Documents disponibles écrits par cet auteur

Reducing fuel emissions by optimizing speed on shipping routes / K. Fagerholt in Journal of the operational research society (JORS), Vol. 61 N° 3 (Mars 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 3 (Mars 2010) . - pp. 523–529 Titre : Reducing fuel emissions by optimizing speed on shipping routes Type de document : texte imprimé Auteurs : K. Fagerholt, Auteur ; G. Laporte, Auteur ; I. Norstad, Auteur Année de publication : 2011 Article en page(s) : pp. 523–529 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Shipping  routes  Fuel  emissions  Speed  optimization  Shortest  paths Index. décimale : 001.424 Résumé : Fuel consumption and emissions on a shipping route are typically a cubic function of speed. Given a shipping route consisting of a sequence of ports with a time window for the start of service, substantial savings can be achieved by optimizing the speed of each leg. This problem is cast as a non-linear continuous program, which can be solved by a non-linear programming solver. We propose an alternative solution methodology, in which the arrival times are discretized and the problem is solved as a shortest path problem on a directed acyclic graph. Extensive computational results confirm the superiority of the shortest path approach and the potential for fuel savings on shipping routes. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n3/abs/jors200977a.html [article] Reducing fuel emissions by optimizing speed on shipping routes [texte imprimé] / K. Fagerholt, Auteur ; G. Laporte, Auteur ; I. Norstad, Auteur . - 2011 . - pp. 523–529. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 3 (Mars 2010) . - pp. 523–529 Mots-clés : Shipping  routes  Fuel  emissions  Speed  optimization  Shortest  paths Index. décimale : 001.424 Résumé : Fuel consumption and emissions on a shipping route are typically a cubic function of speed. Given a shipping route consisting of a sequence of ports with a time window for the start of service, substantial savings can be achieved by optimizing the speed of each leg. This problem is cast as a non-linear continuous program, which can be solved by a non-linear programming solver. We propose an alternative solution methodology, in which the arrival times are discretized and the problem is solved as a shortest path problem on a directed acyclic graph. Extensive computational results confirm the superiority of the shortest path approach and the potential for fuel savings on shipping routes. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n3/abs/jors200977a.html

A tabu search heuristic for ship routing and scheduling / J. E. Korsvik in Journal of the operational research society (JORS), Vol. 61 N° 4 (Avril 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 4 (Avril 2010) . - pp. 594–603 Titre : A tabu search heuristic for ship routing and scheduling Type de document : texte imprimé Auteurs : J. E. Korsvik, Auteur ; K. Fagerholt, Auteur ; G. Laporte, Auteur Année de publication : 2010 Article en page(s) : pp. 594–603 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Ship  routing  and  scheduling  Tramp  shipping  Tabu  search Index. décimale : 001.424 Résumé : The purpose of this paper is to solve a planning problem faced by many shipping companies dealing with the transport of bulk products. These shipping companies are committed to carrying some contract cargoes and will try to derive additional revenue from optional spot cargoes. An efficient tabu search algorithm has been developed to ensure quick decision support for the planners. The solutions generated by the tabu search heuristic are compared with those produced by a previously published multi-start local search heuristic. Computational results show that the tabu search heuristic yields optimal or near-optimal solutions to real-life instances within reasonable time. For large and tigthly constrained cases, the tabu search heuristic provides much better solutions than the multi-start local search heuristic. A version of the tabu search heuristic will be integrated as an improved solver in a prototype decision support system used by several shipping companies. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n4/abs/jors2008192a.html [article] A tabu search heuristic for ship routing and scheduling [texte imprimé] / J. E. Korsvik, Auteur ; K. Fagerholt, Auteur ; G. Laporte, Auteur . - 2010 . - pp. 594–603. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 4 (Avril 2010) . - pp. 594–603 Mots-clés : Ship  routing  and  scheduling  Tramp  shipping  Tabu  search Index. décimale : 001.424 Résumé : The purpose of this paper is to solve a planning problem faced by many shipping companies dealing with the transport of bulk products. These shipping companies are committed to carrying some contract cargoes and will try to derive additional revenue from optional spot cargoes. An efficient tabu search algorithm has been developed to ensure quick decision support for the planners. The solutions generated by the tabu search heuristic are compared with those produced by a previously published multi-start local search heuristic. Computational results show that the tabu search heuristic yields optimal or near-optimal solutions to real-life instances within reasonable time. For large and tigthly constrained cases, the tabu search heuristic provides much better solutions than the multi-start local search heuristic. A version of the tabu search heuristic will be integrated as an improved solver in a prototype decision support system used by several shipping companies. DEWEY : 001.424 ISSN : 0160-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n4/abs/jors2008192a.html