@ARTICLE { Rsds3620,
author = {Nakamori, Yoshiteru and Huynh, Van-Nam}, 
title = {A roughness measure for fuzzy sets}, 
journal = {Information Sciences: An International Journal}, 
number = 	{(no. 1-3)}, 
volume = 173, 
pages = {255-275}, 
publisher = {Elsevier Science Inc.}, 
address = {Amsterdam, The Netherlands}, 
month = {June}, 
year = 2005, 
issn = {0020-0255}, 
abstract = {Recently, an attempt of integration between the theories of fuzzy sets and rough sets has resulted in providing a roughness measure for fuzzy sets [M. Banerjee, S.K. Pal, Roughness of a fuzzy set, Information Sciences 93 (1996) 235-246]. Essentially, Banerjee and Pal's roughness measure depends on parameters that are designed as thresholds of definiteness and possibility in membership of the objects to a fuzzy set. In this paper we first remark that this measure of roughness has several undesirable properties, and then propose a parameter-free roughness measure for fuzzy sets based on the notion of the mass assignment of a fuzzy set. Several interesting properties of this new measure are examined. Furthermore, we also discuss how the proposed approach is used to describe the rough approximation quality of a fuzzy classification.}, 
keywords = {rough sets, fuzzy sets, roughness measure, rough fuzzy sets, }, 
}