A.V. Skiper - Senior Lecturer, Kaluga branch of the Bauman MSTU. E-mail: skiper60@yandex.ru N.S. Lazarev - Student, Kaluga branch of the Bauman MSTU. E-mail: lazarevnikolay05@gmail.com V.S. Zaionchkovskiy - Ph. D. (Phys.-Math.), Associate Professor, Kaluga branch of the Bauman MSTU. E-mail: vz48@post.ru I.A. Rastorguyev - Student, Kaluga branch of the Bauman MSTU. E-mail: rastorguew94@gmail.com

N.V. Cherkesova1, G.A. Mustafaev2, A.G. Mustafaev3

1 Kabardino-Balkarian State University (Nalchik, Russia)
2 Dagestan State University of National Economy (Makhachkala, Russia)
1 natasha07_2002@mail.ru, 2 zoone@mail.ru, 3 arslan_mustafaev@mail.ru