Funding for this research was provided by:
Korea Institute of Science and Technology Information (K-18-L15-C02-S16, K-18-L13-C03)
National Research Foundation of Korea (No. 2019R1C1C1006358)
Received: 3 June 2019
Accepted: 19 November 2019
First Online: 23 December 2019
Ethics approval and consent to participate
: Not applicable.
: The authors declare that they have no competing interests.