双总线结构工业控制计算机网性能指标评估

本文对双总线结构工业控制计算机网给出了其Ｐｅｔｒｉ网和高级Ｐｅｔｒｉ的建模及性能指标评估方法，文中考虑了信包缓冲区容量有限、信包最大允许服务时间有限，不同的站点优先级和系统总线的故障率。等因素影响下的网络性能指评估问题，克服了以往对网络性能评估的某些局限。本文讨论了带计数禁止弧的高级随机Ｐｅｔｒｉ网（ＨＤＳＰＮ）的特性， 并对同的ＤＳＰＮ模型进行了仿真计算，对影响网络性能的系统指标进行了讨论。     

容错型令牌总线局域网建模及性能指标评估

本文对符合ＩＥＥＥ８０２．４标准的容错型令牌总线局域网给出了其Ｐｅｔｒｉ网建模及性能指标评估方法。文中考虑了具有信包重发机制、令牌最大保持时间和信包缓冲区容量有限的令牌网络的性能指标评估问题。克服了以往不能分配具有信包重发机制和令牌最大保持时间等令牌网性能的局域。本文讨论了带计数禁止弧的确定性时延随机Ｐｅｔｒｉ网（ＤＳＰＮ）的特性，并对给出的ＤＳＰＮ模型进行了仿真计算，对影响网络性能的系统指标进行     

计算机网络的Petri网建模及性能指标评估

本文提出了用广义随机Ｐｅｔｒｉ网理论对计算机网络进行性能指标评估建模的具体规则，并给出了其相应的广义随机Ｐｅｔｒｉ网图，导出了依据广义随机Ｐｅｔｒｉ网模型（ＧＳＰＮ）对计算机网络中几个主要性能指标直接进行计算的方程，克服了以往在建模过程中的盲目性和无规则性．提出了从广义随机Ｐｅｔｒｉ网建模到进行计算机网性能指标计算的一系列方法．这些方法可有效地完成对计算机网络的建模和性能指标的计算，对分析和设计计算机网络具有普遍的指导意义．     

MPP系统模型化的广义随机Petri网技术

本文提出一种模型化海量并行处理（ＭＰＰ）系统的广义随机Ｐｅｔｒｉ网技术ＧＳＰＮ。首先，通过外延优先权标记Ｐｅｔｒｉ网，提出了ＧＳＰＮ的定义、时序规范、变迁激光规则和计算公式。然后，讨论使用ＧＳＰＮ模型化ＭＰＰ系统的技术途径和实现方案，分别阐述了ＧＳＰＮ形式化描述共享存储器方式和信息传递方式ＭＰＰ系统的有效怀，并给出了实例。此外，我们还分析和提出了ＣＳＰ（通信顺序进程）理论中主要进程与Ｐｅｔｒｉ网之     

计算机网络的Petri网建模及性能指标平估

本文提出了用户广义随机Ｐｅｔｒｉ网理论对计算机网络进行性能指标评估建模的具体规则，并给出了其相应的广义随机Ｐｅｔｒｉ网图，导出了依据广义随机Ｐｅｔｒｉ网模型对计算机网络中几个主要性能指标直接进行计算的议程，克服了以往在建模过程中的盲目性和无规则性。     

模糊Petri网在FMS故障诊断中的应用研究

针对柔性制造系统（ＦＭＳ）故障诊断的特点，将模糊Ｐｅｔｒｉ网扩展为模糊行为Ｐｅｔｒｉ网（ＦＢＰＮ）．并应用于知识的表示中，讨论了ＦＭＳ系统、ＦＢＰＮ及产生式规则之间的对应关系，提出一种模糊反向推理机制，给出了利用ＦＢＰＮ进行知识表示和推理的实例．     

基于对象Petri网的离散事件系统建模仿真环境(OPMSE)

