Showing papers on "Petri net published in 1980"
TL;DR: In this article, an extended timed Petri net model is used to model the synchronization involved in real-time asynchronous concurrent systems, and procedures for predicting and verifying the system performance are presented.
Abstract: Some analysis techniques for real-time asynchronous concurrent systems are presented. In order to model clearly the synchronization involved in these systems, an extended timed Petri net model is used. The system to be studied is first modeled by a Petri net. Based on the Petri net model, a system is classified into either: 1) a consistent system; or 2) an inconsistent system. Most real-world systems fall into the first class which is further subclassified into i) decision-free systems; ii) safe persistent systems; and iii) general systems. Procedures for predicting and verifying the system performance of all three types are presented. It is found that the computational complexity involved increases in the same order as they are listed above.
503 citations
28 Sep 1980
TL;DR: After a linear algebraic characterization of the minimal support invariant concept, it is proposed a very efficient algorithm to calculate all the minimalSupport invariants of Generalised and Capacity Petri Nets.
Abstract: After a linear algebraic characterization of the minimal support invariant concept, it is proposed a very efficient algorithm to calculate all the minimal support invariants of Generalised and Capacity Petri Nets
252 citations
06 May 1980
TL;DR: It is shown that the behavior of a certain class of timed Petri nets can be represented by a finite labeled directed graph in which the labels describe times and probabilities of transitions between vertices of the graph.
Abstract: It is shown that the behavior of a certain class of timed Petri nets can be represented by a finite labeled directed graph in which the labels describe times and probabilities of transitions between vertices of the graph. Further analysis of such a graph can be done by techniques known for Markov chains. The method is applied to evaluation of some performance indices for two simple processor architectures. The timed Petri nets modeling the processors are shown and the resulting performance indices are compared. Some other architectures are discussed shortly.
204 citations
TL;DR: A three-layer model of a computer network is used to introduce the concept of interface and of end-to-end protocols and models presented here have been successfully used for modeling transport protocols.
Abstract: A three-layer model of a computer network is used to introduce the concept of interface and of end-to-end protocols. Using a simple interface protocol as example, finite state automaton and Petri nets are introduced. The idea of an interface machine is rejected and the problems related to the transmission medium are approached. End-to end protocols request a global model which includes two local models and a transmission medium model. However, the local model has to be generalized. This eventually leads to the association of the state of the automaton with a context. Petri nets have also to be expanded. Models presented here have been successfully used for modeling transport protocols.
105 citations
47 citations
TL;DR: Predicate/transition-nets, a first-order extension of Petri nets, are shown to provide suitable means for concise representation of complex decentralized systems and for their rigorous formal analysis.
Abstract: In this paper, a net model for decentralized control of user accesses to a distributed database is proposed. It is developed in detail for the restricted case of updating distributed copies of a single database. Predicate/transition-nets, a first-order extension of Petri nets, are shown to provide suitable means for concise representation of complex decentralized systems and for their rigorous formal analysis. It will be demonstrated in the present paper how these net models can be constructed and interpreted in a quite natural manner and how they can be analyzed by linear algebraic methods. By this, it will be shown that the modeled distributed database system is deadlock-free and guarantees a consistent database as well as a fair and effective service to the users.
44 citations
41 citations
TL;DR: An approach to software design representation which is consistent with the concept of engineering blueprints is presented and an abstract process network schema ofSoftware design representation is developed and supported by an algebraic system of notation.
Abstract: An approach to software design representation which is consistent with the concept of engineering blueprints is presented. The main criteria for software engineering blueprints are defined and a network scheme of graphical representation is considered through an overview of Petri net techniques. The concept of an abstract process (AP) is introduced as the basic element of system representation. An abstract process network schema of software design representation is developed and supported by an algebraic system of notation. Methods of AP-net construction are presented and illustrated by examples. The advantages of using the proposed approach in different phases of software engineering are pointed out and the main directions for further research have been identified.
36 citations
23 Aug 1980
TL;DR: The computational power of Petri nets is extended up to the power of counter machines by realizing certain priorities of parallelism, but certain concurrent computations can not exactly be reflected by the sets of all sequentialized computations in related systems.
Abstract: The computational power of Petri nets is extended up to the power of counter machines by realizing certain priorities of parallelism. Hence certain concurrent computations can not exactly be reflected by the sets of all sequentialized computations in related systems. Moreover, the reachability, boundedness and liveness problems are undecidable under the modified firing rule.
25 citations
28 Sep 1980
TL;DR: It is known that Petri nets can model a system hierarchically, and a portion of a Petri net may be replaced by a transition or by a place to give a more abstract description of the system.
Abstract: It is known [1] that Petri nets can model a system hierarchically, i. e., a transition or a place of a Petri net representing a system at an abstract level can be refined to model the system in more detail, and conversely, a portion of a Petri net may be replaced by a transition or by a place to give a more abstract description of the system.
