Authors' Address

Ryo Mizuta	Graduate School of Science, Kyoto University
	606-8502	Kyoto JAPAN
	e-mail:	mizuta@kugi.kyoto-u.ac.jp

Kenshi Horii	Graduate School of Science, Kyoto University
	606-8502	Kyoto JAPAN
	（Present address： SUMITOMO BANK）

Shigeo Yoden	Graduate School of Science, Kyoto University
	606-8502	Kyoto JAPAN
	e-mail:	yoden@kugi.kyoto-u.ac.jp

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