Hideki TATSUMOTO, Jongsuk PARK*,† and Masami AIKAWA††
Faculty of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba-shi 263-8522 Japan † Graduate School of Science and Technology, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba-shi 263-8522 Japan †† Faculty of Science, Kisarazu National College of Technology, 11-1 Kiyomidai- higashi 2-chome, Kisarazu-shi 292-0041 Japan