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:
“The last and greatest Herald of Heaven’s King,
Girt with rough skins, hies to the deserts wild,
Among that savage brood the woods forth bring,
Which he than man more harmless found and mild.”
—William Drummond, of Hawthornden (1585–1649)
“Fortunate they
Who, though once only and then but far away,
Have heard her massive sandal set on stone.”
—Edna St. Vincent Millay (1892–1950)