1. Department of Photonics & Display Institute, National Chiao Tung University, 30010 Hsinchu, Taiwan
2. Department of Computer Science & Institute of Biomedical Engineering, National Chiao Tung University, 30010 Hsinchu, Taiwan
3. Swartz Center for Computational Neuroscience, Institute for Neural Computational, University of California, San Diego, La Jolla, 92093 CA, USA