PIMS PDF Hansol Park, aligning patience with academic velocity
By Robyn Humphreys, Communications and Event Assistant
Hansol was looking forward to returning to Vancouver, for a long-overdue visit. But right now, it’s proving to be a long wait! He had planned to move to Canada in the middle of August and start his Postdoc with Professor Razvan Fetecau at Simon Fraser University (SFU). He first visited Vancouver in 2019 and enjoyed touring this West Coast City, going on hikes and jaunts along the Sea Wall and Stanley Park. He was quite taken with the harmony of nature and the city.
However, the Pandemic, along with issues arising from the crisis in Afghanistan, has slowed down his visa processing application and he is yet to set foot at SFU. Fortunately, Hansol’s advisor provided him with a short-term postdoc position at Seoul National University (SNU) where he finished his undergraduate and doctorate degrees. This “soft introduction” into the PDF life is quite different than life as a graduate student.
Though the wait may take a few more days, Hansol is still looking forward to his move: “Canada has a very large territory, different from Korea.”, Hansol tells us, “In fact, Canada’s territory is 45 times that of South Korea, but the population of Canada is less than that of South Korea. So the number of cars is fewer than in Korea, and most of the parking lots in Vancouver are available!” We hope he’ll be able to secure a parking spot, up the mountain, at the SFU Burnaby Campus!
You’ve worked with Professor Razvan Fetecau in the past. Can you share with us how that relationship developed?
My adviser (Prof. Ha) and Prof. Fetecau have known each other for a long time, but did not work together until October 2019. They participated in the same conference at Jeju Island, Korea. My advisor presented some results on the Lohe matrix model, a consensus model on the unitary group. Prof. Fetecau saw my advisor’s presentation and he wanted to use the Lohe matrix model to complete his project on intrinsic models on a manifold. Intrinsic models on the manifold are models defined by the intrinsic distance (geodesic distance), so Prof. Fetecau decided to work with my advisor.
My advisor was busy at the time, so he decided to send me to work with Prof. Fetecau. Our first meeting was in October 2019. Prof. Fetecau wanted to study the intrinsic model on a manifold. For two weeks, I calculated some estimates on the unit sphere and the special orthogonal group. From these results, we wrote papers [1] and [2] on the sphere and the special orthogonal group, respectively. Both papers were accepted in Analysis and Applications and Journal of Nonlinear Science, respectively, so we could finish the project on the intrinsic model successfully.
After this project, we began a second project; the Cucker-Smale model on rotation matrices. The Cucker-Smale model is a velocity alignment model defined on a manifold. Since we considered the special orthogonal group as the domain of the system, we were confident to study a system given in the same domain. From this work, we wrote a paper [3], and now it has been submitted. From April this year, we began to study the minimization problem of energy functionals. It is related to the variational method. We will submit the paper on this topic soon.
Is this your first Postdoc? Do you feel there is a difference between your graduate and PDF research?
This will be my first Postdoc, except for the short-term Postdoc at SNU. I think the main difference between graduate and PDF is that now I am an independent researcher. At the beginning of my doctoral period, I got a research topic from my advisor; as a Postdoctoral researcher, I find a research topic myself. These give me both freedom and responsibility.
Was your research affected by the pandemic? How did you adjust to working online?
When the pandemic began, I was a third-year Ph.D. student. It was a hectic time for me, and other than wearing a mask every day, I was not affected by the Pandemic much. Fortunately, Korea did not lockdown so the research I was doing with my coworker at SNU was not interrupted. However, at the beginning of 2021, my trip to the University of South Carolina (Prof. Wuchen Li, Topic: Information geometry), was affected. At that time, the number of confirmed cases had increased sharply. I canceled my trip, and instead, we conducted our meeting online. I have done online meetings before; however, it was the first time to conduct a joint research project online from the very start. Since the topic is not familiar to me, the online meeting was a little tough at the beginning. However, after adapting to the topic, the discussion became better. From this experience, I realized that online meetings are very efficient since they allow us to work with other researchers on the other side of the globe.
Were you teaching online, and are you now teaching in-person?
In the last semester of my doctoral period, I used zoom for my TA class (calculus). This was a new experience for me and I found it very inefficient. Checking students’ body language was restrictive, therefore I could not provide a proper explanation. I do not have any teaching duties at the moment but I hope to teach students in person soon.
What do you do to balance your research and life?
I registered for a gym membership near my office so I could exercise in my spare time when I want to refresh myself. I also enjoy walking around the boundary of SNU, which is the biggest university in Korea. It is located in Gwanak Mountain and sometimes I hike to the top; the scenery is so lovely.
Does anything stand out for you from your last trip to Vancouver?
I was surprised by the system to stop the bus. For Canadians, this system is very natural, but for me, it was amazing. In Korea, we only have buttons to stop the bus. However, buses in Canada have a string. If we pull the line, then the button at the end of the line is pulled. I think this system is very clever! When I take a bus in Korea, sometimes I cannot find the stop button immediately. However, the string system allows stopping the bus easily. I thought it would be nice to introduce this system in Korea.
Hansol will be speaking at the PIMS Emergent Research Seminar Series, on December 8, 2021, at 9:30 AM Pacific. Details on his talk, An Algebraic Approach on Fusions of Synchronization Models, can be found here.
[1] Razvan C. Fetecau, Hansol Park, and Francesco S. Patacchini: “Well-posedness and asymptotic behaviour of an aggregation model with intrinsic interactions on sphere and other manifolds,” Analysis and Applications, 19 (2021), 965–1017.
[2] Razvan C. Fetecau, Seung-Yeal Ha, and Hansol Park: “An intrinsic aggregation model on the special orthogonal group SO(3): well-posedness and collective behaviours,” Journal of Nonlinear Science, 31 (2021), 74.
[3] Razvan C. Fetecau, Seung-Yeal Ha, and Hansol Park: “Emergent behaviors of rotation matrix flocks,” submitted to SIAM Journal on Applied Dynamical Systems.
