Bi-annual Newsletters Vol. 4 | Page 5

research highlights We exploited this low-rank property of PMU data matrix for multiple data management tasks. Take missing data recovery as an example. Data losses can happen in an unpredictable way during the communication between PMUs and the phasor data concentrator at the central operator. Losing measurements makes the system unobservable and degrades the performance of the state estimator. We formulated the missing data recovery problem as a low-rank matrix completion problem and developed computationally efficient data recovery methods. Fig. 5 compares the recovery performance of multiple recovery methods. For the dataset shown in Figs. 2~4, even when 30% of the measurements are lost at random locations, our methods can accurately recovery the missing points. Using MATLAB running on a desktop with Intel i7-4770 @ 3.40GHz and 12 GB DDR3 RAM, our developed online data recovery method took less than 1 millisecond to fill in the missing points in each sampling instant. Hitachi America is interested in implementing our methods in their prototype of new remedial action scheme (RAS) for Bonneville Power Administration (BPA). Fun Fact Did you know that data loss and computer downtime can cost enterprises $1.7 trillion per year or the equivalent of nearly 50% of Germany’s GDP? f a c u l t y s p o t l i g h t Professor Meng Wang is e the newest CURENT faculty member. She says, “CURENT is a unique organization that brings people of diverse backgrounds and expertise together. The intellectual communication within CURRENT happens very naturally and smoothly and I really enjoy the synergy of our research. It is exciting and fun to be a team member here.” Prof. Wang is also an assistant professor in the Department of Electrical, Computer and Systems Engineering at Rensselaer Polytechnic Institute (RPI). She obtained her B.S. and M.S in Electrical Engineering from Tsinghua University in 2005 and 2007, respectively, and earned her PhD degree in Electrical and Computer Engineering from Cornell University in August 2012. She was a postdoc research scholar at Duke University before she joined RPI in Spring, 2013. When asked how she came to the field of power systems in academia, Prof. Wang stated, “I like math and physics and wanted to explore fundamental science. I also like to know how things work and want to do something to contribute to everyday life. Electrical Engineering is a field that combines these two objectives perfectly. I can work on problems that have clear practical applications, while I still have the freedom to explore fundamental theoretical developments beyond applications. For example, one project that our group is currently working on is the data management and information extraction of large amounts of synchrophasor measurements in power systems. It is an important question in power system monitoring and operation. The techniques we develop exploit low-dimensional models of signals in high-dimensional space. These techniques are generic and thus can be applied to other fields like image processing, social network analysis, etc. This type of exploration makes academia a natural choice for me. I very much enjoy the freedom of research. Another big bonus of academia life is that I get to work with many brilliant students, both undergraduate and graduate students. I am happy to share my experiences and to learn with them.” Prof. Wang’s current research focuses on high-dimensional data analysis and its application in power system monitoring. Her boarder research interests include signal processing, optimization and networked systems. Welcome, Professor Wang! newsletter Spring newsletter Summer 2015 4