23 citations
01 Sep 1980
TL;DR: A new framework to compare the descriptive power of different types of Petri nets is proposed, and in the proposed framework, it is shown that this extension has the same descriptive power as condition/event-nets.
Abstract: This paper proposes a new framework to compare the descriptive power of different types of Petri nets. An extension of condition/event-nets is defined, and in the proposed framework, it is shown that this extension has the same descriptive power as condition/event-nets.This paper proposes a new framework to compare the descriptive power of different types of Petri nets. An extension of condition/event-nets is defined, and in the proposed framework, it is shown that this extension has the same descriptive power as condition/event-nets.
Proceedings Article•
01 Jan 1980
15 Jun 1980
TL;DR: A marked Petri net may be considered as a finite description of an (in general) infinite set of nonsequential processes; thus the process set of a marked net is a graph language.
Abstract: A marked Petri net may be considered as a finite description of an (in general) infinite set of nonsequential processes. Such a process is represented as a labelled graph; thus the process set of a marked net is a graph language. This language is produced by a graph grammar which can be derived from the net. This construction yields a bijection between the set of marked Petri nets and a distinguished class of graph grammars.
TL;DR: A technique utilising the concept of reachability in a Petri net is proposed to enumerate all simple paths between two specified nodes of a graph.
Abstract: A technique utilising the concept of reachability in a Petri net is proposed to enumerate all simple paths between two specified nodes of a graph. It is simple and requires little computation.
28 Sep 1980
TL;DR: The aim of this paper is to show how the iterative methods for the analysis of discrete systems presented in [1][2][3] can be applied to Petri nets and their extensions.
Abstract: The aim of this paper is to show how the iterative methods for the analysis of discrete systems presented in [1][2][3] can be applied to Petri nets and their extensions. The results given in this paper have been obtained by direct application of those exposed in the references.
TL;DR: A Petri net approach to the determination of an optimal assembly language code and it appears to be useful for code optimization in the process of compilation.
Abstract: This paper gives a Petri net approach to the determination of an optimal assembly language code and it appears to be useful for code optimization in the process of compilation. The proposed technique is novel in the sense that only vector addition on a matrix is needed. It is simple and requires little computation.
28 Sep 1980
28 Sep 1980
TL;DR: One possible way of investigating the functioning of a system is to examine the sequences of labels corresponding to the firing sequences of transitions of the Petri net that models the system.
Abstract: One way of using Petri nets for modelling systems is to represent states by markings, and actions that modify the states by transitions. In order to represent the fact that one event can cause different modifications of the system, one has to label the transitions. For example, in a school, the beginning and the end of classes are signalled, or labelled, by the ringing of a bell. One possible way of investigating the functioning of a system is to examine the sequences of labels corresponding to the firing sequences of transitions of the Petri net that models the system. Several classes of languages have been defined and studied: languages of sequences of firing of transitions when one event or signal causes one action, and languages of words labelling firing sequences of transitions when one event can cause several actions.
TL;DR: A transformation algorithm is given to find a “Petri” net representation corresponding to a reliability block diagram and as an application the authors derive probability expressions from the "Petri" net representation.
22 Apr 1980
TL;DR: It turns out that nets representing sequential systems and processes are atoms of this lattice, and this fact provides the natural way of building nets representing.
Abstract: The paper concerns algebraic properties of Petrinets. A wide class of nets, called simple nets, is introduced and a lattice of these nets is defined. It turns out that nets representing sequential systems and processes are atoms of this lattice, and this fact provides the natural way of building nets representing. concurrent systems as the superposition of nets representing sequential system components.
28 Sep 1980
TL;DR: Petri nets (PT-nets) have proved as an excellent tool for the description and analysis of dynamic systems exhibiting concurrency, but applications to problems in practice are rare.
Abstract: Petri nets (PT-nets) have proved as an excellent tool for the description and analysis of dynamic systems exhibiting concurrency. Nevertheless applications to problems in practice are rare. Among others one reason is that Petri nets for complex systems rapidly grow in size soon loosing their clearness and becoming unmanageable. In order to increase the abilities of Petri nets several extensions have been suggested in a more or less systematic way (e. g., inhibitor, reset arcs, transitions with special properties etc.).
28 Sep 1980
TL;DR: This work uses Timed Petri Nets (TPN) in its general modelling tool for sociotechnical systems, called Function Nets, and discusses the influence of timing to basic net-properties.
Abstract: We use Timed Petri Nets (TPN) in our general modelling tool for sociotechnical systems, called Function Nets. Our interest is to find the general differences in behaviour between Petri Nets and TPN. The influence of timing to basic net-properties is discussed: The time-concept imposes a restriction to the set of firing-sequences in a given net, which in turn influences the liveness of the net. The standard-liveness is not suitable for our purpose. The use of more basic liveness-definitions is suggested. A modelling example utilizing a TPN is given.
