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 landscape was clothed in a mild and quiet light, in which the woods and fences checkered and partitioned it with new regularity, and rough and uneven fields stretched away with lawn-like smoothness to the horizon, and the clouds, finely distinct and picturesque, seemed a fit drapery to hang over fairyland. The world seemed decked for some holiday or prouder pageantry ... like a green lane into a country maze, at the season when fruit-trees are in blossom.”
—Henry David Thoreau (1817–1862)
“O, he’s drunk, Sir Toby, an hour agone; his eyes were set at eight i’ th’ morning.”
—William Shakespeare (1564–1616)