Knapsack Polytopes – A Survey

The 0/1 knapsack polytope is the convex hull of all 0/1 vectors that satisfy a given single linear inequality with non-negative coefficients. This paper provides a comprehensive overview of knapsack polytopes. We discuss basic polyhedral properties, (lifted) cover and other valid inequalities, cases for which complete linear descriptions are known, geometric properties for small dimensions, … Read more

Integer Programming Solution Approach for Inventory-Production-Distribution Problems with Direct Shipments

We construct an integrated multi-period inventory-production-distribution replenishment plan for three-stage supply chains. The supply chain maintains close-relationships with a small group of suppliers, and the nature of the products (bulk, chemical, etc.) makes it more economical to rely upon a direct shipment, full-truck load distribution policy between supply chain nodes. In this paper, we formulate … Read more

Cover Inequalities for Binary-Integer Knapsack Constraints

We consider knapsack constraints involving one general integer and many binary variables. We introduce the concept of a cover for such a constraint and we construct a new family of valid inequalities based on this concept. We generalize this idea to extended covers, and we propose a specialized lifting procedure for cover inequalities. Finally, we … Read more