不完备XML信息系统的粗糙集模型

Rough Set Models for Incomplete XML Information System

随着XML成为网络信息表示和交换的标准以及不确定数据的广泛存在,不确定XML数据库管理技术成为了当今研究的热点。首先,允许XML文档叶子节点的信息值为丢失的或遗漏的空值,提出不完备的XML信息系统;其次,提出节点的相容关系、限制相容关系以及阈值相容关系等概念,基于粗糙集理论分别定义这3种关系对应的粗糙集模型;最后,通过实例分析表明,限制相容关系模型能克服相容关系模型分类粗糙的缺点,阈值相容关系模型通过合理地设置阈值可达到更好的分类效果,从而提高了对XML数据的预测、分类的精确度。

The management technology of uncertain XML database becomes today＇ s research focus with XML being the standards of information representation and data exchange on the Internet and uncertain data existing in various fields. Firstly, the leaf nodes~ information value of XML document being lost or missing null values was allowed and the in- complete XML information system was proposed. Secondly, the definitions of node tolerance relation, limited tolerance relation and threshold tolerance relation were given,and three kinds of rough set models for incomplete XML informa- tion system were defined respectively based on rough set theory. Finally, the analysis of examples shows that limited tolerance relation can overcome the disadvantage of tolerance relation rough classification,and threshold tolerance rela- tion can achieve better classification results through reasonable threshold setting, so as to enhance the prediction and the classification accuracy of XML data.