Funding for this research was provided by:
Israel Science Foundation (246/08 and 1536/14)
National Science Foundation (CCF-1217423 and CCF-1065125)
National Science Foundation (CCF-1217423 and CCF-1065125)
Israel Science Foundation (1536/14)
National Science Foundation (CCF-1217423, CCF-1065125, CCF-1420692)
Article History
Received: 11 March 2015
Accepted: 10 December 2015
First Online: 2 February 2016
Compliance with Ethical Standards
:
: The authors declare that they have no conflict of interest.