Book•
01 Jan 1980
TL;DR: Structured representation of knowledge by Petri nets as an aid for teaching and research and a dictionary of some basic notions of net theory are published.
Abstract: to general net theory.- Elements of general net theory.- Formal properties of place/transition nets.- Linear algebra in net theory.- Atomicity of activities.- Concurrency.- The relative strength of K-density.- Reductions of nets and parallel programs.- Adequacy of path programs.- Performance evaluation of systems using nets.- Survey of French research and applications based on Petri nets.- Nets in modeling and simulation.- Abstractions of net models.- Applications of net-based models.- The application of general net theory - A personal history.- Petri-nets from the engineer's viewpoint lecture I.- Nets as a tool in teaching and in terminology work.- Structured representation of knowledge by Petri nets as an aid for teaching and research.- A dictionary of some basic notions of net theory.- Addresses of all authors.
TL;DR: The problem of graphic representation of recursive program structures is discussed in this article, where modified Petri nets are introduced which only slightly differ from the common state machine flowcharts, but have much more representation power.
Abstract: The problem of graphic representation of recursive program structures is discussed. On the basis of the stack mechanism, modified Petri nets are introduced which only slightly differ from the common state machine flowcharts, but have much more representation power.
TL;DR: It is shown that leaving out one of the restrictions ( a ) to ( c ) yields classes of formulae whose decision problem can assume any prescribed recursively enumerable complexity in terms of many-one degrees of unsolvability.
01 Jan 1980
TL;DR: Time Valued Petri nets as discussed by the authors are a simple tool for modelling, decomposing and analysing centralized real-time control algorithms for parallel processing. But their use is limited to the case of multi-processor systems.
Abstract: When a real time control algorithm is to be executed in several computational facilities (multiple processor, multi-processor, network etc.), the problem of how to decompose the control algorithm arises. The decomposition should consider the concurrent process synchronization, interprocess communication and performance problems. In this paper a single formal tool that allows one to treat different aspects of the above problems is developed: Time Valued Petri Nets.
Time Valued Petri Nets are a simple tool for modelling, decomposing and analysing centralized real time control algorithms for parallel processing. A great variety of aspects can be analysed with this tool: decomposition, data flow, concurrency, error propagation, execution time, interprocess communication, trade off of system management requirements and number of processes, assignment of processes to processors and number of processors required.
The application of Time Valued Petri Nets to a life size multivariable model reference adaptive control algorithm has shown the ease and power of its use.
01 Jan 1980
TL;DR: The Component-Net as mentioned in this paper is a special form corresponding to the state-machine concept of the Automata-Theory, which is well suited for simulation of hardware systems, for instance for the problems of Switching Algebra.
Abstract: In lecture I the different aspects of Theoreticians and Engineers are discussed. The Component-Net is a special form corresponding to the state-machine-concept of the Automata-Theory. Some special symbols are suggested. Side-conditions and side effects are well appropriate for the simulation of hardware systems, for instance for the problems of Switching Algebra.
28 Sep 1980
TL;DR: Some aspects of nets augmented by inhibitor arcs are discussed, i.
Abstract: In this note we discuss some aspects of nets (i. e. Petri-nets, place/transition nets, P/T-nets) augmented by inhibitor arcs. An inhibitor arc connects a transition t with a place p. For such a transition the firing rule is modified as follows. Transition t fires under the usual conventions, when p is empty, but is inhibited from firing, if p contains at least one token. This behaviour can be represented by ordinary nets only in those cases, where p is a bounded place. Nets, where inhibitor arcs are allowed, will be called inhibitor nets or I-nets in this paper.
01 May 1980
TL;DR: A theory of software reliability based on the nature of the input domain of the program, i.e., the size of the errors and the number, complexity and continuity of equivalence classes formed in the inputdomain is developed.
Abstract: : This is a final report for research in distributed computer systems. Chapter 2 describes top-down development approach. The development process is divided into four successive phases: (1) requirement and specification phase; (2) design phase; (3) implementation phase; (4) evaluation and validation phase. Guidelines and automated tools for the first two phases are developed. A graphical method (using the max. flow min. cut algorithm and cut-tree concept) to decompose and partition a computer system into loosely coupled subsystems is proposed. The implementation and the evaluation and validation phases are outlined briefly only because they are very technology and architecture dependent. Chapter 3 examines Petri net model for asynchronous concurrent systems. Procedures based on Petri net for predicting and verifying the system performance are presented. The computational complexities of these procedures are also shown. Chapter 4 examines the analysis techniques for deadlocks in asynchronous concurrent systems. In particular, we study in detail deadlocks caused by conflicts in mutual exclusive access to resources with the constraint that each resource type has only one member. Chapter 5 first classifies and then evaluates several existing software reliability models according to some proposed criteria. Then it develops a theory of software reliability based on the nature of the input domain of the program, i.e., the size of the errors and the number, complexity and continuity of equivalence classes formed in the input domain. (Author)