1989.1-1990.7: Visiting scholar at Aichi University of Technology, Japan.

1996.9-2000.5438+00: Doctor of Northeastern University.

1998.1-1998.12: Senior Visiting Scholar at Aichi University of Technology, Japan.

July 2006-September 2006: Senior Visiting Scholar of Toyama University, Aichi University of Technology and Kobe University in Japan.

2009.7-2009.7: Senior Visiting Scholar of Kyushu Institute of Technology and Aichi Institute of Technology, Japan.