Fuzzy Covering based Rough Sets Revisited
Lynn D’eer, Chris Cornelis, Daniel Sánchez · Advances in intelligent systems research/Advances in Intelligent Systems Research · 2015
In this paper we review four fuzzy extensions of the socalled tight pair of covering based rough set approximation operators.Furthermore, we propose two new extensions of the tight pair: for the first model, we apply the technique of representation by levels to define the approximation operators, while the second model is an intuitive extension of the crisp operators.For the six models, we study which theoretical properties they satisfy.Moreover, we discuss interrelationships between the models.