[pt] Este trabalho visa apresentar a integração de várias mídias de informação, como voz, texto, imagem e gráficos em um ambiente de troca de mensagens como a melhor resposta às solicitações de evolução de sistemas de troca de informação. Assim, será apresentado do LANBRETA-DMS (LAN-Based real Time Áudio-Data Message System), com ênfase na especificação de seus serviços, descrevendo-se a sintaxe do protocolo empregado e sua semântica, sendo esta última apresentada sob a forma de uma pseudo-linguagem de programação e sob a forma de redes de Petri. Uma implementação do LANBRETA-DMS, realizada nos laboratórios da PUC-RJ será também apresentada, seguindo- se proposições para extensões futuras. / [en] This work presents the integration of information media such as voice, text, imge and graphics in a message Exchange environment as the best answer to evolution of information Exchange systems. LANBRETA-DMS (LAN-Based Real Time Audio-Data Messege System) will be presented, with enphasis on the specification of its services, the protocol sintax used and its semantics, the latter being presented in a pseudo- programming language and in Petri Networks. An implementation of LANBRETA-DMS, made at PUC-RJ, will alos be introced, with some proposais for future extrensions following.

Les systèmes logiciels complexes sont omniprésents dans notre vie quotidienne. De ce fait, un dysfonctionnement peut occasionner aussi bien une simple gêne qu'un danger mettant en péril des vies humaines. Le test est l'une des techniques les plus répandues (en particulier dans l'industrie) pour détecter les erreurs d'un système. Lorsque le cahier des charges d'un système est décrit par une spécification formelle, le test de conformité est utilisé pour garantir un certain niveau de confiance dans la correction d'une implémentation de ce système - dans ce cadre, la relation de conformité formalise la notion de correction. Cette thèse se focalise sur le test de conformité pour les systèmes concurrents. Le test de conformité pour les systèmes concurrents utilise principalement des modèles qui interprètent la concurrence par des entrelacements. Néanmoins, cette approche souffre du problème de l'explosion de l'espace d'états et elle n'offre pas la possibilité de tester certaines propriétés de la spécification telle que l'indépendance entre actions. Pour ces raisons, nous utilisons une sémantique d'ordres partiels pour la concurrence. De plus, nous proposons une nouvelle sémantique qui permet à certaines actions concurrentes d'être entrelacées et en force d'autres à être implémentées indépendamment. Nous proposons une généralisation de la relation de conformité ioco où les spécifications sont des réseaux de Petri et leur sémantique d'ordres partiels est donnée par leur dépliage. Cette relation de conformité permet de préserver l'indépendance, dans l'implémentation, des actions spécifiées comme concurrentes. Nous présentons un cadre de test complet pour cette relation. Nous définissons la notion de cas de test globaux gérant la concurrence, réduisant ainsi non seulement la taille des cas de test mais aussi celle de la suite de tests. Nous montrons comment les cas de test globaux peuvent être construits à partir du dépliage de la spécification en s'appuyant sur une traduction SAT, et nous réduisons le problème de la sélection de tests à la sélection d'un préfixe fini de ce dépliage : nous définissons différents critères de sélection à partir de la notion d'événement limite (cut-off event). Enfin, en supposant que chaque processus d'un système distribué possède une horloge locale, nous montrons que la conformité globale peut être testée dans une architecture de test distribuée en utilisant seulement des testeurs locaux ne communiquant pas entre eux. / Complex systems are everywhere and are part of our daily life. As a consequence, their failures can range from being inconvenient to being life-threatening. Testing is one of the most widely accepted techniques (especially in industry) to detect errors in a system. When the requirements of the system are described by a formal specification, conformance testing is used to guarantee a certain degree of confidence in the correctness of an implementation- in this setting a conformance relation formalizes the notion of correctness. This thesis focuses on conformance testing for concurrent systems. Conformance testing for concurrent system has mainly focused on models that interpret concurrency by interleavings. This approach does not only suf- fer from the state space explosion problem, but also lacks the ability to test properties of the specification such as independence between actions. For such reasons, we focus not only on partial order semantics for concurrency, but also propose a new semantics that allows to interleave some actions while forcing others to be implemented as independent. We propose a generalization of the ioco conformance relation, based on Petri nets specifications and their partial order semantics given by their unfoldings, preserving thus independence of actions from the specification. A complete testing framework for this conformance relation is presented. We introduce the notion of global test cases which handle concurrency, reducing not only the size of the test case, but also the number of tests in the test suite. We show how global test cases can be constructed from the unfolding of the specification based on a SAT encoding and we reduce the test selection problem to select a finite prefix of such unfolding: different testing criteria are defined based on the notion of cut-off events. Finally, we show that assuming each process of a distributed system has a local clock, global conformance can be tested in a distributed testing architecture using only local testers without any communication.

No description available.

L'accession a l'éducation d'un nombre toujours plus grand d'individus a conduit a considérer la performance des systèmes de formation comme un véritable facteur de développement économique. C'est dans ce contexte que s'inscrivent nos travaux de thèse qui ont visé au développement de méthodes et outils pour l'aide à la conception de la partie opérationnelle d'un système de formation et notamment tout le système de transformation permettant l'accroissements de compétences chez les apprenants. Après avoir présenté un bilan des systèmes de formation en définissant leur périmètre puis leur fonctionnement et résultats, nous précisons alors les facteurs qui nous ont conduits a nous préoccuper des processus opérationnels des systèmes de formation. Dans un deuxième chapitre, nous précisons la démarche que nous avons choisi d'adopter et déclinons ainsi l'ensemble de notre méthode, associée a des outils spécifiques, qui vise à l'aide a la conception et la mise en oeuvre des formations. Nous nous éloignons de la logique de l'offre pour migrer vers une logique de la demande. Nous proposons une identification contraintes subies par un système de formation (ressources à capacité finie, cohérence pédagogique, indisponibilité de ressources, compétences et aptitudes des ressources, etc.) - - Dans une troisième partie, nous illustrons notre propos en appliquant les méthodes et outils développes a un cas pratique. Enfin, nous concluons sur l'apport scientifique constitué par ces travaux et ouvrons la voie vers de nombreuses perspectives, le domaine de l'ingénierie de la formation étant encore à ses balbutiements / The accession with the education of a number increasingly larger indivlduals resulted in regarding the performance of the systems of formation as a true factor of economic development. It is in ths context that our work of thesis is registered which aimed to the development of methods and tools for the assistance with the design of the operational part of an education system and in particular al the transformation s y s t v leading to the increase of students competences. After having presented an assessment of the education systems by defining their perimeter, their operation and results, we specify the factors whch led us to worry us about operational processes of the education systems. In a second chapter, we specifi the steps whch we chose to adopt and we decline the whole of our method, associated to specific tools, which aims to the assistance to the design and the setting of formations. We move away from the logic of supply to migrate towards logic of demand. We propose an identification of constraints in education systems (resources with limited capaciîy, teachmg coherence, unavailability of resources, competences and aptitudes of the resources, etc.) In a third part, we illustrate our concept by applying methods and tools developed with a practical case. Lastly, we conclude on the scientific contribution made up by t h work and open the way towards rnany prospects, the field of the engineering of the formation being still to its beginnings

Rede de Petri é uma poderosa ferramenta de modelagem gráfica e matemática bastante aplicada no desenvolvimento de projetos de sistemas de eventos discretos. Porém a sua aplicação na análise e interpretação de tais sistemas torna-se inviável por resultar em modelos grandes, com muitos elementos gráficos. Para solucionar tal problema, vários pesquisadores têm concentrado esforços no desenvolvimento de novas extensões e métodos de síntese de rede de Petri, para reduzir o tamanho dos modelos e assim facilitar a sua aplicação e análise de sistemas grandes e complexos. Rede de Petri Virtual é uma nova extensão de rede de Petri que possibilita a modelagem de tais sistemas de forma modular. Cada elemento do sistema é representado por um módulo e a comunicação entre eles é feita através dos nós virtuais. Esse trabalho formaliza a definição de rede de Petri virtual, desenvolve algoritmo e procedimento de junção dos módulos para gerar o modelo final, uma rede de Petri ordinária que representa o sistema completo. / Petri net is a powerful graphical and mathematical modeling tool commonly used to project Discrete Events Systems. The increasing complexity of such systems does not allow the use of Petri net tools due to the large size of the models (many graphical elements), which is difficult to understand and analyze. Due to this fact, researchers have been made efforts to the development of new synthesis methods for Petri nets, in order to reduce the models size and become easier its use and the analysis task of the systems properties. Virtual Petri net is a new kind (extension) of Petri net, combining its best in control and representation of discrete events systems to the best of modular modeling. This king of Petri net allows to build up models of complex systems from the modules that represent its elements, linked by the virtual nodes. The present work formalizes the definition of Virtual Petri Net. Also develops an algorithm to its use in the discrete events systems and presents a procedure to link and assemble the modules in the whole model. The modular modeling makes easier the understanding and graphical visualization of the system, keeping the final model the same features of the common Petri nets.

In the past decade, events like 9/11 terror attacks, the recent financial crisis and other major crisis has proved that there is strong interaction and interdependency of a supply chain network with its external environments in various channels and thus a need to focus on building resiliency (in short, the ability of the system to recover from damage or disruption) of the entire network system. Although literature has discussed some way of improving resiliency of an individual firm which is a member of the network system, it lacked to capture a holistic view of the supply chain network. Pertaining to this observation, this work proposes to improve resiliency of a supply chain network from a systems perspective rather concentrate on an individual firm. For this purpose, this thesis proposes a conceptual framework to promote early identification and timely information of the disruptions arising in a supply chain network and timely sharing of this information among all the members of the network. The key principle emphasized in this thesis is that recovery from an inevitable disruption has a better possibility if a member of the supply chain network has an early indication or knowledge of the upcoming disruption. A discrete event dynamic system simulation tool called Petri nets is utilized to realize the proposed conceptual framework. Furthermore, the practical benefits and implications of the proposed model and tool are demonstrated with help of two case studies. This thesis has several contributions to the field of operation management and supply chain. First, a new paradigm for supply chain management to avoid large scale failures such as financial crisis is available to the field, which may be applied by governments or regulatory bodies. Second, a new framework which allows for a quantitative analysis of failures of an entire supply chain network is available to the field, which is easy to be used. Third, a novel application of Petri nets to this new problem in supply chain management is available.

No description available.

In the past decade, events like 9/11 terror attacks, the recent financial crisis and other major crisis has proved that there is strong interaction and interdependency of a supply chain network with its external environments in various channels and thus a need to focus on building resiliency (in short, the ability of the system to recover from damage or disruption) of the entire network system. Although literature has discussed some way of improving resiliency of an individual firm which is a member of the network system, it lacked to capture a holistic view of the supply chain network. Pertaining to this observation, this work proposes to improve resiliency of a supply chain network from a systems perspective rather concentrate on an individual firm. For this purpose, this thesis proposes a conceptual framework to promote early identification and timely information of the disruptions arising in a supply chain network and timely sharing of this information among all the members of the network. The key principle emphasized in this thesis is that recovery from an inevitable disruption has a better possibility if a member of the supply chain network has an early indication or knowledge of the upcoming disruption. A discrete event dynamic system simulation tool called Petri nets is utilized to realize the proposed conceptual framework. Furthermore, the practical benefits and implications of the proposed model and tool are demonstrated with help of two case studies. This thesis has several contributions to the field of operation management and supply chain. First, a new paradigm for supply chain management to avoid large scale failures such as financial crisis is available to the field, which may be applied by governments or regulatory bodies. Second, a new framework which allows for a quantitative analysis of failures of an entire supply chain network is available to the field, which is easy to be used. Third, a novel application of Petri nets to this new problem in supply chain management is available.

Diss.--Informatik--Universität Hamburg, 1999. / Bibliogr. p. 175-184. Index.

Thèse de doctorat : Sciences de l'ingénieur : Automatique : Metz : 2005. / Thèse soutenue sur ensemble de travaux. Bibliogr. p.103-106.