Dennis received his PhD in Computer Science from UC Irvine, where he was advised by Deva Ramanan. His research interests span computer vision and machine learning with a focus on visual recognition. His work on tracking people and their 2D body poses in videos was published in CVPR, ECCV, and ICCV. During his PhD, he worked as a research intern in Los Alamos National Laboratory and Microsoft Research, and was a recipient of ARCS award. He received his B.S in Physics from Seoul National University, South Korea.