Askar Zadeh (Persian: لطفی علیعسکرزاده, Azerbaijani: Lütfəli
Əsgərzadə, born February 4, 1921) is an Iranian- American
mathematician and computer scientist, and a professor of computer
science at the University of California, Berkeley.
He was born in Baku, to a Russian mother and an Iranian Azeri father
(from Ardabil, center of Ardabil province of Iran),
grew up in Iran, studied at Alborz High School and Faculty of
Engineering, University of Tehran (Fanni), and moved to the United
States in 1944. He received an MS degree in electrical engineering
from MIT in 1946, and a PhD in electrical engineering from Columbia
University in 1949,
He taught for ten years at Columbia University and was promoted to
full professor in 1957. He has taught at the University of California,
Berkeley since 1959. He published his seminal work on fuzzy sets in
1965 in which he detailed the mathematics of fuzzy set theory. In 1973
he proposed his theory of fuzzy logic.
Zadeh is married to Fay Zadeh and has two children, Stella Zadeh and
In 1994 he was inducted as a Fellow of the Association for Computing
Machinery. He was awarded the IEEE Medal of Honor in 1995 "For
pioneering development of fuzzy logic and its many diverse
Zadeh has a long list of achievements, but since 2003, Zadeh has
received the following awards.
In 1993 Azerbaijan bestowed him an honorary Professorship from the
Azerbaijan State Oil Academy.
Outstanding Contribution Award, Web Intelligence Consortium (WIC),
Halifax, Canada, 2003.
Wall of Fame, Heinz Nixdorf MuseumsForum (HNF), Paderborn, Germany,
Civitate Honoris Causa, Budapest Tech Polytechnical Institution,
Budapest, Hungary; Sept. 4, 2004.
Doctor Honoris Causa, Muroran Institute of Technology, Muroran, Japan;
Oct. 29, 2004.
Doctor Honoris Causa, Hong Kong Baptist University, Hong Kong, China;
Nov. 9, 2004.
V. Kaufmann Prize and Gold Medal, International Association for
Fuzzy-Set Management and Economy (SIGEF), Barcelona, Spain, Nov. 15,
Foreign member of the Polish Academy of Sciences, 2005.
Nicolaus Copernicus Medal of the Polish Academy of Sciences, 2005.
J. Keith Brimacombe IPMM Award in recognition of his development of
fuzzy set theory and fuzzy logic, 2005.
Doctor Honoris Causa, Universidad Politécnica de Madrid, Madrid,
Spain; Jan. 29, 2007.
Richard E. Bellman Control Heritage Award
Doctor Honoris Causa, Ryerson University, Toronto , Ontario, Canada;
June 10th 2008.
Zadeh is noted to "quick(ly) shrug off nationalism, insisting there
are much deeper issues in life", where he himself is quoted stating:
"The question really isn't whether I'm American, Russian, Iranian,
Azerbaijani, or anything else, I've been shaped by all these people
and cultures and I feel quite comfortable among all of them."
Zadeh also notes in the same interview: "Obstinacy and tenacity. Not
being afraid to get embroiled in controversy. That's very much a
Turkish tradition. That's part of my character, too. I can be very
stubborn. That's probably been beneficial for the development of Fuzzy
Fuzzy Sets and Systems
Aristotle introduced the laws of thought, which consisted of three
Principle of identity
Law of the excluded middle
Law of contradiction
The law of the excluded middle states that for all propositions p,
either p or ~p must be true, there being no middle true proposition
between them. This should not be confused with the principle of
bivalence, which states that either p must be true or false.
It was Jan Łukasiewicz who first proposed a systematic alternative to
the bi-valued logic of Aristotle and described the 3-valued logic,
with the third value being Possible. Zadeh, in his theory of fuzzy
logic, proposed the making of the membership function operate over the
range of real numbers [0,1]. He proposed new operations for the
calculus of logic and showed that fuzzy logic was a generalisation of
Because of the importance of the retraction/relaxation of Aristotelian
logic, which opens up applicability of rational methods to the
majority of practical situations without dichotomous truth values,
Zadeh is one of the most referenced authors in the fields of applied
math and the computer sciences among others but his contributions are
not limited to fuzzy sets and systems.
Zadeh is also credited, along with John R. Ragazzini, in 1952, to have
pioneered the development of the z-transform method in discrete time
signal processing and analysis. These methods are now standard in
digital signal processing, digital control, and other discrete-time
systems used in industry and research.
Zadeh's latest work includes computing with words and perceptions. His
recent papers include From Search Engines to Question-Answering
Systems—The Role of Fuzzy Logic, Progress in Informatics, No. 1, 1-3,
2005; and Toward a Generalized Theory of Uncertainty (GTU)—An Outline,
Information Sciences, Elsevier, Vol. 172, 1-40, 2005.
Zafeh wrote several articles. A selection:
1965. Fuzzy sets. Information and Control. 1965; 8: 338–353.
1965. Fuzzy sets and systems. In: Fox J, editor. System Theory.
Brooklyn, NY: Polytechnic Press, 1965: 29–39.
1972. A fuzzy-set-theoretical interpretation of linguistic hedges.
Journal of Cybernetics 1972; 2: 4–34.
1973. Outline of a new approach to the analysis of complex systems and
decision processes. IEEE Trans. Systems, Man and Cybernetics, 1973; 3:
1974. Fuzzy logic and its application to approximate reasoning. In:
Information Processing 74, Proc. IFIP Congr. 1974 (3), pp. 591–594.
1975. Fuzzy logic and approximate reasoning. Synthese, 1975; 30:
1975. Calculus of fuzzy restrictions. In: Zadeh LA, Fu KS, Tanaka K,
Shimura M, editors. Fuzzy Sets and their Applications to Cognitive and
Decision Processes. New York: Academic Press, 1975: 1–39.
1975. The concept of a linguistic variable and its application to
approximate reasoning, I-III, Information Sciences 8 (1975) 199–251,
301–357; 9 (1976) 43–80.
About Lotfi Asker Zadeh
Fuzzy Sets and Systems. The main journal of the field which contains
many contributions by its founder.
Aristotle : Metaphysics, Chapter 7.
Zadeh : From computing with numbers to computing with words — from
manipulation of measurements to manipulation of perceptions in
International Journal of Applied Math and Computer Science, pp.
307-324, vol. 12, no. 3, 2002.
Fay Zadeh. "My Life and Travels with the Father of Fuzzy Logic". 1998,
TSI Press, Albuquerque, NM.