Figure 1. The sequence of graphs representation of the contacts in Table I.
In each discrete time point, the network has a different formation shown as 
.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.