This paper proposes, as a solution of this problem modeling hyper-presentation specification program with MTPN for advance judgment on describability of given hyper-presentation and also proposes the algorithm to find Critical Path in the hyper-presentation that specified QoS requirements because sometimes synchronization of hyper-presentation may not be properly made or QoS of multimedia presentation is deteriorated due to the feature of multimedia presentation and network problem.
When specifying synchronization between presentations with Cue or Hyper-link, inconsistency problem that cycle occurs is the same in the model that described this (synchronization) with MTPN. Therefore, consistency in specification program can verify by detecting the cycle in MTPN Model.
Next (Figure 19) shows a model of hyper-presentation in (Figure 18) with MTPN and it is easy to know that the cycle occurs between the presentations due to connection of cue.
(Figure 19) that is a modeling with MTPN shows occurrence of cycle between the presentations and (Figure 21) also shows that the cycle occurs when the modeling was described with MTPN.
In definition of MTPN C=(P,T,B,F, [[mu].sub.0], [tau], [epsilon]), the set of place P is described as follows.
On the basis of such description, this paper proposes the algorithm to detect cycle on a MTPN Model.
To detect cycle on a MTPN Model, allocate the set of place P that is executed first to time function [tau] between the presentations and every time when the time function [tau] moves one by one, put this value to [w.sub.j] the set element of time function (that is, the result value [alpha] acquired from comparison of (j and k[j].