18,663 research outputs found

    A model driven approach to analysis and synthesis of sequence diagrams

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    Software design is a vital phase in a software development life cycle as it creates a blueprint for the implementation of the software. It is crucial that software designs are error-free since any unresolved design-errors could lead to costly implementation errors. To minimize these errors, the software community adopted the concept of modelling from various other engineering disciplines. Modelling provides a platform to create and share abstract or conceptual representations of the software system – leading to various modelling languages, among them Unified Modelling Language (UML) and Petri Nets. While Petri Nets strong mathematical capability allows various formal analyses to be performed on the models, UMLs user-friendly nature presented a more appealing platform for system designers. Using Multi Paradigm Modelling, this thesis presents an approach where system designers may have the best of both worlds; SD2PN, a model transformation that maps UML Sequence Diagrams into Petri Nets allows system designers to perform modelling in UML while still using Petri Nets to perform the analysis. Multi Paradigm Modelling also provided a platform for a well-established theory in Petri Nets – synthesis to be adopted into Sequence Diagram as a method of putting-together different Sequence Diagrams based on a set of techniques and algorithms

    Synthesis and Analysis of Petri Nets from Causal Specifications

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    Petri nets are one of the most prominent system-level formalisms for the specification of causality in concurrent, distributed, or multi-agent systems. This formalism is abstract enough to be analyzed using theoretical tools, and at the same time, concrete enough to eliminate ambiguities that would arise at implementation level. One interesting feature of Petri nets is that they can be studied from the point of view of true concurrency, where causal scenarios are specified using partial orders, instead of approaches based on interleaving. On the other hand, message sequence chart (MSC) languages, are a standard formalism for the specification of causality from a purely behavioral perspective. In other words, this formalism specifies a set of causal scenarios between actions of a system, without providing any implementation-level details about the system. In this work, we establish several new connections between MSC languages and Petri nets, and show that several computational problems involving these formalisms are decidable. Our results fill some gaps in the literature that had been open for several years. To obtain our results we develop new techniques in the realm of slice automata theory, a framework introduced one decade ago in the study of the partial order behavior of bounded Petri nets. These techniques can also be applied to establish connections between Petri nets and other well studied behavioral formalisms, such as the notion of Mazurkiewicz trace languages.publishedVersio

    Computer implementation of Mason\u27s rule and software development of stochastic petri nets

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    A symbolic performance analysis approach for discrete event systems can be formulated based on the integration of Petri nets and Moment Generating Function concepts [1-3]. The key steps in the method include modeling a system with arbitrary stochastic Petri nets (ASPN), generation of state machine Petri nets with transfer functions, derivation of equivalent transfer functions, and symbolic derivation of transfer functions to obtain the performance measures. Since Mason\u27s rule can be used to effectively derive the closed-form transfer function, its computer implementation plays a very important role in automating the above procedure. This thesis develops the computer implementation of Mason\u27s rule (CIMR). The algorithms and their complexity analysis are also given. Examples are used to illustrate CIMR method\u27s application for performance evaluation of ASPN and linear control systems. Finally, suggestions for future software development of ASPN are made

    SMT-based Abstract Temporal Planning

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    These are the proceedings of the International Workshop on Petri Nets and Software Engineering (PNSE’14) in Tunis, Tunisia, June 23–24, 2014. It is a co-located event of Petri Nets 2014, the 35th international conference on Applications and Theory of Petri Nets and Concurrency and ACSD 2014, the 14th International Conference on Application of Concurrency to System Design.An abstract planning is the first phase of the web service composition in the PlanICS framework. A user query specifies the initial and the expected state of a plan in request. The paper extends PlanICS with a module for temporal planning, by extending the user query with an LTL_k-X formula specifying temporal aspects of world transformations in a plan. Our solution comes together with an example, an implementation, and experimental results

    Augmenting High-Level Petri Nets to Support GALS Distributed Embedded Systems Specification

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    Part 9: Embedded Systems and Petri NetsInternational audienceHigh-level Petri net classes are suited to specify concurrent processes with emphasis both in control and data processing, making them appropriate to specify distributed embedded systems (DES). Embedded systems components are usually synchronous, which means that DES can be seen as Globally-Asynchronous Locally-Synchronous (GALS) systems. This paper proposes to include in high-level Petri nets a set of concepts already introduced for low-level Petri nets allowing the specification of GALS systems, namely time domains, test arcs and priorities. Additionally, this paper proposes external messages and three types of (high-level) asynchronous communication channels, to specify the interaction between distributed components based on message exchange. With these extensions, GALS-DES can be specified using high-level Petri nets. The resulting models include the specification of each component with well-defined boundaries and interface, and also the explicit specification of the asynchronous interaction between components. These models will be used not only to specify the system behavior, but also to be the input for model-checking tools (supporting its verification) and automatic code generation tools (supporting its implementation in software and hardware platforms), giving a contribution to the model-based development approach and hardware-software co-design of DES based on high-level Petri nets

