It is easily shown that every digraph with m edges has a directed cut of size at least m/4, and that 1/4 cannot be replaced by any larger constant. We investigate the size of a largest directed cut in acyclic digraphs, and prove a number of related results concerning cuts in digraphs and acyclic digraphs.

Hajnal, A. and N. Sauer, Cut-sets in infinite graphs and partial orders. Discrete Mathematics 117 (1993) 113-125. The set S c V(U) is a cut-set of the vertex v of a graph 9 if v is not adjacent to any vertex in S and, for every maximal clique C of Q, ({v} u S) n C # 0. S is a cut-set of the element v of a partial order 9 if S is a cut-set of v in the comparability graph of 8. Given upper bounds...

Traditionally, the min-cut problem was solved by solving n − 1 min-st-cut problems. In the min-st-cut problem we are given as input two vertices s and t, our aim is to find the set S where s ∈ S and t / ∈ S which minimizes the size of the cut (S, S), i.e., |δ(S)|. The size of the min-st-cut is equal to the value of the max-st-flow (equivalent by linear programming duality). The fastest algorith...

SUMMARY This paper presents the results of a simulation study of blocking and non-blocking switching for hierarchical ring networks. The switching techniques include wormhole, virtual cut-through, and slotted ring. We conclude that slotted ring network performs better than the more popular wormhole and virtual cut-through networks. We also show that the size of the node buuers is an important p...

SUMMARY This paper presents the results of a simulation study of blocking and non-blocking switching for hierarchical ring networks. The switching techniques include wormhole, virtual cut-through, and slotted ring. We conclude that slotted ring network performs better than the more popular wormhole and virtual cut-through networks. We also show that the size of the node buuers is an important p...