Lotfi A. Zadeh

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Lotfi A. Zadeh
Zadeh, L.A. 2005.jpg
(5 November 2005)
Lotfi Aliasker Zadeh

(1921-02-04)February 4, 1921
DiedSeptember 6, 2017(2017-09-06) (aged 96)[1][2]
Alma materUniversity of Tehran
Columbia University
Known forFounder of fuzzy mathematics,
fuzzy set theory, and fuzzy logic, Z numbers, Z-transform
AwardsEringen Medal (1976)
IEEE Hamming Medal (1992)
Rufus Oldenburger Medal (1993)
IEEE Medal of Honor (1995)
2012 BBVA Foundation Frontiers of Knowledge Award
Honorary Doctorate of Tehran University (2016)[4]
ACM Fellow
IEEE Fellow
AAAS Fellow
AAAI Fellow
Member of the National Academy of Engineering
Founding Member of Eurasian Academy
Scientific career
FieldsMath, Electrical Engineering, AI
InstitutionsUC Berkeley
ThesisFrequency analysis of variable networks (1949)
Doctoral advisorJohn R. Ragazzini
Doctoral studentsJoseph Goguen

Lotfi Aliasker Zadeh[5] (/ˈzɑːd/; Azerbaijani: Lütfi Rəhim oğlu Ələsgərzadə;[6] Persian: لطفی علی‌عسکرزاده‎;[4] February 4, 1921 – September 6, 2017)[1][2] was a mathematician, computer scientist, electrical engineer, artificial intelligence researcher and professor emeritus[7] of computer science at the University of California, Berkeley.

Zadeh was best known for proposing fuzzy mathematics consisting of these fuzzy-related concepts: fuzzy sets,[8] fuzzy logic,[9] fuzzy algorithms,[10] fuzzy semantics,[11] fuzzy languages,[12] fuzzy control,[13] fuzzy systems,[14] fuzzy probabilities,[15] fuzzy events,[15] and fuzzy information.[16]

Zadeh was a founding member of the Eurasian Academy.[17]

Early life and career[edit]

Zadeh was born in Baku, Azerbaijan SSR,[18] as Lotfi Aliaskerzadeh,[19] to Rahim Aleskerzade, an Iranian Azerbaijani journalist from Ardabil on assignment from Iran, and Fanya Korenman, a Russian Jewish pediatrician from Odessa and an Iranian citizen.[20][21][22][23] The Soviet government at this time courted foreign correspondents, and the family lived well while in Baku.[24] Zadeh attended elementary school for three years there,[24] which he said "had a significant and long-lasting influence on my thinking and my way of looking at things."[25]

In 1931, when Zadeh was ten years old, his family moved to Tehran in Iran, his father's homeland. Zadeh was enrolled in Alborz College, which was a Presbyterian missionary school, where he was educated for the next eight years, and where he met his future wife, Fay.[24] Zadeh says that he was "deeply influenced" by the "extremely decent, fine, honest and helpful" missionaries from the United States who ran the college. "To me they represented the best that you could find in the United States – people from the Midwest with strong roots. They were really 'Good Samaritans' – willing to give of themselves for the benefit of others. So this kind of attitude influenced me deeply. It also instilled in me a deep desire to live in the United States."[25] During this time, Zadeh was awarded several patents.[24]

Despite being more fluent in Russian than in Persian, Zadeh sat for the national university exams and placed third in the entire country.[24] As a student, he ranked first in his class in his first two years. In 1942, he graduated from the University of Tehran with a degree in electrical engineering, one of only three students in that field to graduate that year, due to the turmoil created by World War II, when the United States, Britain and the Soviet Union invaded Iran. Over 30,000 American soldiers were based there, and Zadeh worked with his father, who did business with them as a contractor for hardware and building materials.[26]

In 1943, Zadeh decided to emigrate to the United States, and traveled to Philadelphia by way of Cairo after months of delay waiting for the proper papers or for the right ship to appear. He arrived in mid-1944, and entered the Massachusetts Institute of Technology (MIT) as a graduate student later that year.[26] While in the United States, he changed his name to Lotfi Aliasker Zadeh.[19]

He received an MS degree in electrical engineering from MIT in 1946, and then applied to Columbia University, as his parents had settled in New York City.[26] Columbia admitted him as a doctoral student, and offered him an instructorship as well.[26] He received his Ph.D. in electrical engineering from Columbia in 1949, and became an assistant professor the next year.[23][26]

Zadeh taught for ten years at Columbia, was promoted to Full Professor in 1957, and taught at the University of California, Berkeley from 1959 on. 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.

