Lotfi Aliasker Zadeh[5] (/ˈzɑːdeɪ/; Azerbaijani: Lütfi Rəhim oğlu Ələsgərzadə;[6] Persian: لطفی علی‌عسکرزاده;[2] 4 February 1921 – 6 September 2017)[1][3] was a mathematician, computer scientist, electrical engineer, artificial intelligence researcher, and professor[7] of computer science at the University of California, Berkeley.

[26] Zadeh attended elementary school for three years there,[26] which he said "had a significant and long-lasting influence on my thinking and my way of looking at things.

"[27] In 1931, when Stalin began agricultural collectivization,[21] and Zadeh was ten, his father moved his family back to Tehran, Iran.

Zadeh was enrolled in Alborz High School, a missionary school,[21] where he was educated for the next eight years, and where he met his future wife,[26] Fay (Faina[21]) Zadeh, who said that he was "deeply influenced" by the "extremely decent, fine, honest and helpful" Presbyterian missionaries from the United States who ran the college.

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.

[21] He travelled to Philadelphia by way of Cairo after months of delay waiting first for the proper papers and later for the right ship to appear.

[citation needed] He arrived in mid-1944, lived in New York and worked for an electronic association,[21] and entered the Massachusetts Institute of Technology (MIT) as a graduate student in September that year.

[28][21] While in the United States, he shortened his family name, creating a new middle name from the part he removed, and was thenceforth known as Lotfi Aliasker Zadeh.

[29] Zadeh's first important research contribution, well known among scholars of his generation in the electrical engineering community, was in the area of classical control systems.

In 1973, Lotfi Zadeh received the prestigious (Institute of Electronic and Electrical Engineers) IEEE Education Award, largely in recognition of his performance as chair of EE and then EECS.

Professor Zadeh graduated more than 50 PhD students, many of whom went on to become leaders in various areas of engineering, management and information sciences.

[32] 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.

"[35] He described himself as "an American, mathematically oriented, electrical engineer of Iranian descent, born in Russia.

"[38] A month prior to his death, the University of Tehran had released an erroneous report that Zadeh had died, but withdrew it several days later.

[41] 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.

Zadeh was also an active contributor to the AI community, including at the Dartmouth Workshop that coined the term "artificial intelligence".

Zadeh is 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.

His later papers include "From Search Engines to Question-Answering Systems"[43] and "Toward a Generalized Theory of Uncertainty (GTU)—An Outline".

[55] On 4 February 2021, the IEEE Computational Intelligence Society and the International Fuzzy Systems Association (IFSA) jointly celebrated the centenary of Zadeh's birth.