Characterization of Level Non-planar Graphs by Minimal Patterns
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چکیده
In this paper we develop a characterisation of minimal non-planarity of level graphs. We show that a level minimal non-planar (LMNP) graph is completely characterised by either a tree, a level non-planar cycle or a level planar cycle with certain path augmentations. We discuss the usefulness of these characterisations in the context of an branch-and-cut Integer Linear Programming implementation of the Maximum Level Planar Subgraph (MLPS) problem and conjecture that the inequalities associated with level minimal non-planar subgraphs are facet-deening for the MLPS polytope.
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تاریخ انتشار 2000