作者：Margot, F; Queyranne, M; Wang, YG
作者单位：Carnegie Mellon University; University of British Columbia
摘要：We present an in-depth theoretical, algorithmic, and computational study of a linear programming (LP) relaxation to the precedence constrained single-machine scheduling problem 1\prec\Sigma(j)w(j)C(j) to minimize a weighted sum of job completion times. On the theoretical side, we study the structure of tight parallel inequalities in the LP relaxation and show that every permutation schedule that is consistent with Sidney's decomposition has total cost no more than twice the optimum. On the alg...
作者：Frank, KC; Zhang, RQ; Duenyas, I
作者单位：Delft University of Technology; Cornell University; University of Michigan System; University of Michigan
摘要：We consider a periodic review inventory system with two priority demand classes, one deterministic and the other stochastic. The deterministic demand must be met immediately in each period. However, the units of stochastic demand that are not satisfied during the period when demand occurs are treated as lost sales. At each decision epoch, one has to decide not only whether an order should be placed and how much to order, but also how much demand to fill from the stochastic source. The firm has...
