1. 1) K. Imazu: J. Jpn. Inst. Light Met., 44 (1994), 110 (in Japanese).
2. 2) I. Komatsu and M. Horiguchi: Jpn. Packag. Inst. J., 41 (2003), 312.
3. 3) A. Tanaka and T. Okamura: CAMP-ISIJ, 6 (1993), 536 (in Japanese).
4. 4) N. Maida, S. Takahashi, L. Hu and M. Itoh: Toyo Kohan, 34 (2004), 1.
5. 5) M. Kai, S. Taya and H. Tomaru: Testu-to-Hagané, 99 (2013), 20 (in Japanese).