首先论述了Ｐｅｔｒｉ网和高级Ｐｅｔｒｉ网发展状况,提出了一种高级Ｐｅｔｒｉ网,即对象Ｐｅｔｒｉ网。然后介绍了基于对象Ｐｅｔｒｉ网的离散事件系统建模仿真环境ＯＰＭＳＥ。文中详细介绍了ＯＰＭＳＥ的特点与组成,并对ＯＰＭＳＥ的核心－对象Ｐｅｔｒｉ网（ＯＰＮ）的语法描述进行了重点介绍。     

离散事件系统的协调反馈控制

本文探讨以Ｐｅｔｒｉ网为模型的离散事件系统（ＤＥＳ）的某种禁止状态避免问题，提出了以Ｐｅｔｒｉ网Ｎ为基网，设计具有外部输入位置Ｐｅｔｒｉ网（ＰＮＩＰ），对Ｎ进行协调反馈控制的方法。由Ｎ现行状态反馈决定的ＰＮＩＰ的控制状态，既保证Ｎ避免禁止状态，又使Ｎ具有最大自由度。     

分布式多媒体同步事务规划

文章针对分布式多媒体应用所含的复杂时态关系和分布性特性,利用同步代理构建了一个基于代理的分布式多媒体同步规划系统。并通过对传统Ｐｅｔｒｉ网的扩展,对分布式同步Ｐｅｔｒｉ网（ＤＳＰＮ）进行了定义,并利用ＤＳＰＮ对同步代理进行建模。最后通过对多媒体应用实例的分析,简要说明系统的操作流程。     

面向对象的Petri网方法及其在软件工程中的应用

本文介绍了面向对象Ｐｅｔｒｉ网方法，给出了ＯＯＰＮ的基本定义和图形表示，讨论了ＯＯＰＮ的特性和子网细化方法。     

A computer network based control architecture for autonomous distributed multirobot systems

This paper presents the specification and implementation procedure using a microcomputer network based autonomous distributed control architecture for industrial multirobot systems. The procedure is based on the concept of data flow network controlled by communicating sequential processes to perform coordinated tasks. Robots and other computerized industrial devices such as conveyors and manufacturing machines are defined as object-oriented Petri nets. A modular and hierarchical approach is adopted to define a set of Petri net type diagrams which represent concurrent activities of control processes for such devices. Asynchronous and synchronous interactions are modelled by places and transitions, respectively, in global process interaction nets. The control software is implemented on a computer network using Inmos transputers with true parallel processing and message passing primitives efficiently handled in hardware. Petri net based models are directly and efficiently transformed to corresponding codes in occam, the high level parallel programming language defined for the transputer.     

Complex-valued token Petri nets

This paper presents a new extension to ordinary Petri nets (PNs) that uses complex-valued tokens. By allowing two kinds of tokens, "real" and "imaginary," each place marking contains both quantity and type information. Complex-valued token PNs were designed to integrate seamlessly with other popular Petri net extensions such as timed nets, stochastic nets, and colored nets. This simple and intuitive application of complex numbers and complex arithmetic to PNs provides a unique modeling tool. Some examples show the capabilities of this proposed class of PNs. Note to Practitioners-Discrete-event systems are often man-made systems such as transportation systems, computer communication networks, distributed software, and manufacturing systems. They typically involve the flow of information and physical goods through a network. The flow itself evolves in continuous time but the initiation or completion of the event happens at a discrete point in time. Analyzing the system's performance is key to their successful operation. This paper presents a new approach to performance analysis with application to supply-chain management.     

