I am a Ph.D. candidate from the Department of Geography, Environment, and Spatial Sciences at Michigan State University. My research interests include health geography, GIS, agent-based modeling and social network analysis. The focus of my research integrates the above categories by looking at the joint impact of the built environment and social network on adolescents’ physical activity. Obesity among adolescents is a serious public health problem in many countries. Regular physical activity can not only help with weight control but provide other physical and mental health benefits. However, there are a lot of adolescents who do not do enough physical activity every day. Their behavior can be influenced by many factors, and I believe it is important to detangle different impacts to better understand the underlying decision-making process of behavioral change, which can facilitate policymakers to develop effective interventions that promote public health.