TY JOUR TI Construction and research of root surface characteristic equation of the automatic control system KW characteristic equation KW root surface. JO Actual directions of scientific researches of the XXI century: theory and practice AU Tabolin, I.. AU Vasilev, E.. PY 2015 IS 3 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov