"Advances in sensor networking and the availability of every day, low-cost sensor enabled devices has led to integrating sensors to instrument the physical world in a variety of economically vital sectors of agriculture, transportation, healthcare, critical infrastructures and emergency response. At the same time, social computing is now undergoing a major revolution: social networks, as exemplified by Twitter or Facebook, have significantly changed the way humans interact with one another. We are now entering a new era where people and systems are becoming increasingly integrated and this development is effectively leading us to large-scale mobile human-centered systems. Our goal is to develop a comprehensive framework to simplify the development of mobile human-centered systems, as well as make them predictable and reliable. Our work has the following research thrusts: First, we develop techniques for dealing efficiently with dynamic unpredictable factors that such complex systems face, including dynamic workloads, unpredictable occurrence of events, real-time demands of applications, as well as user changes and urban dynamics. To achieve this, we will investigate the use of mathematical models to control the behavior of the applications in the absence of perfect system models and a priori information on load and human usage patterns. Second, we will develop the foundations needed to meet the end-to-end timeliness and reliability demands for the range of distributed systems that we will consider by developing novel techniques at different layers of the distributed environment and studying the tradeoffs involved. Third, we will develop general techniques to push computation and data storage as much as possible to the mobile devices, and to integrate participatory sensing and crowdsourcing techniques. The outcome of the proposed work is expected to have significant impact on a wide variety of distributed systems application domains."