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Mobility management addresses the issues of how to track and locate a mobile node (MN) efficiently. Service management addresses the issues of how to efficiently deliver services to MNs. This dissertation aims to design and analyze integrated mobility and service management schemes for future all-IP based wireless systems. We propose and analyze per-user regional registration schemes extending from Mobile IP Regional Registration and Hierarchical Mobile IPv6 for integrated mobility and service management with the goal to minimize the network signaling and packet delivery cost in future all-IP based wireless networks. If access routers in future all-IP based wireless networks are restricted to perform network layer functions only, we investigate the design of intelligent routers, called dynamic mobility anchor points (DMAPs), to implement per-user regional management in IP wireless networks. These DMAPs are access routers (ARs) chosen by individual MNs to act as regional routers to reduce the signaling overhead for intra-regional movements. The DMAP domain size is based on a MN's mobility and service characteristics. A MN optimally determines when and where to launch a DMAP to minimize the network cost in serving the user's mobility and service management operations. We show that there exists an optimal DMAP domain size for each individual MN. We also demonstrate that the DMAP design can easily support failure recovery because of the flexibility of allowing a MN to choose any AR to be the DMAP for mobility and service management. If access routers are powerful and flexible in future all-IP based networks to perform network-layer and application-layer functions, we propose the use of per-user proxies that can run on access routers. The user proxies can carry service context information such as cached data items and Web processing objects, and perform context-aware functions such as content adaptation for services engaged by the MN to help application executions. We investigate a proxy-based integrated mobility and service management architecture (IMSA) under which a client-side proxy is created on a per-user basis to serve as a gateway between a MN and all services engaged by the MN. Leveraging Mobile IP with route optimization, the proxy runs on an access router and cooperates with the home agent and foreign agent of the MN to maintain the location information of the MN to facilitate data delivery by services engaged by the MN. Further, the proxy optimally determines when to move with the MN so as to minimize the network cost associated with the user's mobility and service management operations. Finally we investigate a proxy-based integrated cache consistency and mobility management scheme called PICMM to support client-server query-based mobile applications, to improve query performance, the MN stores frequently used data in its cache. The MN's proxy receives invalidation reports or updated data objects from application servers, i.e., corresponding nodes (Cans) for cached data objects stored in the MN. If the MN is connected, the proxy will forward invalidation reports or fresh data objects to the MN. If the MN is disconnected, the proxy will store the invalidation reports or fresh data objects, and, once the MN is reconnected, the proxy will forward the latest cache invalidation report or data objects to the MN. We show that there is an optimal ``service area'' under which the overall cost due to query processing, cache consistency management and mobility management is minimized. To further reduce network traffic, we develop a threshold-based hybrid cache consistency management policy such that whenever a data object is updated at the server, the server sends an invalidation report to the MN through the proxy to invalidate the cached data object only if the size of the data object exceeds the given threshold. Otherwise, the server sends a fresh copy of the data object through the proxy to the MN. We identify the best ``threshold'' value that would minimize the overall network cost. We develop mathematical models to analyze performance characteristics of DMAP, IMSA and PICMM developed in the dissertation research and demonstrate that they outperform existing schemes that do not consider integrated mobility and service management or that use static regional routers to serve all MNs in the system. The analytical results obtained are validated through extensive simulation. We conclude that integrated mobility and service management can greatly reduce the overall network cost for mobile multimedia and database applications, especially when the application's data service rate is high compared with the MN's mobility rate. / Ph. D.

