G. Conte

Bio: G. Conte is an academic researcher from University of Parma. The author has contributed to research in topics: Stochastic Petri net & Petri net. The author has an hindex of 18, co-authored 28 publications receiving 4392 citations. Previous affiliations of G. Conte include Instituto Politécnico Nacional & Polytechnic University of Turin.

Modelling with Generalized Stochastic Petri Nets

Abstract: From the Publisher: This book presents a unified theory of Generalized Stochastic Petri Nets (GSPNs) together with a set of illustrative examples from different application fields. The continuing success of GSPNs and the increasing interest in using them as a modelling paradigm for the quantitative analysis of distributed systems suggested the preparation of this volume with the intent of providing newcomers to the field with a useful tool for their first approach. Readers will find a clear and informal explanation of the concepts followed by formal definitions when necessary or helpful. The largest section of the book however is devoted to showing how this methodology can be applied in a range of domains.

A class of generalized stochastic Petri nets for the performance evaluation of multiprocessor systems

Abstract: Generalized stochastic Petri nets (GSPNs) are presented and are applied to the performance evaluation of multiprocessor systems. GSPNs are derived from standard Petri nets by partitioning the set of transitions into two subsets comprising timed and immediate transitions. An exponentially distributed random firing time is associated with each timed transition, whereas immediate transitions fire in zero time. It is shown that GSPN are equivalent to continuous-time stochastic processes, and solution methods for the derivation of the steady state probability distribution are presented. Examples of application of gspn models to the performance evaluation of multiprocessor systems show the usefulness and the effectiveness of this modeling tool. 15 references.

Performance models of multiprocessor systems

Abstract: While there are several studies of computer systems modeling and performance evaluation where models of multiprocessor systems can be found as examples of applications of general modeling techniques, this is the first to focus entirely on the problem of modeling and performance evaluation of multiprocessor systems using analytical methods.Increasingly sophisticated and fast-moving technologies require models that can estimate the performance of a computer system without having actually to build and test it, models that can help designers make the correct architectural choices. The area of distributed computer architectures, or multiprocessor systems, has numerous such choices and can greatly benefit from an extensive use of performance evaluation techniques in the system design stage.The multiprocessor features that are studied here focus on contention for physical system resources, such as shared devices and interconnection networks. A brief overview covers the modeling of other important system characteristics, such as failures of components and synchronizations at the software level.Contents: Stochastic Processes. Queuing Models. Stochastic Petri Nets. Multiprocessor Architectures. Analysis of Crossbar Multiprocessor Architecture. Single Bus Multiprocessors with External Common Memory. Multiple Bus Multiprocessors with External Common Memory. Single Bus Multiprocessors with Distributed Common Memory. Multiple Bus Multiprocessors with Distributed Common Memory.The authors are affiliated with Politecnico and Universita di Torino in Italy. Performance "Models of Multiprocessor Systems" is included in The MIT Press Series in Computer Systems, edited by Herb Schwetman.

Generalized stochastic Petri nets: a definition at the net level and its implications

Abstract: The class of Petri nets obtained by eliminating timing from generalized stochastic Petri net (GSPN) models while preserving the qualitative behavior is identified. Structural results for those nets are derived, obtaining the first structural analysis of Petri nets with priority and inhibitor arcs. A revision of the GSPN definition based on the structural properties of the models is presented. It is shown that for a (wide) class of nets, the definition of firing probabilities of conflicting immediate transitions does not require the information on reachable markings. Identification of the class of models for which the net-level specification is possible is also based on the structural analysis results. The procedure for the model specification is illustrated by means of an example. It is also shown that a net-level specification of the model associated with efficient structural analysis techniques can have a substantial impact on model analysis. >

The effect of execution policies on the semantics and analysis of stochastic Petri nets

Abstract: Petri nets in which random delays are associated with atomic transitions are defined in a comprehensive framework that contains most of the models already proposed in the literature. To include generally distributed firing times into the model one must specify the way in which the next transition to fire is chosen, and how the model keeps track of its past history; this set of specifications is called an execution policy. A discussion is presented of the impact that different execution policies have on semantics of the mode, as well as the characteristics of the stochastic process associated with each of these policies. When the execution policy is completely specified by the transition with the minimum delay (race policy) and the firing distributions are of the phase type, an algorithm is provided that automatically converts the stochastic process into a continuous time homogeneous Markov chain. An execution policy based on the choice of the next transition to fire independently of the associated delay (preselection policy) is introduced, and its semantics is discussed together with possible implementation strategies. >

Petri nets: Properties, analysis and applications

Abstract: Starts with a brief review of the history and the application areas considered in the literature. The author then proceeds with introductory modeling examples, behavioral and structural properties, three methods of analysis, subclasses of Petri nets and their analysis. In particular, one section is devoted to marked graphs, the concurrent system model most amenable to analysis. Introductory discussions on stochastic nets with their application to performance modeling, and on high-level nets with their application to logic programming, are provided. Also included are recent results on reachability criteria. Suggestions are provided for further reading on many subject areas of Petri nets. >

The application of Petri-nets to workflow management

Abstract: Workflow management promises a new solution to an age-old problem: controlling, monitoring, optimizing and supporting business processes. What is new about workflow management is the explicit representation of the business process logic which allows for computerized support. This paper discusses the use of Petri nets in the context of workflow management. Petri nets are an established tool for modeling and analyzing processes. On the one hand, Petri nets can be used as a design language for the specification of complex workflows. On the other hand, Petri net theory provides for powerful analysis techniques which can be used to verify the correctness of workflow procedures. This paper introduces workflow management as an application domain for Petri nets, presents state-of-the-art results with respect to the verification of workflows, and highlights some Petri-net-based workflow tools.

A logic for reasoning about time and reability

Abstract: We present a logic for stating properties such as, "after a request for service there is at least a 98\045 probability that the service will be carried out within 2 seconds". The logic extends the temporal logic CTL by Emerson, Clarke and Sistla with time and probabil- ities. Formulas are interpreted over discrete time Markov chains. We give algorithms for checking that a given Markov chain satis- fies a formula in the logic. The algorithms require a polynomial number of arithmetic operations, in size of both the formula and\003This research report is a revised and extended version of a paper that has appeared under the title "A Framework for Reasoning about Time and Reliability" in the Proceeding of the 10thIEEE Real-time Systems Symposium, Santa Monica CA, December 1989. This work was partially supported by the Swedish Board for Technical Development (STU) as part of Esprit BRA Project SPEC, and by the Swedish Telecommunication Administration.1the Markov chain. A simple example is included to illustrate the algorithms.

Synchronization and Linearity: An Algebra for Discrete Event Systems

Abstract: This book proposes a unified mathematical treatment of a class of 'linear' discrete event systems, which contains important subclasses of Petri nets and queuing networks with synchronization constraints. The linearity has to be understood with respect to nonstandard algebraic structures, e.g. the 'max-plus algebra'. A calculus is developed based on such structures, which is followed by tools for computing the time behaviour to such systems. This algebraic vision lays the foundation of a bona fide 'discrete event system theory', which is shown to parallel the classical linear system theory in several ways.