I.V. Sivchek - Post-graduate Student, St. Petersburg State Polytechnical University. E-mail: cotgreat@gmail.com
V.A. Sorotsky - Dr. Sc. (Eng.), Head of Department, St. Petersburg State Polytechnical University. E-mail: sorotsky@mail.spbstu.ru

O.V. Nepomnyashchiy1, I.E. Sazonov2, A.P. Yablonskiy3, V.N. Khaidukova4

1-4 Siberian Federal University (Krasnoyarsk, Russia)