Funding for this research was provided by:
Army Research Office (W911NF-15-1-0562)
National Science Foundation (DMS-1462156, EAR-1344280)
National Science Foundation (DMS-1307470, DMS-1309856)
National Science Foundation (DMS-1612885)
Deutsche Forschungsgemeinschaft (KE1741/6-1)
Article History
Received: 27 June 2016
First Online: 4 November 2016