Showing papers on "Petri net published in 2010"

Elements of Distributed Algorithms: Modeling and Analysis with Petri Nets

Abstract: Distributed Computing is rapidly becoming the principal computing paradigm in diverse areas of computing, communication, and control. Processor clusters, local and wide area networks, and the information highway evolved a new kind of problems which can be solved with distributed algorithms.In this textbook a variety of distributed algorithms are presented independently of particular programming languages or hardware, using the graphically suggestive technique of Petri nets which is both easy to comprehend intuitively and formally rigorous. By means of temporal logic the author provides surprisingly simple yet powerful correctness proofs for the algorithms.The scope of the book ranges from distributed control and synchronization of two sites up to algorithms on any kind of networks. Numerous examples show that description and analysis of distributed algorithms in this framework are intuitive and technically transparent.

On Probabilistic Automata in Continuous Time

Abstract: We develop a compositional behavioural model that integrates a variation of probabilistic automata into a conservative extension of interactive Markov chains. The model is rich enough to embody the semantics of generalised stochastic Petri nets. We define strong and weak bisimulations and discuss their compositionality properties. Weak bisimulation is partly oblivious to the probabilistic branching structure, in order to reflect some natural equalities in this spectrum of models. As a result, the standard way to associate a stochastic process to a generalised stochastic Petri net can be proven sound with respect to weak bisimulation.

Snoopy - a unifying Petri net framework to investigate biomolecular networks

Abstract: Summary: To investigate biomolecular networks, Snoopy provides a unifying Petri net framework comprising a family of related Petri net classes. Models can be hierarchically structured, allowing for the mastering of larger networks. To move easily between the qualitative, stochastic and continuous modelling paradigms, models can be converted into each other. We get models sharing structure, but specialized by their kinetic information. The analysis and iterative reverse engineering of biomolecular networks is supported by the simultaneous use of several Petri net classes, while the graphical user interface adapts dynamically to the active one. Built-in animation and simulation are complemented by exports to various analysis tools. Snoopy facilitates the addition of new Petri net classes thanks to its generic design. Availability: Our tool with Petri net samples is available free of charge for non-commercial use at http://www-dssz.informatik.tu-cottbus.de/snoopy.html; supported operating systems: Mac OS X, Windows and Linux (selected distributions). Contact: snoopy@informatik.tu-cottbus.de

A Petri Net Approach to Analysis and Composition of Web Services

Abstract: Business process execution language for Web services (BPEL) is becoming the industrial standard for modeling Web-service-based business processes. Behavioral compatibility for Web service composition is one of the most important topics. The commonly used reachability exploration method focuses on verifying deadlock freeness. When this property is violated, the states and traces in the reachability graph only give clues to redesign the composition. The redesign must then repeat itself until no deadlock is found. In this paper, multiple Web service interaction is modeled with a Petri net called composition net (C-net for short). The problem of behavioral compatibility among Web services is hence transformed into the deadlock structure problem of a C-net. If services are incompatible, a policy based on appending additional information channels is proposed. It is proved that the policy can offer a good solution that can be mapped back into the BPEL models automatically.

Dynamic cutoff detection in parameterized concurrent programs

Abstract: We consider the class of finite-state programs executed by an unbounded number of replicated threads communicating via shared variables The thread-state reachability problem for this class is essential in software verification using predicate abstraction While this problem is decidable via Petri net coverability analysis, techniques solely based on coverability suffer from the problem's exponential-space complexity In this paper, we present an alternative method based on a thread-state cutoff: a number n of threads that suffice to generate all reachable thread states We give a condition, verifiable dynamically during reachability analysis for increasing n, that is sufficient to conclude that n is a cutoff We then make the method complete, via a coverability query that is of low cost in practice We demonstrate the efficiency of the approach on Petri net encodings of communication protocols, as well as on non-recursive Boolean programs run by arbitrarily many parallel threads.

Automated Modeling of Dynamic Reliability Block Diagrams Using Colored Petri Nets

Abstract: Computer system reliability is conventionally modeled and analyzed using techniques such as fault tree analysis and reliability block diagrams (RBDs), which provide static representations of system reliability properties. A recent extension to RBDs, called dynamic RBDs (DRBD), defines a framework for modeling the dynamic reliability behavior of computer-based systems. However, analyzing a DRBD model in order to locate and identify design errors, such as a deadlock error or faulty state, is not trivial when done manually. A feasible approach to verifying it is to develop its formal model and then analyze it using programmatic methods. In this paper, we first define a reliability markup language that can be used to formally describe DRBD models. Then, we present an algorithm that automatically converts a DRBD model into a colored Petri net. We use a case study to illustrate the effectiveness of our approach and demonstrate how system properties of a DRBD model can be verified using an existing Petri net tool. Our formal modeling approach is compositional; thus, it provides a potential solution to automated verification of DRBD models.

