“…Some years later, many researchers incorporated machine learning algorithms to their systems, but there was still a strong dependency on external resources and domain-specific features and rules (Tjong Kim Sang and De Meulder, 2003). In addition, the majority of the systems used Maximum Entropy (Bender et al, 2003;Chieu and Ng, 2003b;Curran and Clark, 2003;Florian et al, 2003b;Klein et al, 2003) and Hidden Markov Models (Florian et al, 2003b;Klein et al, 2003;Mayfield et al, 2003;Whitelaw and Patrick, 2003). Furthermore, McCallum and Li (2003) used a CRF combined with webaugmented lexicons.…”