Sistemas Instrumentados de Segurança (SIS) são projetados para prevenir e/ou mitigar acidentes, evitando indesejáveis cenários com alto potencial de risco, assegurando a proteção da saúde das pessoas, proteção do meio ambiente e economia de custos com equipamentos industriais. Desta forma, é extremamente recomendado neste projeto de SIS o uso de métodos formais para garantir as especificações de segurança em conformidade com as normas regulamentadoras vigentes, principalmente para atingir o nível de integridade de segurança (SIL) desejado. Adicionalmente, algumas das normas de segurança como ANSI / ISA S.84.01; IEC 61508, IEC 61511, entre outras, recomendam uma série de procedimentos relacionados ao ciclo de vida de segurança de um projeto de SIS. Desta forma, destacam-se as atividades que compreendem o desenvolvimento e a validação dos algoritmos de controle em que se separam semanticamente os aspectos voltados para o diagnóstico de falhas críticas e o tratamento destas falhas associado a um controle de coordenação para filtrar a ocorrência de falhas espúrias. Portanto, a contribuição deste trabalho é propor um método formal para a modelagem e análise de SIS, incluindo o diagnóstico e o tratamento de falhas críticas, baseado em rede Bayesiana (BN) e rede de Petri (PN). Este trabalho considera o diagnóstico e o tratamento para cada função instrumentada de segurança (SIF) a partir do resultado do estudo de análise de riscos, de acordo com a metodologia de HAZOP (Hazard and Operability). / Safety Instrumented Systems (SIS) are design to prevent and/or mitigate accidents, avoiding undesirable high potential risk scenarios, assuring protection of people health, protecting the environment and saving costs of industrial equipment. It is strongly recommended in this design formal method to assure the safety specifications in accordance to standards regulations, mainly for reaching desired safety integrity level (SIL). Additionally, some of the safety standards such as ANSI/ISA S.84.01; IEC 61508, IEC 61511, among others, guide different activities related to Safety Life Cycle (SLC) design of SIS. In special, there are design activities that involves the development and validation of control algorithm that separate semantically aspects oriented to diagnosis and treatment of critical faults associated with a control coordination to filter spurious failures occurrence. In this context, the contribution of this work is to propose a formal method for modeling and analysis of SIS designed including diagnostic and treatment of critical faults based on Bayesian networks (BN) and Petri nets (PN). This approach considers diagnostic and treatment for each safety instrumented function (SIF) obtained according hazard and operability (HAZOP) methodology.

O sistema de proteção técnica contra incêndio (SPTCI) é um dos principais sistemas que compõem o edifício inteligente (EI), pois a eficiência do seu funcionamento afeta diretamente a segurança das pessoas e o patrimônio do prédio. O SPTCI é composto de diferentes dispositivos, estratégias de controle e atua segundo legislação específica. Devido à complexidade do SPTCI, torna-se fundamental uma modelagem adequada que permita verificar a dinâmica do sistema e sua relação com outros sistemas prediais. Neste contexto, este trabalho propõe um procedimento para a modelagem e análise de estratégias de controle para o SPTCI, integrado com outros sistemas prediais dentro do contexto de EI. A abordagem considerada para este propósito baseia-se na teoria dos sistemas a eventos discretos, na aplicação de técnicas derivadas da rede de Petri e em técnicas de análise através de simulação discreta. Com esta abordagem são desenvolvidos modelos do sistema de controle do SPTCI onde é considerada a sua relação com outros sistemas prediais. Particularmente, explora-se as extensões da rede de Petri como as técnicas Production Flow Schema e Mark Flow Graph. Um estudo de caso é apresentado para ilustrar as principais características deste procedimento. / From the point of view of property damage and personal security, the fire protection system (FPS) is one of the most important systems in an intelligent building (IB). The FPS is composed of several devices and control strategies. Furthermore, it must act in accordance with specific laws. As a consequence the design of FPSs is a complex task and it is very important to provide an adequate model that supports the verification of the FPS dynamics and its integration with others building systems, facilitating its test and validation. In this context, this work proposes a procedure to model in a systematic and rational way a FPS in the IB context. Considering the nature of the structure and processes of FPS the approach is based on the discrete event dynamic system theory and the application of the Petri net. Then, the models the FPS control system and the controlled plant must include its integration with other building systems. Particularly, it explores Petri net extensions such as Production Flow Schema and Mark Flow Graph techniques. Through an example it is illustrated the main aspects of the proposed procedure.

