1. School of Computer and Information Technology, Shanxi University; School of Modern Logistics, Shanxi Vocational University of Engineering Science and Technology, China
2. School of Computer and Information Technology, Shanxi University, Taiyuan, China
3. Institute for Infocomm Research, A*Star, Singapore
4. The MOE Key Laboratory of Computational Linguistics, Peking University, China
5. School of Computer and Information Technology, Shanxi University, China