| 1. Visiting Professor | Departamento Fisica Teorica I Universidad Complutense Madrid (Spain) |
December 1988- January 1989 |
| 2. Visiting Research Fellow | Institute for Electromagnetic Field Theory and
Plasma Physics Chalmers University Goteborg (Sweden) |
September 1989 |
| 3. Collaborator | Center for Nonlinear Studies Los Alamos National Laboratory Los Alamos (USA) |
April-May 1990 October 1996 May 1997 |
| 4. Visiting Assoc. Prof. | Laboratoire OSC, University of Bourgogne, Dijon (France) | September 1990 |
| 5. JSPS Fellow | Osaka Institute of Technology Osaka (Japan) |
October-December, 1996 |
| 6. Bede Morris Fellow Aust. Acad. of Science |
Ecole Normale Superieure de Lyon (France) |
October-November, 1997 |