1. Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, USA
2. ABB US Research Center, ABB. Inc., Raleigh, NC, USA
3. College of Engineering, Computing and Applied Sciences, Clemson University, North Charleston, SC, USA
4. Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA