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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Synthesis of orchestrators from service choreographies

McIlvenna, Stephen January 2009 (has links)
With service interaction modelling, it is customary to distinguish between two types of models: choreographies and orchestrations. A choreography describes interactions within a collection of services from a global perspective, where no service plays a privileged role. Instead, services interact in a peer-to-peer manner. In contrast, an orchestration describes the interactions between one particular service, the orchestrator, and a number of partner services. The main proposition of this work is an approach to bridge these two modelling viewpoints by synthesising orchestrators from choreographies. To start with, choreographies are defined using a simple behaviour description language based on communicating finite state machines. From such a model, orchestrators are initially synthesised in the form of state machines. It turns out that state machines are not suitable for orchestration modelling, because orchestrators generally need to engage in concurrent interactions. To address this issue, a technique is proposed to transform state machines into process models in the Business Process Modelling Notation (BPMN). Orchestrations represented in BPMN can then be augmented with additional business logic to achieve value-adding mediation. In addition, techniques exist for refining BPMN models into executable process definitions. The transformation from state machines to BPMN relies on Petri nets as an intermediary representation and leverages techniques from theory of regions to identify concurrency in the initial Petri net. Once concurrency has been identified, the resulting Petri net is transformed into a BPMN model. The original contributions of this work are: an algorithm to synthesise orchestrators from choreographies and a rules-based transformation from Petri nets into BPMN.
42

Using an extended object model for object-oriented parallel simulation of VLSI microprocessors /

Wang, Yi-ke, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 217-223). Also available on the Internet.
43

Using an extended object model for object-oriented parallel simulation of VLSI microprocessors

Wang, Yi-ke, January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 217-223). Also available on the Internet.
44

Performance evaluation of stochastic timed decision-free Petri nets

January 1985 (has links)
R. Paul Wiley, Robert R. Tenney. / Bibliography: p. 34-35. / "March 1985." "24th CDC and Transactions" / "ONR/N00014-77-C-0532 (NR 041-519)" "ONR/N00014-84-K-0519 (NR 649-003)"
45

Structured petri nets for the design and implementation of manufacturing control software with fault monitoring capabilities

Stanton, Martin January 1998 (has links)
The thesis describes a method for the design and implementation of manufacturing control software using structured Petri nets. An earlier design method is presented from which a more formal approach is developed, and a definition for structured Petri nets is given. This definition is then compared to other classes of Petri net found in the literature. A comparison is also made between the proposed design method and other methods described in the literature. The structured Petri nets are then used to create a control structure, which is shown to have properties that allow the detection and diagnosis of faults originating both in the hardware and the software of the system. A detailed discussion is also presented concerning the implementation of structured Petri nets on various types of manufacturing controller and on general-purpose computers. In particular, results are presented from experiments with various implementation methods on programmable logic controllers. Conclusions are then drawn on the various aspects of the work and details of further research possibilities are described.
46

Time Series Petri Net Models - Enrichment and Prediction

Rogge-Solti, Andreas, Vana, Laura, Mendling, Jan 09 December 2015 (has links) (PDF)
Operational support as an area of process mining aims to predict the temporal performance of individual cases and the overall business process. Although seasonal effects, delays and performance trends are well-known to exist for business processes, there is up until now no prediction model available that explicitly captures this. In this paper, we introduce time series Petri net models. These models integrate the control flow perspective of Petri nets with time series prediction. Our evaluation on the basis of our prototypical implementation demonstrates the merits of this model in terms of better accuracy in the presence of time series effects.
47

Um simulador de redes de petri de alto nível para uso didático / A petri-net simulator for didactic use

