When I am free, I enjoy playing badminton and swimming.

[1] For swimming, I usually adopt the following training session:

Flutterkick for 100 meters + Freestyle for 300 meters + Medley for 400 meters + Medley for 400 meters + Backstroke for 100 meters+ Breaststroke for 100 meters + Medley for 200 meters + Medley for 200 meters +  Freestyle for 200 meters : All 2000 meters in 40 minutes.

[2] For badminton, I particularly enjoyed playing singles. I have attended NCKU open men single in 2025 summer, to the round of 16.  I will also participate in another badminton competition in Taipei. (https://www.youtube.com/watch?v=W_5bIHZK1gw&t=24861s)

[3] Even though I worked on elliptic PDE and free boundary problems, the most beautiful subject in mathematics from my taste is group theory! I wrote a short classroom note, On Groups Whose Squares Are Subgroups, during my undergraduate years!