

Introduction
Richard James Duffin (1909 – October 29, 1996) was an American physicist, known for his contributions to electrical transmission theory and to the development of geometric programming and other areas within operations research.
Education and career
Duffin obtained a BSc in physics at the University of Illinois, where he was elected to Sigma Xi in 1932. He stayed at Illinois for his PhD, which was advised by Harold Mott-Smith and David Bourgin, producing a thesis entitled Galvanomagnetic and Thermomagnetic Phenomena (1935).
Duffin lectured at Purdue University and Illinois before joining the Carnegie Institute in Washington, D.C. during World War II. His wartime work was devoted to the development of navigational equipment and mine detectors. In 1946, he became Professor of Mathematics at Carnegie Mellon University, from where he wrote the letter of recommendation with which the Nobel laureate John F. Nash Jr. entered to Princeton University. He would remain at Carnegie Mellon until his retirement in 1988. Duffin was also a consultant to Westinghouse Electric Corporation.
Duffin was inducted to the National Academy of Sciences in 1972 and to the American Academy of Arts and Sciences in 1984. He was joint winner of the 1982 John von Neumann Theory Prize, and winner of Sigma Xi's Monie A. Ferst Award for 1984 in recognition of his ability as a teacher and communicator.
Selected publications
- 1949: With Raoul Bott, "Impedance synthesis without the use of transformers", Journal of Applied Physics 20:816.
- 1952: With A.C.Schaeffer, "A class of nonharmonic Fourier series". Trans. Amer. Math. Soc. 72: 341–366. doi:10.1090/s0002-9947-1952-0047179-6. MR 0047179.
- 1953: With R. Bott, "On the algebra of networks". Trans. Amer. Math. Soc. 74: 99–109. doi:10.1090/s0002-9947-1953-0056573-x. MR 0056573.
- 1956: "Exponential decays in nonlinear networks". Proc. Amer. Math. Soc. 7: 1094–1106. doi:10.1090/s0002-9939-1956-0083366-8. MR 0083366.
- 1959: "An analysis of the Wang algebra of networks". Trans. Amer. Math. Soc. 93: 114–131. doi:10.1090/s0002-9947-1959-0109161-6. MR 0109161.
- 1962: "The reciprocal of a Fourier series". Proc. Amer. Math. Soc. 13: 965–970. doi:10.1090/s0002-9939-1962-0145259-x. MR 0145259.
- 1967: With Elmor Peterson and Clarence M. Zener, Geometric programming. John Wiley, xi + 278 pp.
- 1974: "Some problems of mathematics and science". Bull. Amer. Math. Soc. 80 (6): 1053–1070. doi:10.1090/s0002-9904-1974-13618-9. MR 0359436.
- Ben–Israel, Adi. "Review of Geometric Programming—Theory and Applications. By R. J. Duffin, E. L. Peterson and C. Zener". SIAM Review. 10 (2): 235–236. doi:10.1137/1010047.