**Daniel Pettingill, Daniel Kurtz and Daniel Smalley \***

Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA; dptres16@gmail.com (D.P.); kurtz117@yahoo.com (D.K.)

**\*** Correspondence: smalley@byu.edu; Tel.: +1-1-801-422-4343

† It is an invited paper for the special issue.

Received: 20 December 2018; Accepted: 7 January 2019; Published: 11 January 2019
