School of Software;
Beihang University;
Beijing 100191;
China;
State Key Laboratory of Intelligent Technology and Systems;
Tsinghua University;
Beijing 100084;
China;
Tsinghua National Laboratory for Information Science and Technology;
Tsinghua University;
Beijing 100084;
China;
Department of Computer Science and Technology;
Tsinghua University;
Beijing 100084;
China;
Jiangsu Collaborative Innovation Center for Language Competence;
Xuzhou 221009;
China;
unlabeled; data; grammatical; error; detection; neural; network;