TY JOUR TI FORECASTING VARIANTS OF THE CALCULATION PERIOD DURATION WHEN MODELING LOGGING MACHINE OPERATION KW cutting area works KW modeling KW machine set KW operating day number JO Bulletin of KSAU AU Zaikin, A.N. AU Merkelov, V.M. AU Ryzhykova, E.G. AU Teremkova, I.I. PY 2013 IS PB Krasnoyarsk State Agrarian University