N.I. Chervyakov - Dr.Sc. (Eng.), Professor, Head of the Department of Applied Mathematics and Mathematical Modeling, North-Caucasus Federal University, Stavropol, Russia. E-mail: k-fmf-primath@stavsu.ru
M.G. Babenko - Ph.D. (Phys.-Math.), Associate Professor, Department of Applied Mathematics and Mathematical Modeling, North-Caucasus Federal University, Stavropol, Russia. E-mail: whbear@yandex.ru

D.A. Tavalinsky1, N.V. Shishkin2, D.A. Krasikov3

1 Military Order of Zhukov University of Radio Electronics (Cherepovets, Russia)
2 Academy of the Federal Security Service of the Russian Federation (Oryol, Russia)