Assistant in mathematics Shimane University, Matsue, Japan, 1952-1959, lecturer, 1959-1963, associate professor, 1963-1967, professor, since 1967, member board regents, since 1969. Instructor University Utah, Salt Lake City, 1961-1962. Assistant professor California State University, Sacramento, 1964-1965, University Arkansas, Fayetteville, 1968-1969.
Visiting professor Monash University, Australia, 1971, 79. Dean Faculty Literature and Science, Shimane University, 1979, dean Faculty of Science, 1980-1982. Visiting professor University California, 1982.