1. College of Science and Engineering; Ritsumeikan University; 1-1-1 Noji-higashi Kusatsu Shiga 525-8577 Japan
2. Faculty of Engineering; University of Toyama; 3190 Gofuku Toyama 930-8555 Japan
3. Hitachi High-Technologies Corporation; 11-1 Ishikawa-cho Hitachinaka Ibaraki 312-0057 Japan