@ARTICLE { Rsds3585,
author = {Yao, Yiyu}, 
title = {A comparative study of fuzzy sets and rough sets}, 
journal = {Information Sciences: An International Journal}, 
number = 	{(no. 1-4)}, 
volume = 109, 
pages = {227-242}, 
publisher = {Elsevier Science Inc.}, 
address = {Amsterdam, The Netherlands}, 
month = {August}, 
year = 1998, 
issn = {0020-0255}, 
abstract = {This paper reviews and compares theories of fuzzy sets and rough sets. Two approaches for the formulation of fuzzy sets are reviewed, one is based on many-valued logic and the other is based on modal logic. Two views of rough sets are presented, set-oriented view and operator-oriented view. Rough sets under set-oriented view are closely related to fuzzy sets, which leads to non-truth-functional fuzzy set operators. Both of them may be considered as deviations of classical set algebra. In contrast, rough sets under operator-oriented view are different from fuzzy sets, and may be regarded as an extension of classical set algebra.}, 
keywords = {approximation operators, fuzzy sets, modal logic, many-valued logic, rough sets, }, 
}