Text and Data Mining valid from 2019-12-01
Received: 17 February 2019
Accepted: 5 December 2019
First Online: 20 December 2019
: This research did not receive specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Y.W., A.S., H. Kaneda, S.S. and Y.T. are employees of SAPPORO HOLDINGS LTD. The remaining authors have no conflict of interest to disclose.