2002 Head of Department of Mathematics and Physics in Computer Science College
2001 Professor of Mathematics in Computer Science College.
1982 Full Professor in Institute of Physics of the Estonian Academy of Sciences (IPEAS).
1994-1995: Scientific Director of CSC.
1993-1994: Head of the Department of Applied Mathematics, International University (IU), Tallin, Estonia
1992-1994: Professor of Applied Mathematics (IU)
Discovered the isotope effect of exciton binding energy (Wannier-Mott exciton model), experimental evidence of self-trapped electrons and quantum diffusion of Vk center in insulators as well as the effect of the isotope disorder on the phonon and exciton states