• Title, Summary, Keyword: Petri Nets

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Application of fuzzy Petri nets for discrete event system control and monitoring (이산사건 시스템 제어 및 모니터링을 위한 퍼지 패트리네트 응용)

  • 노명균;홍상은
    • 제어로봇시스템학회:학술대회논문집
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    • pp.403-406
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    • 1997
  • This paper presents a Petri net approach for the control and monitoring of discrete event system. The proposed model is fuzzy Petri nets based on the fuzzy logic with Petri nets and the hierarchy concept. Fuzzy Petri nets have been used to model the imprecise situations which can arise within automated manufacturing system, and also the hierarchy concept allow to handle the refinement of places and transition in Petri nets model. These will form the foundation of a simulator-tool with manipulation interface for application of fuzzy Petri nets.

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Compositional Analysis of Petri Net Models using Petri net Slices (페트리네트 Slice를 이용한 페트리네트 모델의 합성적 분석)

  • Lee, Woo-Jin;Cha, Sung-Deok;Kwon, Yong-Rae;Kim, Heung-Nam
    • Journal of KIISE:Software and Applications
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    • v.27 no.3
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    • pp.210-216
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    • 2000
  • Place/Transition(P/T) nets has been used in protocol verification and concurrent system verification since it is suitable for describing concurrency and provides several well-established verification techniques. And it has been used as a base formalism for such high-level Petri nets as colored Petri nets, object-oriented Petri nets and etc. However, when analyzing complex models using P/T nets and P/T nets-based high-level Petri nets, there may be state explosion in reachability analysis due to improper handling of concurrency. In this paper, we define a structural concurrency in P/T nets, propose a partitioning algorithm based on the detected structural concurrency, and provide analysis techniques for such properties as boundedness of places and liveness of transitions, which are performed on compositional reachability graphs. The analysis techniques based on Petri net slices can be used in efficiently analyzing P/T nets-based high-level Petri net models as well as P/T net models.

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Algorithm for Transformation of Timed Petri Nets to DEVS Formalism (시간 페트리네트를 DEVS 형식론으로 변환하는 알고리즘)

  • 김영찬;김탁곤
    • Journal of the Korea Society for Simulation
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    • v.11 no.2
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    • pp.77-88
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    • 2002
  • Petri nets is a widely used formalism for specification and analysis of concurrent systems which is a subclass of discrete event systems. The DEVS (Discrete Event System Specification) formalism provides a general framework for specification of discrete event systems in a hierarchical, modular form. Often, modeling a discrete event system may employ both Petri Nets and DEVS formalism. In such a case low-level operational logics are modeled by Petri Nets and high-level managements by the DEVS formalism. Analysis of the system requires simulation of the overall system. This paper presents an algorithm for transformation of Petri Nets to DEVS formalism. The transformation enables modelers to simulate an overall system, which consists of DEVS models and Petri Nets models, in a unified DEVS simulation environment such as DEVSim++. An example for such transformation will be given.

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Parallel Simulation of Bounded Petri Nets using Data Packing Scheme (데이터 중첩을 통한 페트리네트의 병렬 시뮬레이션)

  • 김영찬;김탁곤
    • Journal of the Korea Society for Simulation
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    • v.11 no.2
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    • pp.67-75
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    • 2002
  • This paper proposes a parallel simulation algorithm for bounded Petri nets in a single processor, which exploits the SIMD(Single Instruction Multiple Data)-type parallelism. The proposed algorithm is based on a data packing scheme which packs multiple bytes data in a single register, thereby being manipulated simultaneously. The parallelism can reduce simulation time of bounded Petri nets in a single processor environment. The effectiveness of the algorithm is demonstrated by presenting speed-up of simulation time for two bounded Petri nets.

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A Study on the Analysis of FMS Throughout-Rate by Development of Petri Nets Model (Petri nets 모델 개발에 의한 FMS 출력율 분석에 관한 연구)

  • 황규완;하정진
    • Journal of the Korean Operations Research and Management Science Society
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    • v.19 no.3
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    • pp.131-138
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    • 1994
  • Petri Nets are a graphical and mathematical modeling and promising tool for describing and studying that are characterized as being concurrent, asychronous, dynamic, distributed and parrallel. The purpose of this paper is to analyze FMS Throughout-Rate by development of Petri Nets So, it applied to FMS composed of 7 machines and 4 different job types. The result of this paper shows the advantage of using Petri Nets.