A capacidade de reconfiguração de sistemas de manufatura tem sido procurada pelas empresas para assegurar características de agilidade, eficiência e exibilidade para atender as mudanças de tipo/quantidade de produtos, processos, recursos e, além disso, para assegurar a devida reação à ocorrência de falhas. Por outro lado, a Indústria 4.0\" impõe novos desafios para os sistemas de controle, tais como a integração de tecnologias de interação entre homem e máquina em cadeias de valor compondo uma rede de plantas industriais geograficamente dispersas. O controle de sistemas reconfiguráveis de manufatura deve considerar: (i) funcionalidades de sistemas distribuídos e dispersos, tais como agilidade de resposta às mudanças, autonomia e colaboração entre os componentes para alcançar os objetivos do sistema de forma conjunta; (ii) interfaces para sua interoperabilidade e portabilidade; (iii) modularização para facilitar a manutenção, expansão e atualização do sistema, evitando a sobreposição de escopos; e (iv) mecanismos de controle para supervisionar as ações e interações dos componentes, o diagnóstico e a tomada de decisão. O pleno atendimento a estes requisitos não é trivial e formalismos para o desenvolvimento de soluções devem ser adotados. Uma solução é combinar técnicas voltadas para sistema multiagente e holon com arquitetura orientada a serviço através de uma adequada técnica de modelagem usando extensões de rede de Petri: Production Flow Schema e Input Output Place Transition. Portanto, este trabalho prop~oe uma arquitetura de controle e o método de modelagem de seus componentes para sistemas reconfiguráveis de manufatura combinando estas técnicas e considerando os aspectos de personalização, convertibilidade, escalabilidade, modularidade, integrabilidade, diagnosticabilidade, interoperabilidade e colaboração entre os componentes do sistema de controle, inclusive do homem. Um exemplo de aplicação é apresentado para demonstrar a viabilidade da proposta e comprovar os resultados alcançados. / The reconfiguration ability of the manufacturing systems has been approached by companies to ensure agility, efficiency and exibility characteristics to address the changes of type/quantity of products, processes and resources and, furthermore, to ensure proper reaction to the fault occurrence. On the other hand, the\"Industry 4.0\" imposes new challenges for control systems, such as interaction between man and machine into value chains composing a network of geographically dispersed industrial plants. The control of reconfigurable manufacturing systems should consider: (i) functionalities requirements of distributed and disperse systems, such as responsiveness to changes, autonomy and collaboration among components to achieve the global system aim; (ii) interfaces for interoperability and portability; (iii) modularity to facilitate maintenance, expansion and upgrade of the system, avoiding the overlapping of scopes; and (iv) control mechanisms to supervise the actions and interactions among components, diagnosis and decision making. The compliance with these requirements is not trivial and formalisms to develop solutions must be adopted. A solution is combining techniques based on holonic and multi-agent system with service-oriented architecture through appropriate modeling using Petri net extensions: Production Flow Schema and Input Output Place Transition. Therefore, this paper proposes control architecture and a method to model components for reconfigurable manufacturing systems, combining these techniques and considering aspects of customization, convertibility, scalability, modularity, integrability, diagnosability, interoperability and collaboration among control system components, including humans. An application example is presented to demonstrate the feasibility of the proposal and verify the results.

