He received his Ph.D. degree in computer science from Keio University, Tokyo, Japan, in 2009. During 2009-2011, he was a post-doctoral researcher at Institut TELECOM SudParis in France. His research interests include ubiquitous computing, mobile social networking, and cross-community mining. Dr. Guo has served as an editor of IEEE Communications Magazine, ACM/Springer Personal and Ubiquitous Computing (PUC), and the guest editor of ACM Transactions on Intelligent Systems and Technology (TIST). He has served as the general chair of the SCI-11, the publicity chair of UIC’12, ICTH’13, the workshop chair of iThings’13, and the TPC member for a number of conferences. He has published over 50 scientific papers in referred journals, conferences, and book chapters. He won the best paper award of AMT’2012 and GPC’2012.