S.E. Stepanov - Ph. D. (Phys.-Math.), Associate Professor, Kaluga branch of the Bauman MSTU. E-mail: stepanov@bmstu-kaluga.ru E.Yu. Agu - Master, Post-graduate Student, Kaluga branch of the Bauman MSTU. E-mail: liza.kornyushina@gmail.com V.Yu. Zakharov - Ph. D. (Phys.-Math.), Associate Professor, Kaluga branch of the Bauman MSTU. E-mail: vladiyuz@mail.ru