Can I get into a good university if I write a great application even with low scores?

Can I get into universities in the Seoul metropolitan area, like Chung-Ang, Kyung Hee, Hankuk Univ. of Foreign Studies, University of Seoul, Konkuk, Dongguk, or Hongik??
Is it possible if I just write a good application, even if my scores are only good enough for a regional university??
Or do I need to have high scores from the very beginning?