My main interest is building real-life biomedical text applications for better healthcare. My background are natural language processing (NLP) and machine learning. I obtained PhD degree from Japan Advanced Institute of Science and Technology (JAIST), Japan in 2005 in computer science. I joined Kaiser Permanente Southern California since October 2015. Prior to that, I researched at National Institute of Informatics (Japan), Vanderbilt University, and DBMI, UC San Diego. I had been working on public mood tracking on Twitter data. Several our research results was mentioned to public, e.g., research on social media in epidemic intelligence (Nature), or the research on public mood tracking in 2011 Tohoku earthquake in Japan (New Scientist, CorpComm).