DES COMMUNICATIONS) POUR L'OPTIMISATION DE L'EXECUTION. NOUS UTILISONS UNE DEMARCHE DE TEST PERMETTANT DE MESURER L'IMPACT DE CHAQUE PARAMETRE SUR L'OPTIMISATION. LES RESULTATS QUE NOUS OBTENONS NOUS PERMETTE D'AFFIRMER LA COMPLEMENTARITE DE L'OPTIMISATION DES CHEMINS D'INVOCATION ET DE LA MINIMISATION DE LA CHARGE DES SITES POUR LES SYSTEMES REPARTIS A OBJETS.

Download or read book Approche d allocation de t ches complexes pour les SMA massifs written by Zaki Brahmi and published by Editions Universitaires Europeennes. This book was released on 2011-12 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le probleme d'allocation de taches complexes est un probleme fondamental dans les Systemes Multi-Agents Massifs (SMAM). Chercher une allocation optimale et admissible est un probleme NP-Complet. Bien que plusieurs travaux ont ete developpes dans la litterature, et ont montre leurs efficacites pour des SMA de petite taille, ils s'averent inefficace dans le contexte des SMAM. Ces systemes exigent de nouvelles approches d'allocation de taches permettant de supporter differents aspects: la dynamicite, l'heterogeneite a la fois des agents et des taches complexes et le passage a l'echelle du nombre d'agents. Ainsi, dans cette these, nous avons propose une approche scalable et decentralisee d'allocation de taches complexes pour les SMAM. Cette approche est basee sur deux methodes. La premiere est consacree a la recherche d'une allocation admissible de taches complexes de telle sorte que la somme des couts proposes par les agents afin d'executer les taches soit minimisee. La deuxieme utilise le modele d'espace partage LINDA afin de minimiser la communication entre agents. Pour illustrer notre approche, nous l'avons appliquee au domaine d'orchestration des services web.

Download or read book Constraint Based Scheduling written by Philippe Baptiste and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Constraint Programming is a problem-solving paradigm that establishes a clear distinction between two pivotal aspects of a problem: (1) a precise definition of the constraints that define the problem to be solved and (2) the algorithms and heuristics enabling the selection of decisions to solve the problem. It is because of these capabilities that Constraint Programming is increasingly being employed as a problem-solving tool to solve scheduling problems. Hence the development of Constraint-Based Scheduling as a field of study. The aim of this book is to provide an overview of the most widely used Constraint-Based Scheduling techniques. Following the principles of Constraint Programming, the book consists of three distinct parts: The first chapter introduces the basic principles of Constraint Programming and provides a model of the constraints that are the most often encountered in scheduling problems. Chapters 2, 3, 4, and 5 are focused on the propagation of resource constraints, which usually are responsible for the "hardness" of the scheduling problem. Chapters 6, 7, and 8 are dedicated to the resolution of several scheduling problems. These examples illustrate the use and the practical efficiency of the constraint propagation methods of the previous chapters. They also show that besides constraint propagation, the exploration of the search space must be carefully designed, taking into account specific properties of the considered problem (e.g., dominance relations, symmetries, possible use of decomposition rules). Chapter 9 mentions various extensions of the model and presents promising research directions.

Download or read book 7th International Conference on Practical Applications of Agents and Multi Agent Systems PAAMS 09 written by Yves Demazeau and published by Springer Science & Business Media. This book was released on 2009-03-08 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems. This volume presents the papers that have been accepted for the 2009 edition. These articles capture the most innovative results and this year’s trends: Assisted Cognition, E-Commerce, Grid Computing, Human Modelling, Information Systems, Knowledge Management, Agent-Based Simulation, Software Development, Transports, Trust and Security. Each paper has been reviewed by three different reviewers, from an international committee composed of 64 members from 20 different countries. From the 92 submissions received, 35 were selected for full presentation at the conference, and 26 were accepted as posters.

Download or read book Quantum Communications and Cryptography written by Alexander V. Sergienko and published by CRC Press. This book was released on 2018-10-03 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: All current methods of secure communication such as public-key cryptography can eventually be broken by faster computing. At the interface of physics and computer science lies a powerful solution for secure communications: quantum cryptography. Because eavesdropping changes the physical nature of the information, users in a quantum exchange can easily detect eavesdroppers. This allows for totally secure random key distribution, a central requirement for use of the one-time pad. Since the one-time pad is theoretically proven to be undecipherable, quantum cryptography is the key to perfect secrecy. Quantum Communications and Cryptography is the first comprehensive review of the past, present, and potential developments in this dynamic field. Leading expert contributors from around the world discuss the scientific foundations, experimental and theoretical developments, and cutting-edge technical and engineering advances in quantum communications and cryptography. The book describes the engineering principles and practical implementations in a real-world metropolitan network as well as physical principles and experimental results of such technologies as entanglement swapping and quantum teleportation. It also offers the first detailed treatment of quantum information processing with continuous variables. Technologies include both free-space and fiber-based communications systems along with the necessary protocols and information processing approaches. Bridging the gap between physics and engineering, Quantum Communications and Cryptography supplies a springboard for further developments and breakthroughs in this rapidly growing area.

