1. Hitachi, Ltd., Center for Technology Innovation, Research and Development Group, 1-280, Higashi-Koigakubo, Kokubunji, Tokyo 185-8601, Japan
2. Hitachi, Ltd., Center for Exploratory Research, Research and Development Group, 1-280, Higashi-Koigakubo, Kokubunji, Tokyo 185-8601, Japan