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the date of receipt and acceptance should be inserted later Abstract. When a column generation approach is applied to decomposable mixed integer programming problems, it is standard to formulate and solve the master problem as a linear program. Seen in the dual space, this results in the algorithm known in the nonlinear programming community as the(More)
If G is a triangle-free graph, then two Gallai identities can be written as α(G) + χ(L(G)) = |V (G)| = α(L(G)) + χ(G), where α and χ denote the stability number and the clique-partition number, and L(G) is the line graph of G. We show that, surprisingly, both equalities can be preserved for any graph G by deleting the edges of the line graph corresponding(More)
We observe that ω(G) + χ(S(G)) = n = ω(S(G)) + χ(G) for any graph G with n vertices, where G is any acyclic orientation of G and where S(G) is the (complement of the) auxiliary line graph introduced in [1]. (Where as usual, ω and χ denote the clique number and the chromatic number.) It follows that, for any graph parameter β(G) sandwiched between ω(G) and(More)
For vehicles spread on an operations eld, with multiset radiosets, hopping frequency is used to optimize (densify) the frequency allocation with respect to quality criteria of multicast communication. We propose primal-dual heuristics for graph coloring problems-with enriched cost functions to satisfy technological needs-arising from a pre-treatment phase(More)
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