有界Petri网等价性的判定算法

Petri网语言是系统行为分析的一种重要工具,为了分析有界Petri网的行为等价,借助于有限自动机的等价性问题和算法,研究了有界Petri网的等价性问题和算法.定义了带标注Petri网语言等价性,证明了带标注的有界Petri网到有限自动机的等价转化,给出了判定有界Petri网的等价性算法,为模拟系统的性能比较提供了处理方法.     

基于蚁群优化的时间Petri网及其在柔性制造系统调度优化中的应用

Petri网的优化调度求解主要采用基于状态空间的智能搜索方法,执行效率往往不高.提出基于蚁群优化的时间Petri网,通过在Petri网的变迁和进化规则中引入蚁群优化机制,改变Petri网原有的非确定性选择行为,使之具备蚁群寻优选择智能行为,克服了需要基于状态空间进行启发式搜索的缺陷,提高了调度优化的计算效率.最后应用蚁群优化时间Petri网模型,对柔性制造系统的区间Job Shop调度问题进行建模和优化求解.实验结果进一步验证了所提模型和方法的有效性.     

扩展的模糊时间Petri网

网络实时系统对时间和QoS有严格要求.扩展的模糊时间Petri网是一种对网络实时系统进行建模和分析的形式化模型,Petri网数学理论基础能保证并发系统的可靠性和正确性.本文介绍了扩展的模糊时间Petri网的定义,模型检验方法,仿真工具,网精简技术和应用领域,并探讨了进一步研究的方向.     

基于CPN Tools研究综述

仿真工具CPN Tools是一款优秀的Petri网仿真工具,是仿真和分析着色petri网建立的模型。CPN Tools不仅支持基础着色Petri网建立模型,也支持带有时间和分层的着色petri网建立模型。CPN Tools支持CPN ML编程语言,颜色集,时间,层次化建模等,大大增加了它的描述能力和应用范围。同时,CPN Tools提供丰富的模型分析工具,如监视器,状态空间分析等,增强了它的模型分析能力和模型验证能力。     

实时模型检测中基于驻留环的精确加速

在控制系统和外界环境之间经常会出现时间度量差距.对这些系统用时间自动机建模,并运用符号模型检测技术进行验证时,会引起符号状态空间的片段问题.精确加速技术在不改变系统可达性的前提下解决了片段问题.针对可加速环引起的片段问题,本文提出一种基于驻留环实现精确加速的方法.驻留环的长度固定,不依赖于可加速环的窗口,因而构造的自动机模型更简单,能提高精确加速的速度,并能够降低精确加速的时间和空间开销.     

一种随机Petri网性能等价化简与分析方法

随机Petri网模型是系统性能评价的有力工具,但其状态空间随模型规模的增长而指数性增长的问题限制了其对复杂和大规模系统模型的性能数量分析能力.因此,在对模型进行分析之前,先对其进行适当的性能等价化简,是一种更为可行的分析方法.本文首先讨论了一类随机Petri网-基本随机Petri网(ESPN)的性能等价分析方法,这类随机Petri网由顺序、并行、选择和循环等四种基本结构及其组合构成.作者推导出这四种基本结构的性能等价公式,并运用自底向上逐步综合替代的分层分析方法,给出这类随机Petri网模型的性能等价化简分析方法,该方法的复杂性随模型增长而线性增长,有效解决了其性能数量分析问题.然后,讨论了两种非基本结构到基本结构的转换规则,使得复杂的随机Petri网模型也可能转换为ESPN模型,从而使性能等价算法可应用于一般随机Petri网.     

基于Petri网的安全协议形式化分析

本文提出了一种基于Petri网的安全协议形式化描述和安全性验证的方法.该方法的特点是,利用逆向状态分析判定协议运行过程中可能出现的不安全状态,利用Petri网的状态可达性分析判断这些不安全状态是否可达.通过实例,我们证明了这种方法的有效性.     

基于自动机模型的平面调车软件设计方法

 平面调车是一种铁路调车过程中的离散事件系统.可靠性高、易测试的平面调车软件对保障铁路运输安全极为重要,因此需要建立一种规范模型基础上的平面调车软件设计方法.分析了平面调车系统中事件驱动过程的复杂性以及自然语言规则描述方式的缺陷,提出通过自动机模型描述平面调车系统,具体讨论了平面调车系统与时间自动机(TA)、下推自动机(PDA)和分层自动机的关系.从状态划分、数据结构设计、状态转移流程等方面说明了基于自动机模型的平面调车软件的设计方法.     

基于Petri网的入侵检测技术研究

Petri网是一种非常广泛的建模工具.文中研究了Petri网在入侵检测技术中的应用,分析了基于Petri网的入侵检测系统的主要优势以及随着网络的发展给入侵检测系统带来的问题.基于这些问题,提出了基于Petri网的入侵检测系统的改进方法,设计了一个入侵检测系统的原型并进行了实例分析.     

