D.V. Ivanov1, V.A. Ivanov2, M.I. Ryabova3, V.V. Ovchinnikov4

1-4 Volga State University of Technology (Yoshkar-Ola, Russia)

1 IvanovDV@volgatech.net; 2 IvanovVA@volgatech.net; 3 RyabovaMI@volgatech.net; 4 OvchinnikovVV@volgatech.net