Download or read book Graph Colouring and the Probabilistic Method written by Michael Molloy and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade, many major advances have been made in the field of graph coloring via the probabilistic method. This monograph, by two of the best on the topic, provides an accessible and unified treatment of these results, using tools such as the Lovasz Local Lemma and Talagrand's concentration inequality.

Download or read book Ultra Wide Band Antennas written by Xavier Begaud and published by John Wiley & Sons. This book was released on 2013-03-04 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recognized studies.

Download or read book The Quadratic Assignment Problem written by E. Cela and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: The quadratic assignment problem (QAP) was introduced in 1957 by Koopmans and Beckmann to model a plant location problem. Since then the QAP has been object of numerous investigations by mathematicians, computers scientists, ope- tions researchers and practitioners. Nowadays the QAP is widely considered as a classical combinatorial optimization problem which is (still) attractive from many points of view. In our opinion there are at last three main reasons which make the QAP a popular problem in combinatorial optimization. First, the number of re- life problems which are mathematically modeled by QAPs has been continuously increasing and the variety of the fields they belong to is astonishing. To recall just a restricted number among the applications of the QAP let us mention placement problems, scheduling, manufacturing, VLSI design, statistical data analysis, and parallel and distributed computing. Secondly, a number of other well known c- binatorial optimization problems can be formulated as QAPs. Typical examples are the traveling salesman problem and a large number of optimization problems in graphs such as the maximum clique problem, the graph partitioning problem and the minimum feedback arc set problem. Finally, from a computational point of view the QAP is a very difficult problem. The QAP is not only NP-hard and - hard to approximate, but it is also practically intractable: it is generally considered as impossible to solve (to optimality) QAP instances of size larger than 20 within reasonable time limits.

Download or read book MIMO written by Alain Sibille and published by Academic Press. This book was released on 2010-12-03 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: Foreword from Arogyaswami Paulraj, Professor (Emeritus), Stanford University (USA) - The first book to show how MIMO principles can be implemented in today's mobile broadband networks and components - Explains and solves some of the practical difficulties that arise in designing and implementing MIMO systems - Both theory and implementation sections are written in the context of the most recent standards: IEEE 802.11n (WiFi); IEEE 802.16 (WIMAX); 4G networks (3GPP/3GPP2, LTE)

Download or read book Progress in Graph Theory written by John Adrian Bondy and published by Toronto ; Orlando : Academic Press. This book was released on 1984 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evolution of Awareness written by Kia Marlene and published by . This book was released on 2022-03-08 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evolution of Awareness, the debut poetry collection from Kia Marlene, is a book about a spiritual journey towards enlightenment. The collection consists of 6 chapters, titled "The Egg," "The Caterpillar," "Intermission (heartbreak&love)," "The Cocoon," "The Butterfly," and a chapter titled "Knock Knock." Through numerous poems this book outlines various thoughts, questions and eventual answers concerning our collective greater purpose in life, self love, consciousness, and personhood. The author intends for this book to help broaden the reader's general perception, view of their environment, awareness, and sense of self.

Download or read book Pervasive Mobile and Ambient Wireless Communications written by Roberto Verdone and published by Springer Science & Business Media. This book was released on 2012-01-02 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reporting the findings of COST 2100, a major European intergovernmental project, this volume offers system designers a good source of guidelines based on channel characterization and measurement-based modeling, as well as worthwhile ideas for future research.

Download or read book Metaheuristic Optimization via Memory and Evolution written by Cesar Rego and published by Springer Science & Business Media. This book was released on 2006-03-30 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tabu Search (TS) and, more recently, Scatter Search (SS) have proved highly effective in solving a wide range of optimization problems, and have had a variety of applications in industry, science, and government. The goal of Metaheuristic Optimization via Memory and Evolution: Tabu Search and Scatter Search is to report original research on algorithms and applications of tabu search, scatter search or both, as well as variations and extensions having "adaptive memory programming" as a primary focus. Individual chapters identify useful new implementations or new ways to integrate and apply the principles of TS and SS, or that prove new theoretical results, or describe the successful application of these methods to real world problems.

Download or read book All it Is It s a Carnival written by Mária Németh Lenke and published by . This book was released on 2007 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: