Abstract:
Energy-efficiency is a critical concern in continuously-running mobile applications, such as those for health and context monitoring. Unfortunately, developers must implement complex and customized power-management policies for each application. This involves using low-level power-management primitives and writing error-prone multithreaded code to monitor the phone's hardware state. To address this problem, we propose an annotation language and middleware service that eases the development of energy-efficient Android applications. Our power annotations are used to demarcate power-hungry code segments whose execution is deferred until the device enters a state that minimizes the energy consumed during their execution. While a wide range of power management policies can be specified using our power annotations, a potential challenge is that introducing delays to save power may have a detrimental impact on the user experience. The impact of power management on timeliness is managed by associating delay budgets with objects that contain time-sensitive data. We use static analysis to help the programmer determine the impact of introducing power-related delays in an application, which may lead to difficult-to-debug errors due to concurrency. In combination, the static analysis and the run-time service ensure that power management policies will not delay an object more than its assigned budget. Detailed experiments show that our approach may effectively control the energy-delay trade-off in realistic mobile applications.

Biography:
Octav Chipara is an Assistant Professor in the Department of Computer Science at the University of Iowa and part of the Aging Mind and Brain Initiative. He received his PhD from Washington University in St. Louis and completed his Postdoctoral Fellowship at the University of California San Diego. His research focuses on the systems, networking, and software engineering aspects of developing mobile health (mHealth) systems that continuously monitor and infer the health status of patients in spite of operating in dynamic environments and on limited battery resources. A central theme of his research is that in order to harness the full potential of mHealth systems, we must have better tools for programming and analyzing their properties. Dr. Chipara's work combines the design of communication protocols, middleware, and programming tools with large-scale real-world deployments of mHealth systems.

Host:
Dr. Guoliang Xing and Dr. Xiaoming Liu