1. Information and Communication Technology Division Railway Technical Research Institute 2‐8‐38, Hikari‐cho Kokubunji‐shi Tokyo 185‐8540 Japan
2. Graduate School of Science and Engineering Chiba University 1‐33, Yayoi‐cho, Inage‐ku, Chiba‐shi Chiba 263‐8522 Japan
3. Research and Development Promotion Division Railway Technical Research Institute 2‐8‐38, Hikari‐cho Kokubunji‐shi, Tokyo 185‐8540 Japan
4. Signalling and Operation Systems Technology Division Railway Technical Research Institute 2‐8‐38, Hikari‐cho Kokubunji‐shi, Tokyo 185‐8540 Japan
5. Product Division Hitachi‐Kokusai Electric Inc. 32 Miyuki‐cho Kodaira‐shi, Tokyo 187‐8511 Japan
6. Center for Frontier Medical Engineering Chiba University 1‐33, Yayoicho, Chiba‐shi Chiba 263‐8522 Japan