基于petri网的文件审批系统工作流建模

以工作流技术为基础,将基于petri网的建模方法应用到文件审批系统的分析过程中,构建系统的petri网模型,并利用petri网化简规则,对该模型进行了结构上的正确性验证;同时,通过模型的可覆盖树对模型的可达性、活性、有界性等petri网的性质进行了验证.结果证明,该技术能够在文件审批系统中进行建模和可行性验证.     

新型Petri网故障诊断算法研究

Petri网是一种高效的离散事件动态系统建模工具。该文基于Petri网的基本原理,结合故障诊断问题的特点,对petri网在故障诊断中的应用进行了研究,提出了新型Petri网故障诊断算法。并以多轴机床为例建立了Petri网故障模型,分析了故障传播的机理,验证了该算法的有效性。     

基于petri网学校工作流模型设计与触发机制的研究

基于petri网的工作流模型具有结构简明、描述能力强的特点。本文总结了基于Petri网的工作流建模技术,并将其应用于学校办公自动化系统的业务分析与建模过程中。给出了学校办公自动化系统的的基于petri网的工作流模型,提出工作流过程模型的触发机制．时探讨基于Petri网的工作流技术在办公自动化系统中的应用具有指导和参考意义。     

可达性等价于状态方程可满足性的一个petri网子类

本文定义了一个petri网子类： ,满足条件 。本文证明：当目标标识 时,此petri网子类的可达性等价于状态方程 的可满足性。同时,当此petri网子类的可达性等价于状态方程可满足性时,可得出如下两点结论：①对于满足 的每个非平凡的非负整数向量 ,都 ;②对于满足 的每个非平凡的非负整数向量 , 都是 的一个可执行向量。     

基于赋时有色petri网的维修过程模型

维修过程模型是研究维修保障系统结构与运行的基础。petri网模型具有直观、形象的优点，又是严格定义的数学对象，既可用于静态的结构分析，又可用于动态的行为分析，具有灵活的建模和强大的系统性能分析能力，是描述维修过程的有力工具。该文介绍了petri网方法的有关概念、特性。假定了典型的维修资源配置环境，对维修资源进行了分类。描述了典型的维修过程，应用赋时着色Petri网建立了维修过程的petri网模型。文章最后讨论了模型的应用。     

petri网分析工具对增广petri网模型的验证

petri网分析工具支持增广petri网模型的建立、分析和验证。本文举例分析了用增广petri网描述的数学公式排列A m/n及幕指数n~m的分析和验证。     

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。     

分布式状态空间生成的有色petri网模型

该文旨在为分布式的状态空间生成系统设计一个有色petri网模型,并对模型进行性能分析,得出状态空间的分割对分布式系统性能的影响。基于通信时延是系统的性能瓶颈,必须使用与模型结构属性相适应的分割算法,以提高系统的加速比及分布式状态空间生成的性能。     

基于混合petri网的网络建模与仿真

该文基于网络交换节点传输特性的辨识模型,提出了一种基于混合petri网的节点仿真模型,以及利用该模型进行网络建模的方法。分析了交换节点混合petri网模型的仿真精度,给出了保证信息量守恒的仿真条件。对于不能消除的误差,分析了其在仿真过程中的动态范围,得出了模型能够自动补偿的结论。通过建立一个网络的混合petri网模型,并利用visual object net2.0进行了信息传输过程仿真。仿真结果说明该网络模型能够很好地模拟信息传输的动态过程,能够体现网络交换节点的非线性传输特性。     

时间Petri网分析工具的实现

时间Petri网是非常适合描述实时系统的模型工具,由于时间的复杂性因素使得它的可达性分析变得非常困难。该文在分析了基于全局时间变量的时间Petri网的可达性算法的基础上,采用OOP技术,实现了一个时间petri网的分析工具。     

Determination of path identifiers for reliability analysis of a broadcasting network using Petri nets

A Petri net approach for determination of the sets of path identifiers for reliability analysis of a broadcasting network is presented. The firing concept of Petri nets is exploited to give a Petri net interpretation to certain properties of the network. The dynamic behaviour of the system under study is represented in the form of token movements within the model. The various entities of Petri nets are assigned an appropriate interpretation for studying the behaviour of the system at different levels. Corresponding to the source node and each of the terminal nodes, a vector, representing the state of the Petri net interpreted model, is defined by assuming a token initially at the source place and finally at one of the terminal places. The reachability and marking concepts are then used to determine all success states of the system. The developed algorithm has been coded into FORTRAN-77 and the complete package is available. The proposed technique is extremely simple as it uses only vector additions on the columns of the place-to-transition incident matrix.     

模糊推理Petri网及其在故障诊断中的应用

分析了推理Petri网与传统Petri网的共性和区别,给出了模糊产生式规则推理 Petri网模型.在此基础上,给出了有效的推理算法,并以极大代数矩阵算子进行了形式化表 示,此算法充分利用了Petri网的数学理论基础和描述并发系统的能力,具有并行推理能力, 可以同时得到推理后系统的全部状态值.最后举例说明了其在故障诊断中的应用.     

Automating the Conversion of Colored Petri Nets with Qualitative Tokens Into Colored Petri Nets with Quantitative Tokens

The authors describe an algorithm for conversion of colored Petri nets with qualitative tokens into a colored Petri net with quantitative tokens preserving boundedness, mutual exclusion, and liveness properties. This conversion allows the invariance method to be applied to colored Petri nets, which uses the Truncated Set of Solutions finding algorithm for Petri net state equations expressed through systems of linear homogenous Diophantine equations. To show the algorithm’s efficiency, it is applied to the colored Petri net that models the operation of a grid system. Equivalence of net models is tested by constructing and analyzing equal finite-state machine.     

基于Petri网模型的FMS死锁结构

死锁是柔性制造系统中容易发生的异常现象，如不加以消除，将会导致整个系统的瘫痪。文中通过Petri网模型对FMS的结构分析，揭示出导致FMS死锁的结构元素和活性特征，在此基础上，提出了FMS的无死锁Petri网控制器算法，并举例说明这种控制器算法在FMS中的应用。     

一种改进的基于规则的带权模糊推理算法

给出了一种基于带权模糊Petri网的模糊推理算法，这种算法可以适用于一类基于规则的系统，即可以对该类系统的带权模糊Petri网模型进行相应的处理。对系统建立了知识表示的带权模糊Petri网模型，使用该算法可以确定用户给定的库所之间是否存在联系，即相应的命题之间是否存在因果关系，可以计算出命题的模糊真值。对具体的算例进行了分析并与已有的算法进行了比较，得出该算法的优点。     

A novel reduction approach for Petri net systems based on matching theory

In this paper, an efficient method is presented to solve the state explosion problem in Petri nets by using matching theory. It is difficult to analyze a Petri net when there are too many existing states. In order to solve such a problem, it is addressed to label a weight value on a transition according to the relationship between a place and a transition. Then, the transition with the largest weight value is selected. The selected transition is the most important and connective in the entire Petri net. After selecting each transition for several times, the last one denotes the least connective in the whole Petri net and the redundant place is obtained. Furthermore, the Petri net model can be reduced by fusing the transition with the largest weight value and the redundant place. In this novel approach, an incidence matrix, a weight vector, a matching matrix, a compressed incidence matrix, and a reduced and compressed incidence matrix are sequentially built based on the original Petri net model so as to obtain a reduced and compressed Petri net model. Finally, the experimental results regarding the CAVE automatic virtual reality environment demonstrate the high viability of the proposed approach.     

基于Petri网的柔性制造系统无死锁遗传调度算法

对以最小化加工时间为目标的柔性制造系统无死锁调度问题, 提出了一种遗传调度算法. 算法考虑到同类工件具有预先确定的相同加工路径, 而各工序的处理时间与工件有关. 用Petri网对工序和资源分配进行逻辑建模,利用遗传算法, 采用工序自然编码方式, 基于系统的最佳避免死锁Petri网控制器, 检测染色体的可行性, 修复不可行染色体使其对应的调度满足资源约束和无死锁控制约束, 从而保证算法所利用的所有染色体都对应系统的可行调度. 仿真结果表明了算法的可行性和有效性.     

高级综合中VHDL描述向Petri网转换方法的研究

提出一种基于执行路径的Petri网生成算法,该算法提取VHDL源描述中的功能和时序信息,生成与源描述完全等价的Petri网结构．算法采用条件树结构保存条件,语句执行条件和Petri网迁移条件都依据条件树生成．生成的Petri网能够准确地保存源描述中的I／O时序信息,形成调度过程中I／O操作处理的基础．从该结构出发,能够方便地实现各种I／O模式的调度。     

Inhibitor Petri net executing an arbitrary given Markov normal algorithm

An inhibitor Petri net with a fixed structure that executes an arbitrary given Markov normal algorithm is constructed. The algorithm and its input string are encoded by nonnegative integer numbers and put into dedicated places of the Petri net, which implements the application of the algorithm productions over the string of symbols. Rules of encoding sequential, branching, and cyclic processes by Petri nets are used. Upon completion of the net operation, the output string is restored (decoded) from the integer form of the representation. Within the paradigm of computations on Petri nets, the constructed net provides the compatibility of systems.     

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.