ner_tags: O B-Person I-Person O O O O O B-Organization I-Organization I-Organization I-Organization O O O O O O O O B-Person I-Person O O B-Location O O O B-Person I-Person O O O O O O O O O O O O O O O O O O
tokens: ACKNOWLEDGEMENTS K. C-j has been supported by the Kim Il Sung University during this investigation, and would like to thank Jo Jong-won for providing Korean historical data and Mun Ui-ri for help with the English. The authors are grateful to an anonymous referee for detailed and helpful comments.