Glock, Flavio Soibelmann January 1992 (has links)
O presente trabalho consiste na apresentação da implementação de um software projetado para auxiliar o ensino de redes de Petri de alto nível. A partir da fundamentação sobre o assunto desenvolvida em cursos introdut6rios de modelagem de sistemas com redes de Petri foi especificado um sistema para ser usado em sala de aula. O sistema desenvolvido permite a demonstração das características gráficas e da semântica de alguns modelos tradicionais de redes de Petri, tais como redes condicao/evento, redes predicado-transição e redes coloridas. Redes de baixo nivel tambem podem ser demonstradas. O software foi elaborado de forma a permitir a utilização de redes já definidas em disquete. O usuário pode também definir novas redes utilizando o editor gráfico/compilador ou se valer de uma linguagem textual de baixo nível para descrever as redes. Após a obtenção da rede desejada, é possível a realização de demonstrações, simulando o funcionamento da mesma. O software permite ainda a execução de passos, o funcionamento "para trás" da rede e identifica, a cada estado alcançado, quais alterações estão habilitadas e quais estão em conflito. Um comando permite obter o caminho entre duas marcações da rede. O usuário pode selecionar regiões de interesse sobre a rede, que sera° mostradas com mais detalhe na tela. Usando o editor gráfico/compilador o usuário pode modificar redes durante o decorrer da apresentação. A interface com o usuário, voltada para o use em sala de aula, necessita como hardware um projetor de vídeo apropriado e um computador pessoal equipado com mouse. A utilização do compilador em sala de aula exige, no entanto, mais recursos computacionais que o simulador. Alguns modelos de redes de Petri não são suportados pelo compilador, mas podem ser implementados utilizando a linguagem de baixo nível do sistema. 0 usuário, professor ou aluno, encontrará neste trabalho instruções para o emprego pratico do sistema como instrumento para a realização de demonstrações didáticas. / This work describes the implementation of a software designed as a teaching aid for instructors of high-level Petri nets. A system for class-room use is described that is based on material developed during introductory courses of systems modelling with Petri nets. The class-room system permits the demonstration of the graphic properties and the semantics of some traditional nets, such as condition/event nets, predicate-transition nets and coloured nets, as well as low level nets. The software was designed to permit the use of nets already defined in diskettes. The user can define new nets using either the graphic editor/compiler or a low level textual language. Some models of Petri nets are not supported by the compiler, but can be implemented using the low level language. After obtaining the desired net, it is possible to perform demonstrations, simulating its operation.The software also allows step by step execution of nets, including backwards execution, and identifies, for every state, which alterations may happen and which are in conflict. A command permits the user to obtain the path between two markings of the net. The user may select regions of interest over the net, that will be shown with more detail in the screen. Using the graphic editor/compiler the user may modify the nets during the presentation. The hardware needs are a video projector and a personal computer equiped with a mouse.
48

LEMMA 2000 - Uma linguagem para análise e representação de protocolos para diagnósticos em Medicina / Lemma 2000 – A language for analysing and representing protocols for diagnoses in medicine

Netto, Guilherme Tomaschewski January 2007 (has links)
A qualidade dos serviços de saúde tornou-se um tema relevante e cada vez mais esforços são dedicados para definir metodologias e ferramentas para medir e assegurar a qualidade. São exigidos novos métodos para aperfeiçoar os processos de saúde, garantindo assim uma alto padrão de qualidade utilizando os recursos disponíveis. A otimização da utilização destes recursos de forma a preservar a qualidade do atendimento bem como baixar os custos requer modelos rigorosos dos processos médicos. Neste contexto apresentamos LEMMA 2000 (Language for an Easy Medical Model Analysis) uma notação destinada a modelar processos médicos, desenvolvida em cooperação com o Politécnico de Milão.. Esta notação disponibiliza aos médicos elementos simples e intuitivos para representar os modelos de diagnóstico. Simultaneamente um modelo de Redes de Petri Temporizadas é gerado automaticamente. Deste modo os modelos de LEMMA podem ser validados e analisados através de simulações e testes.O objetivo desta dupla modelagem é permitir aos médicos ganhar todos os benefícios de uma notação formal sem a necessidade de conhecer esta notação abstrata. Os usuários administram os elementos mais simples da notação, enquanto redes de Petri asseguram formalidade e capacidades de validação. Desta maneira LEMMA integra notações formais e intuitivas superando os problemas de ambos enfoques. A definição da notação LEMMA 2000 foi apoiada pela implementação de um ambiente para projetar os modelos. Este ambiente além de permitir a administração dos elementos da notação menos formal permite a geração e analise dos modelos mais formais. / The quality of health services has become an important subject. Efforts have been dedicated more and more to define methodologies and tools to measure and to guarantee quality. People demand new methods in order to improve health processes. This way a high standard of quality is guaranteed by using available resources. The optimization of using these resources in such a way as to keep the quality of attendance as well as to reduce expenses, needs strict patterns of medical processes. In this context we present LEMMA 2000 a notation for modeling medical processes developed in co-operation with the Politecnico di Milano. This notation provides doctors with common and intuitive elements to represent the patterns of diagnoses. At the same time a model of Timed Petri nets is created automatically. Because of this the patterns of LEMMA can be validated and analysed through simulations and tests. The aim of this double modelling is to allow doctors to gain all the benefits of a formal notation without the need to know this abstract notation. The users manage the most simple elements of the notation while Petri nets guarantee formality and ways of validation. This way LEMMA integrates formal and intuitive notations overcoming problems of both focuses.The definition of LEMMA 2000 notation was supported by the implementation of an environment for projecting the patterns. This environment not only allows the management of the elements of the less formal notation but it also allows the creation and analysis of most formal patterns.
49