Edsger W. Dijkstra prägte im Jahr 1974 den Begriff Selbststabilisierung (self-stabilization) in der Informatik. Ein System ist selbststabilisierend, wenn es von jedem denkbaren Zustand aus nach einer endlichen Anzahl von Aktionen ein stabiles Verhalten erreicht. Im Mittelpunkt dieser Arbeit steht der Entwurf selbststabilisierender Algorithmen. Wir stellen eine Petrinetz-basierte Methode zum Entwurf selbststabilisierender Algorithmen vor. Wir validieren unsere Methode an mehreren Fallstudien: Ausgehend von algorithmischen Ideen existierender Algorithmen beschreiben wir jeweils die die schrittweise Entwicklung eines neuen Algorithmus. Dazu gehört ein neuer randomisierter selbststabilisierender Algorithmus zur Leader Election in einem Ring von Prozessoren. Dieser Algorithmus ist abgeleitet aus einem publizierten Algorithmus, von dem wir hier erstmals zeigen, daß er fehlerhaft arbeitet. Wir weisen die Speicherminimalität unseres Algorithmus nach. Ein weiteres Ergebnis ist der erste Algorithmus, der ohne Time-Out-Aktionen selbststabilisierenden Tokenaustausch in asynchronen Systemen realisiert. Petrinetze bilden einen einheitlichen formalen Rahmen für die Modellierung und Verifikation dieser Algorithmen. / In 1974, Edsger W. Dijkstra suggested the notion of self-stabilization. A system is self-stabilizing if regardless of the initial state it eventually reaches a stable behaviour. This thesis focuses on the design of self-stabilizing algorithms. We introduce a new Petri net based method for the design of self-stabilizing algorithms. We validate our method on several case studies. In each of the case studies, our stepwise design starts from an algorithmic idea and leads to a new self-stabilizing algorithm. One of these algorithms is a new randomized self-stabilizing algorithm for leader election in a ring of processors. This algorithm is derived from a published algorithm which we show to be incorrect. We prove that our algorithm is space-minimal. A further result is the first algorithm for token-passing in a asynchronous environment which works without time-out actions. Petri nets form a unique framework for modelling and verification of these algorithms.

Un Système de production peut être représenté par les systèmes à événements discrets. En dehors de la planification (où les gens travaillent avec des ratios de produits fabriqués par semaine ou par jour), la modélisation pourrait être basée sur les concepts d'événement et d'activités. Un événement correspond à un changement d'état. Une activité est une boîte noire d'encapsulation de ce qui se passe entre deux événements. En utilisant les réseaux de Petri (RdP), les événements sont représentés par les transitions, et les activités par les lieux. Notre travail propose une synthèse de commande par supervision pour les systèmes d'événements discrets modélisés par une classe de réseaux de Petri appelé graphe d'événements. L'objective de cette thèse est de concevoir un superviseur capable d'aider à améliorer la performance de système et de protéger le système en respectant des spécifications données par le fabricant ou le client selon les besoins et les conditions de travail. Pour modéliser ces spécifications, nous avons proposé un nouveau modèle mathématique de contrainte, appelé Contrainte d'Exclusion de Marquage (CEM). La deuxième contribution principale de ma thèse est de synthétiser une technique efficace et simple pour construire un superviseur qui impose le système de respecter des contraintes en évitant l'ensemble des états interdits modélisé par CEM. Nous avons également développé cette synthèse pour résoudre le problème d'existence des événements incontrôlables et des événements inobservables. Parfois, afin d'étudier les aspects liés à la performance, nous devons prendre le temps en considération. Donc, nous avons résolu aussi le problème des événements temporisé en utilisant RdP temporisés soumis à CEM / A manufacturing system may be represented by Discrete Event System (DES). Apart from planning (where people work with ratios of products fabricated per week or per day), any modelling could be based on the concepts of event and activities. An event corresponds to a state change. An activity is a black-box summarizing what is occurring between two events. When using Petri Nets, events are associated with transitions, and activities with places. Our work proposes a supervisory synthesis for Discrete Event System modelled by a class of Petri Net called Marked Graph. The objective of this synthesis is to build a control law that enforces the system to respect a set of given specifications. To model these specifications, we propose new mathematical formulas called Marking Exclusion Constraint (MEC). This model is our first contribution. The Second main contribution of my thesis is to synthesize a computationally efficient technique to build a supervisor that enforces the system to respect the constraints by avoiding a set of forbidden states modelled by MEC specifications. We extend this synthesis technique to solve the problem in the presence of uncontrollable events and unobservable events. Sometimes in order to study the performance aspects, we must take in consideration the time data. Thus we address control synthesis for Timed Discrete Event Systems under MEC specifications by using Timed Petri Nets

