1. “AIBO Official Site.” http://www.sony.jp/products/Consumer/aibo/
2. “Aldebaran Robotics, the creators of Nao – Aldebaran Robotics.” http://www.aldebaran-robotics.com/
3. “iRobot Corporation: Home Page.” http://www.irobot.com/
4. “CCP Co.,Limited – so-zi Robotic Vacuum Cleaner,” (in Japanese). http://www.ccp-jp.com/life/so-zi/
5. Y. Cui and J. J. Weng, “View-Based Hand Segmentation and Hand-Sequence Recognition with Complex Backgrounds,” In Proc. of the Int. Conf. on Pattern Recognition, pp. 617-621, 1996.