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.
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Famous quotes containing the words rough and/or set:
“I’ve stayed in the front yard all my life.
I want a peek at the back
Where it’s rough and untended and hungry weed grows.
A girl gets sick of a rose.”
—Gwendolyn Brooks (b. 1917)
“If you set to work to believe everything, you will tire out the believing-muscles of your mind, and then you’ll be so weak you won’t be able to believe the simplest true things.”
—Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)