1. National Key Laboratory of Science and Technology on Communication, University of Electronic Science and Technology of China, Chengdu, China
2. ABB Corporate Research, Västerås, Sweden
3. Hangzhou Dianzi University, Hangzhou, China
4. Institute of Intelligent Information Processing and dean of the School of Electronics and Information Engineering, Taizhou University, Taizhou, China
5. Department of Computer Science and Information Technology, La Trobe University, Bendigo Campus, Victoria, Australia