1. National Institute of Technology, Toyama College, 13 Hongo-machi, Toyama City, Toyama 939-8630, Japan
2. National Institute of Technology, Oshima College, 1091-1 Komatsu, Suouoshima, Yamaguchi 742-2193, Japan
3. Tateyama Machine Co., Ltd., 30 Shimonoban, Toyama City, Toyama 930-1305, Japan
4. Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan