Petri net

About: Petri net is a research topic. Over the lifetime, 25039 publications have been published within this topic receiving 406994 citations.

A Maximally Permissive Deadlock Prevention Policy for FMS Based on Petri Net Siphon Control and the Theory of Regions

Abstract: This paper addresses the deadlock problems in flexible manufacturing systems (FMS) by using a Petri net siphon control method and the theory of regions. The proposed policy consists of two stages. The first one, called siphons control, is to add, for every siphon that we identify, a monitor to the original net model such that it is optimally invariant controlled. In the second stage, the theory of regions is utilized to derive the net supervisors such that deadlocks can be prevented. The first-stage work significantly lowers the computational cost compared with the approach where the theory of regions is used alone. An FMS example is presented to illustrate the technique. By varying the markings of given net structures, this paper shows its computational advantages.

Understanding Petri Nets

Abstract: s of type t o k e n . It also has a precondition saying that the value of the token in c o 1 must be y e 11 ow. If the precondition is satisfied, the processor may fire, consuming the token in the store. Upon firing, it produces two tokens, one in c o l with value r e d , and one in s with value t okenval. Informally, the processor may fire only when the traffic light is yellow. As a result of firing the processor, the traffic light turns red, a t the same time signaling the other light that it may turn green. T h e specification of the other processors is very similar and so is omitted. T h e specification of y2 r does not contain a conditional statement. This means that its behavior does not depend on the values of the consumed tokens. Consequently, it is very similar to the transitions in P/T nets. For this reason, a processor whose behavior is not conditional is often called a transition. This class of processors is important because we can apply analysis techniques like Sand T-invariants to ExSpect specifications only if the specification consists entirely of transitions. ExSpect has a tool to transform any specification into such a transitions-only specification with the same dynamic behavior.

Supporting user-oriented analysis for multi-view domain-specific visual languages

Abstract: The integration of usable and flexible analysis support in modelling environments is a key success factor in Model-Driven Development In this paradigm, models are the core asset from which code is automatically generated, and thus ensuring model correctness is a fundamental quality control activity For this purpose, a common approach is to transform the system models into formal semantic domains for verification However, if the analysis results are not shown in a proper way to the end-user (eg in terms of the original language) they may become useless In this paper we present a novel DSVL called BaVeL that facilitates the flexible annotation of verification results obtained in semantic domains to different formats, including the context of the original language BaVeL is used in combination with a consistency framework, providing support for all steps in a verification process: acquisition of additional input data, transformation of the system models into semantic domains, verification, and flexible annotation of analysis results The approach has been validated analytically by the cognitive dimensions framework, and empirically by its implementation and application to several DSVLs Here we present a case study of a notation in the area of Digital Libraries, where the analysis is performed by transformations into Petri nets and a process algebra

Graph processes

Abstract: We first give a new definition of graph grammars, which, although following the algebraic double-pushout approach, is more general than the classical one because of the use of a graph of types where all involved graphs are mapped to. Then, we develop a process-based semantics for such (typed) graph grammars, in the line of processes as normally used for providing a semantics to Petri nets. More precisely, we represent each equivalence class of derivations as a graph process, which can be seen as an acyclic graph grammar, plus a mapping of its items onto the items of the given grammar. Finally, we show that such processes represent exactly the equivalence classes of derivations up to the well-known shift-equivalence, which have always been used in the literature on graph grammars. Therefore graph processes are attractive alternative representatives for such classes. The advantage of dealing with graph processes instead of equivalence classes (or also representatives belonging to the equivalence classes) is that dependency and/or concurrency of derivation steps is explicitly represented.

Stochastic Petri Nets: Modelling, Stability, Simulation

Abstract: Written by a leading researcher this book presents an introduction to Stochastic Petri Nets covering the modeling power of the proposed SPN model, the stability conditions and the simulation methods. Its unique and well-written approach provides a timely and important addition to the literature. Appeals to a wide range of researchers in engineering, computer science, mathematics and OR.