Funding for this research was provided by:
National Research Foundation of Korea (NRF-2009-093818 and NRF-2014R1A4A1071686)
Korea Evaluation Institute of Industrial Technology (10050296)
Text and Data Mining valid from 2018-07-06
Received: 12 January 2018
Accepted: 21 March 2018
First Online: 6 July 2018
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.