Donald Shell

Donald L. Shell (born March 1, 1924) is a retired American computer scientist who designed the Shell sort sorting algorithm. He acquired his Ph.D. in Mathematics from the University of Cincinnati in 1959, after publishing the shell sort algorithm in the Communications of the ACM in July the same year.^[1]

After acquiring the B.S. from Michigan Technological University, he went into the Army Corps of Engineers, and from there to the Philippines to help repair damages during World War II. When he returned after the war, he married Alice McCullough and returned to Michigan Technological University, where he taught mathematics. After, he moved to Cincinnati, Ohio, and worked for General Electric's engines division, where he developed a convergence algorithm and wrote a program to perform performance cycle calculations for aircraft jet engines. He also went to the University of Cincinnati, where in 1951 he acquired a M.S. in mathematics and, in 1959, acquired his Ph.D. in Mathematics. In July of that year he published the shell sort algorithm^[1] and "The Share 709 System: A Cooperative Effort". In 1958, he and A. Spitzbart had published "A Chebycheff Fitting Criterion".

Although he is most widely known for his shell sort algorithm, his Ph.D. is also considered by some to be the first major investigation of the convergence of infinite exponentials, with some very deep results of the convergence into the complex plane. This area has grown considerably and research related to it is now investigated in what is more commonly called Tetration.

After acquiring his Ph.D., Shell moved to Schenectady, New York, to become Manager of Engineering for General Electric's new Information Services Department, the first commercial enterprise to link computers together using the client–server architecture. In October 1962 he wrote "On the Convergence of Infinite Exponentials" in the Proceedings of the American Mathematical Society. He worked with John George Kemeny and Thomas Eugene Kurtz to commercialize the Dartmouth Time-Sharing System in 1963.

In 1971 Shell wrote "Optimizing the Polyphase Sort" in the Communications of the ACM, and in 1972 he joined with a close friend and colleague, Mr. Ralph Mosher (who designed the walking truck), to start a business called Robotics Inc. where he was the General Manager and chief software engineer. Four years later, in 1976, they sold the company and Shell returned to General Electric Information Services Corporation.

In 1984 he retired and moved to North Carolina where he lives today.^[2]

Marriages

Donald Shell married Alice McCullough after returning from World War II. They had two sons, Allyn and Peter. Alice died of cancer after years of being cared for by Donald. About a year after Alice's death Donald married Virginia Law whose husband had died in Africa. Virginia had three children from her first marriage, David, Paul and Margret. Virginia died of congestive heart failure due to malaria acquired in Africa. Donald had cared for Virginia for many years prior to her death. A year after Virginia's death at age 81 Donald married Helen Whiting who had also cared for two invalid spouses who had died. Helen also brought sons and daughters into the marriage, but all of them are married with their own families as are all of Donald's children. Donald and Helen currently live in Lake Junaluska, North Carolina. Both of them are in reasonably good health.

References

1. ^ ^{a b} Shell, D.L. (1959). "A high-speed sorting procedure". Communications of the ACM 2 (7): 30–32. doi:10.1145/368370.368387. 
2. ^ {{Biographical sketch}}

External links

• Biographical sketch
• www.informatik.uni-trier.de/~ley/db/indices/a-tree/s/Shell:Donald_L=.html
• ioannis.virtualcomposer2000.com/math/IERefs.html

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Name	Shell, Donald
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Date of birth	March 1, 1924
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