时序逻辑电路的Petri网分析方法

本文应用带抑止弧的增广Ｐｅｔｒｉ网，建立了基本门电路和常用触发器的Ｐｅｔｒｉ网模型，讨论了运用该模型描述同步和异步时序逻辑电路，给出了增广Ｐｅｔｒｉ网的矩阵描述和状态转移方程，在此基础上提出了同步和异步时序逻辑电路统一分析的Ｐｅｔｒｉ网方法。     

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．     

有色Petri网在网络通信协议上的应用

自１９６２年Ｃ．Ａ．Ｐｅｔｒｉ在其博士论文中首先提出Ｐｅｔｒｉ网后,Ｐｅｔｒｉ网理论和应用都取得了长足的进步。有色Ｐｅｔｒｉ网是由Ｋ．Ｊｅｎｓｅｎ提出的一种高级网系统,可以为系统建模提供强有力的支持。文章介绍了有色Ｐｅｔｒｉ网,并利用仿真工具Ｄｅｓｉｇｎ／ＣＰＮ对一个通信协议停－等协议进行分析。     

模糊Petri我在带权不精确知识表示和推理中的应用研究

Ｐｅｔｒｉ网是一种适合于描述异步并发事件的计算机系统模型,可以有效地对并行和并发系统进行形式化验证和行为分析,以模糊Ｐｅｔｒｉ网的基本定义为基础,讨论了带权模糊的模糊产生式系统表示法,建立了这种表示法与模糊Ｐｅｔｒｉ网之间的映射关系和转换算法;在对模糊Ｐｅｔｒｉ网进一步扩充的基础上,解决了与知识的模糊Ｐｅｔｒｉ网表示相关的几个问题;最后给出了模糊Ｐｅｔｒｉ网中不确定性的计算方法和相应的不精确推理算     

H－网：一个基于Petri网的超文本形式模型

本文提出了一个基于Ｐｅｔｒｉ网的超文本形式模型Ｈ－网．Ｈ－网自然地从本质上刻画了超文本的所有主要性质，有助于超文本中各种主要问题的解决，并可以成为超文本系统设计和超文本标准化的理论基础．由于创造性地以基于Ｐｅｔｒｉ网的形式框架统一超文本信息和知识，Ｈ－网还非常适于智能超文本系统的建模．文中重点讨论了Ｈ－网的原理和定义，并用Ｈ－网对超文本进行了简单的描述．     

基于资源配置混杂Petri网的混杂系统生产过程建模

为了增强混杂Ｐｅｔｒｉ网解决资源共享和资源冲突的能力,定义一种新的混杂Ｐｅｔｒｉ网模型———资源配置混杂Ｐｅｔｒｉ网,提出了相应的使能和激发规则．将对连续变迁和离散变迁的控制作用引入混杂Ｐｅｔｒｉ网,同时,增加了资源配置变迁和资源释放变迁,用于有效分配可重复利用的资源．以典型的混杂生产过程为例,研究混杂系统生产过程建模．研究结果表明,所定义的模型描述能力强,模型语义正确合理,能够有效描述和分析混杂系统生产过程．     

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。     

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     

工作流时序约束模型分析与验证方法

为了解决工作流时间建模与时序一致性验证问题,以时序逻辑和模型检查为基础,提出了一种工作流时间建模与时序一致性验证方法.该方法用一阶逻辑描述工作流模型及其时间信息,用时序逻辑描述工作流的时序约束,用模型检查算法对时序约束进行验证与分析.该方法不是针对某一种时序约束提出来的,而是能够验证任何用时序逻辑描述的工作流时序约束.该方法还能够对未通过验证的时序约束提供工作流运行实例作为反例,帮助用户定位模型的问题.以一个工作流时间建模和时序一致性验证的实例证实了所提出方法的有效性.     

软件构架动态行为建模与检测

针对软件构架描述语言在分析、验证软件构架动态行为中的不足,用抽象代数对构件、连接器和体系结构配置进行抽象,提出了软件构架层次模型,并采用Pr／T网对软件构架动态行为建模．提出基于线性时序逻辑的软件构架动态行为模型检测方法,给出了该方法的算法描述．最后,详细描述了电子商务系统中并发控制机制的建模过程和检测结果．提出的软件构架动态行为建模与检测方法结合了Pr／T网和线性时序逻辑的优点,为开展软件构架动态行为的分析、验证提供了理论基础．     

Deadlock p revention f or flexible manufacturing system

Deadlock must be prevented via the shop controller during the flexible manufacturing system (FMS) performing. Various models have been tried for the analysis and design of shop controller. Petri net is suitable to describe the dynamic behavior of the discrete event system , such as concurrency , conflict and deadlock , however , the verification of the system behavior needs ructure analysis with complex theoretical proof method. Temporal logic model checking has important advantages over traditional theorem prover. It is fully automatic and can produce possible unter- example which is particularly important in finding subtle error in complex transition systems. In this paper ,a new method for the deadlock prevention based on Petri net and Temporal Logic model checking is presented. The specification in the Temporal Logic is expressed according to some result of structure analysis of the Petri net . The model checking is employed to execute the formal verification ,which will conduct an exhaustive exploration of all possible behaviors. Finally ,an example is presented to demonstrate how the method works.     

Deadlock prevention for flexible manufacturing system

Deadlock must be prevented via the shop controller during the flexible manufacturing system （FMS） performing. Various models have been tried for the analysis and design of shop controller. Petri net is suitable to describe the dynamic behavior of the discrete event system, such as concurrency, conflict and deadlock, however, the verification of the .system behavior needs structure analysis with complex theoretical proof method. Temporal logic model checking has important advantages over traditional theorem prover. It is flatly automatic and can produce possible counter-example which is particularly important in finding subtle error in complex transition systems. In this paper, a new method for the deadlock prevention based on Petri net and Temporal Logic model checking is presented. The specification in the Temporal Logic is expressed according to some result of structure analysis of the Petri net. The model checking is employed to execute the formal verification, which will conduct an exhaustive exploration of all possible behaviors. Finally, an example is presented to demonstrate how the method works.     

Extension of Petri Nets for Representing and Reasoning with Tasks with Imprecise Durations

This paper presents an extension of Petri net framework with imprecise temporal properties. We use possibility theory to represent imprecise time by time-stamping tokens and assigning durations to firing of the transitions. A method for approximation of an arbitrary temporal distribution with a set of possibilistic intervals is used to introduce the composition operation for two possibilistic temporal distributions. We developed a method to determining an effective enabling time of a transition with incoming tokens with possibilistic distributions. The utility of the proposed theory is illustrated using an example of an automated manufacturing system. The proposed approach is novel and has a broad utility beyond a timed Petri network and its applications.     

着色Petri网模型检测工具的扩展及其在Web服务组合中的应用

Web服务组合的形式化描述和验证是一个重要的研究问题.为了更好地完成验证工作,提出了扩展着色Petri网的模型检测方法.首先,在着色Petri网原有的基于CTL的局部模型检测算法基础上,给出了获取模型检测证据/反例的算法,并在着色Petri网模型检测工具--CPN Tools--中使用ML(meta language)语言实现了这些算法,然后将扩展后的CPN模型检测工具应用在Web服务组合的验证问题中.该方法不仅可以验证Web服务组合是否存在逻辑错误,还能告诉用户发生错误的原因,为Web服务组合的验证提供了技术上的保障.实验表明对着色Petri网的模型检测工具的扩展是正确、有效的.     

Nondeterministic Probabilistic Petri Net — A New Method to Study Qualitative and Quantitative Behaviors of System

There are many variants of Petri net at present,and some of them can be used to model system with both function and performance specification,such as stochastic Petri net,generalized stochastic Petri net and probabilistic Petri net.In this paper,we utilize extended Petri net to address the issue of modeling and verifying system with probability and nondeterminism besides function aspects.Using probabilistic Petri net as reference,we propose a new mixed model NPPN(Nondeterministic Probabilistic Petri Net) system,which can model and verify systems with qualitative and quantitative behaviours.Then we develop a kind of process algebra for NPPN system to interpret its algebraic semantics,and an actionbased PCTL(Probabilistic Computation Tree Logic) to interpret its logical semantics.Afterwards we present the rules for compositional operation of NPPN system based on NPPN system process algebra,and the model checking algorithm based on the action-based PCTL.In order to put the NPPN system into practice,we develop a friendly and visual tool for modeling,analyzing,simulating,and verifying NPPN system using action-based PCTL.The usefulness and effectiveness of the NPPN system are illustrated by modeling and model checking an elaborate model of travel arrangements workflow.     

