1. Department of Intelligent Engineering, College of Engineering; Ibaraki University; 4-12-1 Nakanarusawa-cho; Hitachi-shi; Ibaraki; 316-8511; Japan
2. TOPY Industries Ltd; 2-3-1 Ohue; Ayase-shi; Kanagawa; 252-1104; Japan
3. Graduate School of Science and Engineering; Ibaraki University; 4-12-1 Nakanarusawa-cho; Hitachi-shi; Ibaraki; 316-8511; Japan