TY JOUR TI Modelling a Rail Supply Chain for Railway Track Maintenance KW Logistics KW logistics chain KW track maintenance work KW welded rail lengths KW resource logistics for track work KW delivery timelines KW logistics of welded rail supply chain JO Proceedings of Petersburg Transport University AU Pakulina, E.V. PY 2025 IS 22 PB FSBEI HE "Emperor Alexander I St. Petersburg State Transport University"