【摘要】 超媒体建模研究是当前一个重要研究方向。基于Petri网理论的模型是对有向图模型的改进,与其他模型比较,能够更好地刻画超媒体系统。原因如下:Petri网是一个二部有向图,适合于说明超媒体的链接机制;Petri网是一种天然的具有并行执行语义的自动机,模型可以自然地表达超媒体系统中的动态执行语义;Petri网能够说明各种顺序、并发和同步活动,满足描述多媒体表现的需要;利用Petri网的图形特性和严格的数学基础,人们可以检查和分析超媒体中的潜在问题。该文着重对四个典型的基于Petri网的超媒体模型:MHPN、HCPN、MORENA和HTSPN模型进行分析和比较。更多还原

【Abstract】 Hypermedia modeling is one of the key research fields.Petri net-based model of hypermedia is the better-ment of directed graph model.Compared with others,it can character the hypermedia system better.The reason s are as follows :Petri net is a kind of bipartite directed graphs,thus can specify the link mechanism of hypermedia;Petri net is a kind of automata with asynchronous concurrent execution semantic and can naturally represent dynamic execution se-mantic of hypermedia;Petri net can specify sequential,concurrent and synchronistic activities,thus satisfy the presenta-tion requirements;people can check and analysis potential errors with the help of petri net.This paper analyzes and compare the hypermedia formal model of MHPN,HCPN,MORENA and HTSPN.更多还原