Fuzzy control: Difference between revisions

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By the expression '''Fuzzy logic''' one denotes several topics which are related with the notion of [[fuzzy subset|fuzzy subset]] defined in [[1965]] by [[Lotfi Asker Zadeh|Lotfi Zadeh]]. The idea is that we can represent the extension of a vague property by a generalized characteristic function.
By the expression ''"Fuzzy logic"'' one denotes several topics which are related with the notion of [[fuzzy subset|fuzzy subset]] defined in [[1965]] by [[Lotfi Asker Zadeh|Lotfi Zadeh]]. The idea is that we can represent the extension of a vague property by a generalized characteristic function.


'''Definition''' Given a nonempty set ''S'', a ''fuzzy subset'' of ''S'' is a map ''s'' from ''S'' into the interval [0,1].  
'''Definition''' Given a nonempty set ''S'', a ''fuzzy subset'' of ''S'' is a map ''s'' from ''S'' into the interval [0,1].  

Revision as of 11:20, 1 July 2007

By the expression "Fuzzy logic" one denotes several topics which are related with the notion of fuzzy subset defined in 1965 by Lotfi Zadeh. The idea is that we can represent the extension of a vague property by a generalized characteristic function.

Definition Given a nonempty set S, a fuzzy subset of S is a map s from S into the interval [0,1].

The elements in [0,1] are interpreted as truth values and, in accordance, for every x in S, the value s(x) is interpreted as the membership degree of x to s.


We have to distinguish two possible interpretations of the expression "fuzzy logic". The first one is given by people interested to applications and to an informal utilization of the notion of fuzzy subset. In such a case should be better expressions as "fuzzy logic in board sense" or "fuzzy set theory".

Another interpretation is given by people which consider fuzzy logic as a chapter of formal logic, more precisely of multi-valued logic. In such a case one uses the expression "fuzzy logic in narrow sense" or "formal fuzzy logic".


See also

Bibliography

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  • Elkan C.. The Paradoxical Success of Fuzzy Logic. November 1993. Available from Elkan's home page.
  • Gerla G., Fuzzy logic: Mathematical Tools for Approximate Reasoning, Kluwer, 2001.
  • Hájek P., Metamathematics of fuzzy logic. Kluwer 1998.
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  • Klir G. and Bo Yuan, Fuzzy Sets and Fuzzy Logic (1995) ISBN 0-13-101171-5
  • Bart Kosko, Fuzzy Thinking: The New Science of Fuzzy Logic (1993), Hyperion. ISBN 0-7868-8021-X
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  • Kevin M. Passino and Stephen Yurkovich, Fuzzy Control, Addison Wesley Longman, Menlo Park, CA, 1998.
  • Wiedermann J. , Characterizing the super-Turing computing power and efficiency of classical fuzzy Turing machines, Theor. Comput. Sci. 317, (2004), 61-69.
  • Zadeh L.A., Fuzzy algorithms, Information and Control, 5,(1968), 94-102.
  • Zadeh L.A., Fuzzy Sets, ‘’Information and Control’’, 8 (1965) 338­353.