公平Petri网中同步距离计算的一个实现算法

An Algorithm of Computing Synchronic Distance in Fair Petri Nets

同步距离是对两组事件间同步程度的定量描述,也是刻画系统动态行为的工具。提出了公平Petri网中同步距离的求解方法,利用观察库所的原理来求变迁之间的同步距离。我们在原Petri网的基础上通过给变迁和观察库所之间的弧引入适当的权值构造出一个带观察库所的加权网系统SWNet,并且提出了增广(可覆盖)树的概念。在原网系统的可覆盖的基础上构造出一个增广(可覆盖)树,通过增广(可覆盖)树可以准确的得到观察库所初始标识,最后给出了对观察库所配置初始标识的算法和计算同步距离的算法。

The synchronic distance is not only an analyzing metric to describe the synchronic relationship between two events, but also a tool to representing dynamic behavior of systems. A method of getting synchronic distance in fair Petri net is presented in this paper, the principle of which adopts observe-place. Weighted net system with observe-place （SWNet） is constructed based on original Petri net by introducing suitable weight value for an arc between transition and observe-place, the concept of augumented （coverability） tree is introduced simultaneously. A augumented （coverability） tree is constructed based on coverability tree of original net system, by means of which, initial tokens of observe-place is obtained. Finally the algorithm of setting initial marking of observe-place and computing synchronic distance are given.