1. S. Moriyama. T. Harada and T. Takanashi: Bull. Jpn, Soc, Precis. Eng, Vol. 22 (1998) No. 1, pp.13-17.
2. S. Baek, S.H. Chang, H.L. Chan and et al: IEEE Transactions on Magnetics, Vol. 39 (2003) No. 5, pp.2965-2967.
3. Y. Gao, S. Tse, D. Zhang and et al: Journal of Materials Processing Technology, Vol. 129 (2002), pp.485-489.
4. G.H. Xu and L.S. Qu: Proceedings of the IEEE International Conference on Industrial Technology (1996), pp.771-775.
5. J.Y. Byung, B.C. Goo, Y.N. Heung and et al: IEEE Transactions on Robotics and Automation, Vol. 19 (2003) No. 4, pp.604-612.