Zobrazeno 1 - 10
of 103
pro vyhledávání: '"Adam N. Letchford"'
Publikováno v:
Operations Research Letters. 50:674-678
The multidimensional knapsack problem (MKP) is a classic problem in combinatorial optimisation. Several authors have proposed to use surrogate relaxation to compute upper bounds for the MKP. In their papers, the surrogate dual is solved heuristically
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https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2aaeba05a1cc55a0f1bfa7675e44651f
https://doi.org/10.1016/j.orl.2022.10.003
https://doi.org/10.1016/j.orl.2022.10.003
In integer programming and combinatorial optimisation, people use the term matheuristics to refer to methods that are heuristic in nature, but draw on concepts from the literature on exact methods. We survey the literature on this topic, with a parti
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https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5eb7f7dff8c0f379e5f3a04221d7b3f8
https://doi.org/10.1111/itor.13301
https://doi.org/10.1111/itor.13301
Arc routing problems (ARPs) are a special kind of vehicle routing problem, in which the demands are located on edges or arcs, instead of nodes. There is a huge literature on ARPs, and a variety of exact and heuristic algorithms are available. Recentl
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https://explore.openaire.eu/search/publication?articleId=doi_dedup___::98617e11ec5bd2bda351b4db0278e7d3
https://doi.org/10.1002/net.22120
https://doi.org/10.1002/net.22120
The general routing problem (GRP) is a fundamental (Formula presented.) -hard vehicle routing problem, first defined by Orloff in 1974. It contains as special cases the Chinese postman problem, the rural postman problem, the graphical TSP, and the St
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b459fe813c2b5b64fbcdaa1bb4f807ef
https://doi.org/10.1002/net.22119
https://doi.org/10.1002/net.22119
Publikováno v:
Networks. 79:20-31
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::8c04477f6ad7392ee4ebd155d9e01625
https://doi.org/10.1002/net.22033
https://doi.org/10.1002/net.22033
The max-cut problem is a fundamental combinatorial optimisation problem, with many applications. Poljak and Turzik found some facet-defining inequalities for the associated polytope, which we call 2-circulant inequalities. We present a more general f
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https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f8ab3509975f7d509993be7f334cb776
https://doi.org/10.1016/j.orl.2022.01.005
https://doi.org/10.1016/j.orl.2022.01.005
Autor:
Adam N. Letchford, Georgia Souli
Publikováno v:
Operations Research Letters. 48:607-611
Valid inequalities for the knapsack polytope have proven to be very useful in exact algorithms for mixed-integer linear programming. In this paper, we focus on the knapsack cover inequalities, introduced in 2000 by Carr and co-authors. In general, th
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https://doi.org/10.1016/j.orl.2020.07.010
https://doi.org/10.1016/j.orl.2020.07.010
Autor:
Adam N. Letchford
Publikováno v:
The Quadratic Unconstrained Binary Optimization Problem ISBN: 9783031045196
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https://explore.openaire.eu/search/publication?articleId=doi_________::5f850b04e955dcbd626c6680cab3edea
https://doi.org/10.1007/978-3-031-04520-2_4
https://doi.org/10.1007/978-3-031-04520-2_4
Perspective functions have long been used to convert fractional programs into convex programs. More recently, they have been used to form tight relaxations of mixed-integer nonlinear programs with so-called indicator variables. Motivated by a practic
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https://doi.org/10.1007/s10107-020-01519-9
https://doi.org/10.1007/s10107-020-01519-9
Autor:
Adam N. Letchford, Laura Galli
In 2013, Buchheim and Wiegele introduced a quadratic optimisation problem, in which the domain of each variable is a closed subset of the reals. This problem includes several other important problems as special cases. We study some convex sets and po
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https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3953258351fd0552f7b5400bc509ec70
https://doi.org/10.1016/j.disopt.2021.100661
https://doi.org/10.1016/j.disopt.2021.100661