Who wrote the word "Woong San" in Tianjin Zoo?

This is written by the great calligrapher Zuo Fu.

Bears travel most of the time at night and rest in tree holes or caves during the day. In autumn, they go out less during the day. Although they are huge, they are all good swimmers and tree climbers. They can also stand on their hind legs for a long time, attack their opponents with their front paws or get food.