Xiaoguo Zhang is a visiting associate professor visiting CGIS and UMIACS at the University of Maryland. He received the M.S. and Ph.D. degrees in the CAD and GIS from Southeast University, Nanjing, China, in 1998 and 2001, respectively. From 2002 to 2003, he was with the Maritime Research Center, Nanyang Technological University, Singapore, where his research was focused on maritime GIS and optimal path finding. In April 2003, he joined Motorola China as a senior software engineer, and later as a project leader and senior staff software engineer. His R&D work has been mainly on embedded Java virtual machine and location-based services. He is now an associate professor in the School of Instrument Science and Engineering, Southeast University, China. Dr. Xiaoguo Zhang’s current research interests are mainly in geospatial data analysis using computational topology, spatial data structures, and image processing.