I.S. Zamulin - Ph.D. (Phys.-Math.), Research Scientist, Khakas State University, Abakan. E-mail: zamulin_ivan@mail.ru М.D. Starostenkov - Dr.Sc. (Phys.-Math.), Professor, Polzunov Altai State Technical University (AltSTU), Barnaul. E-mail: genphys@mail.ru