“…In terms of transliteration unit, existing machine transliteration models can be classified into three categories, phoneme-based (Knight and Graehl, 1997;Lee and Choi, 1998;Wan and Verspoor, 1998;Jung et al, 2000;Meng et al, 2001;Oh and Choi, 2002;Virga and Khudanpur, 2003;Gao et al, 2005), grapheme-based Ekbal et al, 2006;Ganesh et al, 2008;Das et al, 2009;Chinnakotla et al, 2010;Finch and Sumita, 2010), and hybrid (Al-Onaizan and Knight, 2002;Bilac and Tanaka, 2004;Oh and Choi, 2005;Oh et al, 2006;Kim et al, 1999).…”