Funding for this research was provided by:
Ministry of Science, ICT and Future Planning (NRF-2017M3C7A1044964)
Ministry of Education, Science and Technology (NRF-2016R1A2B4015381)
Text and Data Mining valid from 2019-07-24
Received: 25 February 2019
Revised: 21 June 2019
Accepted: 15 July 2019
First Online: 24 July 2019
Compliance with ethical standards
: All authors declare that they have no conflicts of interest.
: This work did not involve any studies with human participants or animals performed by any of the authors.