TY JOUR TI Efficiency Rise in Functioning of Low-Intensity Lines: Problem Statement and Mathematical Models KW railway transport KW managing approach KW low-intensity lines KW transportation process management KW transportation management KW fuzzy cognitive maps JO Proceedings of Petersburg Transport University AU Kovalev, K.E. AU Novichihin, A.V. PY 2022 IS 19 PB FSBEI HE "Emperor Alexander I St. Petersburg State Transport University"