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上下文无关Petri网语言的Pumping引理 总被引:1,自引:0,他引:1
Petri网语言可分为正规Petri网语言、上下文无关Petri网语言和Petri网语言三类,Pumping引理反映了一类语言的共性.对于正规Petri网语言类和Petri网语言类都已给出了其相应的Pumping引理,而对于上下文无关Petri网语言类的Pumping引理却一直未给出.本文通过分析上下文无关Petri网语言的结构性质,给出了上下文无关Petri网语言的Pumping引理,并且正规Petri网语言的Pumping引理是上下文无关Petri网语言的Pumping引理的一种特殊形式,而上下文无关Petri网语言的Pumping引理又是Petri网语言Pumping引理的一种特殊形式,从而完整地解决了三类Petri网语言Pumping引理以及它们之间的关系. 相似文献
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基于P-不变量的Petri网并行化方法的研究 总被引:1,自引:1,他引:0
为使Petri网系统能够并行执行或模拟运行,提出了基于P-不变量的Petri网并行化方法.根据Petri网系统具有同步与并发的特点,给出基于P-不变量的Petri网模型分割、进程创建条件与并行化分析.在此基础上,提出并行进程创建条件拓展定理并给予证明和实例验证.给出实现并行化所需要解决的Petri网模型行为规范的形式化、P-不变量求解与基于P-不变量的Petri网并行化方法.实验结果表明,基于P-不变量的Petri网系统的并行化方法是可行和有效的. 相似文献
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为了更好地刻画单个Asent的行为和多Asent间复杂、并行的动态交互,将面向Agent的设计思想与Petri网建模方法相结合,形成了一种面向Agent的Petri网(AOPN)模型.首先给出了面向Agent的Petri网的形式化定义,然后利用Petri网的建模工具,以网上购物背景下买卖双方简单交互为例,对基于面向Agent的Petri网模型的系统建模方法进行了研究和分析,有效地解决了系统结构复杂性的问题. 相似文献
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利用时间约束Petri网进行项目绩效分析 总被引:1,自引:0,他引:1
时间Petri网(Time Petri Net)以及时延Petri网(Timed Petri Net)通过将时间约束引入到变迁中,广泛运用于任务调度以及性能分析,但是对于项目绩效分析所要求的关键路径、最短工期、成本分析等问题却无法有效解决.提出一种新的时间约束Petri网:将时间约束引入到库所中,在全局时钟的基础上,同时赋予Petri网的库所以延迟时间域和持续时间域两种时间约束,并且为T→P流关系的权函数赋予有色资源属性.给出时间约束Petri网的形式化定义,定义了变迁的发生规则,并引入状态类来计算状态的成本空间,给出状态类的计算方法.最后结合一个实例说明了利用时间约束Petri网进行项目的绩效分析的可行性.并用双色甘特图对时间约束Petri网的可达标识进行表述. 相似文献
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模糊Petri网在带权不精确知识表示和推理中的应用研究 总被引:15,自引:0,他引:15
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 ,讨论了带权模糊知识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法 相似文献
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基于Petri网的哲学分析 总被引:3,自引:1,他引:2
Petri网以其优秀的描述异步并发的能力以及简单、清晰的图形表示方法获得了长足的发展.Petri网技术和其它技术的完美结合使其在应用领域发挥作用.从哲学高度分析了Petri网获得成功的思想渊源.通过诠释Petri网思想与哲学思想的诸多相通之处,提出了一种以哲学观点认识和理解Petri网的新思想.Petri网理论的晦涩性在很大程度上限制了其更好发展.鉴于此,笔者在简化Petri网理论方面做了许多尝试,以期促进Petri网的流行与发展. 相似文献
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首先分析了一类结构简单的Petri网--S-网的语言性质,得到了它们的行为描述方法.拓展了Petri网同步合成的概念,证明了给定一个结构复杂的Petri网都可通过一组S-网的同步合成运算而得到,并给出了相应的求解算法.引入语言的同步交运算,分析了结构复杂的Petri网与其同步合成子网之间的行为关系,给出了结构复杂Petri网的行为描述算法,为利用网语言分析实际系统的行为特征提供了可靠的理论依据和方法. 相似文献
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为了更有效地对工作流模型进行分析验证,提出了一种基于Petri网化简技术的工作流模型正确性验证方法。在对各种工作流模型验证技术深入研究的基础上,通过对非自由选择网结构活性和有界性的分析,给出了针对Petri网中非自由选择部分的分析方法。在保持活性和有界性的前提下,给出了将活的且有界的非自由选择部分转化为自由选择部分的转化方法,从而将非自由选择的Petri网验证问题转化为自由选择Petri网的验证问题。通过一个例子说明了如何使用该文提出的方法来验证模型的正确性。 相似文献
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We investigate the property of self-stabilization in bounded Petri nets. We give characterizations for both self-stabilizing bounded ordinary Petri nets (i.e., Petri nets without multiple arcs) and self-stabilizing bounded general Petri nets (i.e., Petri nets with multiple arcs). These characterizations allow us to determine the complexity of deciding self-stabilization for each of these classes. In particular, we show the self-stabilization problem to be PTIME-complete for bounded ordinary Petri nets and PSPACE-complete for bounded general Petri nets.Louis Rosier passed away on May 6, 1991, while this paper was under review 相似文献
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For bounded Petri nets, Cabasino et al. propose a diagnosability test method that is based on the analysis of a modified basis reachability graph and a basis reachability diagnoser. However, its complexity is exponential in the number of nodes of the basis reachability diagnoser. In order to reduce the complexity of their method, this paper presents a new diagnosability test approach for bounded Petri nets. We present the concept of an extended basis reachability graph and prove that our approach is of polynomial complexity in the number of nodes of extended basis reachability graphs. An example is given to illustrate the application of the presented approach. 相似文献
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李宣东 《计算机科学技术学报》2001,16(1):0-0
The paper proposes an approach to solving some verification problems of time petri nets using linear programming.The approach is based on the observation that for loop-closed time Ptri nets,it is only necessary to investigate a finite prefix of an untimed run of the underlying Petri net.Using the technique the paper gives solutions to reachabiltiy and bounded delay timing analysis problems.For both problems algorithms are given,that are decision procedures for loop-closed time Petri nets.and semi-decision procedures for general time Petri nets. 相似文献
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This paper addresses the problem of diagnosability for dynamic discrete event systems modeled with bounded or unbounded Petri nets that are deadlock-free and monitored with sensor configurations with marking and event measurements. The proposed method gives necessary and sufficient conditions for diagnosability. It is based on the transformation of the coverability graph into an observation graph that encodes all observation sequences of measured markings and events with respect to the sensor configuration. This graph also encodes all sequences of transitions that may fire from any reachable marking of the Petri net. Diagnosability is determined by analyzing the paths and circuits in the observation graph. The method is illustrated with several examples of bounded or unbounded Petri nets. 相似文献
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Zhen Liu 《IEEE transactions on pattern analysis and machine intelligence》1998,24(11):1014-1030
Stochastic timed Petri nets are a useful tool in the performance analysis of concurrent systems such as parallel computers, communication networks and flexible manufacturing systems. In general, performance measures of stochastic timed Petri nets are difficult to obtain for practical problems due to their sizes. In this paper, we provide a method to efficiently compute upper and lower bounds for the throughputs and mean token numbers for a large class of stochastic timed Petri nets. Our approach is based on uniformization technique and linear programming 相似文献