- 1997 - 現在 Kyushu University
- 1997 - 1998 Kyushu University
- 1997 - 1998 Visiting Professor, Groduate School of Math.,
- 1984 - 1997 Kyushu University School of Sciences
- 1984 - 1997 Dept. Math., Fac. Sciences. Kyushu Univ.
- 1997 - - 佐賀大学 教授
- 1987 - 1987 カリフォルニア大学ロスアンゼルス分校 客員教授
- 1987 - 1987 Visiting Professor. Math. Dept., UCLA
- 1982 - 1984 University of Tsukuba Institute of Mathematics
- 1982 - 1984 Dept. Math., Tsukuba Univ. Professor
- 1974 - 1982 University of Tsukuba Institute of Mathematics
- 1974 - 1982 Dept. Math., Tsukuba Univ.,
- 1979 - 1980 ボン大学 客員教授
- 1979 - 1980 Visiting Professor, Bonn Univ.
- 1978 - 1978 カリフォルニア大ロスアンゼルス分校 客員教授
- 1978 - 1978 Visiting Profesor, Math. Dept., UCLA
- 1977 - - Professor Emerthrs, Kyushu Univ.
- 1975 - 1976 オーステッド研究所,コペンハーゲン大学 客員教授
- 1975 - 1976 Visiting Professor, Orsted Institut,
- 1967 - 1974 Tokyo Institute of Technology
- 1967 - 1974 Tokyo Inst. Tech., Fac. Sci and Engineering,
- 1970 - 1972 ボン大学 客員研究員
- 1970 - 1972 Visiting Researcher at Bonn University
- Kyushu Univ.
- Professor
- Mathematik SFB-40)
- (Sonderforschungsbereich Theoretische
- Copenhagen Univ.
- Associate Professor
- (Alexandafov Humboldt Stiperdiant)
- Assistant