Modeling timed user-interactions in multimedia documents

Interactive multimedia documents (or systems) can be characterized by active user participation and the diversity of multimedia information accessed at various levels of granularity. They need to support extensive user participation in selecting and tailoring the information and its presentation. Multimedia information fragments may vary from portions of video, pieces of audio, newspaper quotations or chapters of a book. Effectively managing the creation, evolution and complexity of multimedia documents formed by combining media fragments is an essential capability. We consider the hyperstory model of a multimedia document, where a document is structured hierarchically in three dimensions: time, space and asynchrony. The model provides a layered approach in structuring multimedia documents, thus reducing the complexities of large systems. The hyperstory model supports user interactions that are timed, and also supports preemptive resuming. Timed user interactions with the document are modeled with a newly introduced timed Petri-net (TPN*). TPN* is used to infer the behavior of the system. This paper describes TPN*´s modeling and analysis and its application to the hyperstory model