Global roughness of approximation and boundary rough sets
Yingjie Yang, Robert John · 2008
This paper defines a new parameter for describing the uncertainty of rough sets. Different from the roughness of a rough set, a global roughness measures the uncertainty of rough sets with respect to the entire information system. This is essential especially for a special rough set - boundary rough sets.We give the definition of global roughness of approximation and boundary rough sets, and analyse their properties. Some examples are also provided to show the complementary features of global roughness and roughness of rough sets.