The certificate was obtained through the self-study exam. The full-time self-study certificate of Jincheng College of Nanjing University of Aeronautics and Astronautics refers to the graduation certificate obtained by the student through self-study and school examination, which is also recognized by the Ministry of Education. The graduation certificate of national institutions of higher learning includes self-study examination and unified examination. Unified examination is a graduation certificate obtained through college entrance examination and school examination. Self-taught examination is a graduation certificate obtained by students who register themselves and pass the school examination by themselves.