Title
Lifting valid inequalities for the precedence constrained knapsack problem
Abstract
.   This paper considers the precedence constrained knapsack problem. More specifically, we are interested in classes of valid inequalities which are facet-defining for the precedence constrained knapsack polytope. We study the complexity of obtaining these facets using the standard sequential lifting procedure. Applying this procedure requires solving a combinatorial problem. For valid inequalities arising from minimal induced covers, we identify a class of lifting coefficients for which this problem can be solved in polynomial time, by using a supermodular function, and for which the values of the lifting coefficients have a combinatorial interpretation. For the remaining lifting coefficients it is shown that this optimization problem is strongly NP-hard. The same lifting procedure can be applied to (1,k)-configurations, although in this case, the same combinatorial interpretation no longer applies. We also consider K-covers, to which the same procedure need not apply in general. We show that facets of the polytope can still be generated using a similar lifting technique. For tree knapsack problems, we observe that all lifting coefficients can be obtained in polynomial time. Computational experiments indicate that these facets significantly strengthen the LP-relaxation.
Year
DOI
Venue
1999
10.1007/s101070050084
Math. Program.
Keywords
Field
DocType
Mathematics Subject Classification (1991): 90C10
Mathematical optimization,Continuous knapsack problem,Combinatorial optimization,Polytope,Knapsack problem,Time complexity,Optimization problem,Mathematics,Supermodular function,Constrained optimization
Journal
Volume
Issue
ISSN
86
1
0025-5610
Citations 
PageRank 
References 
14
1.27
8
Authors
3
Name
Order
Citations
PageRank
R. L. M. J. van de Leensel1141.27
C. P. M. Van Hoesel2938.07
J. J. van de Klundert3141.27