节点文献
有色时间Petri网与随机Petri网应用研究
Research on the Use of Colored Timed Petri Net and Stochastic Petri Net
【作者】 丁峰；
【导师】 陆阳；
【作者基本信息】 合肥工业大学 ， 计算机应用技术， 2009， 硕士
【摘要】 Petri网是一种适合于描述异步并发现象的系统模型,是离散事件系统建模的一种强有力工具,但是在使用基本Petri网来为复杂系统建模时会出现“节点爆炸”问题,有色时间Petri网(CTPN)是克服该问题的有效途径之一。多范式建模通过耦合和转换以整合不同方法建立的模型来综合利用多种形式化方法,可以全面准确地描述建模对象,可以大大的减轻仿真建模的工作量、提高整个仿真过程的效率。依据多范式建模理论,本文提出了基于规则化描述方法的CTPN建模方法,同时发挥两种建模方法的优势,有利于全面准确地反映系统的设计内容,并以汽车车身控制系统为例为其建立模型,为复杂系统建模和模拟验证提供一定的借鉴。工作流管理技术是90年代初兴起的软件技术,工作流是一个业务过程的全部或部分自动执行,为了实现工作流管理功能,我们必须将业务过程从现实世界中抽象出来,并用一种形式化方法对其进行描述,其结果称为是工作流模型。Petri网作为一种图形化的数学建模工具,适合于工作流领域的建模需求,提出了基于广义随机Petri网(GSPN)的工作流建模方法,将工作流模型映射为广义随机工作流网模型,并运用可达图法对工作流正确性和可靠性进行检查;利用GSPN与马尔可夫链的同构关系,采用GSPN和马尔可夫链相结合的工作流性能分析方法,为工作流性能的有效评估提供理论依据;并通过实例验证该方法的有效性。
【Abstract】 Petri Net is a formal, graphical, executable technique for the specification and analysis of concurrent, discrete-event dynamic systems. However, when modeling complicated control systems, basic Petri net may lead to the problem of node number explosion. Colored Timed Petri Net(CTPN) is a way to solve this problem. Multi-paradigm modeling, concerned with the coupling of and transformation between models described in different formalisms, can give a representation of models in diverse formalisms, at different levels of abstraction, and the behavior-conserving transformation between the formalisms is demonstrated. So modeling of CTPN derived from rule description method, which takes advantages of two modeling methods, is presented. And also the method is illustrated through modeling process of auto-body control system, which will help to model, analyze and simulate for complicated systems.Workflow management techniques were developed in early 1990s. Workflow is the automation of a business process in whole or part. To achieve the function of workflow management, the business process must be abstracted from the real world and described by a kind of formal method. The result is workflow model. As a kind of graphical and mathematical modeling tools, Petri Net is applicable to the modeling requirement of workflow. A method of modeling for workflow based on Generalized Stochastic Petri Net (GSPN) is proposed, the workflow definition of Workflow Management Coalition is mapped to generalized stochastic workflow net. The validity and reliability is checked using reachable graph method. By utilizing the equivalence relation between GSPN and Markov chain, a method of combining GSPN and Markov chain is used to analyze the performance of workflow. The effectiveness of this method is verified by an application case.