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Modeling, Analysis of Flexible Manufacturing System by Petri Nets (유연제조시스템을 Petri Nets으로 구현하고, 결과를 다른 시뮬레이션과 비교, 검토)

  • Lee, Jong-Hwan
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.28 no.3
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    • pp.36-41
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    • 2005
  • 페트리 네트(Petri Nets)는 이산 사건 시스템을 모델링할 수 있는 그래픽하고, 수학적인 도구이다. 본 연구는 유연제조 시스템을 확률적인 페트리 네트(Stochastic Petri Nets)중의 하나인 임베디드 마코프 체인(Embeded Markov Chain)에 도입하고, 임베디드 마코프 체인의 방법 중에 하나인 일반화된 확률적 페트리 네트(Generalized Stochastic Perti Nets)에 적용시켰다. 그리고 결과치의 정확성을 알아내기 위하여, 페트리 네트 시뮬레이션과 아레나를 사용하여 실행하였다.

Design for Sequential Control System Using Petri Nets with Hierarchical Expression (II) -composition of Sub Petri nets by Bottom up Oriented Method- (페트리네트의 계층화를 통한 시퀀스제어계의 설계(II) -Bottom up에 의한 서브PN의 합성-)

  • 정석권;정영미;유삼상
    • Journal of Ocean Engineering and Technology
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    • v.15 no.4
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    • pp.108-114
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    • 2001
  • Petri nets have been introduced as a powerful analyzing and design tool for the discrete systems such as sequential control systems. However, one of the important problems in its applications is that the model can be analyzed hardly when we deal with large scale systems because of increase of the number of Petri net components. To overcome this problem, some methods for dividing or reducing of Petri net have been suggested. In this paper, an approach for hierarchical expression of Petri net based on Sequential function Chart(SFC) and Bottom Up oriented Mehodology(BUM) is proposed. Especially, some definitions and rules are defined in order to divide and compose sub Petri nets. A measuring tank system will be described as a typical kind of discrete systems and modeled by some sub Petri nets based on the SFC and BUM by the proposed method in this paper.

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Modelling the Decision Support System in Flexible Manufacturing Systems Using Petri Nets (Petri Nets를 사용한 유연생산체제(FMS)에서의 의사결정지원체계(DSS)설계)

  • Kim, Jin-Gyu
    • Journal of the Korean Society for Quality Management
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    • v.18 no.2
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    • pp.54-68
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    • 1990
  • Contingency response in a FMS system requires that the system be able to identify and evaluate a number of alternatives. This paper is outlined that DSS completes with a problem processor in corporating Timed Petri Nets model, and a data base system. DSS enables the FMS user to get the maximum benefit from a FMS. The structure of this DSS parallels the organizational activities involved in running the FMS. In designing a shop floor controller for FMS, interactions between the different real time, discrete event functions must be established. The specification of the machine tool and material handling system functions working as a concurrent and cooperative system is given in terms of Timed Petri Nets. In addition, the basic concepts and uses of Petri Nets are surveyed. The system to be studied is first modelled by a Timed Petri Nets and then procedure for evaluating the FMS system performance are presented. Numerical examples are studied to illustrate a session of the FMS used-DSS interaction.

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Design for Sequential Control System Using Petri Nets with Hierarchical Expression(I) - Division of Petri Nets Based on SFC (페트리네트의 계층화를 통한 시퀀스제어계의 설계(I) - SFC에 근거한 페트리네트의 분할)

  • Jeong, Seok-Kwon;Yang, Joo-Ho
    • Journal of Ocean Engineering and Technology
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    • v.13 no.3B
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    • pp.106-115
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    • 1999
  • Modeling a discrete event system such as a sequential control system is difficult compared with a continuous system. Petri nets have been introduced as an analyzing and design tool for the discrete systems. One of the problems in its applications is that the model can not be analyzed easily in the case of large scale or complicated systems because of increase of the number of components of the system. To overcome this problem, some methods for dividing or reducing Petri nets have been suggested. In this paper, an approach for a hierarchical expression of Petri nets based on Sequential Function Chart(SFC) is proposed. A measuring tank system will be described as a typical kind of discrete systems. The system is modeled by sub Petri nets based on SFC in order to analyze and visualize efficiently about the dynamic behaviors of the system. Some numerical simulations using state equations are performed to prove the validity of the proposed method.

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A Subclass of Petri Net with Reachability Equivalent to State Equation Satisfiability: Live Single Branch Petri Net

  • Gao, Qian;Cho, Young Im
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.13 no.3
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    • pp.200-207
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    • 2013
  • Petri Nets are a system description and analysis tool. Reachability is one of the most basic properties in Petri Net research. In a sense, reachability research is the foundation study for other dynamic properties of Petri Nets through which many problems involving Petri Nets can be described. Nowadays, there are two mature analysis methods-the matrix equation and the reachability tree. However, both methods are localized, i.e., it is difficult to find a general algorithm that can determine reachability for an arbitrary Petri Net, especially an unbounded Petri Net. This paper proposes and proves three propositions in order to present a subclass of a Petri Net, the live single-branch Petri Net, whose reachability is equivalent to the satisfiability of the state equation.