基于Petri网自动化构建BPEL流程的SMV模型

针对使用BPEL进行Web服务组合过程中,复杂业务流程的正确性验证繁琐且易出错问题,论文提出了一种自动化构建BPEL流程的SMV模型方法.该方法将BPEL流程自动化映射到Petri网,借由Petri网直观展示组合流程并进行边界值、死锁等性质的检查,再由Petri网可达图自动化生成SMV模型,使用模型检测工具验证系统的安全性和行为属性,从而在流程的设计阶段发现服务组合中可能存在的问题.实验结果表明论文工作可以有效地减少验证过程的复杂性,有助于提高服务组合流程的正确性.     

语义标记Petri网的组合Web服务建模与验证(英文)

随着Web服务组合的发展,整合业务过程成为可能。组合Web服务可以被看作是基于过程的工作流。由于死锁、不安全和不可达等流的设计错误会影响组合Web服务的有效执行,因此这些错误应在组合Web服务执行前被检测出并修改。提出了基于语义标记Petri网的组合Web服务建模与验证方法。首先提出语义标记Petri网(SaPNs),并给出其语义;用受限描述逻辑tableau算法获得组合Web服务;使用SaPNs描述组合Web服务及其组成部分;最后,使用基于SaPNs的分析方法验证了组合Web服务。使用该方法在开放的Internet环境下可以获得满足客户需求的、可靠的组合Web服务。     

语义Web服务组合的形式化描述与验证研究

Web服务组合是Web服务的主要研究方向之一,对语义Web服务组合进行形式化描述并进行分析和验证是组合服务正确运行的保证.本文首先给出了基于有色Petri网的语义Web服务形式化模型,形式化描述了OWL-S的ServiceModel中8种基本的Web服务组合模式,利用这些组合模式可以构造出满足需求的组合Web服务.然后,对服务组合形式化模型的正确性分析和验证进行研究后,给出了组合模型语法正确性、可达性、活性和有界性的算法.最后,通过一个具体的建模实例展示了Web服务组合的Petri网建模.     

基于Petri网的Web服务组合与分析

Web服务为互联网提供了一种新的应用环境。然而，Web服务还有许多需要进一步研究的问题。Web服务的组合及其验证就是需要深入研究的问题。本文针对通用构件描述语言（UCDL）提出一种Petri网模拟和验证方法，即对于Web服务的元活动和构件，提出相应的Petri网模型和建模方法。在此基础上进一步研究了Web服务系统Petri网的语言表达式生成算法，从而为Web服务系统的验证分析提供了有效工具。     

基于扩展CPN的OWL-S过程语义建模及分析方法研究

OWL-S过程语义的建模与分析是语义Web服务相关领域需要重点研究的问题。分析了目前OWL-S过程语义研究中存在的问题,提出了一种扩展的着色Petri网PM_ net(过程模型网,Process Model net)来对OWL-S的过程语义进行转化与分析。结合OWL-S过程模型元素的特点,PM_ nct对基本着色Pctri网的变迁和触发规则进行了扩展,使OWL-S的原子过程、组合过程和数据流等核心元素能够等价映射到PM net。同时说明了如何基于PM_ net对OWL-S的过程语义一致性进行分析,为OWL-S本体演化、语义Web服务组合和验证提供了合理的理论基础。     

基于组合着色Petri网的空间复合事件检测机制

通过建立空间事件模型,扩展定义了空间事件复合算子及其语义;采用组合着色Petri网构造基于空间关系的复合事件检测模型并提出基于该模型的检测算法;通过应用实例验证该检测模型是一个简洁、有效的复合事件检测机制。     

基于着色Petri网的Web合成服务会话协议

基于着色Petri网的会话协议不仅能准确地描述Web服务的业务流程特征,而且具备强大的数据承载能力。该文以BPEL4WS语言为例,在对Web服务特性进行分析的基础上,给出了基于着色Petri网的会话协议以及相应的Web合成服务设计方法。通过这种框架,可以运用成熟的Petri网技术,对Web服务模型进行进一步的分析和验证,以提高服务的正确性和可靠性。     

