Showing papers on "Petri net published in 1983"
TL;DR: Some theorems relating K -density, cut finiteness, and discreteness are proved and the result that a place/transition net is bounded if and only if its processes are K -dense is obtained.
Abstract: The idea of representing non-sequential processes as partially ordered sets (occurrence nets) is applied to place/transition nets (Petri nets), based on the well known notion of process for condition/event-systems. For occurrence nets some theorems relating K -density, cut finiteness, and discreteness are proved. With these theorems the result that a place/transition net is bounded if and only if its processes are K -dense is obtained.
320 citations
TL;DR: Conditions under which a subnet can be substituted for a single transition while preserving properties such as liveness and boundedness are presented.
309 citations
Proceedings Article•
01 Jan 1983
301 citations
TL;DR: In this article, the notion of a "time-driven" system is introduced which is formalized using a Petri net model augmented with timing information, and several subclasses of time-driven systems are defined with increasing levels of complexity.
Abstract: A methodology for the statement of timing requirements is presented for a class of embedded computer systems. The notion of a "time-driven" system is introduced which is formalized using a Petri net model augmented with timing information. Several subclasses of time-driven systems are defined with increasing levels of complexity. By deriving the conditions under which the Petri net model can be proven to be safe in the presence of time, timing requirements for modules in the system can be obtained. Analytical techniques are developed for proving safeness in the presence of time for the net constructions used in the defined subclasses of time-driven systems.
205 citations
29 Aug 1983
TL;DR: Graph models have been proposed by many authors as a useful tool for the analysis of peculiar features of computer systems such as concurrency, synchronization, communication, and cooperation among subsystems.
Abstract: Graph models have been proposed by many authors as a useful tool for the analysis of peculiar features of computer systems such as concurrency, synchronization, communication, and cooperation among subsystems. Much of the work in this field is related to the original ideas developed by C. A. Petri. These graph models are today generally known as Petri Nets (PNs).
159 citations
01 Dec 1983
TL;DR: It is shown that, under some structural assumptions, timed Petri net models of manufacturing processes translate into linear equations in a (max, +)- based algebra, which can solve these equations for the purposes of both performance evaluation and real-time control.
Abstract: A preliminary investigation, and extension of the power, of timed Petri nets to describe, model, and analyze production processes is reported. In particular, insights into real-time control aspects as well as the performance of flexible manufacturing systems are sought. Comparisons with previous investigative models are made. New and general modeling conventions are provided, which extend the realm of Petri net modeling capabilities. Various realistic aspects of manufacturing processes are modeled. Efficient algebraic tools to analyze a certain class of Petri nets are described [1]. We show that, under some structural assumptions, timed Petri net models of manufacturing processes translate into linear equations in a (max, +)- based algebra. Efficient algorithms can solve these equations for the purposes of both performance evaluation and real-time control.
141 citations
TL;DR: The model is based on a modified form of Petri net, and enables one to represent both the structure and the behavior of a distributed software system at a desired level of design.
Abstract: A model for representing and analyzing the design of a distributed software system is presented. The model is based on a modified form of Petri net, and enables one to represent both the structure and the behavior of a distributed software system at a desired level of design. Behavioral properties of the design representation can be verified by translating the modified Petri net into an equivalent ordinary Petri net and then analyzing that resulting Petri net. The model emphasizes the unified representation of control and data flows, partially ordered software components, hierarchical component structure, abstract data types, data objects, local control, and distributed system state. At any design level, the distributed software system is viewed as a collection of software components. Software components are externally described in terms of their input and output control states, abstract data types, data objects, and a set of control and data transfer specifications. They are interconnected through the shared control states and through the shared data objects. A system component can be viewed internally as a collection of subcomponents, local control states, local abstract data types, and local data objects.
75 citations
TL;DR: Stochastic models of contention for shared resources in an experimental multiprocessor prototype are presented and are validated with simulation and measurement results that show that the accuracy of the analytical results is excellent.
Abstract: Stochastic models of contention for shared resources in an experimental multiprocessor prototype are presented and are validated with simulation and measurement results. Three modeling techniques are used (stochastic Petri nets, Markov chains, and queueing networks) that represent the system operations as Markovian stochastic processes. Each technique is best suited to a specific stage of the analysis. An integrated use of these techniques represents a very powerful tool for the performance analysis of multiprocessor systems and provides ways of investigating several extensions of the prototype architecture. Simulation results and measurements performed on the hardware prototype validate the analysis and show that the accuracy of the analytical results is excellent.