一种基于Petri网的特定手语词汇识别方法

本文尝试使用Petri网进行简单的手语词汇识别。首先采用模板匹配方法检测到一系列简单的手势,如手掌张开直立、握拳、伸出大小拇指。其中,每个简单手势的发生对应于Petri网中的一个变迁。待识别的手语词汇是由一串特定的手势序列构成的,如手掌张开直立一握争伸出大小拇指。通过Petri网记录手势的动态变化,并在每次新变迁发生时检测目标库所的标志增加情况,从而实现特定手语词汇的识别。     

一种有效的基于LTL和Petri网的模型检测方法

模型检测的一个主要方法是构建线性与时序逻辑（LTL）公式φ的否定形式等价的Büchi自动机Aφ和系统模型M的正交积，并检测正交积的可接受语言是否为空。通过对Generalized Büchi自动机进行化简，可以减小自动机的状态空间，从而提高模型检测的效率。根据所提出的方法设计并实现的基于LTL和Petri网进行模型检测的工具包，可以有效地对基于Petri网表示的系统模型进行模型检测。     

基于on-the-fly的Petri网模型检查技术研究与实现

Petri网是一种应用非常广泛的建模工具,它能深刻、简洁地描述控制系统,特别是能较好地描述并发系统的结构,并能对系统的动态性质进行分析。在探讨了Petri网的模型检查的基础上,采用双DFS算法,对基于Petri网的模型检查的算法进行了改进,提出了针对Petri网的on-the-fly算法,同时给出了基于on-the-fly的Petri网模型检查的实现和测试,从而可以有效地对Petri网表示的系统模型进行模型检查。     

基于Time Petri Nets的实时系统资源冲突检测

Time Petri Nets在实时系统的建模和性能分析中得到广泛应用,而冲突是Petri网及其扩展模型的重要行为,解决冲突是正确分析模型动态行为的关键.目前随机Petri网、混合Petri网和区间速率连续Petri网的冲突检测方法由于没有考虑到时间约束因此无法在TPN网中使用.时间约束的引入使得Time Petri Nets模型的使能和触发语义比Petri网模型的语义复杂,冲突检测变得更加困难.为了计算冲突发生的时间和概率,首先根据时间约束,给出了变迁持续使能时延迟区间的计算方法,并证明了该方法的合理性和完备性;然后在此基础上定义并证明了Time Petri Nets模型中不冲突的检测方法;并提出了Time Petri Nets模型的冲突检测方法,给出了冲突时间区间和变迁实施概率的计算方法;最后通过实例验证说明了该方法的正确性和有效性.     

An object-oriented approach to formally analyze the UML 2.0 activity partitions

Nowadays, UML is the de-facto standard for object-oriented analysis and design. Unfortunately, the deficiency of its dynamic semantics limits the possibility of early specification analysis. UML 2.0 comes to precise and complete this semantics but it remains informal and still lacks tools for automatic validation. The main purpose of this study is to automate the formal validation, according a value-oriented approach, of the behavior of systems expressed in UML. The marriage of Petri nets with temporal logics seems a suitable formalism for translating and then validating UML state-based models. The contributions of the paper are threefold. We first, consider how UML 2.0 activity partitions can be transformed into Object Petri Nets to formalize the object dynamics, in an object-oriented context. Second, we develop an approach based on the object and sequence diagram information to initialize the derived Petri nets in terms of objects and events. Finally, to thoroughly verify if the UML model meets the system required properties, we suggest to use the OCL invariants exploiting their association end constructs. The verification is performed on a predicate/transition net explored by model checking. A case study is given to illustrate this methodology throughout the paper.