It is known that for every integer k ≥ 4, each k-map graph with n vertices has at most kn − 2k edges. Previously, it was open whether this bound is tight or not. We show that ...
For a given connected graph G on n vertices and m edges, we prove that its independence number α(G) is at least ((2m+n+2) -((2m+n+2)2 -16n2 )½ )/8. Keywords : independence numbe...
The barycenter heuristic is often used to solve the NP-hard two-layer edge crossing minimization problem. It is well-known that the barycenter heuristic can give solutions as bad a...