Renhe University is in Incheon. It is a very good university with strong science and engineering.
Business and economics at Jianguo University are better.
There are many people in China, Jianguo University, but the location is convenient.
You studied economics and management. I think it's better to go to Jianguo University, because the transportation there is convenient, and it's in Seoul, and many foreigners here have English courses in economics and management.