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:
“This far outstripped the other;
Yet ever runs she with reverted face,
And looks and listens for the boy behind:
For he, alas! is blind!
O’er rough and smooth with even step he passed,
And knows not whether he be first or last.”
—Samuel Taylor Coleridge (1772–1834)
“The Bostonians are really, as a race, far inferior in point of anything beyond mere intellect to any other set upon the continent of North America. They are decidedly the most servile imitators of the English it is possible to conceive.”
—Edgar Allan Poe (1809–1845)