Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.|Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.|Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.|Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.|Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.|Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.|Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.|Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.|Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.|Electrical and Computer Engineering Department, Duke University, Durham, NC, USA.