180 Abstract— Attribute reduction of an information system is a key problem in rough set theory and its application. It has been proven that finding the minimal reduct of an information system is a NP-hard problem. Main reason of causing NP-hard is combination problem. In this paper, we theoretically study covering rough sets and propose an attribute reduction algorithm of decision systems. It ...

Attribute reduction and reducts are important notions in rough set theory that can preserve discriminatory properties to the highest possible extent similar to the entire set of attributes. In this paper, the relationships among 13 types of alternative objective functions for attribute reduction are systematically analyzed in complete decision tables. For inconsistent and consistent decision ta...

The differences of attribute reduction and attribute core between Pawlak’s rough set model (RSM) and variable precision rough set model (VPRSM) are analyzed in detail. According to the interval properties of precision parameter b with respect to the quality of classification, the definition of attribute reduction is extended from a specific b value to a specific b interval in order to overcome ...

From the most important issues in the design of large logistics network in times of crisis are providing a timely quick reaction for treating of injured people and the rapid distribution of medicines and medical equipment. In this paper, a multi-objective model is presented that aims to determine the location of transfer points and hospitals to provide timely quick reaction for treating injured...

Consider the expansion [Formula: see text] of a theory by predicate for submodel reduct text]. We present setup in which this admits model companion show that some nice features transfer to In particular, we study conditions preserves text]-ness, simplicity or stability starting give concrete examples new not simple theories obtained process, among them perfect text]-free field positive charact...

Knowledge based system need quality knowledge to provide an accurate decision. Due to irrelevant and incorrect information of expert during knowledge acquisition, the information extraction from data mining approach can reduce the biases and misconceptions of multiple experts. Moreover, the real world data which is huge and incomplete has made it complicated to extract only the quality knowledg...

Ordered bands are regarded as semirings whose multiplicative reduct is a band and whose additive reduct is a chain. We find the variety of semirings generated by all ordered bands and we determine part of the lattice of its subvarieties. Mathematics Subject Classification (2000): 16Y60, 08B05, 20M07.

Dimensionality refers to number of terms in a web page. While classifying web pages high dimensionality of web pages causes problem. The main objective of reducing dimensionality of web pages is improving the performance of classifier. Processing time and accuracy are two parameters which influence the performance of a classifier. To reduce the processing time, less informative and redundant te...