On basis of the distribution graph, {HEAD ~ the shortest paths} from {TAIL ~ the distribution node} to each of the other nodes are calculated 
from
On basis of the distribution graph , { HEAD ~ the shortest paths } from { TAIL ~ the distribution node } to each of the other nodes are calculated
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH