Funding for this research was provided by:
Korea Polar Research Institute (PE20150, PE19180)
Text and Data Mining valid from 2020-02-01
Received: 18 November 2019
Accepted: 21 January 2020
First Online: 1 February 2020
Ethics approval and consent to participate
: Not applicable.
: All the authors agree to the submission and publication of this manuscript.
: The authors declare that they have no competing interests.