Web服务组合形式化验证方法研究

Web服务组合验证是确保组合服务正常执行的关键,现有的许多Web服务组合描述都是半形式化的,容易出错和不容易检测,因此正确性难以保证。采用转移矩阵方法来分析Web服务组合中存在的死锁问题,并采用关联矩阵的方法确认组合的可达性。利用模糊推理Petri网算法进行可信度验证、计算服务组合的可信度及可达性,对于Web服务组合是一种可以推理的形式化验证方法。实验结果表明这种方法是一种很好的验证方法。     

基于扩展时间Petri网的Web服务组合的分析与验证

为了进一步研究Web服务组合的时间成本问题,提出一种扩展时间Petri网,在变迁上添加了触发时间区间和发生优先级函数,在分析过程中提出了时间成本的计算方法,定义了变迁冲突的检测规则,更好地解决了可达分析中出现的冲突问题和时间成本问题,并给出了一个服务组合算法的描述,最后用实例验证了方法的可行性。     

面向组合的Web服务间数据关联定位方法研究

Petri网因其在描述和分析并发、分布式系统方面的优势,越来越多地被用于Web服务组合中。在基于Petri网描述的Web服务组合中,如何确定各个子服务参数之间的关联关系,并以此为基础得到Web服务组合的Petri网,是对Web服务组合性质进行分析的前提与基础。首先给出Web服务的Petri网描述和基于Petri网的Web服务注册系统,定义了Web服务参数间的数据关联及定位算法,并通过例子说明数据关联在自动生成Web组合服务Petri网中的应用。     

Efficient Verification of Parallel Real–Time Systems

This paper presents an efficient model checking algorithm for one–safe time Petri nets and a timed temporal logic. The approach is based on the idea of (1) using only differences of timing variables to be able to construct a finite representation of the set of all reachable states and (2) further reducing the size of this representation by exploiting the concurrency in the net. This reduction of the state space is possible, because the considered linear–time temporal logic is stuttering invariant. The firings of transitions are only partially ordered by causality and a given formula; therefore the order of firings of independent transitions is irrelevant, and only one of several equivalent interleavings has to be generated for the evaluation of the given formula. In this paper the theory of timing verification with time Petri nets and temporal logic is presented, a concrete model checking algorithm is developed and proved to be correct, and some experimental results demonstrating the efficiency of the method are given.     

Modeling and verification of the SDL-specified communication protocols using high-level Petri nets

To simplify modeling and verification of communication protocols presented in the SDL language, the so-called hierarchical typed timed Petri nets (HTT nets), which are substantial modifications of colored Petri nets, are introduced. A method of translation of the SDL language into HTT nets is described. A program complex SPV (SDL Protocol Verifier), which includes a translator from SDL into HTT nets and means for editing, simulation, visualization, and verification of these net models, is presented. For the verification, a model checking method for properties presented by μ-calculus formulas is used. Experiments on application of the SPV complex for modeling and verifying two ring protocols (RE and ATMR protocols), an optimized version of the sliding window protocol (i-protocol), and a dynamic version of the InRes protocol are described     

Verification of telecommunication systems specified using communicating finite-state automata using colored Petri nets

Uniform systems of communicating extended finite-state automata are considered. These systems can be used for the initial specification of telecommunication systems such as ring protocols and telephone networks. This paper aims to present an automata systems verifier tool (ASV) designed for the analysis and verification of automata specifications. It is based on an algorithm for the translation of automata systems into colored Petri nets (CPN) presented and justified in [4]. The ASV tool uses CPN Tools [10] for analysis and simulation of CPN, also it uses Petri Net Verifier [12] to verify CPN properties by applying the model checking method to CPN reachability graph with respect to the properties expressed in μ-calculus. The application of the ASV tool is described for the ring RE-protocol verification and the study of the feature interaction in telephone networks.     

自动化仓库输送调度问题的建模与控制研究

基于面向对象着色Petri网模型和时态逻辑方法,对自动化仓库输送系统运行过程的调度问题进行研究。建立了系统的面向对象着色Petri网模型,讨论了该过程的死锁分析问题,给出了系统行为的时态逻辑规范和死锁避免的最大允许反馈控制策略。     

ITL semantics of composite Petri nets

interval temporal logic (itl) and Petri nets are two well developed formalisms for the specification and analysis of concurrent systems. itl allows one to specify both the system design and correctness requirements within the same logic based on intervals (sequences of states). As a result, verification of system properties can be carried out by checking that the formula describing a system implies the formula describing a requirement. Petri nets, on the other hand, have action and local state based semantics which allows for a direct expression of causality aspects in system behaviour. As a result, verification of system properties can be carried out using partial order reductions or invariant based techniques. In this paper, we investigate a basic semantical link between temporal logics and compositionally defined Petri nets. In particular, we aim at providing a support for the verification of behavioural properties of Petri nets using methods and techniques developed for itl.     

