1. a Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
2. b School of Engineering Science, Simon Fraser University, 250-23450, 102nd Avenue, Surrey, BC V3T 0A3, Canada;, Email: arad@sfu.ca
3. c Department of Electrical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
4. d Department of Automatic Control, Beijing Institute of Technology, Beijing 100081, P. R. China
5. e Department of Automatic Control, Beijing Institute of Technology, Beijing 100081, P. R. China