TY JOUR TI Mathematical model for optimization of the renewal of the melioration machine fleet KW melioration complex KW fleet of melioration machines KW minimization of energy costs KW working time fund KW optimality coefficient of choice KW mathematical model KW control solution JO Melioration and Water Management AU Abdrazakov, F.K. AU Chumakova Svetlana Valentinovna, S.V. AU Goryunov, D.G. PY 2026 IS 2025 PB ANO Editorial Board Melioration and water management