1. Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
2. Department of Computer Science, City University of Hong Kong, Pokfulam, Hong Kong
3. Department of Computing, Imperial College London, London, U.K.
4. Department of Research and Development, YEESTOR Microelectronics Company Ltd., Shenzhen, China
5. Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan