Funding for this research was provided by:
Samsung Advanced Institute of Technology
National Research Foundation of Korea (NRF-2017R1C1B5075685, NRF-2019R1A4A1024732)
Text and Data Mining valid from 2019-11-21
Received: 29 August 2019
Accepted: 13 November 2019
First Online: 21 November 2019
: The authors declare that they have no competing interests.