Simplify the following text for a Grade 6 native English-speaking person.
Original: Chung Yong-Dae ( Korean : ì ì ë , Hanja : é å è , born 4 February 1978 ) , is a former Japanese-born South Korean midfielder .
Simplified: Chung Yong-Dae ( born 4 February 1978 ) is a South Korean football player .