共查询到20条相似文献,搜索用时 15 毫秒
2.
Petri nets for protocol engineering 总被引:8,自引:0,他引:8
To-yat Cheung 《Computer Communications》1996,19(14):1250-1257
3.
介绍了Petri网的基本定义和对并发系统的描述.指出网格是完全异步并发的基础环境。分析了Web服务和网格资源是构造Petri网格的变化元素和状态元素,进而基于Web services标准和WSRF规范构造了Petri网格体系结构的层次模型,指出Petri网格应用就是构造Petri网模型实例。 相似文献
4.
The goal of net reduction is to increase the effectiveness of Petri-netbased real-time program analysis. Petri-net-based analysis, like all reachabilitybased methods, suffers from the state explosion problem. Petri net reduction is one key method for combating this problem. In this paper, we extend several rules for the reduction of ordinary Petri nets to work with time Petri nets. We introduce a notion of equivalence among time Petri nets, and prove that our reduction rules yield equivalent nets. This notion of equivalence guarantees that crucial timing and concurrency properties are preserved. 相似文献
5.
D. A. Zaitsev 《Cybernetics and Systems Analysis》2004,40(5):739-746
The problem of splitting any given Petri net into functional subnets is considered. The properties of functional subnets and sets that induce them are investigated. An algorithm of polynomial complexity is constructed for decomposition of nets.Translated from Kibernetika i Sistemnyi Analiz, No. 5, pp. 131–140, September–October 2004. 相似文献
6.
Reduction rules for time Petri nets 总被引:7,自引:0,他引:7
The goal of net reduction is to increase the effectiveness of Petri-net-based real-time program analysis. Petri-net-based
analysis, like all reachability-based methods, suffers from the state explosion problem. Petri net reduction is one key method
for combating this problem.
In this paper, we extend several rules for the reduction of ordinary Petri nets to work with time Petri nets. We introduce
a notion of equivalence among time Petri nets, and prove that our reduction rules yield equivalent nets. This notion of equivalence
guarantees that crucial timing and concurrency properties are preserved.
Received September 12, 1994/July 4, 1995 相似文献
7.
S. Bernardi S. Donatelli A. Horváth 《International Journal on Software Tools for Technology Transfer (STTT)》2001,3(4):417-430
An implementation of compositionality for stochastic well-formed nets (SWN) and, consequently, for generalized stochastic
Petri nets (GSPN) has been recently included in the GreatSPN tool. Given two SWNs and a labelling function for places and
transitions, it is possible to produce a third one as a superposition of places and transitions of equal label. Colour domains
and arc functions of SWNs have to be treated appropriately. The main motivation for this extension was the need to evaluate
a library of fault-tolerant “mechanisms” that have been recently defined, and are now under implementation, in a European
project called TIRAN. The goal of the TIRAN project is to devise a portable software solution to the problem of fault tolerance
in embedded systems, while the goal of the evaluation is to provide evidence of the efficacy of the proposed solution. Modularity
being a natural “must” for the project, we have tried to reflect it in our modelling effort. In this paper, we discuss the
implementation of compositionality in the GreatSPN tool, and we show its use for the modelling of one of the TIRAN mechanisms,
the so-called local voter.
Published online: 24 August 2001 相似文献
8.
9.
Branching processes of Petri nets 总被引:1,自引:0,他引:1
Joost Engelfriet 《Acta Informatica》1991,28(6):575-591
Summary The notion of a branching process is introduced, as a formalization of an initial part of a run of a Petri net, including nondeterministic choices. This generalizes the notion of a process in a natural way. It is shown that the set of branching processes of a Petri net is a complete lattice, with respect to the natural notion of partial order. The largest element of this lattice is the unfolding of the Petri net. 相似文献
10.
Robert Gold 《Acta Informatica》1995,32(7):627-645
We give a semantics for place/transition nets, which describes the input/out-put behaviour using fixed point techniques. The semantics is shown to be compositional w.r.t. the net operators parallel composition, feedback and output merging. We prove consistency with the step sequence semantics and thus give an equivalent operational semantics.This work was partially supported by the Deutsche Forschungsgemeinschaft, SFB 342 相似文献
11.
