USA:   One year as American Field Service exchange student, graduating from Minnetonka High School, Minnesota.  One year sabbatical in Physics Department, Princeton University, USA.  Three month sabbatical in Biochemistry Dept., Stanford University, California. 

France: Two years working in Service de Physique Theorique at French Atomic Energy Commission's lab in Saclay, outside Paris.

England:   Eight months of sabbatical at Isaac Newton Institute for Mathematical Sciences, Cambridge University.

Germany: Two years as scientist in super-computer-calculations center at Forshungszentrum Juelich.

Hong Kong: Two month sabbatical in Physics Department, Hong Kong University of Science and Technology.

Mathematical, statistical, numerical, and physical modeling