关键词: P/T_网, 公平分支, 带权观察库所, 带权同步观察P/T_系统, 本原权函数, 同步距离

Abstract: The synchronic distance is not only an analyzing metric to describe the synchronic relationship between two events, but also a tool to represent the dynamic behavior of systems. However, it’s difficult to calculate the synchronic distance in a Petri net. The paper discusses the synchronic distance between any two subsets of transition in a P/T_net by using the principle of a weighted observe-place, and it points out that how to allocate a weight to an arc connecting a weighted observe-place and a transition by the definition of primitive weight function. In order to obtain the synchronic distance between two subsets of transition which are in the same fair-components, a synchronic observed P/T_system with weight is constructed. The maximum tokens and the minimum tokens in a weighted observe-place can be yielded during constructing the coverability tree of a original net system, therefore the synchronic distance between two subsets of transition is obtained, the corresponding algorithm is also given. The algorithm of computing the synchronic distance between any two subsets of transition in a P/T_system is given.

Key words: P/T_net, fair-components, weighted observe-place, synchronic observed P/T_system with weight, primitive weight function, synchronic distance