In this note, we prove NP-completeness of the following problem: Given a set of trams of diierent types, which are stacked on sidings in their depot and an order in which trams of speciied types areâ€¦ (More)

The critical exponents for T â†’ 0 of the two-dimensional Ising spin-glass model with Gaussian couplings are determined with the help of exact ground states for system sizes up to L = 50 and by a Monteâ€¦ (More)

The solid-on-solid model provides a commonly used framework for the description of surfaces. In recent it has been extended in order to investigate the effect of defects in the bulk on the roughnessâ€¦ (More)

The solid-on-solid model provides a commonly used framework for the description of surfaces. In the last years it has been extended in order to investigate the eeect of defects in the bulk on theâ€¦ (More)

In this report, we introduce and study the Steiner-diagram-problem. Given a transitive digraph G = (V; A; w) with non-negative edge-weights and a set of demand edges B, the objective is to nd anâ€¦ (More)

In this report, we introduce and study two problems derived from reload problems in transport logistics. Given a transitive digraph G = (V; A; w) with non-negative edge-weights and a set of demandâ€¦ (More)

The successful application of Branch and Cut methods to the TSP has drawn attention also to the polyhedral properties of the symmetric capacitated vehicle routing problem, which is the capacitatedâ€¦ (More)