基于结构特性的超媒体模型

HYPERMEDIA MODEL BASED ON STRUCTURE PROPERTY

将超媒体的结构特性研究与形式语言学理论相结合 ,提供了一种有效地分析超媒体动态结构特性的方法 .该方法将超媒体组件集合映射为语言中的抽象符号集合 ,组件集合之上的链映射为语言中建立单词的方法 ,超媒体的结构化机制映射为语言中描述单词集合构造机制的语法 .超媒体模拟为转换机 ,“链引导”动作模拟为“匹配对”序列 ,“链引导”的计算结果产生与上下文无关文法相对应的虚拟文档 。

The combination of formal language theory with the research on structure properties of hypermedia can provide a new framework to investigate the dynamic structure properties of hypermedia. The hypermedia component corresponds to the formal symbol in language, links between the components of hypermedia correspond to the rules of constructing words, and thus the syntax, which describes the constructing rules of words, corresponds to the constituting mechanism of hypermedia structure. Hypermedia can be modeled as a transformation device, and the link following operation is transformed into a sequence of matched pairs(units that could be connected). The set of all link following is shown to be a regular set and the set of all possible outcomes of link following is described by a context free grammar. Hence it provides the basis for the structal computing. The system constructs the virtual document based on the computing result of link following operation and thus generates the adaptive view to the user. Context free grammar used to model the construction of virtual document in hypermedia supports the automatic generation of hypermedia structure grammar, thus providing a novice approach for structural analysis. The method proposed brings into correspondence the construction of virtual documents in hypermedia with the generation of words in context free language and thus constitutes the theory foundation of the further research on browsing semantics and other dynamic characteristics of hypermedia.