CONCUR 2010 - concurrency theory : 21st International Conference, CONCUR 2010, Paris, France, August 31-September 3, 2010 : proceedings

Abstract: Dating Concurrent Objects: Real-Time Modeling and Schedulability Analysis.- Applications of Shellable Complexes to Distributed Computing.- Concurrency and Composition in a Stochastic World.- Taming Distributed Asynchronous Systems.- Trust in Anonymity Networks.- Learning I/O Automata.- Constrained Monotonic Abstraction: A CEGAR for Parameterized Verification.- Information Flow in Interactive Systems.- From Multi to Single Stack Automata.- A Geometric Approach to the Problem of Unique Decomposition of Processes.- A Logic for True Concurrency.- A Theory of Design-by-Contract for Distributed Multiparty Interactions.- Bisimilarity of One-Counter Processes Is PSPACE-Complete.- Nash Equilibria for Reachability Objectives in Multi-player Timed Games.- Stochastic Real-Time Games with Qualitative Timed Automata Objectives.- Session Types as Intuitionistic Linear Propositions.- Session Types for Access and Information Flow Control.- Simulation Distances.- Mean-Payoff Automaton Expressions.- Obliging Games.- Multipebble Simulations for Alternating Automata.- Parameterized Verification of Ad Hoc Networks.- Termination in Impure Concurrent Languages.- Buffered Communication Analysis in Distributed Multiparty Sessions.- Efficient Bisimilarities from Second-Order Reaction Semantics for ?-Calculus.- On the Use of Non-deterministic Automata for Presburger Arithmetic.- Reasoning about Optimistic Concurrency Using a Program Logic for History.- Theory by Process.- On the Compositionality of Round Abstraction.- A Linear Account of Session Types in the Pi Calculus.- Generic Forward and Backward Simulations II: Probabilistic Simulation.- Kleene, Rabin, and Scott Are Available.- Reversing Higher-Order Pi.- Modal Logic over Higher Dimensional Automata.- A Communication Based Model for Games of Imperfect Information.- Flat Coalgebraic Fixed Point Logics.- Conditional Automata: A Tool for Safe Removal of Negligible Events.- Representations of Petri Net Interactions.- Communicating Transactions.- Consistent Correlations for Parameterised Boolean Equation Systems with Applications in Correctness Proofs for Manipulations.

Modeling in Systems Biology: The Petri Net Approach

Abstract: The emerging, multi-disciplinary field of systems biology is devoted to the study of the relationships between various parts of a biological system, and computer modeling plays a vital role in the drive to understand the processes of life from an holistic viewpoint. Advancements in experimental technologies in biology and medicine have generated an enormous amount of biological data on the dependencies and interactions of many different molecular cell processes, fueling the development of numerous computational methods for exploring this data. The mathematical formalism of Petri net theory is able to encompass many of these techniques. This essential text/reference presents a comprehensive overview of cutting-edge research in applications of Petri nets in systems biology, with contributions from an international selection of experts. Those unfamiliar with the field are also provided with a general introduction to systems biology, the foundations of biochemistry, and the basics of Petri net theory. Further chapters address Petri net modeling techniques for building and analyzing biological models, as well as network prediction approaches, before reviewing the applications to networks of different biological classification. Topics and features: investigates the modular, qualitative modeling of regulatory networks using Petri nets, and examines an Hybrid Functional Petri net simulation case study; contains a glossary of the concepts and notation used in the book, in addition to exercises at the end of each chapter; covers the topological analysis of metabolic and regulatory networks, the analysis of models of signaling networks, and the prediction of network structure; provides a biological case study on the conversion of logical networks into Petri nets; discusses discrete modeling, stochastic modeling, fuzzy modeling, dynamic pathway modeling, genetic regulatory network modeling, and quantitative analysis techniques; includes a Foreword by Professor Jens Reich, Professor of Bioinformatics at Humboldt University and Max Delbrck Center for Molecular Medicine in Berlin. This unique guide to the modeling of biochemical systems using Petri net concepts will be of real utility to researchers and students of computational biology, systems biology, bioinformatics, computer science, and biochemistry.

