- 1979 - 1997 筑波大学, 数学系, 講師
- 1979 - 1997 Assistant Professor, Institute of Mathematics, University of Tsukuba
- 1997 - - 筑波大学, 数学系, 助教授(准教授)
- 1997 - - Associate Professor, Institute of Mathematics, University of Tsukuba
- 1986 - 1987 カリフォルニア大学サンタ・バーバラ校, 客員助教授・研究員
- 1986 - 1987 Visiting Assistant Professor and Researcher, Department of Mathematics, Univerty of California at Santa Barbara
- 1985 - 1986 ルイジアナ州立大学, 客員助教授
- 1985 - 1986 Visiting Assistant Professor, Department of Mathematics, Lousiana State University
- 1977 - 1979 香川大学, 教育学部, 講師
- 1977 - 1979 Assistant Professor, Faculty of Education, Kagawa University
- 1974 - 1977 香川大学, 教育学部, 助手
- 1974 - 1977 Assistant, Faculty of Education, Kagawa University
- 筑波大学 数理物質系 准教授