基于RST的粗关系数据库的熵研究

熵是度量信息不确定性的重要工具,粗集数据分析方法研究粗关系数据库熵的重要方法。首次利用复合粗近似算子概念和方法,由属性值域上的二元关系导出了粗关系模式实例元组之间的二元关系,为利用粗集理论来研究粗关系数据库提供了必需的前提条件。在此基础上,提出了基于粗集的粗关系模式及其实例的信息熵和粗糙熵的概念,同时给出了它们的计算公式。最后以一个工程实例的计算验证了本文方法的有效性。

Entropy of rough relational database based on RST

Entropy has been a useful mechanism for characterizing the uncertainty of information content,and the rough sets data analysis(RSDA) is an important method to research the entropy of rough relational database.A new binary relation between tuples(objects) of rough relational database instances,which is an essential condition for the further research of rough relational databases by use of the rough sets theory,has been constructed from the binary relation on attributes values domain by using the concept and method of composed rough approximation operators in rough sets theory.The concepts of information entropy and rough entropy of rough relational databases from the view of rough sets theory are also studied;their computational algorithms have been presented too.Lastly,an example from practical reality is given out to prove the effects of the results.