When Doowon Koh came from Korea to work with me at the University of Missouri, I immediately knew that he was an outstanding student. He was willing to read very difficult papers and always came to meeting prepared. What was wonderful and somewhat humorous was the contrast between him and Derrick Hart. If I sent a calculation to Derrick that was not correct, he would walk into my office and say something like: "Alex! The calculation is wrong!". Doowon approached such things very differently. He would usual say: "Professor Iosevich! How should formula in line 5 on page 7 of your draft be interprepeted?" What he mean was that line 5 was completely wrong. My usual reaction was to ask him how he "interprets" that line. Doowon would inevitably tell me that he "took the liberty of rephrasing" line 5 and hand me a new draft where everything was completely correct.

One of the most amazing moments of my interaction with Doowon was on the day when he defended his thesis. This was the first time he called me by my first name instead of "Professor Iosevich". Our collaboration and friendship has continued to this day.