1. Division of Electronic Engineering, School of Science and Engineering, Tokyo Denki University, Saitama, Japan
2. Division of Information Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara, Japan
3. Graduate School of Robotics and Design, Osaka Institute of Technology, Osaka, Japan
4. Applied Robotics Research, Microsoft Corporation, Redmond, WA, USA