Controle de acesso é um tópico de pesquisa importante tanto para a academia quanto para a indústria. Controle de Acesso Baseado em Papéis (CABP) foi desenvolvido no início dos anos 1990, tornando-se um padrão generalizado para controle de acesso em vários produtos e soluções computacionais. Embora modelos CABP sejam largamente aceitos e adotados, ainda existem questões para responder. Um dos principais desafios de pesquisa em segurança baseada em papéis é determinar se uma política de controle de acesso é consistente em um ambiente altamente dinâmico. Nossa pesquisa visa preencher essa lacuna fornecendo um método para analisar políticas CABP com respeito a dois aspectos significativos: segurança e dinamismo envolvendo papéis e objetos. Para este propósito, desenvolvemos um modelo de descrição e simulação de política usando rede de Petri colorida e CPN Tools. O modelo descreve e é capaz de simular vários estados CABP em um contexto de educação a distância típico. Usando este modelo, foi possível analisar o espaço de estados produzido pela rede de Petri colorida em um cenário dinâmico envolvendo a criação de novos papéis e objetos. O resultado da análise de alcançabilidade da rede de Petri da política demonstrou que é possível verificar a consistência de políticas de controle de acesso considerando a dinamicidade de papéis e objetos, e apontou vantagens de aplicabilidade da modelagem de políticas de segurança em ambientes distribuídos utilizando rede de Petri colorida. / Access control is an important research topic both for academia and industry. Role Based Access Control (RBAC) was developed in the early 1990s, becoming a generalized standard of access control for many products and computing solutions. Although RBAC models have been widely accepted and adopted, there are issues to answer. One of the key challenges for role-based security research is to characterize whether an access control policy is consistent in a highly dynamic environment. Our research aims filling this gap providing a method to analyze RBAC policies with respect to two significant aspects: security and dynamics involving roles and objects. For this purpose, we developed a policy description and simulation model using colored Petri net and the CPN Tools. The model describes and is capable to simulate many RBAC states in a typical distance education context. Using this model it was possible to analyze the state space provided by colored Petri net that simulates a dynamic environment and the creation of new roles and objects. The result of the reachability analysis of Petri net policy showed that it is possible to check the consistency of access control policies considering dynamic of roles and objects, and point out the advantages and applicability of modeling security policies in distributed environments using colored Petri net.

Sistemas de controle de edifícios inteligentes têm evoluído consideravelmente e a sua confiabilidade também tem melhorado. Mesmo assim, falhas são inevitáveis em sistemas concebidos, construídos e operados pelo homem e uma abordagem alternativa envolve a minimização das conseqüências das falhas. Isto é possível através da reconfiguração do sistema que se faz realocando funções de controle e escolhendo outras formas de interação entre os processos. Apesar disso, na literatura ainda não existe muito material que trate da modelagem de processos em que desde a sua concepção as falhas são consideradas. Assim, propõe-se neste trabalho o desenvolvimento de um procedimento para a modelagem de sistemas de controle considerando além das especificações funcionais, em situação normal, a ocorrência de falhas. Em função da base teórica existente e ferramentas disponíveis a abordagem proposta adota o conceito de sistemas a eventos discretos, holon e a técnica de rede de Petri e suas extensões para descrever a estrutura e o funcionamento deste sistema de controle. Um exemplo de aplicação é aqui apresentado para ilustrar as principais características deste procedimento. / Control systems of intelligent buildings have evolved and its reliability has evidently improved. However, faults are inevitable in systems conceived, constructed and operated by humans and an alternative approach is the minimization of the faults consequences. This is possible through the reconfiguration of the system, i.e., re-allocating control functions and choosing other forms of interaction between the processes. Despite this, there are few publications that deal with the modeling of processes where since its conception the faults are considered. Thus, this work proposes the development of a procedure for the modeling of control systems considering beyond the functional specifications in normal situation, the occurrence of faults. Based on the existing theoretical base and available tools the proposal adopts the concept of discrete event system, holon and Petri net technique with its extensions to describe the structure and the operation of these control systems. An application example is here presented to illustrate the principal characteristics of this proceeding.

