1. Advanced Power Electronics Research CenterNational Institute of Advanced Industrial Science and TechnologyTsukubaIbarakiJapan
2. Department of Electronics and Applied PhysicsTokyo Institute of TechnologyYokohamaKanagawaJapan
3. Frontier Research CenterTokyo Institute of TechnologyYokohamaKanagawaJapan
4. Research Institute for Applied MechanicsKyushu UniversityKasuga, FukuokaJapan