Given G = (V;E) an undirected graph and a nonnegative cost function c : E → ℚ, the 2-edge connected spanning subgraph problem (TECSP for short) is to find a two-edge connected subgraph HP = (V; F) of G with minimum cost (i.e., c(F) = Σ<sub>e∈F</sub> c(e) is minimum). If c(e) > 0 for all e ∈ E then every optimal solutionâ€¦ (More)

In this paper we discuss a variant of the well-known k-separator problem. Given a simple graph G = (V ∪ T, E) with V ∪ T the set of vertices, where T is a set of distinguished vertices called terminals, and E a set of edges, the multi-terminal vertex separator problem consists in partitioning V ∪T into k+1 subsets {S, V<sub>1</sub>,â€¦ (More)

This thesis deals with the multi-terminal vertex separator problem. Given a graph G = (V âˆªT,E) with V âˆªT the set of vertices, where T is a set of terminals, and a weight function w : V â†’ Z, associated with nonterminal nodes, the multi-terminal vertex separator problem consists in partitioning V âˆªT into k+1 subsets {S, V1, . . . , Vk} such that there is noâ€¦ (More)

In this paper we discuss a variant of the well-known k-separator problem. Consider the simple graph G = (V âˆªT,E) with V âˆªT the set of vertices, where T is a set of distinguished vertices called terminals, inducing a stable set and E a set of edges. Given a weight function w : V â†’ N, the multi-terminal vertex separator problem consists in finding a subset Sâ€¦ (More)

Let G = (V âˆª T, E) be an undirected graph such that V is a set of vertices, E a set of edges and T a set of terminal vertices. The Multi-terminal vertex separator problem consists in partitioning V into k + 1 subsets {S, V1,..., Vk} minimizing the size of S and such that there is no edge between two subsets Vi and Vj and each subset Vi contains exactly oneâ€¦ (More)