Lloyd R. Welch

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Lloyd Richard Welch (born September 28, 1927 in Detroit , Michigan ) is an American mathematician who deals with coding theory.

Welch studied mathematics at the University of Illinois with a bachelor's degree in 1951 and received his doctorate in 1958 under Frederic Bohnenblust at Caltech ( The rearrangement of functions and maximization of a convolution integral ). From 1956 to 1959 he was at the Jet Propulsion Laboratory , from 1969 to 1965 at the Institute for Defense Analyzes ; In 1965 he became a professor at the University of Southern California . He retired in 1999.

Among other things, he is known for the MMRW barriers for binary codes (with Robert J. McEliece , R. Rodemick, Howard Rumsey) and the Baum-Welch algorithm (also named after Leonard E. Baum , who worked at the institute in the late 1960s for Defense Analyzes pioneered HMM and published in 1970) for setting parameters in a Hidden Markov Model (HMM). His contribution to this is in his Shannon Lecture 2003. The Welch-Berlekamp algorithm for efficient error correction in BCH and Reed-Solomon codes is named after him and Elwyn Berlekamp .

He is a Fellow of the IEEE and the National Academy of Engineering . In 2003 he received the Claude E. Shannon Award .

Fonts

  • Lower Bounds on the Maximum Cross Correlation of Signals , IEEE Transactions on Information Theory, Vol. IT-20, pp. 397-399, 1974.
  • with RJ McEliece, R. Rodemick, H. Rumsey New Upper Bounds on the Rate of a Code via the Delsarte-Mac Williams Inequalities , IEEE Transactions on Information Theory, March 1977.
  • with W. Ke Binary Sequences with Non-Positive Autocorrelation Values , ACTA Electronics Sinica, September 1982.
  • with J. Olsen, RA Scholtz Bent Function Sequences , IEEE Transactions on Information Theory, November 1982.
  • with RA Scholtz GMW Sequences , IEEE Transactions on Information Theory, May 1984.
  • with PV Kumar, RA Scholtz Generalized Bent Functions and their Properties , Journal of Combinatorial Theory, September 1985

Web links

Individual evidence

  1. ↑ Life data according to American Men and Women of Science , Thomson Gale 2004
  2. ^ Mathematics Genealogy Project
  3. ^ IEEE Information Theory Society Newsletter, 2003, pdf
  4. ↑ Welch, Berlekamp, ​​US Patent 4633470, Error Correction for Algebraic Block Codes , received 1983, issued 1986
personal data
SURNAME Welch, Lloyd R.
ALTERNATIVE NAMES Welch, Lloyd Richard (full name)
BRIEF DESCRIPTION American mathematician
DATE OF BIRTH September 28, 1927
PLACE OF BIRTH Detroit , Michigan