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Lotfi Asker Zadeh

Lotfi Asker Zadeh

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Lotfali Askar Zadeh better known as Lotfi A. Zadeh, is a mathematician, electrical engineer, computer scientist, artifical intelligence researcher and professor emeritus of computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

 at the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...


Life and career

Zadeh was born in Baku
Baku , sometimes spelled as Baki or Bakou, is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. It is located on the southern shore of the Absheron Peninsula, which projects into the Caspian Sea. The city consists of two principal...

, Azerbaijan SSR
Azerbaijan SSR
The Azerbaijan Soviet Socialist Republic , also known as the Azerbaijan SSR for short, was one of the republics that made up the former Soviet Union....

, as Lotfi Aliaskerzadeh, to an Iranian Azeri father from Ardabil
Ardabil is a historical city in north-western Iran. The name Ardabil probably comes from the Zoroastrian name of "Artavil" which means a holy place. Ardabil is the center of Ardabil Province. At the 2006 census, its population was 412,669, in 102,818 families...

, Rahim Aleskerzade, who was a journalist on assignment from Iran, and a Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

n Jewish mother, Fanya Koriman, who was a pediatrician. The Soviet government at this time courted foreign correspondents, and the family lived well while in Baku. Zadeh attended elementary school for three years there, which he has said "had a significant and long-lasting influence on my thinking and my way of looking at things."

In 1931, when Zadeh was ten years old, his family moved to Teheran in Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

, his father's homeland. Zadeh was enrolled in Alborz College, which was a Presbyterian missionary school
A missionary is a member of a religious group sent into an area to do evangelism or ministries of service, such as education, literacy, social justice, health care and economic development. The word "mission" originates from 1598 when the Jesuits sent members abroad, derived from the Latin...

, where he was educated for the next eight years, and where he met his future wife, Fay. 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." During this time, Zadeh was awarded several patents.

Despite being more fluent in Russian than in Persian, Zadeh sat for the national university exams and placed third in the entire country. As a student, he ranked first in his class in his first two years. In 1942, he graduated from the University of Tehran
University of Tehran
The University of Tehran , also known as Tehran University and UT, is Iran's oldest university. Located in Tehran, the university is among the most prestigious in the country, and is consistently selected as the first choice of many applicants in the annual nationwide entrance exam for top Iranian...

 with a degree in electrical engineering
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...

 (Fanni), one of only three students in that field to graduate that year, due to the turmoil created by World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, when the Soviet Union invaded Iran – whose ruler, the Shah
Reza Shah
Rezā Shāh, also known as Rezā Shāh Pahlavi and Rezā Shāh Kabir , , was the Shah of the Imperial State of Iran from December 15, 1925, until he was forced to abdicate by the Anglo-Soviet invasion of Iran on September 16, 1941.In 1925, Reza Shah overthrew Ahmad Shah Qajar, the last Shah of the Qajar...

, was pro-German – and split the administration of the country with the British. Over 30,000 American soldiers were also based there, and Zadeh worked with his father, who did business with them as a contractor for hardware and building materials.

In 1943, Zadeh decided to emigrate to the United States, and traveled to Philadelphia by way of Cairo
Cairo , is the capital of Egypt and the largest city in the Arab world and Africa, and the 16th largest metropolitan area in the world. Nicknamed "The City of a Thousand Minarets" for its preponderance of Islamic architecture, Cairo has long been a centre of the region's political and cultural life...

 after months of delay waiting for the proper papers or for the right ship to appear. He arrived in mid-1944, and entered M.I.T. as a graduate student later that year. While in the United States, he changed his name to Lotfi Asker Zadeh.

He received an MS degree
Master of Science
A Master of Science is a postgraduate academic master's degree awarded by universities in many countries. The degree is typically studied for in the sciences including the social sciences.-Brazil, Argentina and Uruguay:...

 in electrical engineering from M.I.T. in 1946, and then applied to Columbia University
Columbia University
Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...

, as his parents had settled in New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

. Columbia admitted him as a doctoral student, and offered him an instructorship as well. He received his PhD
PHD may refer to:*Ph.D., a doctorate of philosophy*Ph.D. , a 1980s British group*PHD finger, a protein sequence*PHD Mountain Software, an outdoor clothing and equipment company*PhD Docbook renderer, an XML renderer...

 in electrical engineering from Columbia in 1949, and became an assistant professor the next year.

Zadeh taught for ten years at Columbia, was promoted to Full Professor in 1957, and has taught at the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...

 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
Fuzzy logic
Fuzzy logic is a form of many-valued logic; it deals with reasoning that is approximate rather than fixed and exact. In contrast with traditional logic theory, where binary sets have two-valued logic: true or false, fuzzy logic variables may have a truth value that ranges in degree between 0 and 1...


Personal life and beliefs

Zadeh is noted to be "quick to shrug off nationalism, insisting there are much deeper issues in life", and is quoted as stating 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." 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 Logic." He describes himself as "an American, mathematically oriented, electrical engineer of Iranian descent, born in Russia."

Zadeh is married to Fay Zadeh and has two children, Stella Zadeh and Norman Zadeh
Norm Zada
Norm Zada is the founder of Perfect 10, an adult magazine focusing on women without cosmetic surgery. Zada launched the magazine after a friend was rejected from Playboy magazine because her proportions did not fit the magazine's tastes.He estimates losing approximately $46 million on Perfect 10...


Fuzzy sets and systems

Zadeh, in his theory of fuzzy set
Fuzzy set
Fuzzy sets are sets whose elements have degrees of membership. Fuzzy sets were introduced simultaneously by Lotfi A. Zadeh and Dieter Klaua in 1965 as an extension of the classical notion of set. In classical set theory, the membership of elements in a set is assessed in binary terms according to...

s, proposed using a membership function (with a range
Interval (mathematics)
In mathematics, a interval is a set of real numbers with the property that any number that lies between two numbers in the set is also included in the set. For example, the set of all numbers satisfying is an interval which contains and , as well as all numbers between them...

 covering the interval
Interval (mathematics)
In mathematics, a interval is a set of real numbers with the property that any number that lies between two numbers in the set is also included in the set. For example, the set of all numbers satisfying is an interval which contains and , as well as all numbers between them...

 [0,1]) operating on the domain of all possible values. He proposed new operations for the calculus of logic and showed that fuzzy logic
Fuzzy logic
Fuzzy logic is a form of many-valued logic; it deals with reasoning that is approximate rather than fixed and exact. In contrast with traditional logic theory, where binary sets have two-valued logic: true or false, fuzzy logic variables may have a truth value that ranges in degree between 0 and 1...

 was a generalisation of classical and Boolean logic
In philosophy, Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science...

. He also proposed fuzzy number
Fuzzy number
A fuzzy number is an extension of a regular number in the sense that it does not refer to one single value but rather to a connected set of possible values, where each possible value has its own weight between 0 and 1. This weight is called the membership function. A fuzzy number is thus a special...

s as a special case of fuzzy sets, as well as the corresponding rules for consistent mathematical operations (fuzzy arithmetic).

Other contributions

Lotfi Zadeh is also credited, along with John R. Ragazzini
John R. Ragazzini
John Ralph Ragazzini was an American electrical engineer and a professor of Electrical Engineering. Ragazzini was born in New York and received the degrees of B.S. and E.E. at the City College of New York in 1932 and 1933 and earned the degrees of A.M. and Ph.D...

, in 1952, with having pioneered the development of the z-transform
In mathematics and signal processing, the Z-transform converts a discrete time-domain signal, which is a sequence of real or complex numbers, into a complex frequency-domain representation....

 method in discrete time signal processing and analysis. These methods are now standard in digital signal processing
Digital signal processing
Digital signal processing is concerned with the representation of discrete time signals by a sequence of numbers or symbols and the processing of these signals. Digital signal processing and analog signal processing are subfields of signal processing...

, digital control
Digital control
Digital control is a branch of control theory that uses digital computers to act as system controllers.Depending on the requirements, a digital control system can take the form of a microcontroller to an ASIC to a standard desktop computer....

, and other discrete-time systems used in industry and research. He is an editor of International Journal of Computational Cognition
International Journal of Computational Cognition
The International Journal of Computational Cognition was established in 2003. It focuses on all aspects of cognition. It is also a forum for related topics including: computational verb theory, fuzzy logic, artificial intelligence, control theory, robotics, linguistics , etc. Its founding editor...


Zadeh's latest work includes computing with words and perceptions
Computing with words and perceptions
In computing with words and perceptions , the objects of computation are words, perceptions, and propositions drawn from a natural language. The central theme of CWP is the concept of a generalised constraint...

. 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

  • 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: 28–44.
  • 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: 407–428.
  • 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.
  • 2002. "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.

Awards and honors

Zadeh is a Fellow of the Institute of Electrical and Electronics Engineers
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...

, the American Academy of Arts and Science, the Association for Computing Machinery
Association for Computing Machinery
The Association for Computing Machinery is a learned society for computing. It was founded in 1947 as the world's first scientific and educational computing society. Its membership is more than 92,000 as of 2009...

, the Association for the Advancement of Artificial Intelligence
Association for the Advancement of Artificial Intelligence
The Association for the Advancement of Artificial Intelligence or AAAI is an international, nonprofit, scientific society devoted to advancing the scientific understanding of the mechanisms underlying thought and intelligent behavior and their embodiment in machines...

 and the International Fuzzy Systems Association, and a member of the National Academy of Engineering
National Academy of Engineering
The National Academy of Engineering is a government-created non-profit institution in the United States, that was founded in 1964 under the same congressional act that led to the founding of the National Academy of Sciences...