基于C＋＋的城市报建工作流petri网的算法设计

城市报建工作是一个阳光工程,在信息技术发展的今天,实现城市报建工作的网络化管理,通过建立城市报建工作流的petri网,设计相应的计算机算法来实现计算机程序化管理。文中重点设计了报建审批工作流的Petri网,依据工作流的Petri网,应用C＋＋语言设计报建工作主控模块的算法。     

Timed Petri Nets in Hybrid Systems: Stability and Supervisory Control

In this paper, timed Petri nets are used to model and control hybrid systems. Petri nets are used instead of finite automata primarily because of the advantages they offer in dealing with concurrency and complexity issues. A brief overview of existing results on hybrid systems that are based on Petri nets is first presented. A class of timed Petri nets named programmable timed Petri nets (PTPN) is then used to model hybrid systems. Using the PTPN, the stability and supervisory control of hybrid systems are addressed and efficient algorithms are introduced. In particular, we present sufficient conditions for the uniform ultimate boundness of hybrid systems composed of multiple linear time invariant plants which are switched between using a logical rule described by a Petri net. This paper also examines the supervisory control of a hybrid system in which the continuous state is transfered to a region of the state space in a way that respects safety specifications on the plant's discrete and continuous dynamics.     

Estimation of the firing frequencies in discrete and continuous Petri nets models

Production frequencies provide useful information for performance analysis, monitoring and control applications of manufacturing systems. However, such frequencies are not always measurable. In this case, they must be estimated from the observation of other variables. This paper deals with production frequencies estimation for systems modelled by discrete or continuous Petri nets. For this purpose, the content of the buffers is measured on-line with a sampling period, and the evolution equations of the model are reversed. In the case of timed Petri nets, the production frequencies estimation is obtained from the approximation of the firing sequences and in the case of continuous Petri nets it results directly from the variations of the marking vector. The exact and approximated solutions of the estimation problem are described. Accuracy of the estimation is related to measurement error, Petri net structure and sampling period. Moreover, when the estimation provides several solutions, the Petri net model is extended such that a unique solution is obtained.     

计算机网络的建模与分析

计算机网络具有既随机又相关的特点，因此选择计算机网络性能评价的数学工具要考虑到网络数据流的特性，排队模型是一种确定性的数学模型，用确定性的模型描述网络既随机又相关的动态行为是不够的。Ｐｅ＃簦颍? Ｎｅｔｓ（ＰＮ）能够比较方便地刻画网络的相关录枋鐾绲木赫⑴鲎埠妥枞樱校谓肜┏浞⒄苟吹乃婊校危梢员冉戏奖愕目袒缡录乃婊裕呓岷掀鹄创酉嗟背潭壬匣汉土思扑慊缃Ｓ敕治鲋涞     

Differential Petri nets: representing continuous systems in adiscrete-event world

Differential Petri nets are a new extension of Petri nets. Through the introduction of the differential place, the differential transition, and suitable evolution rules, it is possible to model concurrently discrete-event processes and continuous-time dynamic processes, represented by systems of linear ordinary differential equations. This model can contribute to the performance analysis and design of industrial supervisory control systems and of hybrid control systems in general     

Risk assessment and management for supply chain networks: A case study

The aim of this study is to show how a timed Petri nets framework can be used to model and analyze a supply chain (SC) network which is subject to various risks. The method is illustrated by an industrial case study. We first investigate the disruption factors of the SC network by a failure mode, effects and criticality analysis (FMECA) technique. We then integrate the risk management procedures into design, planning, and performance evaluation process of supply chain networks through Petri net (PN) based simulation. The developed PN model provides an efficient environment for defining uncertainties in the system and evaluating the added value of the risk mitigation actions. The findings of the case study shows that the system performance can be improved using risk management actions and the overall system costs can be reduced by mitigation scenarios.     

代谢网络结构与功能的Petri网分析

发展基因组尺度代谢网络模型的模拟和分析方法有助于学习这些网络的结构与功能关系,是当前计算系统生物学领域的一个重要研究主题。由于具备严格的数学描述,直观的图形表达,外加存在众多的算法和工具,Petri网可能成为代谢网络模拟和分析的有力工具。应用位置/变迁网来分析代谢网络的结构与功能特征,首先建立了巴斯德毕赤酵母代谢的Petri网模型,随后计算了该模型中的P、T不变量,并讨论了它们的生物学意义。