1. School of Computer Science, Dalian University of Technology, Dalian, China
2. College of Mathematics and Computer Science, Fuzhou University, Fuzhou, China
3. Northwestern Polytechnical University, Xi’an, China
4. Department of Computer Science, The University of Hong Kong, Hong Kong, China
5. SIASUN Robot & Automation Company Ltd., Shenyang, China
6. Dalian University of Technology, Dalian, China