Decision Support Improved bounds for the traveling umpire problem : A stronger formulation and a relax-and-fix heuristic q

0377-2217/$ see front matter 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ejor.2013.12.019 q This research was supported by Grant 01-P-01965-2012 from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brazil) and Grants 142278/2013-0, 477692/2012-5 and 302804/2010-2 from Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brazil). ⇑ Corresponding author. Address: School of Business Administration, University of Miami, 5250 University Drive, Room KE405, Coral Gables, FL 33146, USA. Tel.: +1 305 284 5107; fax: +1 305 284 2321. E-mail addresses: lucas.oliveira@ic.unicamp.br (L. de Oliveira), cid@ic.unicamp.br (C.C. de Souza), tallys@miami.edu (T. Yunes). Lucas de Oliveira , Cid C. de Souza , Tallys Yunes b,⇑