Tamami Maruyama, Masashi Nakatsugawa, Takahiko Nakamura, National Institute of Technology, Hakodate College, Japan; Yasuhiro Tamayama, Nagaoka University of Technology, Japan; Tsunayuki Yamamoto, NIT, Tsuyama College, Japan; Manabu Omiya, Hokkaido University, Japan; Keiichi Ito, NIT, Akita College, Japan; Kouzoh Ohshima, NIT, Asahikawa College, Japan; Mitsuru Muramoto, Yutaka Nasuno, NIT, Tomakomai College, Japan