1. Department of Mathematics and Statistics, The Arctic University of Norway, N-9037,Tromso, Norway</br> 2. V.A. Trapeznikov Institute of Control Sciences of Russian Academy of Sciences, 117997 Moscow, Russia
Dr. Valentin Lychagin
1. Department of Mathematics and Statistics, The Arctic University of Norway, N-9037,Tromso, Norway</br> 2. V.A. Trapeznikov Institute of Control Sciences of Russian Academy of Sciences, 117997 Moscow, Russia