The demand for performance and functionality of embedded systems is increasing over the years. Many applications that require high-speed processing such as multimedia streaming, medical imaging and HDTVs, are commonly implemented on embedded systems. These embedded systems are often implemented on platforms comprising of multiple heterogeneous processing units such as general purpose central processing units (CPU), digital signal processors (DSP) and application specific integrated circuits (ASIC). Energy management is an essential and an imperative requirement in these devices in order to extend their battery life. Therefore, the scheduler in such devices needs to optimize the performance with respect to energy consumption.

In this talk, we present two heuristic energy-aware scheduling algorithms (EGMS and EGMSIV) for scheduling task precedence graphs in an embedded multiprocessor system having processing elements with dynamic voltage scaling(DVS) capabilities. Unlike most energy-aware scheduling algorithms that consider task ordering and voltage scaling separately from task mapping, our algorithms consider them in an integrated way. In EGMS we use the concept of energy gradient to select tasks to be mapped onto new processors and voltage levels. EGMSIV is an extended version of EGMS by introducing intra-task voltage scaling to further reduce the energy consumption. We will discuss on the performance of these strategies with respect to energy savings and optimization times on a wide range of synthetic graphs and real-life tasks.

The Speaker:
Bharadwaj Veeravalli (http://cnds.ece.nus.edu.sg/elebv), Senior MIEEE & MIEEE-CS, received his BSc in Physics, from Madurai-Kamaraj University, India in 1987, Master's in Electrical Communication Engineering from Indian Institute of Science, Bangalore, India in 1991 and PhD from Department of Aerospace Engineering, Indian Institute of Science, Bangalore, India in 1994. He received Gold Medals for his Bachelor's Degree overall performance and for an outstanding PhD thesis (Sabitha Chowdhary Gold Medal, IISc, Bangalore India) in the years 1987 and 1994, respectively.. He did his post-doctoral research in the Department of Computer Science, Concordia University, Montreal, Canada, in 1996. He is currently with the Department of Electrical and Computer Engineering, Communications and Information Engineering (CIE) division, at The National University of Singapore, Singapore, as a tenured Associate Professor. His main stream research interests include, Cloud/Grid/Cluster Computing, Scheduling in Parallel and Distributed Systems, Bioinformatics & Computational Biology, and Multimedia Computing. He is one of the earliest researchers in the field of Divisible Load Theory (DLT). He had successfully secured several externally funded projects. He has published over 100 papers in high-quality International Journals and Conferences. He has co-authored three research monographs in the areas of PDS, Distributed Databases (Competitive Algorithms), and Networked Multimedia Systems, in the years 1996, 2003, and 2005, respectively. He had guest edited a special issue on Cluster/Grid Computing for IJCA, USA journal in 2004. He is a Visiting Professor with HUST, Wuhan, China, since June 2007. He had served as a program committee member and as a Session Chair in several International Conferences and had been recently invited to contribute to Multimedia Encyclopedia, Kluwer Academic Publishers, 2005. He is currently serving the Editorial Board of IEEE Transactions on Computers, IEEE Transactions on SMC-A, Multimedia Tools & Applications (MTAP) and Cluster Computing, as an Associate Editor.

* ALL ARE WELCOME
Contact : Prof. George Baciu
Email : csgeorge@comp.polyu.edu.hk
Tel : 2766-7295 or 2766-7272