1. Research Laboratory of Resources Utilization, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Japan
2. DIT Laboratory, Kansai Paint Co., Ltd., Hiratsuka, Kanagawa, Japan
3. Ibaraki Electrical Communication Laboratory, Nippon Telegraph and Telephone Public Corporation, Tokai-Mura, Ibaraki, Japan