74 citations
IBM1
TL;DR: A programming system has been implemented in which annotated Petri nets are used as machine-processable high-evel design representations that can be used to express the parallelism and the dynamic sequential dependencies found in complex software.
Abstract: A programming system has been implemented in which annotated Petri nets are used as machine-processable high-evel design representations. The nets can be used to express the parallelism and the dynamic sequential dependencies found in complex software. They can then be interactively fired to facilitate debugging of the design. The nets are processed into a procedure language, called XL/1, to which a variety of transformations are applied in order to produce more efficient programs. These programs are generated for either a serial or a parallel processing environment. Finally, the XL/1 programs may be translated into PL/I or PL/S. The serial processing versions have been compiled and run successfully, but the parallel processing versions have not yet been run in a parallel processing environment.
65 citations
01 Jan 1983
41 citations
01 Jan 1983
TL;DR: The aim of the paper is to present a systematic research exploring the properties of Petri nets as generators of subset languages as well as pointing out several differences between the standard ‘string language’ approach and the ‘subset language” approach.
TL;DR: Two hierarchies are established and their interrelation is studied for the well-known notion of i -acceptance for i ∈{1, 1, 1',2,2',3} for the set of infinite, labelled or unlabelled firing sequences of a Petri net.
01 Jan 1983
TL;DR: In this paper, the authors present a conceptual framework to systematize concepts introduced in different PLCs specifically designed for safe (1-bounded) Petri net simulation.
Abstract: In a Petri Net (PN) model of a system, a small subset of transition can usually be fired. Therefore several special Programmable Logic Controllers (PLCs) have been proposed looking for more performant simulation schemas. Some of them are general purpose microcomputer-based. Others are constructed using specialised microprocessors (microprogrammed or not).
This paper presents a conceptual framework to systematize concepts introduced in different PLCs specifically designed for safe (1-bounded) PN simulation. To compare their “conceptual” performances, basic proposed schemas (and other new ones) were programmed on a same microcomputer (M 6801). The technique used for comparison of performances consists of:(1) building different data structures to represent PN and its marking and (2) building performance models using a small set of parameters that caracterizes the complexity of PN-models.
It is shown that there is no “optimum” schema. The “best” one is a function of the net to be realised.
01 Jan 1983
TL;DR: It is shown how Petri nets can be generalized to allow processes to be described by a common subnet, without losing the ability to distinguish between them.
Abstract: In many systems a number of different processes have a similar structure and behaviour. To shorten system description and system analysis it is desirable to be able to treat such similar processes in a uniform and succinct way. In this paper it is shown how Petri nets can be generalized to allow processes to be described by a common subnet, without losing the ability to distinguish between them. Our generalization, called coloured Petri nets, is heavily influenced by predicate/transition-nets introduced by H.J. Genrich and K. Lautenbach. Moreover our paper shows how the invariant-method, introduced for Petri nets by K. Lautenbach can be generalized to coloured Petri nets. Revised version (first version 1979)
TL;DR: The problem of deciding whether a given weight vector yields a finite distance is shown to be equivalent to the reachability problem and it is shown that a basis of the linear space of weight vectors for which the weighted sum of token counts is bounded over all reachable markings can be obtained effectively.
Abstract: Three notions of distance for measuring the synchronic dependence of transition firings in Petri nets are studied. For the first two notions we present algorithms for obtaining a basis of the linear space of weight vectors for which the distance is finite, and methods for computing the distance for any given weight vector by examining a finite set of vectors obtained a priori. For the third notion of distance, the problem of deciding whether a given weight vector yields a finite distance is shown to be equivalent to the reachability problem. Finally it is shown that a basis of the linear space of weight vectors for which the weighted sum of token counts is bounded over all reachable markings can be obtained effectively. Also some complexity results are given.
01 Jan 1983
TL;DR: It is proved that CCS defines a subclass of the concurrent systems definable by means of net theory, i.e. the class of systems composed of interacting sequential automata, to transfer analytic concepts and techniques from a theory to the other, as for example the observation equivalence notion defined inside the CCS.
Abstract: The comparison between Milner’s CCS and Petri nets leads to prove that CCS defines a subclass of the concurrent systems definable by means of net theory, i.e. the class of systems composed of interacting sequential automata. The proof is based on (the construction of) an isomorphism between Milner’s communicating systems class and a subclass of Petri nets.The paper fully presents the proof for a subclass of communicating systems (where neither value passing nor finite unlimited instances of agents are allowed) and a specific subclass of nets, the SA2 PT class (a restriction of the Superposed Automata nets class). Some hints how to extend the proof to the whole CCS conclude the paper. This result allows to transfer analytic concepts and techniques from a theory to the other, as for example the observation equivalence notion defined inside the CCS. The paper is fully self-consistent.
01 Jan 1983
TL;DR: A model of non-sequential processes and a generalization of Dedekind's definition of the continuity (completeness) of the reals which is applicable to both totally and partially ordered sets as also to both dense and discrete structures is proposed.
TL;DR: Closure properties of various classes of subset languages of Petri nets considered by Rozenberg and Verraedt (1983) are investigated.
TL;DR: A model of the fuzzy Petri net, which is derived by fuzzification of transitions and places from the classical PetriNet, is proposed, which results from intuitions and experiences of specialists.
TL;DR: A Petri Net based design method which supports the initial phases of the software development process and allows for the systematic specification and analysis of system requirements and software requirements.
Abstract: We present a Petri Net based design method which supports the initial phases of the software development process. This method allows for the systematic specification and analysis of system requirements and software requirements.
TL;DR: The proposed technique is simple and tackles the problem of determining the S-T paths between specified nodes S and T in a systematic way and is amenable to computer implementation.
01 Mar 1983
TL;DR: The aim is to better understand the relationships between choice and concurrency that lead to the good behaviour of distributed systems and to formulate a model based on Petri nets and develop its theory, called bipolar synchronisation schemes (bp schemes).
Abstract: The aim is to better understand the relationships between choice and concurrency that lead to the good behaviour of distributed systems. In order to do so, we formulate a model based on Petri nets and develop its theory. The model is called bipolar synchronisation schemes (bp schemes) and the theory we construct is mainly devoted to synthesizing, in a systematic fashion, all well behaved bp schemes. We also provide a computational interpretation of well behaved bp schemes. Through this interpretation the insights gained by developing the theory of bp schemes can be transferred to concurrent programs.
01 Jan 1983
TL;DR: A distributed simulation methodology is presented on the basis of a special class of Petri Nets (P-Ta-Nets), which admits both time reversal simulation and (local) changes of meaning, of influences, and/or of parameters.
Abstract: A distributed simulation methodology is presented on the basis of a special class of Petri Nets (P-Ta-Nets). Examples taken from Problem Study 3 show how a partial (or local) reorganization of a real system and its simulation can be arranged. A special reversion technique admits both time reversal simulation and (local) changes of meaning, of influences, and/or of parameters. All topics from the questionnaire will be discussed, some in great detail.
01 Jan 1983
TL;DR: This dissertation defines a modeling framework in which performance and correctness can be studied and is applied to evaluate the performance of a ring network proposed for distributed execution of functional programs.
Abstract: Existing methods support one of two approaches to the design of distributed, high-performance architectures. Queueing models support performance evaluation at a very abstract level of the design. Logical design models support evaluation of correctness and realizability at lower levels in the design process. This dissertation defines a modeling framework in which performance and correctness can be studied. The UCLA Graph Model of Behavior is selected and extended to support integrated Performance-Oriented Design. The GMB supports formal Control Flow Analysis, similar to the Petri net, which is useful for detecting the potential for deadlock, the potential for unbounded demands on system resources, and other control flow anomalies. Extensions defined and implemented in this work are proven to be consistent with the control flow analysis formalism. The proposed extensions include the capability to specify finite-capacity service centers, pre-emptive and non-preemptive service disciplines, data domain queues which support customer classes, deterministic customer routing, and under certain restrictions, priority service. The resulting framework is applied to evaluate the performance of a ring network proposed for distributed execution of functional programs. Issues in modeling of low-level hardware and concurrent software which can be partially solved by the above extensions are also discussed, leading to better support for realization of graph models.