Preserving correctness during business process model configuration

Abstract: A configurable process model captures a family of related process models in a single artifact. Such models are intended to be configured to fit the requirements of specific organizations or projects, leading to individualized process models that are subsequently used for domain analysis or solution design. This article proposes a formal foundation for individualizing configurable process models incrementally, while preserving correctness, both with respect to syntax and behavioral semantics. Specifically, assuming the configurable process model is behaviorally sound, the individualized process models are guaranteed to be sound. The theory is first developed in the context of Petri nets and then extended to a process modeling notation widely used in practice, namely Event-driven Process Chains.

Revisiting Ackermann-hardness for lossy counter machines and reset Petri nets

Abstract: We prove that coverability and termination are not primitive-recursive for lossy counter machines and for Reset Petri nets.

Petri nets for modelling metabolic pathways: a survey

Abstract: In the last 15 years, several research efforts have been directed towards the representation and the analysis of metabolic pathways by using Petri nets. The goal of this paper is twofold. First, we discuss how the knowledge about metabolic pathways can be represented with Petri nets. We point out the main problems that arise in the construction of a Petri net model of a metabolic pathway and we outline some solutions proposed in the literature. Second, we present a comprehensive review of recent research on this topic, in order to assess the maturity of the field and the availability of a methodology for modelling a metabolic pathway by a corresponding Petri net.

Polynomial algebra of discrete models in systems biology

Abstract: Motivation: An increasing number of discrete mathematical models are being published in Systems Biology, ranging from Boolean network models to logical models and Petri nets. They are used to model a variety of biochemical networks, such as metabolic networks, gene regulatory networks and signal transduction networks. There is increasing evidence that such models can capture key dynamic features of biological networks and can be used successfully for hypothesis generation. Results: This article provides a unified framework that can aid the mathematical analysis of Boolean network models, logical models and Petri nets. They can be represented as polynomial dynamical systems, which allows the use of a variety of mathematical tools from computer algebra for their analysis. Algorithms are presented for the translation into polynomial dynamical systems. Examples are given of how polynomial algebra can be used for the model analysis. Contact: alanavc@vt.edu Supplementary information: Supplementary data are available at Bioinformatics online.

Modeling Distributed Transportation Systems Composed of Flexible Automated Guided Vehicles in Flexible Manufacturing Systems

Abstract: This paper proposes a methodology for modeling and controlling a flexible material handling system (MHS), composed of multiple automated guided vehicles (AGVs), suitable for Flexible Manufacturing Systems (FMSs). The AGVs incorporate artificial intelligent techniques to: i) facilitate the configuration and adaptation when there are layout modifications and ii) simplify the interaction between them using simple coordination models. In order to achieve higher flexibility, the MHS makes use of a decentralized navigation control, which increases autonomy and scalability, and a distributed Petri net for solving task allocation and traffic control problems. In order to facilitate the integration with the manufacturing processes, tasks dispatched by manufacturing cells are allocated by the MHS itself, taking into account pending transportation tasks and the system's performance. The whole system has been tested in a real factory and is currently in operational use.

Petri Net Decomposition Approach to Optimization of Route Planning Problems for AGV Systems

Abstract: In this paper, we propose a Petri Net (PN) decomposition approach to the optimization of route planning problems for automated guided vehicles (AGVs) in semiconductor fabrication bays. An augmented PN is developed to model the concurrent dynamics for multiple AGVs. The route planning problem to minimize the total transportation time is formulated as an optimal transition firing sequence problem for the PN. The PN is decomposed into several subnets such that the subnets are made independent by removing the original shared places and creating its own set of resource places for each subnet with the appropriate connections. The partial solution derived at each subnet is not usually making a feasible solution for the entire PN. The penalty function algorithm is used to integrate the solutions derived at the decomposed subnets. The optimal solution for each subnet is repeatedly generated by using the shortest-path algorithm in polynomial time with a penalty function embedded in the objective function. The effectiveness of the proposed method is demonstrated for a practical-sized route planning problem in semiconductor fabrication bay from computational experiments.

