Kobayashi, Akemi https://orcid.org/0000-0002-4519-9370
Kimura, Toshitaka https://orcid.org/0000-0002-1334-3438
Article History
Received: 13 March 2021
Accepted: 28 February 2022
First Online: 1 April 2022
Competing interests
: A.K. and T.K. are affiliated with Nippon Telegraph and Telephone Co. The authors have no other competing interests to declare.