Lotfi Zadeh

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Lotfi A. Zadeh (2005)

Lotfi A. Zadeh (actually Lotfali Askar-Zadeh , Azerbaijani Lütfi Zadə / Lütfəli Rəhim oğlu Əsgərzadə ; Persian لطفی علی‌عسگرزاده; * February 4, 1921 in Baku , Azerbaijan ; † September 6, 2017 in Berkeley , California ) was an American mathematician , computer scientist , electrical engineer, and professor emeritus of computer science at the University of California, Berkeley . He is the creator of the theory of fuzzy sets (1965) and the founder of fuzzy logic (1973), and he also coined the term soft computing (1994).

Life

Lotfi A. Zadeh was born in Baku as the son of the Iranian journalist Rahim Aleskerzade from Ardabil , who worked here as an Iranian foreign correspondent, and his Ukrainian-Jewish wife, the pediatrician Fanya Koriman.

In 1931 the family went back to Iran , where Askar-Zadeh grew up, attended high school and passed the university entrance exams (Abitur) as the country's second best. He completed his electrical engineering studies at the University of Tehran in 1942 as an electrical engineer .

In the summer of 1943 he went to the United States , where he obtained a Master of Science degree in electrical engineering from MIT in 1946 and a doctorate (PhD) from Columbia University in New York in 1949 .

Zadeh's tomb at the Ehrenallée in Baku

Here he taught for ten years - since 1957 as a life professor - before he accepted an appointment at the University of California, Berkeley , in 1959 , where he taught and researched after his retirement in 1991. Even at the age of 89 (2010) Lotfi Zadeh still gave lectures around the world and was still involved in ongoing research as director of the Berkeley Initiative for Soft Computing (2012) .

In addition to numerous honors and memberships in national and international scientific institutions and academies, he was awarded an honorary doctorate from 24 universities worldwide. In 2012 he received the BBVA Foundation Frontiers of Knowledge Award .

Zadeh died on September 6, 2017, at the age of 96 at his Berkeley home. According to his wishes, he was buried in his native city of Baku in Azerbaijan.

Services

Zadeh began his research in the field of systems theory , he worked on questions of decision theory and information systems as well as pattern recognition . In 1965, in his article Fuzzy Sets, which was cited more than 70,000 times by mid-2017, he presented his concept of a theory of fuzzy sets for the first time, which became the nucleus and basis of the rapidly developing fuzzy logic - (content: the logic of fuzziness) should have a great impact, especially through its diverse application areas in engineering and linguistic data processing information sciences.

The basic idea of ​​the precise detection of the imprecise is not to define fuzzy sets by the objects that are (or are not) elements of this set, but rather by means of the degree to which they belong to this set. This is done using membership functions μ A : X → [0,1] , which assign each element of the definition set X = {x} a number from the real-valued interval [0,1] of the target set , which assigns the degree of membership μ A (x) of each element x for the fuzzy set A defined in this way . This means that every element becomes an element of every fuzzy set, but with different degrees of membership defining a certain subset. Zadeh explained new set operations which, as operations of a new logic calculus , justify the multi-valued fuzzy logic and identify it as a generalization of the two-valued, classical logic , which it contains as a special case.

As part of his possibility theory, Zadeh developed the concept of the distribution of possibilities as a fuzzy restriction that, like an elastic fetter, restricts the values ​​that a variable can assume. Be as F one by the membership function μ F fuzzy subset defined the universe of discourse U = {u} . A proposition of the form " X is F ", in which X is a variable that takes values ​​from U , then induces the possibility distribution П X , which equates the possibility of X to take the value u with μ F (u) . In this way, X becomes a fuzzy variable that is related to the probability distribution П X in a similar way as is the case in probability theory for the connection of random variables and probability distribution . In addition, Zadeh suggested fuzzy numbers as special fuzzy sets which - together with the corresponding rules of consistent mathematical operations on these numbers - led to the emergence of fuzzy arithmetic .

“In general, complexity and precision bear an inverse relation to one another in the sense that, as the complexity of a problem increases, the possibility of analyzing it in precise terms diminishes. [...] From this point of view, the capacity of a human brain to manipulate fuzzy concepts and non-quantitative sensory inputs may well be one of its most important assets. Thus, 'fuzzy thinking' may not be deplorable, after all, if it makes possible the solution of problems which are much too complex for precise analysis. "

Zadeh coined the term soft computing , which essentially dispenses with the (not always possible) exact numerical analysis of a complex system in favor of its qualitative characterization and description in natural language terms. Their intrinsic ( extensional as well as intentional ) vagueness allow empirical inaccuracies and analytical uncertainties to be taken into account. The focus is on the TEST-Score semantics of natural language expressions developed by Zadeh, in which linguistic variables play a decisive role. Its formal meaning representation language PRUF ( Possibilistic, Relational, Universal, Fuzzy ) and the TEST scores achieved via instantiated, explanatory data structures take on a function comparable to the knowledge representation of artificial intelligence . Critics of this approach, who attest such linguistic characterizations of multi-parametric systems at best a black box modeling of system behavior, mostly overlook the fact that it is not about the functional explanation and simulation of such systems, but about the emulative modeling and control of their possible behavior There is uncertainty as to how human ability can do this with efficiency and comparable ease.

Zadeh's ideas turned out to be extremely fruitful and, in the last two decades of the 20th century, experienced a remarkable acceptance and broader reception, also in the research areas of neural networks , expert systems , control theory and artificial intelligence . Recently, Zadeh's research interests to the fuzzy logic, fuzzy (fuzzy) concentrated semantics of natural language, a theory predictable perception ( computational theory of perception ) as well as calculating with words / words ( computing with words ). Zadeh was editor or member of the advisory board of more than 70 scientific journals worldwide, he published numerous articles (over 200 as a single author) from his broad research spectrum on various aspects of the conception, design, implementation and analysis of information and decision-making systems .

In 1966 he was invited speaker at the International Congress of Mathematicians in Moscow ( research on some non-classical control problems in the USA ).

Fonts (selection)

  • Fuzzy sets. In: Information and Control. 8, 1965, pp. 338-353.
  • Fuzzy sets and systems. In: J. Fox (Ed.): System Theory. Polytechnic Press, Brooklyn, NY 1965, pp. 29-39.
  • The concept of system, aggregate, and state in system theory. In: LA Zadeh, E. Polak (eds.): System Theory [Inter-University Electronic Series, Vol. 8], New York: McGraw-Hill, 1969, pp. 3-42.
  • Quantitative fuzzy semantics. In: Information Science 3, 1971, pp. 159-176.
  • A fuzzy set theoretical interpretation of linguistic hedges. In: Journal of Cybernetics 2, 1972, pp. 4-34.
  • Fuzzy Languages ​​and their Relation to Human and Machine Intelligence. In: M. Marois (Ed.): Man and Computer. Karger, Basel 1972, pp. 130-165.
  • Outline of a new approach to the analysis of complex systems and decision processes. In: IEEE Trans. Systems, Man and Cybernetics. 3, 1973, pp. 28-44.
  • Fuzzy logic and its application to approximate reasoning. In: Information Processing. 74, Proc. IFIP Congr. 1974, pp. 591-594.
  • Fuzzy logic and approximate reasoning . Synthesis 30 (1975): 407-428.
  • Calculus of fuzzy restrictions. In: LA Zadeh, KS Fu, K. Tanaka, M. Shimura (Eds.): Fuzzy Sets and their Applications to Cognitive and Decision Processes. Academic Press, New York 1975, pp. 1-39.
  • The concept of a linguistic variable and its application to approximate reasoning. Part I, Information Sciences. 8, 1975, pp. 199-251.
  • The concept of a linguistic variable and its application to approximate reasoning. Part II, Information Sciences. 8, 1975, pp. 301-357.
  • The concept of a linguistic variable and its application to approximate reasoning. Part III, Information Sciences. 9, 1976, pp. 43-80.
  • PRUF - a meaning representation language for natural languages . Intern. Journal Man-Machine Studies 10, 1978, pp. 395-460.
  • TEST-Score Semantics for Natural Languages ​​and Meaning Representation via PRUF. In: Burghard B. Rieger, editor: Empirical Semantics I [Quantitative Linguistics 12], Bochum: Brockmeyer 1981, pp. 281-349.
  • Toward a theory of fuzzy information granulation and its centrality in human reasoning and fuzzy logic . Fuzzy Sets and Systems 90, 1997, pp. 111-127.
  • From Computing with Numbers to Computing with Words - from Manipulation of Measurement to Manipulation of Perception . In: Paul P. Wang (Ed.): Wiley Series on Intelligent Systems . Computing with Words. tape 3 . Wiley & Sons, New York 2001, pp. 35-68 .

literature

  • Fay Zadeh: My Life and Travels with the Father of Fuzzy Logic. TSI-Press, Albuquerque, New Mexico, 1998, ISBN 1-889335-05-3 .

Web links

Commons : Lotfi Zadeh  - collection of images, videos and audio files

Individual evidence

  1. ↑ Electrical Engineering and Computer Science Dept. , UC Berkeley News of September 7, 2017.
  2. ^ Obituary of the New York Times of September 11, 2017 (accessed September 14, 2017).
  3. ^ American since 1957. Fay Zadeh: My Life and Travels ... , p. 21.
  4. ↑ Thomson Gale Lotfi Asker Zadeh Biography World of Computer Science
  5. ↑ Lotfi A. Zadeh: Fuzzy sets. In: Information and Control. 8, 1965, pp. 338-353.
  6. ^ LA Zadeh: Fuzzy Sets as a Basis for a Theory of Possibility. In: Fuzzy Sets and Systems 1, 1978, pp. 3-28.
  7. ^ LA Zadeh: Fuzzy Sets as a Basis for a Theory of Possibility. In: Fuzzy Sets and Systems 1, 1978, p. 4.
  8. ^ LA Zadeh: Fuzzy Languages ​​and their Relation to Human and Machine Intelligence. In: M. Marois (Ed.): Man and Computer. Karger, Basel 1972, p. 132.
  9. ^ LA Zadeh: The concept of a linguistic variable and its application to approximate reasoning. Part I-III, Information Sciences.
  10. ^ LA Zadeh: From Computing with Numbers to Computing with Words - from Manipulation of Measurement to Manipulation of Perception . In: Paul P. Wang (Ed.): Wiley Series on Intelligent Systems . Computing with Words. tape 3 . Wiley & Sons, New York 2001, pp. 35-68 .
personal data
SURNAME Zadeh, Lotfi
ALTERNATIVE NAMES Zadeh, Lotfi Asker (full name); Əsgərzadə, Lütfi Rəhim oğlu (Azerbaijani)
BRIEF DESCRIPTION American computer scientist, father of fuzzy logic
DATE OF BIRTH February 4, 1921
PLACE OF BIRTH Baku , Azerbaijan
DATE OF DEATH 6th September 2017
Place of death Berkeley , California