A Continuous Petri Net Approach for Model Predictive Control of Traffic Systems

Abstract: Traffic systems are often highly populated discrete event systems that exhibit several modes of behavior such as free flow traffic, traffic jams, stop-and-go waves, etc. An appropriate closed loop control of the congested system is crucial in order to avoid undesirable behavior. This paper proposes a macroscopic model based on continuous Petri nets as a tool for designing control laws that improve the behavior of traffic systems. The main reason to use a continuous model is to avoid the state explosion problem inherent to large discrete event systems. The obtained model captures the different operation modes of a traffic system and is highly compositional. In order to handle the variability of the traffic conditions, a model predictive control strategy is proposed and validated.

Hypermedia-driven RESTful service composition

Abstract: Representational State Transfer (REST) services are gaining momentum as a lightweight approach for the provision of services on the Web. Unlike WSDL-based services, in REST the set of operations is reduced, standardized, with well known semantics, and changes the resource's state. Few attempts have been proposed to support composition models for REST, they are mainly operation-centric and fail to acknowledge the hypermedia nature of REST, that is, clients must inspect the served resource state and choose the link to follow from there. We explore RESTful service composition as it is driven by the hypermedia net that is dynamically created while a client interacts with a server resulting in a light-weight approach. We based our proposal on a hypermedia-centric REST service description, the Resource Linking Language (ReLL) and Petri Nets as a mechanism for describing the machine-client navigation.

Beyond Attack Trees: Dynamic Security Modeling with Boolean Logic Driven Markov Processes (BDMP)

Abstract: Boolean logic Driven Markov Processes (BDMP) are a powerful modeling tool used in the reliability and safety domains. We propose to take advantage of their capabilities to go beyond the traditional techniques used to model attack scenarios. In particular we show how this new approach can be seen as preferable to attack trees and Petri net-based methods. Attack trees are inherently static and limited to independent events, whereas BDMP are dynamic and can take into account simple dependences. This allows the modeling of attack sequences, but also of defensive aspects such as detections. Petri net-based approaches are highly flexible but often lack readability and scalability; BDMP representations are close to attack trees, inheriting their readability and easy appropriation. Moreover, BDMP have mathematical properties leading to drastic reductions of combinatorial problems, allowing efficient scenarios processing and time dependent quantifications. Finally, limits and improvement perspectives are discussed.

Advances in Verification of Time Petri Nets and Timed Automata: A Temporal Logic Approach

Abstract: Specifying Timed Systems and Their Properties.- Petri Nets with Time.- Timed Automata.- From Time Petri Nets to Timed Automata.- Main Formalisms for Expressing Temporal Properties.- Model Generation and Verification.- Abstract Models.- Explicit Verification.- Verification Based on Satisfiability Checking.

Process mining from a basis of state regions

Abstract: A central problem in the area of Process Mining is to obtain a formal model that represents selected behavior of a system. The theory of regions has been applied to address this problem, enabling the derivation of a Petri net whose language includes a set of traces. However, when dealing with real-life systems, the available tool support for performing such task is unsatisfactory, due to the complex algorithms that are required. In this paper, the theory of regions is revisited to devise a novel technique that explores the space of regions by combining the elements of a region basis. Due to its light space requirements, the approach can represent an important step for bridging the gap between the theory of regions and its industrial application. Experimental results improve in orders of magnitude state-of-the-art tools for the same task.

New Region-Based Algorithms for Deriving Bounded Petri Nets

Abstract: The theory of regions was introduced in the early nineties as a method to bridge state and event-based models. This paper tackles the problem of deriving a Petri net from a state-based model, using the theory of regions. Some of the restrictions required in the traditional approach are dropped in this paper, together with significant extensions that make the approach applicable in new scenarios. One of these scenarios is Process Mining, where accepting (discovering) additional behavior in the synthesized Petri net is sometimes valued. The algorithmic emphasis used in this paper contributes to the demystification of the theory of regions as been only a good theoretical exercise, opening the door for its application in the industrial domain.

Cell Illustrator 4.0: a computational platform for systems biology.

Abstract: Cell Illustrator is a software platform for Systems Biology that uses the concept of Petri net for modeling and simulating biopathways. It is intended for biological scientists working at bench. The latest version of Cell Illustrator 4.0 uses Java Web Start technology and is enhanced with new capabilities, including: automatic graph grid layout algorithms using ontology information; tools using Cell System Markup Language (CSML) 3.0 and Cell System Ontology 3.0; parameter search module; high-performance simulation module; CSML database management system; conversion from CSML model to programming languages (FORTRAN, C, C++, Java, Python and Perl); import from SBML, CellML, and BioPAX; and, export to SVG and HTML. Cell Illustrator employs an extension of hybrid Petri net in an object-oriented style so that biopathway models can include objects such as DNA sequence, molecular density, 3D localization information, transcription with frame-shift, translation with codon table, as well as biochemical reactions.

