1. (1) Morikawa, H. and Isshiki, N., The Study on a Propulsion System by Fin Stroke, Bulletin of M. E. S. J., Vol. 8, No. 1, (1980).
2. (2) Nakajima, H., Tokuo, K., and Ono, K., Experimental Study of a Two-Joint Dolphinlike Propulsion Mechanism (2nd Report, Experiment of Self-Propelled Large Robot), Transactions of the Japan Society of Mechanical Engineers, Series C, Vol. 66, No. 643, (2000), pp. 695-702.
3. (3) Watanabe, M., Muramatsu, K., and Kobayashi, N., Propulsion Performance of an Aquatic Mobile Robot Using Traveling-Wave Motion of a Flexible Fin (Relationship between Propulsion Efficiency and Flow Pattern, Transactions of the Japan Society of Mechanical Engineers, Series C, Vol. 68, No. 665, (2002), pp. 188-196.
4. (4) Kawamura, S., Yamamoto, T., Ishida, D. Ogata, T., Nakayama, Y., Tabata, O., and Sugiyama, S., Development of Passive Elements with Variable Mechanical Impedance for Wearable Robots, Proceedings of 2002 IEEE International Conference on Robotics and Automation, (2002), pp. 11-15.
5. (5) Umedachi, T., Kishi, H., Yamada, Y., and Ishiguro, A., Development of a Real-time Tunable Spring -Toward Independent Control of Position and Stiffness of Joints-, Proceedings of the 2005 JSME Conference on Robotics and Mechatronics, (CDROM), (2005), 1P2-S-005.