面向服务的企业应用集成系统描述与验证

在对当前面向服务体系架构(service-oriented architecture,简称SOA)研究的基础上,给出了一个以企业服务总线(enterprise service bus,简称ESB)为中心的面向服务软件体系架构参考模型(SOA reference model,简称SOARM),是集Petri网和时序逻辑于一体的形式化SOA分析、验证和确认方法.基于以客户为中心的面向服务架构设计理念,即根据用户提出系统规范/需求,服务提供者提供服务或组合服务来满足服务消费者,服务接口和ESB作为实现面向服务架构的关键部分.虚拟计算环境下,服务语义的一致性验证是十分必要的,SOARM采用新的模式:通过Petri网为服务的行为建模,时序逻辑来描述服务语义一致性约束,综合运用分而治之的精炼检测思想和SOA模型检测合成方法,通过对这些子服务性质的检验来验证整个系统的规范.用商业银行综合前置系统说明了如何使用这种方法来实现面向服务的设计.     

着色Petri网应用研究

着色Petri网是在经典Petri网理论基础上增加了token类型和网的模块这两个功能,它现在已成为一种较完善的语言,可以用来对各种系统规范和协议等进行设计、规范描写、仿真和验证等。文章对着色Petri网的基本理论进行了简单介绍,并对一个简单的通信协议进行建模和分析,提出了今后着色Petri网发展的一个主要方向。     

基于有色Petri网的SysML序列图的分析与验证

针对SysML序列图本身缺乏分析和验证手段的问题,提出了一种序列图到有色Petri网的转换方法:定义了将序列图的常用操作转换为等价有色Petri网的转换规则,重点是把序列图的常用结构如可选结构、条件结构、并行结构以及循环结构等映射为有色Petri网。这当中既包含结构元素,如库所、变迁、输入/输出弧,又包含逻辑元素,如全局声明中的颜色集和变量、颜色集与库所、弧表达式以及初始标志。应用这些规则可以将序列图转换为有色Petri网模型,进而对其进行仿真分析,并可通过有色Petri网工具验证模型的无死锁性、可达性、有界性和活性。最后通过数字证书更新的实例分析了映射前后两种模型的语义,验证了映射的正确性。     

Enhanced high-level Petri nets with multiple colors for knowledgeverification/validation of rule-based expert systems

Exploring the properties of rule-based expert systems through Petri net models has received a lot of attention. Traditional Petri nets provide a straightforward but inadequate method for knowledge verification/validation of rule-based expert systems. We propose an enhanced high-level Petri net model in which variables and negative information can be represented and processed properly. Rule inference is modeled exactly and some important aspects in rule-based systems (RBSs), such as conservation of facts, refraction, and closed-world assumption, are considered in this model. With the coloring scheme proposed in this paper, the tasks involved in checking the logic structure and output correctness of an RES are formally investigated. We focus on the detection of redundancy, conflicts, cycles, unnecessary conditions, dead ends, and unreachable goals in an RES. These knowledge verification/validation (KVV) tasks are formulated as the reachability problem and improper knowledge can be detected by solving a set of equations with respect to multiple colors. The complexity of our method is discussed and a comparison of our model with other Petri net models is presented.     

基于对象着色Petri网的UML模型研究

UML广泛应用于软件建模,但缺乏有效的模型检测的方法,使用形式化方法对UML模型进行分析,可以发现UML模型的设计问题,提高UML模型的质量。对象着色Petri网是一种拥有接口库所的模块化着色Petri网,既是一种图形化建模工具,又是具有严格的语法语义定义的形式化方法。通过引入事件托肯,改进了将UML模型转换为对象着色Petri网的方法,结合实例将UML状态图和协作图映射为对象着色Petri网模型。并用着色Petri网的方法和工具对模型进行了分析,验证了模型的一系列性质。