计算机在电子学方面的应用

TP39 2005021648 基于位置不变l的Petri网分解方法/胡红革,谢阅,黄大贵(电子 科技大学)厅电子测量与仪器学报.一2 004,18(2)一77一80 Petri网是系统模拟和分析的有效工具,然而对大系统的分析由于变迁 和位置的数目大分析起来比较麻烦‘文中着重讨论了一种网分解方法, 给出了I〕etri网分解的定义,并讨论了通过这种分解后,原网与子网在 结构性质方面之间的关系,对用Petri网分析大系统提供了一种有效的 方法参5(刚) IPv6构造树状MAP框架,设计逐跳绑定更新机制对快速移动IPv6 进行改进,实现移动节点的无缝(快速平滑)切换.同时,根据资源预 …     

基于价格时间Petri网的网格计算应用模型及分析

网格计算环境下资源管理和任务调度是当前研究的热点问题,OGSA体系结构提出了网格服务的概念,但缺乏应用对网格服务质量要求的形式化描述.本文对OGSA体系结构进行了必要的扩展,提出网格用户应用的价格时间Petri网模型,利用该模型可对网格应用的QoS需求进行定义,并可利用Petri网的工具分析用户应用模型的正确性和时间特性,给出了具体的分析算法.     

AND/OR net representation for robotic task sequence planning

The paper describes a framework for task sequence planning for a generalized robotic work cell. The AND/OR net provides a compact, distributed, domain-specific representation of geometric configurations of parts and devices in the work cell. The approach maintains a correspondence from geometric state information to task and motion plans and on-line discrete-event control that is not available in traditional action-based planners. The feasibility criteria for each AND/OR net transition guide the geometric reasoning required in the planning of feasible sequences. The resulting search space for plans is often much smaller (due to explicit representation of geometric constraints) than the state space of an action-based task planner. For purposes of analysis, the AND/OR net is mapped into a Petri net and the resulting Petri net is shown to be bounded and have guaranteed properties of liveness, safeness, and reversibility. In this form, the AND/OR net may be viewed as a Petri net synthesis tool in which the resulting Petri net representation may be used for on-line scheduling and control of the system     

A new function block modeling language based on Petri nets for automatic code generation

A component based modeling language with the component interfaces derived from the elements of the Petri net theory called CNet is presented in this paper. In contrast to IEC 61499 function blocks that define the flow of events and data separately, CNet models them combined as colored tokens. The event-discrete behavior of CNet components is described by a special class of colored Petri nets with timed arcs and sharpened semantics in order to allow automatic generation of possibly concurrent Java code. In this paper, the state space of CNet components is analyzed and a novel event-discrete "handler-based" execution model that implicitly models an automaton is introduced.     

Petri net as a modeling tool

Over the last decade, Petri nets have emerged as a most suitable, powerful and widely acceptable modeling tool for representing and studying the asynchronous concurrent hardware (or software) systems/processes. Petri nets can be viewed as formal automata or as an automation which can generate the formal languages or a model to analyse and synthesize various kinds of systems. The structure of Petri nets, their markings, extensions and subclasses are briefly discussed. Several examples of Petri net models of computer hardware and software are presented. Various applications of reachability concepts are also given.     

Modeling and analysis of message passing in distributedmanufacturing systems

This paper addresses the information flow between devices and programs in computer integrated manufacturing systems. Specifically, it presents modeling techniques and methods for detecting the existence of message paths among hardware and software components and the upper bound on time delays along that message path. The modeling technique can be used to analyze interoperability between hardware and software components in the system in initial design and specification. The modeling technique has three components: an object model to describe the message passing protocols between communicating components; a color timed Petri net to describe the dynamic behavior and state dependency within each individual component; and an object synthesis method that integrates the Petri nets of individual objects and message protocols between objects to describe the dynamics of the entire system. The graphical modeling can enhance communication among different groups involved in system design and the analytical method can provide component specifications. The use of the modeling technique and method in early system design can result in time and cost savings in system integration due to better communication, better component selection and early problem identification     

Timed secure colored Petri net based analysis of information flow

We present in this paper a novel framework named Timed Secure Colored Petri Net (Tscpn) to carry out security verification in a formal and systematic manner,Tscpn is a security policy model to both express time constraints on information (availability) and specify a wide range of information flow security requirements (through multilevel security policies such as Bell-LaPadula) in a decentralized way. We also propose a suitable analysis method to verify security properties by constructing and examining the state space of the constructed model. However as timed models are generally infinite, applying this method must pass by contracting its state space into a finite graph (state class graph) preserving properties of interest. According to this graph, it is possible to verify confidentiality and integrity, enforce control on information flow security, specify temporal access control and information availability. By using this formal method, many security drawbacks can be eliminated in advance during the system design.     

面向作战任务的舰艇编队C3I系统结构优化匹配分析

利用有色Petri网(CPN)建模工具,得到了舰艇编队指挥、控制、通信及情报(C3I)系统的可行结构空间,同时结合CPN Tools得到了匹配测度模型,进而得出面向作战任务的舰艇编队C3I系统结构优化匹配模型,最后给出了实例应用,得到了某编队C3I系统的最优匹配结构.提出的方法操作简单,通用性强,为舰艇编队C3I系统结...