He has been active in NLP research, especially on the optimization of core NLP tasks for robustness and scalability. He developed an open source project called NLP4J, previously known as ClearNLP, providing NLP components showing state-of-the-art accuracy and speed, which has been widely used for both academic and industrial research. Recently, he started a new project called “Character Mining” that aims to infer explicit and implicit contexts about individual characters in colloquial writing such as dialogs and emails.