TY JOUR TI System analysis of digital transformation in education KW digital transformation KW sphere of education KW subjects and objects of digital transformation KW system analysis KW criteria for the effectiveness of digital transformation KW educational ecosystem KW digital competencies KW personalization of learning JO Vestnik of Astrakhan State Technical University. Series: Economics AU Kushner, A.. AU Kushner, M.. AU Ugarov, E.. PY 2025 IS 2025 PB Astrakhan State Technical University