1. Nexco-Engineering Hokkaido Co., Ltd., 3-20, 5-jyo 4 chome, Higashi Sapporo 003-0005, Japan
2. Technology Planning Section, Hokkaido Regional Head Office, East Nippon Expressway Co., Ltd., 12-30, Oyachinishi 5-chome, Atsubetsu-ku, Sapporo 004-0042, Japan
3. Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan