I work at the Korea Advanced Institute of Science and Technology (KAIST), although starting fall 2012 I have a one-year position at the University of Puget Sound. I study combinatorics. I maintain the KAIST Sage server at sagenb.kaist.ac.kr.
I'm the main author of SageTeX, a LaTeX package that allows you to integrate Sage code into your documents.
I wrote some notes on setting up a (hopefully) secure Sage virtual machine using Ubuntu JeOS: /JustEnoughSageServer. I'm also expanding the notebook() docstring at StartingTheNotebook; this will likely end up in the official documentation, I think. Ubuntu has dropped the whole "JeOS" thing and I should update that document.
I was one of the organizers of Sage Days 37 in Seoul.
My homepage is http://mathsci.kaist.ac.kr/~drake and my email address is ddrake at member ams org. (I trust you can put in the dots and @ properly.)