1. School of Computer Science and Engineering, The University of Aizu, Aizuwakamatsu, Japan
2. Department of Computer Science and Engineering, Hong Kong University of Science and Technology, Hong Kong, China
3. Department of Electrical and Computer Engineering, The University of Victoria, Victoria, Canada
4. Warwick Manufacturing Group (WMG), The University of Warwick, Coventry, U.K.
5. Department of Electrical and Computer Engineering, Advanced Networking Laboratory, New Jersey Institute of Technology, Newark, NJ, USA