Date: 09/08/97 Value: 638 Who: Susanne Heipcke Method: CLP Computation Time: 38 s Machine: Sun SparcStation 5, 32Mb memory Date: 06/13/97 Value: 597 Who: Cristina C. B. Cavalcante and Cid Carvalho de Souza Method: Tabu Search Computation time: 2 h 9 m 14 s Machine: SUN SPARCstation