Physical Activity Analysis of College Students During the COVID-19 Pandemic Using Smartphones. - Yuuki Nishiyama; Yuui Kakino; Enishi Naka; Yuka Noda; Satsuki Hashiba; Yusuke Yamada; Wataru Sasaki; Tadashi Okoshi; Jin Nakazawa; Masaki Mori; Hisashi Mizutori; Kotomi Shiota; et al. (CoRR, 2021)