premise: Kim Won-sik (Hangul: 김원식 , born February 15, 1993) better known by his stage name Ravi (Hangul: 라비 ), is a South Korean rapper, singer-songwriter, producer, signed under Jellyfish Entertainment. He is a member of the South Korean boy group VIXX and VIXX sub-unit VIXX LR. He debuted as a solo artist on January 9, 2017, with the release of his debut mini album "R.EAL1ZE".
hypothesis: Kim Won-sik is the singer for the album "R.EAL1ZE".
reason: It is correct. Kim was solo for his album "R.EAL1ZE". Maybe the system did not connect singer to solo artist.