M.Yu. Zvjagin - Ph. D. (Phys.-Math.), Associate Professor, Department of functional analysis and its applications, Vladimir State University named after A.&N. Stoletovs. E-mail: muz1953@yandex.ru P.Yu. Shamin - Ph. D. (Eng.), Part-programming engineer, Vladimir State University named after A.&N. Stoletovs. E-mail: spu@vlsu.ru V.G. Prokoshev - Dr. Sc. (Phys.-Math.), Professor, Department of Physics and Applied Mathematics, Vladimir State University named after A.&N. Stoletovs. E-mail: prokoshev_vg@vlsu.ru V.A. Jakovlev - Post-graduate Student, Department of Physics and Applied Mathematics, Vladimir State University named after A.&N. Stoletovs. E-mail: vcrazyv33@gmail.com