David Wei Cai(publication under name David Tsai) received BS degrees in Electrical Engineering from Tsinghua University in 2009 and a Masters in Computer Science from Georgia Institute of Technology in 2012. He is currently on leave from the PhD program in Computer Science from Georgia Institute of Technology specialized in computer vision and machine learning. He interned from 2010/5 to 2012/8 at Google Research and Dotorg, working on several projects including image annotation, visual search for child protection and object understanding in Youtube videos. In 2013 he co-founded a computer vision based startup VisualGraph, a visual search engine for shopping and was acquired by Pinterest in 2013/12. Currently he is a member of the image search group, working on image content annotation and other computer vision/machine learning problems.