Lloyd Richard Welch (born September 28, 1927) is an American

information theorist Information theory is the scientific study of the quantification, storage, and communication of information. The field was originally established by the works of Harry Nyquist and Ralph Hartley, in the 1920s, and Claude Shannon in the 1940s. ...

and applied mathematician, and co-inventor of the

Baum–Welch algorithm In electrical engineering, statistical computing and bioinformatics, the Baum–Welch algorithm is a special case of the expectation–maximization algorithm used to find the unknown parameters of a hidden Markov model (HMM). It makes use of the ...

and the

Berlekamp–Welch algorithm The Berlekamp–Welch algorithm, also known as the Welch–Berlekamp algorithm, is named for Elwyn R. Berlekamp and Lloyd R. Welch. This is a decoder algorithm that efficiently corrects errors in Reed–Solomon codes for an RS(''n'', ''k''), code ...

, also known as the Welch–Berlekamp algorithm. Welch received his B.S. in mathematics from the

University of Illinois The University of Illinois Urbana-Champaign (U of I, Illinois, University of Illinois, or UIUC) is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the University ...

, 1951, and Ph.D. in mathematics from the

California Institute of Technology The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

, 1958, under advisor Frederic Bohnenblust. He worked at the

Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA an ...

1956–1959,

Institute for Defense Analyses The Institute for Defense Analyses (IDA) is an American non-profit corporation that administers three federally funded research and development centers (FFRDCs) – the Systems and Analyses Center (SAC), the Science and Technology Policy Institute ...

in Princeton, 1959–1965, and

University of Southern California The University of Southern California (USC, SC, or Southern Cal) is a Private university, private research university in Los Angeles, California, United States. Founded in 1880 by Robert M. Widney, it is the oldest private research university in C ...

, 1965–1999. He was elected a member of the

National Academy of Engineering The National Academy of Engineering (NAE) is an American nonprofit, non-governmental organization. The National Academy of Engineering is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy ...

in 1979 for "contributions to an understanding of possibilities, limitations, and design of communications coding for reliability, security, and synchronization". He is also an

IEEE Fellow As of 2019, the Institute of Electrical and Electronics Engineers (IEEE) has 5,082 members designated Fellow, each of whom is associated with one of the 41 societies under the IEEE. The Fellow grade of membership is the highest level of membershi ...

, and received the 2003 Claude E. Shannon Award.

References

University of Southern California faculty web page

National Academy of Engineering

Caltech thesis

AMS genealogy
* American information theorists Members of the United States National Academy of Engineering Possibly living people 1927 births University of Illinois alumni California Institute of Technology alumni University of Southern California faculty {{US-scientist-stub