Personal life and beliefs[edit]

Zadeh was called "quick to shrug off nationalism, insisting there are much deeper issues in life", and was quoted as saying in an interview: "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."[27] He noted 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 Logic."[28] He described himself as "an American, mathematically oriented, electrical engineer of Iranian descent, born in Russia."[23]

Zadeh was married to Fay Zadeh and had two children, Stella Zadeh and Norman Zada.

Zadeh died in his home in Berkeley, California,[3] on September 6, 2017, at the age of 96.[1][2] He is buried in the first Alley of Honor in Baku, Azerbaijan, the city in which he was born.[3] His funeral was well attended by "highly respected people", including the President of Azerbaijan, Ilham Aliyev.[29] A month previous to his death, the University of Tehran had released an erroneous report that Zadeh had died, but withdrew it several days later.[citation needed]


According to Google Scholar, as of February 2021, Zadeh's work has been cited about 270,000 times in scholarly works, with the 1965 Fuzzy sets paper receiving more than 115,000 citations.[30]

Fuzzy sets and systems[edit]

Zadeh, in his theory of fuzzy sets, proposed using a membership function (with a range covering the interval [0,1]) operating on the domain of all possible values. He proposed new operations for the calculus of logic and showed that fuzzy logic was a generalisation of classical and Boolean logic. He also proposed fuzzy numbers as a special case of fuzzy sets, as well as the corresponding rules for consistent mathematical operations (fuzzy arithmetic).[31]

Other contributions[edit]

Zadeh is also credited, along with John R. Ragazzini, in 1952, with having 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. He was an editor of the International Journal of Computational Cognition.

Zadeh's most recent work included 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.

Selected publications[edit]

  • Zadeh, L. A. (1965). "Fuzzy sets". Information and Control. 8 (3): 338–353. doi:10.1016/S0019-9958(65)90241-X.
  • Fox J, ed. (1965). "Fuzzy sets and systems". System Theory. Brooklyn, NY: Polytechnic Press. pp. 29–39.
  • Zadeh, L. A. (1972). "A Fuzzy-Set-Theoretic Interpretation of Linguistic Hedges". Journal of Cybernetics. 2 (3): 4–34. doi:10.1080/01969727208542910.
  • Zadeh, Lotfi A. (1973). "Outline of a New Approach to the Analysis of Complex Systems and Decision Processes". IEEE Transactions on Systems, Man, and Cybernetics. SMC-3 (1): 28–44. doi:10.1109/TSMC.1973.5408575.
  • "Fuzzy logic and its application to approximate reasoning". Information Processing 74, Proc. IFIP Congr. 3. 1974. pp. 591–594.
  • Zadeh, L. A. (1975). "Fuzzy logic and approximate reasoning". Synthese. 30 (3–4): 407–428. doi:10.1007/BF00485052.
  • Zadeh LA, Fu KS, Tanaka K, Shimura M, eds. (1975). "Calculus of fuzzy restrictions". Fuzzy Sets and their Applications to Cognitive and Decision Processes. New York: Academic Press. pp. 1–39.
  • Zadeh, L.A. (1975). "The concept of a linguistic variable and its application to approximate reasoning—I". Information Sciences. 8 (3): 199–249. doi:10.1016/0020-0255(75)90036-5.
  • Zadeh, L.A. (1975). "The concept of a linguistic variable and its application to approximate reasoning—II". Information Sciences. 8 (4): 301–357. doi:10.1016/0020-0255(75)90046-8.
  • Zadeh, L.A. (1975). "The concept of a linguistic variable and its application to approximate reasoning-III". Information Sciences. 9 (1): 43–80. doi:10.1016/0020-0255(75)90017-1.
  • Zadeh, Lotfi A. (2006). "From Computing with Numbers to Computing with Words". Annals of the New York Academy of Sciences. 929 (1): 221–252. doi:10.1111/j.1749-6632.2001.tb05718.x. PMID 11357866.
  • 2012. Computing With Words. Principal Concepts and Ideas. Berlin: Springer.

A complete list of publications is available here.

Awards and honors[edit]

Grave of Lotfi A. Zadeh in Baku.

Zadeh was a Fellow of the Institute of Electrical and Electronics Engineers, the American Academy of Arts and Sciences, the Association for Computing Machinery, the Association for the Advancement of Artificial Intelligence and the International Fuzzy Systems Association, and a member of the National Academy of Engineering.[5] He was also a member of the Academies of Science of Azerbaijan, Bulgaria, Finland, Korea and Poland, and of the International Academy of Systems Studies in Moscow. He received 24 honorary doctorates.[7]

Awards received by Zadeh include, among many others:


In 2014, the IEEE Systems, Man, and Cybernetics Society established the "Lotfi A. Zadeh Pioneer Award", which is given "To honor a person or persons with outstanding and pioneering contributions to academic and/or industrial research in systems science and engineering, human-machine systems, and/or cybernetics." The award is funded from a $100,000 donation from Zadeh's son, Norm Zadeh, and is administered by the IEEE. Nominees must have "pioneered and developed innovative research, executed in either academe or industry, and has resulted in major scientific advances that are widely recognized in systems science and engineering, human-machine systems, and/or cybernetics. Contributions must have been made at least 15 years prior to the award date."[40]

In February 2019, ADA University in Baku, Azerbaijan presented the first "Lotfi Zadeh Scholarships", which honor the academic success of undergraduate students in the university's School of IT and Engineering. Winners of the scholarship receive a complete tuition waiver for the semester or semester-equivalent in which they achieved a 4.0 average.[41]

On February 24, 2021, the IEEE Computational Intelligence Society and the International Fuzzy Systems Association (IFSA) jointly celebrated the centenary of Zadeh's birth.[42]

See also[edit]



  1. ^ a b c Staff (September 7, 2017) "Lotfi Zadeh has passed away" Archived 2017-10-22 at the Wayback Machine EECS at UC Berkeley: News
  2. ^ a b c Associated Press (September 8, 2017) "Lotfi Zadeh dead: Computing revolutionary and founder of fuzzy logic dies aged 96" Archived 2017-09-09 at the Wayback Machine International Business Times
  3. ^ a b c Metz, Cade (September 11, 2017) "Lotfi Zadeh: Father of Mathematical Fuzzy Logic, Dies at 96" Archived 2017-09-12 at the Wayback Machine The New York Times
  4. ^ a b "Granting honorary doctorate from Tehran University to professor Lotfizadeh". Official website of University of Tehran (UT) (in Persian). Tehran, Iran. March 9, 2016. Archived from the original on 16 January 2021. Retrieved 1 July 2017.
  5. ^ a b "Dr. Lotfi A. Zadeh was elected in 1973 as a member of National Academy of Engineering in Computer Science & Engineering and Electronics, Communication & Information Systems Engineering". Archived from the original on 2015-12-08. Retrieved 2015-12-08.
  6. ^ "Diasporla İş üzrə Dövlət Komitəsi". Archived from the original on 2014-07-04. Retrieved 2014-06-07.
  7. ^ a b "Lotfi A. Zadeh" Archived 2014-07-15 at the Wayback Machine faculty page from College of Engineering, Electrical Engineering and Computer Science, University of California at Berkeley
  8. ^ Zadeh, L. A. (1965). "Fuzzy sets". Information and Control. 8 (3): 338–353. doi:10.1016/S0019-9958(65)90241-X.
  9. ^ Zadeh, L. A. (1996). "Fuzzy logic = computing with words". IEEE Transactions on Fuzzy Systems. 4 (2): 103–111. doi:10.1109/91.493904.
  10. ^ Zadeh, L. A. (1968). "Fuzzy algorithms". Information and Control. 12 (2): 94–102. doi:10.1016/S0019-9958(68)90211-8.
  11. ^ Zadeh, L. A. (1971). "Quantitative fuzzy semantics". Information Sciences. 3 (2): 159–176. doi:10.1016/S0020-0255(71)80004-X.
  12. ^ Lee, E. T.; Zadeh, L. A. (1969). "Note on fuzzy languages". Information Sciences. 1 (4): 421–434. doi:10.1016/0020-0255(69)90025-5.
  13. ^ Zadeh, L. A. (1972). "A Rationale for Fuzzy Control". Journal of Dynamic Systems, Measurement, and Control. 94: 3. doi:10.1115/1.3426540.
  14. ^ Zadeh, L. (1969). "Toward a theory of fuzzy systems" (PDF). Archived (PDF) from the original on 22 October 2014. Retrieved 18 October 2014.
  15. ^ a b Zadeh, L. A. (1984). "Fuzzy probabilities". Information Processing & Management. 20 (3): 363–372. doi:10.1016/0306-4573(84)90067-0.
  16. ^ Zadeh, L. A. (1997). "Toward a theory of fuzzy information granulation and its centrality in human reasoning and fuzzy logic". Fuzzy Sets and Systems. 90 (2): 111–127. doi:10.1016/S0165-0114(97)00077-8.
  17. ^ "Eurasian Academy Official Site". Archived from the original on 2020-06-21. Retrieved 2021-05-12.
  18. ^ At this time, the Azerbaijan SSR was an independent republic, created by the Red Army. It would become part of the Transcaucasian Socialist Federative Soviet Republic in March 1922, and then part of the Soviet Union in December 1922.
  19. ^ a b McNeil & Freiberger, p. 17
  20. ^ Zadeh, Lotfi A (2015-05-21). "Fuzzy logic—a personal perspective". Fuzzy Sets and Systems. 281: 4–20. doi:10.1016/j.fss.2015.05.009.
  21. ^ "Jews in Computer & Information Science" Archived 2013-01-13 at WebCite on the JINFO.org website
  22. ^ Анвар Унугви "Жанет Селимова" Archived 2014-07-14 at the Wayback Machine (Mamoirs of Lotfi A. Zadeh's cousin in Baku, theatrical director, professor Zhanet Selimova).
  23. ^ a b c Gale, Thomson. Lotfi Asker Zadeh Biography Archived 2010-01-15 at the Wayback Machine World of Computer Science
  24. ^ a b c d e McNeil & Freiberger, p. 18
  25. ^ a b Blair, Betty. Interview with Lotfi Zadeh (December 1999) in "Famous People: Then and Now Lotfi Zadeh, Creator of Fuzzy Logic (1921– )" Archived 2008-06-29 at the Wayback Machine Azerbaijan International (7.4) (Winter 1999)
  26. ^ a b c d e McNeil & Freiberger, p. 19
  27. ^ Blair, Betty. "Short Biographical Sketch" Archived 2005-08-29 at the Wayback Machine. Azerbaijan International, Vol. 2:4 (Winter 1994), p. 49.
  28. ^ Blair, Betty. "Interview with Lotfi Zadeh, Creator of Fuzzy Logic" Archived 2009-01-30 at the Wayback Machine. Azerbaijan International, Vol. 2:4 (Winter 1994), pp. 46 ff.
  29. ^ Brewer, Jared and Shakeel, Azwar (September 17, 2017) "UC Berkeley professor, creator of 'fuzzy logic' Lotfi Zadeh dies at 96" Archived 2017-09-20 at the Wayback Machine The Daily Californian
  30. ^ Lotfi A. Zadeh Archived 2018-03-03 at the Wayback Machine profile page on Google Scholar (accessed October 19, 2019).
  31. ^ McNeil & Freiberger, passim
  32. ^ "IEEE James H. Mulligan, Jr. Education Medal Recipients" (PDF). IEEE. Archived (PDF) from the original on 2010-11-24. Retrieved September 3, 2011.
  33. ^ "IEEE Richard W. Hamming Medal Recipients" (PDF). IEEE. Archived (PDF) from the original on 2015-06-12. Retrieved May 29, 2011.
  34. ^ "Rufus Oldenburger Medal". American Society of Mechanical Engineers. Archived from the original on 2019-11-07. Retrieved February 12, 2013.
  35. ^ "IEEE Medal of Honor Recipients" (PDF). IEEE. Archived from the original (PDF) on 2015-04-22. Retrieved September 3, 2011.
  36. ^ "Richard E. Bellman Control Heritage Award". American Automatic Control Council. Archived from the original on 2018-10-01. Retrieved February 10, 2013.
  37. ^ "AI's Hall of Fame" (PDF). IEEE Intelligent Systems. 26 (4): 5–15. 2011. doi:10.1109/MIS.2011.64. Archived from the original (PDF) on 2011-12-16. Retrieved 2015-09-04.
  38. ^ "IEEE Computer Society Magazine Honors Artificial Intelligence Leaders". DigitalJournal.com. August 24, 2011. Archived from the original on 2019-03-31. Retrieved September 18, 2011. Press release source: PRWeb (Vocus).
  39. ^ "2017: Fuzzy Logic, Clear Impact". The Golden Goose Award. Archived from the original on 2019-12-13. Retrieved 2019-12-13.
  40. ^ "Lotfi A. Zadeh Pioneer Award" Archived 2020-06-18 at the Wayback Machine IEEE Systems, Man, and Cybernetics Society website
  41. ^ Staff (25 February 2019) "Presentation of Inaugural Lotfi Zadeh Scholarships" Archived 2019-03-31 at the Wayback Machine ADA University website
  42. ^ Staff (April 15, 2021) "Celebrating the centenary of Lotfi A. Zadeh (1921–2017)" Archived 2021-05-07 at the Wayback Machine IEEE.TV


  • McNeil, Daniel; Freiberger, Paul (1993). Fuzzy Logic: The discovery of a revolutionary computer technology – and how it is changing our world. New York: Simon & Schuster. ISBN 0-671-73843-7.

Further reading

  • Seising, Rudolf. The Fuzzification of Systems: The Genesis of Fuzzy Set Theory and Its Initial Applications – Developments up to the 1970s (Studies in Fuzziness and Soft Computing, Vol. 216) Berlin, New York, [et al.]: Springer 2007.
  • Zadeh, Fay. "My Life and Travels with the Father of Fuzzy Logic". 1998, TSI Press, Albuquerque, NM.
  • Zadeh, Lofti A. "Lotfi Visions", two-part interview with Jack J. Woehr, Dr. Dobb's Journal, July, 1994 (part 1) and August, 1994 (part 2).

External links[edit]