Hanging node

If a one-route mechanism is supplemented by a "buffer step, the graph will have a "hanging node [Fig. 5(b)]. 

Flows in 2D or 3D geometries using unstructured solution-adaptive triangular/tetrahedral, quadrilateral/hexahedral, or mixed (hybrid) grids that include prisms (wedges) or pyramids (Both conformal and hanging-node meshes are acceptable.) ... 

For a given set H of revoked receivers, let ui,... be the leaves corresponding to the elements in IZ. The method to partition M TZ into disjoint subsets is as follows. Consider the (directed) Steiner Tree ST TZ) defined by the set 71 of vertices and the root, i.e. the minimal subtree of the full binary tree that connects all the leaves in TZ. ST 7Z) is unique. Let Si, ..., Si be all the subtrees of the original tree that hang off ST 7Z), that is, all subtrees whose roots ui,..., are adjacent to nodes of outdegree 1 in ST 7Z), but they are not in ST 7Z). The next claim follows immediately and shows that this construction is indeed a cover, as required. 

Two points are extremely important in such a process. The hrst has to do with the speed of transmission through the network and the time that each packet takes to pass through a node (this is called latency). In actual use, latency has been reduced to about one millisecond. The second point demonstrates the improvement in network efficiency. Each time a packet passes through a node, headed for a transmission link to the next node, the previous link is released. In telephone terms, the computer hangs up. So except for the supervisory information attached to each packet, the efficiency of the system approaches 100 percent. 

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