1. School of Electronics and Information Engineering, Taizhou University, Taizhou, China
2. ABB Corporate Research, Västerås, Sweden
3. ABB Corporate Research, Baden, Switzerland
4. Department of Computer Science and Information Technology, School of Engineering and Mathematical Sciences, La Trobe University, Bendigo Campus, Flora Hill, VIC, Australia
5. School of Electrical Engineering, KTH Royal Institute of Technology, Stockholm, Sweden