1. Department of Electrical and Electronic EngineeringRitsumeikan University 1‐1‐1 Nojihigashi Kusatsu Shiga 525‐8577 Japan
2. Research Organization of Science and TechnologyRitsumeikan University 1‐1‐1 Nojihigashi Kusatsu Shiga 525‐8577 Japan
3. Ritsumeikan Global Innovation Research OrganizationRitsumeikan University 1‐1‐1 Nojihigashi Kusatsu Shiga 525‐8577 Japan
4. Atsugi Research Center, Advanced Technology Research LaboratoriesIdemitsu Kosan Co.,Ltd. Atsugi Kanagawa 243‐0206 Japan