Publicação
A structural Lagrangean relaxation for two-duty period bus driver scheduling problems
| Resumo: | The two-duty period bus driver scheduling problem is a particular case of the generalized set covering problem, min {cTx : Ax ⩾ b, 0 ⩽ x ⩽h and integer) where, each column of the boolean matrix A consists of at most two strings of consecutive ones. Such a denomination for the problem is due to several real life applications, in particular for bus crew scheduling. In this paper, we present a 'structural' lagrangean relaxation and penalties for improving the bounds on the optimum for the problem. Two other lagrangean relaxation approaches, previously reported in the literature, are considered too. A computational study relative to these relaxations was carried out with both randomly generated test problems and real life cases from Rodoviária Nacional, a large mass transport operator in Portugal. The results reported in the paper evidence a better performance for the lagrangean relation approach wich combined with greedy heuristics, yeld a reasonably good and fast procedure for tackling real life problems |
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| Autores principais: | Pinto, José Pinto |
| Outros Autores: | Pato, Margarida Vaz |
| Assunto: | Lagrangean Relaxation Heuristics Generalized Set Covering Network Flows Bus Driver Scheduling |
| Ano: | 1989 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | The two-duty period bus driver scheduling problem is a particular case of the generalized set covering problem, min {cTx : Ax ⩾ b, 0 ⩽ x ⩽h and integer) where, each column of the boolean matrix A consists of at most two strings of consecutive ones. Such a denomination for the problem is due to several real life applications, in particular for bus crew scheduling. In this paper, we present a 'structural' lagrangean relaxation and penalties for improving the bounds on the optimum for the problem. Two other lagrangean relaxation approaches, previously reported in the literature, are considered too. A computational study relative to these relaxations was carried out with both randomly generated test problems and real life cases from Rodoviária Nacional, a large mass transport operator in Portugal. The results reported in the paper evidence a better performance for the lagrangean relation approach wich combined with greedy heuristics, yeld a reasonably good and fast procedure for tackling real life problems |
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