12.
When a computer, manufacturing, telecommunication, or transportation system is modeled as a stochastic Petri net (SPN), many long-run performance characteristics of interest can be expressed as time-average limits of the associated marking process. For nets with generally-distributed firing times, such limits often cannot be computed analytically or numerically, but must be estimated using simulation. Previous work on estimation methods for SPNs has focused on the case in which there exists a sequence of regeneration points for the marking process of the net, so that point estimates and confidence intervals for time-average limits can be obtained using the regenerative method for analysis of simulation output. This paper is concerned with SPNs for which the regenerative method is not applicable. We provide conditions on the clock-setting distributions and new-marking probabilities of an SPN under which time-average limits are well defined and the output process of the simulation obeys a multivariate functional central limit theorem. It then follows from results of Glynn and Iglehart (1990) that methods based on standardized time series can be used to obtain strongly consistent point estimates and asymptotic confidence intervals for time-average limits. In particular, the method of batch means is applicable. Moreover, the methods of Munoz and Glynn can be used to obtain point estimates and confidence intervals for ratios of time-average limits. We illustrate our results using an SPN model of an interactive video-on-demand system 相似文献
13.
The authors prove a reduction theorem for the supervisory control problem for general Petri nets with general legal sets. To design control laws guaranteeing that the marking stays within the legal set, it suffices to consider a sub-Petri net of the full model. This extends existing design algorithms, allows to prove an important property of maximally permissive control laws and limits the number of events which need to be observed 相似文献
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15.
It is suggested that as rule-based system (RBS) technology gains wider acceptance, the need to create and maintain large knowledge bases will assume greater importance. Demonstrating a rule base to be free from error remains one of the obstacles to the adoption of this technology. An approach to RBS verification in which the system is modeled as a Petri net on which error detection is performed is presented. A set of propositions is formulated to locate errors of redundancy, conflict, circularity, and gaps in domain knowledge. Rigorous proofs of these propositions are provided. Difficulties in implementing a Petri net-based verifier and the potential restrictions of the applicability of this approach are discussed 相似文献
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17.
The problem of the synthesis of time bounds enforcing good properties for reactive systems has been much studied in the literature. These works mainly rely on dioid algebra theory and require important restrictions on the structure of the model (notably by restricting to timed event graphs). In this paper, we address the problems of existence and synthesis of shrinkings of the bounds of the time intervals of a time Petri net, such that a given property is verified. We show that this problem is decidable for CTL properties on bounded time Petri nets. We then propose a symbolic algorithm based on the state class graph for a fragment of CTL. If the desired property “includes” k-boundedness, the proposed algorithm terminates even if the net is unbounded. A prototype has been implemented in our tool Romeo and the method is illustrated on a small case study from the literature. 相似文献
18.
This paper presents a novel methodology for modelling and analyzing of behavior relations of concurrent systems. The set of all firing sequences of a Petri net is an important tool for describing the dynamic behavior of concurrent systems. In this paper, the behavior relativity of two concurrent subsystems in their synchronous composition is presented. Such behavior relativities, including Controlled Relativity, United Relativity, Interactive Relativity and Exclusive Relativity, are defined respectively. The properties of the relativities are discussed in detail. The analysis method for these properties is based on minimum T-invariants, when two subsystems are live bounded Petri nets. A well-known example has also been analyaed using the new methodology to demonstrate the advantages of the proposed methodology. 相似文献
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20.
D. A. Zaitsev 《Cybernetics and Systems Analysis》2006,42(1):126-136
Foundations of compositional analysis of Petri nets are presented. This analysis consist of the determination of properties
of a given Petri net from the properties of its functional subnets. Compositional analysis covers the investigation of behavioral
and structural properties of Petri nets with the help of matrix methods that use fundamental equations and invariants. The
exponential acceleration of computations as a function of the dimensionality of a net is obtained.
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Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 143–154, January–February 2006. 相似文献