【作者】 罗鹏程；

【导师】 沙基昌；

【作者基本信息】 国防科学技术大学 ， 管理科学与工程， 2001， 博士

【摘要】 本文围绕当前系统安全性分析中存在的系统安全性模型描述与求解，以及安全性分析方法综合运用等问题进行研究。 目前安全性分析技术在动态系统安全性描述和分析方面存在很多困难，据此论文研究了在经典Petri网及其扩展模型的基础上进行描述和分析的思路，提出采用广义随机Petri网(GSPN)建立系统安全性模型的方法。在安全性定性分析方面，论文提出了关键状态的概念，给出了关键状态分析的搜索算法，研究了采用内锁和时间约束来消除高风险危险路径的方法。在安全性定量分析方面，我们研究发现去除消失标识后，GSPN的可达图与一个连续时间Markov过程(CTMP)是同构的，为此，可利用Markov过程方法进行分析。论文提出了基于Gauss-Seidel方法与动态行列技术的分析方法。在仿真方面，主要探讨了安全性定量分析中稀有事件问题的抽样技术，并提出采用重要性抽样法，以提高抽样效率。在技术方法综合运用方面，根据目前Petri网方法与传统的安全性分析方法结合不足，论文提出了一种综合了Petri网和传统安全性分析技术的方法。最后论文提出一种基于GSPN的系统安全性建模与分析系统的设计框架，并利用软件的原型系统对一个铁路系统进行了实例分析。更多还原

【Abstract】 This dissertation focuses on the problems existing in current system safety analysis,especially,modeling and solution of safety system,and integration of methods of safety analysis.There are still so many difficulties existing in the description and analysis of dynamic systems in current safety analysis techniques. In this case,we study the description and analysis idea based on classical Pctri Nets and its extension for safety systems,and present the way to model such systems using Generalized Stochastic Petri Nets (GSPN). For qualitative solution of the models,we define Critical States and bring forward an algorithm to work out the critical states of a safety system,so the path leading to high risk ha ard state can be eliminated with inner lock and time constraints,two of our new concepts. For quantitative solution,we study GSPN and find that the reachability graph of a GSPN is isomorphic to a Continuous Time Markov Process (CTMP) when the vanishing markings are eliminated,so Markov Process method can be used. And then we bring forward an approach to get the probability of steady-state based on Gauss-Seidel method and dynamic row-column techniques For the application of simulation in safety’ analysis,sampling techniques for sparse events are discussed,and importance sampling method is brought forward to increase sampling efficiency. For integration of methods of safety analysis,we study and bring forward an approach to combine Petri Nets based method with other traditional safety analysis methods in order to make use of the advantages of the two. At last,a design of System Safety Modeling And Analysis Software Based On GSPN is provided,and a case study on a railway system using this prototype software has been carried out.更多还原