[en] A STUDY ON COLORED PETRI NETS AND A PROGRAM TO ANALYZE COLORED PETRI NETS: ANARCO / [pt] UM ESTUDO SOBRE REDES DE PETRI COLORIDAS E UM PROGRAMA DE ANÁLISE DE REDES DE PETRI COLORIDAS: ANARCO

GIOVANNI CORDEIRO BARROSO 18 September 2009 (has links)
[pt] A modelagem de sistemas que apresentam subsistemas idênticos, por intermédio de Redes de Petri, conduz à geração de grafos de grandes dimensões com diversos componentes indênticos. As extensões às Redes de Petri que permitem diferenciar estes diversos subsistemas, por intermédio da distinção das fichas nelas contidas, receberam o nome de Redes de Petri Coloridas. Neste trabalho, são apresentados algumas propostas existentes na literatura sobre Redes de Petri Coloridas, bem como é desenvolvido um programa de análise baseado em uma dessas propostas - a de kurt Jensen. O programa analisa as propriedades de uma Rede de Petri Colorida, tais como limitação, vitalidade e capacidade de reinicialização, através do método de enumeração de marcações. / [en] The modeling of sistems which have identical sub-systems, by means of Petri nets, leads to the generation of large scale graphs with identical components. The extensions of Petri nets, which afford the possibility of distinguishing these sub-systems through the distinction of the tokens within the net, are called colored Petri nets. This work presents some colored Petri net proposals existent in literature and an analysis code based on one of these proposals - the Kurt Jensen one. This program analyses through the mark enumeration method, the colored Petri net properties, such as boundedness, liveness and reinicialization.
50

LEMMA 2000 - Uma linguagem para análise e representação de protocolos para diagnósticos em Medicina / Lemma 2000 – A language for analysing and representing protocols for diagnoses in medicine

Netto, Guilherme Tomaschewski January 2007 (has links)
A qualidade dos serviços de saúde tornou-se um tema relevante e cada vez mais esforços são dedicados para definir metodologias e ferramentas para medir e assegurar a qualidade. São exigidos novos métodos para aperfeiçoar os processos de saúde, garantindo assim uma alto padrão de qualidade utilizando os recursos disponíveis. A otimização da utilização destes recursos de forma a preservar a qualidade do atendimento bem como baixar os custos requer modelos rigorosos dos processos médicos. Neste contexto apresentamos LEMMA 2000 (Language for an Easy Medical Model Analysis) uma notação destinada a modelar processos médicos, desenvolvida em cooperação com o Politécnico de Milão.. Esta notação disponibiliza aos médicos elementos simples e intuitivos para representar os modelos de diagnóstico. Simultaneamente um modelo de Redes de Petri Temporizadas é gerado automaticamente. Deste modo os modelos de LEMMA podem ser validados e analisados através de simulações e testes.O objetivo desta dupla modelagem é permitir aos médicos ganhar todos os benefícios de uma notação formal sem a necessidade de conhecer esta notação abstrata. Os usuários administram os elementos mais simples da notação, enquanto redes de Petri asseguram formalidade e capacidades de validação. Desta maneira LEMMA integra notações formais e intuitivas superando os problemas de ambos enfoques. A definição da notação LEMMA 2000 foi apoiada pela implementação de um ambiente para projetar os modelos. Este ambiente além de permitir a administração dos elementos da notação menos formal permite a geração e analise dos modelos mais formais. / The quality of health services has become an important subject. Efforts have been dedicated more and more to define methodologies and tools to measure and to guarantee quality. People demand new methods in order to improve health processes. This way a high standard of quality is guaranteed by using available resources. The optimization of using these resources in such a way as to keep the quality of attendance as well as to reduce expenses, needs strict patterns of medical processes. In this context we present LEMMA 2000 a notation for modeling medical processes developed in co-operation with the Politecnico di Milano. This notation provides doctors with common and intuitive elements to represent the patterns of diagnoses. At the same time a model of Timed Petri nets is created automatically. Because of this the patterns of LEMMA can be validated and analysed through simulations and tests. The aim of this double modelling is to allow doctors to gain all the benefits of a formal notation without the need to know this abstract notation. The users manage the most simple elements of the notation while Petri nets guarantee formality and ways of validation. This way LEMMA integrates formal and intuitive notations overcoming problems of both focuses.The definition of LEMMA 2000 notation was supported by the implementation of an environment for projecting the patterns. This environment not only allows the management of the elements of the less formal notation but it also allows the creation and analysis of most formal patterns.

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