Oris: a tool for modeling, verification and evaluation of real-time systems

Abstract: Oris is a tool for qualitative verification and quantitative evaluation of reactive timed systems, which supports modeling and analysis of various classes of timed extensions of Petri Nets. As most characterizing features, Oris implements symbolic state space analysis of preemptive Time Petri Nets, which enable schedulability analysis of real-time systems running under priority preemptive scheduling; and stochastic Time Petri Nets, which enable an integrated approach to qualitative verification and quantitative evaluation. In this paper, we present the current version of the tool and we illustrate its application to two different case studies in the areas of qualitative verification and quantitative evaluation, respectively.

Actor Model of Computation: Scalable Robust Information Systems

Abstract: The Actor model is a mathematical theory that treats "Actors" as the universal primitives of concurrent digital computation. The model has been used both as a framework for a theoretical understanding of concurrency, and as the theoretical basis for several practical implementations of concurrent systems. Unlike previous models of computation, the Actor model was inspired by physical laws. It was also influenced by the programming languages Lisp, Simula 67 and Smalltalk-72, as well as ideas for Petri Nets, capability-based systems and packet switching. The advent of massive concurrency through client-cloud computing and many-core computer architectures has galvanized interest in the Actor model. Actor technology will see significant application for integrating all kinds of digital information for individuals, groups, and organizations so their information usefully links together. Information integration needs to make use of the following information system principles: * Persistence. Information is collected and indexed. * Concurrency: Work proceeds interactively and concurrently, overlapping in time. * Quasi-commutativity: Information can be used regardless of whether it initiates new work or become relevant to ongoing work. * Sponsorship: Sponsors provide resources for computation, i.e., processing, storage, and communications. * Pluralism: Information is heterogeneous, overlapping and often inconsistent. * Provenance: The provenance of information is carefully tracked and recorded The Actor Model is intended to provide a foundation for inconsistency robust information integration

Representations of Petri net interactions

Abstract: We introduce a novel compositional algebra of Petri nets, as well as a stateful extension of the calculus of connectors. These two formalisms are shown to have the same expressive power.

Colored timed Petri nets for modeling and analysis of cluser tools

Abstract: In this paper, a colored timed resource-oriented Petri net (CTROPN) is developed to model the cluster tools in semiconductor fabrication. It is structurally simple and concise, since each module in a cluster tool corresponds to a unique place in CTROPN. It is also powerful in modeling the qualitative and temporal behavior of the cluster tools with a single-blade or dual-blade robot. The initial transient behavior, steady-state behavior and the final transient behavior can all be investigated through a single model.

Algebraic Synthesis of Timed Supervisor for Automated Manufacturing Systems Using Petri Nets

Abstract: For practical automated manufacturing systems (AMSs), the time dimension is of great significance and should be integrated in their plant models. Reasonably, many of the realistic general mutual exclusion constraints (GMECs) imposed on these discrete models should be timed rather than merely algebraic or logic. In the past, such a problem was studied on the basis of the Ramadge-Wonham supervisory control technique (SCT) and the theory of regions. It proves to be NP-hard since it necessitates the generation of reachability graphs. This paper shows that it can be solvable in polynomial time by using generalized linear constraints, which are originally proposed to increase the expressive power of the linear marking constraints. By dividing each constraint into marking, firing vector, and Parikh terms, its respective control place can be synthesized algebraically without considering the separation of dangerous states and events. Several examples are used to validate the effectiveness and efficiency of the proposed approach.

Low-Cost and High-Performance Supervision in Ratio-Enforced Automated Manufacturing Systems Using Timed Petri Nets

Abstract: In the context of automated manufacturing, this work proposes a new special class of timed Petri nets, namely, Timed ratio-enforced Augmented Marked Graph (TAMG) and its low-cost and high-performance supervisor synthesis methodology. A supervisor is composed of a set of control places (monitors), each of which is easy to be algebraically specified by a generalized mutual exclusion constraint (GMEC) to prevent certain siphons from being undermarked. In order to make a good tradeoff between the supervisor implementation cost and system performance, a mixed integer programming (MIP) approach is formulated to synthesize the monitors. An example is used to validate the effectiveness and efficiency of the proposed method. The results show that the proposed method remarkably outperforms any existing ones.