1. LG Japan Lab Ltd., Yokohama, Kanagawawa 220-0011, Japan
2. LG Electronics Inc., 19, Yangjae-daero 11gil, Seocho-gu, Seoul 137-130, Korea
3. Graduate School of Information Sciences, Tohoku University, Sendai 980-8579, Japan
4. Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8550, Japan
5. Sigma-i Co. Ltd., Minato, Tokyo 108-0075, Japan