TY JOUR TI Optimization of Spring Suspension Parameters and Evaluation of Dynamic Performance of a High-Speed Electric Train Car KW high-speed electric train KW bogie KW spring suspension KW parameter optimization KW non-stationary random processes KW dynamic performance indicators JO Bulletin of scientific research results AU Savos'kin, A.N. AU Lavlinskaya, N.S. PY 2026 IS 2026 PB FSBEI HE "Emperor Alexander I St. Petersburg State Transport University"