A Indústria 4.0, ou quarta revolução industrial, é o atual cenário industrial que estabelece um novo paradigma para os sistemas de produção. A indústria 4.0 é compreendida como a implementação da fábrica inteligente que opera de forma mais autônoma e com menor intervenção humana, cujo propósito é prover serviços e produtos inteligentes que atendam às necessidades individuais dos consumidores. A Indústria 4.0 está amparada nos sistemas ciber-físicos (CPS) e na Internet das Coisas (IoT). Neste cenário máquinas e produtos se comunicam entre si visando automatizar os processos industriais por meio de informações individuais obtidas em tempo real durante os processos de manufatura. No entanto, a Indústria 4.0 e as pesquisas em torno desse assunto ainda são muito recentes e requerem mais investigações no que diz respeito às arquiteturas que suportem a sua implementação, entre elas a comunicação entre produtos e máquinas. Neste quesito, recentemente foi proposto o modelo de arquitetura de referência para a Indústria 4.0 (RAMI 4.0) com o objetivo de nortear a implementação deste tipo de sistema. Contudo, o RAMI 4.0 ainda requer esforços no campo da pesquisa sob diferentes aspectos, entre eles a integração vertical de recursos do sistema de produção. Neste sentido, este trabalho objetiva apresentar uma arquitetura para a descoberta de equipamentos para processar operações conforme as necessidades dos produtos. A arquitetura foi projetada em camadas baseadas no RAMI 4.0 para prover componentes que permitam a comunicação entre equipamentos e produtos, e um mecanismo similar ao sistema de nomes de domínios (DNS - Domain Name System) para realizar a descoberta de equipamentos para processar uma determinada operação. Nessa arquitetura as informações dos equipamentos são armazenadas em uma estrutura organizada hierarquicamente para auxiliar o serviço de descoberta, e os produtos possuem informações das operações necessárias para o processo de manufatura. Para garantir a eficácia do funcionamento dos componentes e suas interações, é necessário a verificação e validação por meio de métodos formais. Neste trabalho a verificação e validação é realizada por meio da técnica PFS (Production Flow Schema)/RdP (Rede de Petri). Por fim, a arquitetura é aplicada em um sistema de produção modular para demonstrar a sistemática de implementação e a sua efetividade. / The Industry 4.0, also known as fourth industrial revolution, is the current industrial scenario that sets a new paradigm for production systems. The Industry 4.0 can be understood as the implementation of the smart factory that operates more autonomously and with less human intervention. The purposes of it is to provide smart products and services that meet the consumer individual needs. The Industry 4.0 is supported by cyber-physical systems (CPS) and Internet of Things (IoT). In this scenario machines and products communicate with each other to automate industrial processes through individual information that are obtained in real time during manufacturing processes. However, the researches around this issue are still very recent and require further investigations with regard of to the architectures that support its implementation, including communication between products and equipment. Taking into account this problem, a Reference Architectural Model for Industry 4.0 (RAMI 4.0) was recently proposed with the purpose to guide the implementation of this system type. However, the RAMI 4.0 still requires efforts in different aspects, including the vertical integration of resources of the production systems. In this sense, this work aims to present an architecture for the discovery of equipment to process operations according to the product needs. The architecture was designed based on layers of the RAMI 4.0 to provide components that allow communication between equipment and products and a Web Service that offer a mechanism similar to the Domain Name System (DNS) to locate equipment to process a required operation. In this architecture the capable operations supported by the equipment are stored in a structure organized hierarchically to aid the discovery service, and the products have information of the operation required for the manufacturing process. In order to guarantee the effectiveness of the component functionalities and their interactions it is necessary to verify and validate them by formal methods. In this work the Production Flow Schema (PFS)/Petri Net (PN) technique is used to develop the conceptual and functional modeling of the architecture. Finally the architecture is applied in a modular production system to demonstrate its implementation systematics and its effectiveness.