follow Dictionary.com

Yours, Etc.: Origins and Uses of 8 Sign-Offs

fuzzy logic

noun
1.
a branch of logic designed to allow degrees of imprecision in reasoning and knowledge, typified by terms such as `very', `quite possibly', and `unlikely', to be represented in such a way that the information can be processed by computer
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
fuzzy logic in Science
fuzzy logic
  (fŭz'ē)   
A form of algebra employing a range of values from "true" to "false" that is used in making decisions with imprecise data. The outcome of an operation is assigned a value between 0 and 1 corresponding to its degree of truth. Fuzzy logic is used, for example, in artificial intelligence systems.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
fuzzy logic in Technology

A superset of Boolean logic dealing with the concept of partial truth -- truth values between "completely true" and "completely false". It was introduced by Dr. Lotfi Zadeh of UCB in the 1960's as a means to model the uncertainty of natural language.
Any specific theory may be generalised from a discrete (or "crisp") form to a continuous (fuzzy) form, e.g. "fuzzy calculus", "fuzzy differential equations" etc. Fuzzy logic replaces Boolean truth values with degrees of truth which are very similar to probabilities except that they need not sum to one. Instead of an assertion pred(X), meaning that X definitely has the property associated with predicate "pred", we have a truth function truth(pred(X)) which gives the degree of truth that X has that property. We can combine such values using the standard definitions of fuzzy logic:
truth(not x) = 1.0 - truth(x) truth(x and y) = minimum (truth(x), truth(y)) truth(x or y) = maximum (truth(x), truth(y))
(There are other possible definitions for "and" and "or", e.g. using sum and product). If truth values are restricted to 0 and 1 then these functions behave just like their Boolean counterparts. This is known as the "extension principle".
Just as a Boolean predicate asserts that its argument definitely belongs to some subset of all objects, a fuzzy predicate gives the degree of truth with which its argument belongs to a fuzzy subset.
Usenet newsgroup: news:comp.ai.fuzzy.
E-mail servers: , rnalib@its.bldrdoc.gov, .
(ftp://ftp.hiof.no/pub/Fuzzy), (ftp://ntia.its.bldrdoc.gov/pub/fuzzy).
FAQ (ftp://rtfm.mit.edu/pub/usenet-by-group/comp.answers/fuzzy-logic).
James Brule, "Fuzzy systems - a tutorial", 1985 (http://life.anu.edu.au/complex_systems/fuzzy.html).
STB Software Catalog (http://krakatoa.jsc.nasa.gov/stb/catalog.html), includes a few fuzzy tools.
[H.J. Zimmerman, "Fuzzy Sets, Decision Making and Expert Systems", Kluwer, Dordrecht, 1987].
["Fuzzy Logic, State of the Art", Ed. R. Lowen, Marc Roubens, Theory and Decision Library, D: System theory, Knowledge Engineering and Problem Solving 12, Kluwer, Dordrecht, 1993, ISBN 0-7923-2324-6].
(1995-02-21)
The Free On-line Dictionary of Computing, © Denis Howe 2010 http://foldoc.org
Cite This Source

Word of the Day

Word Value for fuzzy

29
29
Scrabble Words With Friends

Nearby words for fuzzy logic