1. 1) S. Miyawaki: Kobe Steel Eng. Rep., 61 (2011), No.2, 1.
2. 2) M. Takahashi, M. Suehiro, T. Ochi and Y. Miyazaki: Shinnittetsu Giho, 391 (2011), 27.
3. 3) S. Matsuoka, K. Hasegawa and Y. Tanaka: JFE Giho, 16 (2007), 16.
4. 4) K. Kasuya and Y. Mukai: Kobe Steel Eng. Rep., 57 (2007), No.2, 27.
5. 5) H. Shirasawa, Y. Tanaka, M. Miyahara and Y. Baba: Trans. Iron Steel Inst. Jpn., 26 (1986), 310.