Article ID: | iaor20082190 |
Country: | United Kingdom |
Volume: | 14 |
Issue: | 4 |
Start Page Number: | 349 |
End Page Number: | 364 |
Publication Date: | Jul 2007 |
Journal: | International Transactions in Operational Research |
Authors: | Lorena Luiz Antonio Nogueira, Pereira Marcos Antonio, Senne Edson Luiz Frana |
Keywords: | lagrange multipliers, programming: linear |
This article presents a column generation algorithm to calculate new improved lower bounds to the solution of maximal covering location problems formulated as a p-median problem. This reformulation leads to instances that are difficult for column generation methods. The traditional column generation method is compared with the new approach, where the reduced cost criterion used at the column selection is modified by a Lagrangean/surrogate multiplier. The efficiency of the new approach is tested with real data, where computational tests were conducted and showed the impact of sparsity and degeneracy on column generation-based methods.