. He is also a member of the Academies of Science of Azerbaijan
Azerbaijan National Academy of Sciences
Azerbaijan National Academy of Sciences , located in Baku, is the main state research organization in Azerbaijan...

, Bulgaria
Bulgarian Academy of Sciences
The Bulgarian Academy of Sciences is the National Academy of Bulgaria, established in 1869. The Academy is autonomous and has a Society of Academicians, Correspondent Members and Foreign Members...

, Finland
Finnish Academy of Science and Letters
The Finnish Academy of Science and Letters is a Finnish learned society. It was founded in 1908 as a Finnish-language counterpart of the Swedish-language Finnish Society of Sciences and Letters, which had existed since 1838.- Members :The academy has a total of 328 seats for Finnish members...

, Korea
Korean Academy of Science and Engineering
The Korean Academy of Science and Technology is the Republic of Korea’s highest academy of science and serves as an integrated think-tank for science and technology of South Korea...

 and Poland
Polish Academy of Sciences
The Polish Academy of Sciences, headquartered in Warsaw, is one of two Polish institutions having the nature of an academy of sciences.-History:...

 and of the International Academy of Systems Studies in Moscow
Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...

. He has received 24 honorary doctorates.

Awards received by Zadeh include, among many others:
  • IEEE Education Medal; 1973
  • IEEE Richard W. Hamming Medal, for "seminal contributions to information science and systems, including the conceptualization of fuzzy sets"; 1992
  • American Society of Mechanical Engineers
    American Society of Mechanical Engineers
    The American Society of Mechanical Engineers is a professional body, specifically an engineering society, focused on mechanical engineering....

     Rufus Oldenburger Medal
    Rufus Oldenburger Medal
    The Rufus Oldenburger Medal is an award given by the American Society of Mechanical Engineers recognizing significant contributions and outstanding achievements in the field of automatic control. It was established in 1968 in the honor of Rufus Oldenburger....

    ; 1993
  • Honorary Professorship from the Azerbaijan State Oil Academy; 1993
  • IEEE Medal of Honor
    IEEE Medal of Honor
    The IEEE Medal of Honor is the highest recognition of the Institute of Electrical and Electronics Engineers . It has been awarded since 1917, when its first recipient was Major Edwin H. Armstrong. It is given for an exceptional contribution or an extraordinary career in the IEEE fields of...

    , for "pioneering development of fuzzy logic and its many diverse applications"; 1995
  • American Automatic Control Council
    American Automatic Control Council
    The American Automatic Control Council is an organization founded in 1956 for research in control theory. It is an association of the control systems divisions of eight member societies and a member of the International Federation of Automatic Control....

     Richard E. Bellman Control Heritage Award
    Richard E. Bellman Control Heritage Award
    The Richard E. Bellman Control Heritage Award is an annual award given by the American Automatic Control Council for achievements in control theory, named after the applied mathematician Richard E. Bellman...

    ; 1998
  • ACM
    ACM is a three-letter acronym that may refer to:* Alkyl acrylate copolymer, a type of rubber commonly found in automotive transmissions and hoses* Arnold-Chiari malformation* Asbestos Containing Material* Association for Computing Machinery...

     Allen Newell Award
    Allen Newell
    Allen Newell was a researcher in computer science and cognitive psychology at the RAND corporation and at Carnegie Mellon University’s School of Computer Science, Tepper School of Business, and Department of Psychology...

    ; 2001
  • Outstanding Contribution Award, Web Intelligence Consortium (WIC), Halifax, Canada, 2003.
  • Wall of Fame, Heinz Nixdorf MuseumsForum (HNF), Paderborn, Germany, 2004.
  • V. Kaufmann Prize and Gold Medal, International Association for Fuzzy-Set Management and Economy (SIGEF), Barcelona, Spain, Nov. 15, 2004.
  • J. Keith Brimacombe IPMM Award in recognition of his development of fuzzy set theory and fuzzy logic, 2005.
  • Benjamin Franklin Medal in Electrical Engineering from the The Franklin Institute in Philadelphia, for inventing and developing the field of "fuzzy logic"; 2009
  • Induction into the IEEE Intelligent Systems
    IEEE Intelligent Systems
    IEEE Intelligent Systems, a bimonthly publication of the IEEE Computer Society. It is an AAAI-sponsored journal. Cosponsors are the British Computer Society and the European Coordinating Committee for Artificial Intelligence....

    ' AI's Hall of Fame, 2011, "for his work on soft computing, fuzzy logic, and neural-net theory".

External links

Zadeh's PhD students: