Compromised multi-granulation rough sets based on an attribute-extension chain

Class-specific attribute reducts based on neighborhood rough sets

Attribute reduction based on rough sets is an effective approach of data learning in intelligent systems, and it has two basic types. Traditional classification-based attribute reducts mainly complete the classification task, while recent class-specific reducts directly realize the class-pattern recognition. Neighborhood rough sets have the covering-structure extension and data-diversity applicability, but their attribute reducts concern only the neighborhood classification-based reducts. This paper proposes class-specific attribute reducts based on neighborhood rough sets, so as to promote the optimal identification and robust processing of specific classes. At first, neighborhood class-specific reducts are defined, and their basic properties and heuristic algorithms are acquired by granulation monotonicity. Then, hierarchical relationships between the neighborhood classification-based and class-specific reducts are analyzed, and mutual derivation algorithms are designed. Finally, the theoretical constructions and mutual relationships are effectively verified by both decision table examples and data set experiments. The neighborhood class-specific reducts robustly extend the existing class-specific reducts, and they also provide a hierarchical mechanism for the neighborhood classification-based reducts, thus facilitating wide applications of class-pattern processing.