1. Department of Computer Science, Mount Holyoke College, 50 College Street, South Hadley, MA 01075, USA
2. Department of Engineering, Trinity College, 300 Summit Street, Hartford, CT 06106, USA
3. Department of Electrical and Computer Engineering, University of Washington, 185 Stevens Way, Paul Allen Center — Room AE100R, Campus Box 352500, Seattle, WA 98195-2500, USA