©Se Young Jung, Jeong-Whun Kim, Hee Hwang, Keehyuck Lee, Rong-Min Baek, Ho-Young Lee, Sooyoung Yoo, Wongeun Song, Jong Soo Han. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 28.05.2019.
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