Branch-and-cut and hybrid local search for themulti-level capacitated minimum spanning tree problem.

Uchoa, EduardoToffolo, Túlio Ângelo MachadoSouza, Maurício Cardoso deMartins, Alexandre XavierFukasawa, Ricardo2017-02-012017-02-012012UCHOA, E. et al. Branch-and-cut and hybrid local search for the multi-level capacitated minimum spanning tree problem. Networks, New York, v. 59, n. 1, p. 148-160, jan. 2012. Disponível em: <http://onlinelibrary.wiley.com/doi/10.1002/net.20485/epdf>. Acesso em: 23 jan. 2017.1097-0037http://www.repositorio.ufop.br/handle/123456789/7176We propose algorithms to compute tight lower boundsand high quality upper bounds (UBs) for the multilevelcapacitated minimum spanning tree problem. We ﬁrstdevelop a branch-and-cut algorithm, introducing somenew features: (i) the exact separation of cuts correspond-ing to some master equality polyhedra found in theformulation; (ii) the separation of Fenchel cuts, solvingLPs considering all the possible solutions restricted tosmall portions of the graph. We then use that branch-and-cut within a GRASP that performs moves by solvingto optimality subproblems corresponding to partial solu-tions. The computational experiments were conductedon 450 benchmark instances from the literature. Numer-ical results show improved best known (UBs) for almostall instances that could not be solved to optimality.en-USabertoNetwork designFenchel cutsBranch-and-cut and hybrid local search for themulti-level capacitated minimum spanning tree problem.Artigo publicado em periodicohttp://onlinelibrary.wiley.com/doi/10.1002/net.20485/epdfhttps://doi.org/10.1002/net.20485