Funding for this research was provided by:
National Research Foundation of Korea (WISET-2019-272, NRF-2017R1A2B4007219)
Universiti Malaya (IIRG001-19FNW)
Text and Data Mining valid from 2020-01-20
Received: 16 September 2019
Accepted: 3 December 2019
First Online: 20 January 2020
: The authors declare that they have no competing interests.