Set-pair Rough Set Extension And Reduction Under Incomplete Decision Information Systems

The classical rough set theory based on complete decision information systems is greatly restricted in incomplete decision information systems.Now there are several extensions. Unfortunately,these extensions have their own limitations.This paper further extend under determinism of incomplete decision information systems and set-pair analysis ,which is rough set extension based on set-pair connectivity similarity relation . attribution reduction in incomplete decision information systems is proposed,which is more extensive than extensive decision matrix.an attribution reduction determination theorem is attained with the upper approximation and lower approximation distributed reduction.Variable precision rough set model is proposed, which can processes data from many levels.Because of neglect of attribution difference in incomplete decision information systems formerly,weignt valued is denned,and a heuristic algorithm is researched.Finally,containing set is defined,and a new approach of ruler extracting is reachered in incomplete decision information systems.