1. Department of Computer Science, University of Cincinnati, Cincinnati, OH, USA
2. Department of Electrical Engineering, University of Wisconsin–Milwaukee, Milwaukee, WI, USA
3. IBM T. J. Watson Research Center, Yorktown Heights, NY, USA
4. Department of Electrical and Computer Engineering, University of Nebraska–Lincoln, Lincoln, NE, USA
5. Department of Computer Science and Engineering, Northeastern University, Shenyang, China