In computer science, a rough set, first described by a Polish computer scientist Zdzisław I. Pawlak, is a formal approximation of a crisp set (i.e., conventional set) in terms of a pair of sets which give the lower and the upper approximation of the original set. In the standard version of rough set theory (Pawlak 1991), the lower- and upper-approximation sets are crisp sets, but in other variations, the approximating sets may be fuzzy sets.
Read more about Rough Set: Definitions, Rule Extraction, Incomplete Data, Applications, Extensions, History
Famous quotes containing the words rough and/or set:
““That rough tooth of the sea,” Kineo, great source of arrows and of spears to the ancients, when weapons of stone were used.”
—Henry David Thoreau (1817–1862)
“Greatness collapses of itself: such limit the gods have set to the growth of prosperous states.”
—Marcus Annaeus Lucan (39–65)