Research and Development Headquarters, NTT DATA Corporation, Tokyo 135-8671, Japan. matsunagat@nttdata.co.jp|Research and Development Headquarters, NTT DATA Corporation, Tokyo 135-8671, Japan. matsunagat@nttdata.co.jp|Research and Development Headquarters, NTT DATA Corporation, Tokyo 135-8671, Japan. matsunagat@nttdata.co.jp|Research and Development Headquarters, NTT DATA Corporation, Tokyo 135-8671, Japan. matsunagat@nttdata.co.jp