Text and Data Mining valid from 2019-05-07
Received: 7 November 2018
Accepted: 29 April 2019
First Online: 7 May 2019
Compliance with ethical standards
: Drs. Se Hyun Paek, Hye Ah Lee, Hyungju Kwon, Kyung Ho Kang, and Sung Jun Park have no conflicts of interest or financial ties to disclose.