PUST maintains a GitHub account for committing changes to open source projects on GitHub: https://github.com/arirang-pust
A sample commit can be found here: https://github.com/mlpack/mlpack/pull/842
Chat logs from the MLPACK developers discussing the change from PUST: https://www.mlpack.org/irc/mlpack.20161220.html
Blog post from the professor at PUST discussing the changes: https://izbicki.me/blog/teaching-open-source-in-north-korea.html
Associated LinkedIn account for PUST can be found here: https://www.linkedin.com/in/arirang-pust-748483144/
Thanks to the person that submitted this over email!