Study On The Liveness And Boundedness Of Time Petri Nets

Petri net is a mathematic model describing dynamic behaviors of system and analyzing dynamic properties of system. It has many advantages of describing and analyzing concurrent phenomena, especially is very fit for modeling asynchronous and parallel systems. In order to describe time factors which are closely related to behaviors of a given system, various Petri nets with time factors are defined and studied.The liveness and boundedness are the most important properties of Petri nets. These properties of classical Petri nets mostly have had satisfying judging criteria, but the corresponding properties of Petri nets with time factors are seldom studied, and a lot of literatures are focusing on concrete applications.The time Petri nets which are discussed in this thesis are very simple and have the same modeling power as the Turing Machine, however, in general, there is just no comparison between the liveness, boundedness behaviors of a given time Petri net and those of its corresponding classical Petri net without time restrictions.Therefore, from this background, this thesis discusses the modeling power of time Petri net, gives an example which explains that time Petri net has the function of "Zero Examination"; presents a method of transforming a timed Petri net to a time Petri net. Then, two necessary and sufficient conditions, defining classes of TPNs which have the same boundedness and liveness behaviors as the corresponding classical Petri nets, are presented in this thesis. Finally, two structural dynamic conditions that are sufficient for a TPN has the same liveness behavior as the corresponding classical Petri net are given. All these give the possibility of judging the properties of time Petri nets using the judging criteria of classical Petri nets.