S. L. Hakimi
Seifollah Louis Hakimi (1932–June 23, 2005)[1] was an Iranian-American mathematician born in Iran, a professor emeritus at Northwestern University, where he chaired the department of electrical engineering from 1973 to 1978.[2] He was chair of the Department of Electrical Engineering at University of California, Davis, from 1986 to 1996.[1] Hakimi received his Ph.D. from the University of Illinois at Urbana-Champaign in 1959, under the supervision of Mac Van Valkenburg.He has over 100 academic descendants, most of them via his student Narsingh Deo.[3] He is known for characterizing the degree sequences of undirected graphs,[4] for formulating the Steiner tree problem on networks,[5] and for his work on facility location problems on networks.