Hybrid attribute reduction based on a novel fuzzy-rough model and information granulation

Feature subset selection has become an important challenge in areas of pattern recognition, machine learning and data mining. As different semantics are hidden in numerical and categorical features, there are two strategies for selecting hybrid attributes: discretizing numerical variables or numericalize categorical features. In this paper, we introduce a simple and efficient hybrid attribute reduction algorithm based on a generalized fuzzy-rough model. A theoretic framework of fuzzy-rough model based on fuzzy relations is presented, which underlies a foundation for algorithm construction. We derive several attribute significance measures based on the proposed fuzzy-rough model and construct a forward greedy algorithm for hybrid attribute reduction. The experiments show that the technique of variable precision fuzzy inclusion in computing decision positive region can get the optimal classification performance. Number of the selected features is the least but accuracy is the best. 2007 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved.