The “cost of survivability” is defined as the ratio of {HEAD ~ the costs} of {TAIL ~ network operation} with and without survivability requirements 
of
The “ cost of survivability ” is defined as the ratio of { HEAD ~ the costs } of { TAIL ~ network operation } with and without survivability requirements
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH