1. School of Electrical Engineering and Computer Science, College of Engineering, Seoul National University, Seoul, Korea.
2. Inter-University Semiconductor Research Center, Seoul National University, Seoul, Korea.
3. Research Institute, Nurobiosys Corporation, Suwon, Korea.
4. Department of Electronics Engineering, College of Engineering, Ewha Womans University, Seoul, Korea.
5. Department of Biomedical Engineering, College of Electronics & Information, Kyung Hee University, Yongin, Korea.
6. Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea.