text: Kim Hyo-yeon ( ; Hanja : é ` å æ ; born September 22 , 1989 ) , better known by her first name Hyoyeon , is a South Korean singer , dancer , and model .
simplified: Kim Hyo-yeon ( born September 22 , 1989 ) , better known by her stage name Hyoyeon , is a South Korean recording artist and entertainer .