    Object oriented design of petri net simulator

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    Petri nets are highly useful for modeling discrete event dynamic systems. The objective of this effort is to develop a tool for drawing, editing and simulating Petri nets using object oriented programming on a standard platform. The object oriented approach was chosen because of its code reuse and extendability features which simplify the task of adding features to the tool as the model evolves. The design stresses on modeling of the problem by objects which closely relate the system design with the implementation. C++ is used for implementing the object oriented design, and the XView toolkit is used for building the graphical editor in compliance with AT&T\u27s OPENLOOK standards on a Sun Sparc IPX running SunOS 4.1.2. The object oriented paradigm was successfully applied to develop a user friendly, graphical editor and a simulator for Petri nets

    Parallel Graph Transformation for Model Simulation applied to Timed Transition Petri Nets

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    Proceedings of the Workshop on Graph Transformation and Visual Modelling Techniques (GT-VMT 2004)This work discusses the use of parallel graph transformation systems for (multi-formalism) modeling and simulation and their implementation in the meta-modeling tool AToM3. As an example, a simulator for Timed Transition Petri Nets (TTPN) is modeled using parallel graph transformation.This work has been partially sponsored by the SEGRAVIS network and the Spanish Ministry of Science and Technology (TIC2002-01948)

    Operációkutatási módszerek műszaki informatikai rendszerek analízisében és verifikációjában = Operation Research Methods for the Analysis and Verification of Information Technology Systems

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    Kidolgoztuk a Petri-hálók és produkciós hálók (PNS) egységes szemléletű leírását. Megfogalmaztuk az "optimális trajektória generálásának" problémáját Petri-hálós modellekre. A megoldásként kidolgozott és implementált algoritmus egyúttal temporális logikai követelményeket is vizsgál a modellen. Az algoritmust gyorsítottuk a PNS logikai bázisa fölötti kereséssel. A SPIN modellellenőrzőt magát használva egy másik megoldást is adtunk a problémára, valamint gráftranszformációs rendszerek optimalizálására. Megadtuk a lineáris korlátozási feltételekkel adott szeparábilis konkáv minimalizálási feladat egy elégséges optimalitási kritériumát, mely a Branch-and-Bound típusú algoritmusban használható fel megállási kritériumként. A magasszintű leírásokból a Petri-hálós modellbe történő transzformációkat matematikai alapokon definiáltuk, megvalósításukra automatikus modelltranszformációs megoldást dolgoztunk ki: egy algoritmust, amely GRM profillal adott modellből generálja a Petri-hálót, és egy általános algoritmust, amely UML modellekből származtat a diagnosztika alapjául szolgáló modelleket. Megvizsgáltuk ezen modellek illeszthetőségét a szabványokhoz. Multiprocesszoros rendszerek diagnosztizálására egy PNS technikákat használó algoritmust adtunk, melynek várható hatékonyságát igazoltuk. Munkálatok folytak a diagnosztika tesztalapú megközelítésére, és diagnosztikai modellek kísérletes paraméterezésére. Kísérleteket végeztünk az IBM Holosofx ipari workflow modellező eszköz illesztésére. | A unified treatment for Petri nets and process network (PNS) problems was defined. The 'optimal trajectory generation problem' for Petri nets was defined. Elaboration and implementation of an algorithm that is able not only to give the optimal trajectory but to verify temporal logic requirements for Petri nets. This algorithm was accelerated using Branch-and-Bound method over the logical basis of the feasible process networks. Another algorithm to solve the problem using only the SPIN model checker was elaborated. The optimization of graph transformation systems with time was solved based on the same technique. A sufficient optimality criteria was given for constrained, concave minimization problems. The precise mathematics of the model transformation from high-level models to Petri nets was defined, and automatic model transformations were carried out to realize these transformations: a transformation from UML models given by the GRM profile to Petri nets and a general algorithm that delivers models to diagnose from UML models. The conformancy of these models to standards was investigated. The probabilistic diagnosis problem in multiprocessor systems was solved using PNS techniques. The efficiency of the method was shown. There were efforts to elaborate a test-based approach of diagnostics, and to parameterize diagnostics models based on dependability experiments. Experiments were carried out to transform IBM Holosofx models to Petri nets
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