 From 1951 to 1966 he worked in applied mathematics at the Westinghouse Research Laboratories, Pittsburgh, PA. On leave during the 1963-1964 academic year, he lectured in the Department of Engineering, University of California, Los Angeles.He joined the University of California, San Diego in 1966, where he was Professor, then Professor Emeritus of Electrical Engineering.From 1971 to 1973 and 1974 to 1977 he was Chairman of his Electrical Engineering and Computer Sciences department, and during the 1973-1974 and 1986-1987 academic years he was Professeur Associé at the Université de Paris-Sud.