1. Korea University of Science and Technology, Department of HCI and Robotics, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of KoreabKorea Institute of Science and Technology, Center of Opto-Electronic Materials and Devices, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea
2. Sejong University, Department of Information and Communication Engineering, 98, Kunja-dong, Kwangjin-ku, Seoul 143-747, Republic of Korea
3. Korea Institute of Science and Technology, Center of Opto-Electronic Materials and Devices, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea