N.I. Chervyakov - Dr.Sc. (Eng.), Professor, Head of the Department of Applied Mathematics and Mathematical Modeling, Institute of Mathematics and Natural Sciences, North-Caucasus Federal University, Stavropol, Russia. E-mail: k-fmf-primath@stavsu.ru
P.A. Lyakhov - Ph.D. (Phys.-Math.), Associate Professor, Department of Applied Mathematics and Mathematical Modeling, Institute of Mathematics and Natural Sciences, North-Caucasus Federal University, Stavropol, Russia. E-mail: ljahov@mail.ru