Learning Generalized Strong Branching for Set Covering, Set Packing, and 0-1 Knapsack Problems

Branching on a set of variables, rather than on a single variable, can give tighter bounds at the child nodes and can result in smaller search trees. However, selecting a good set of variables to branch on is even more challenging than selecting a good single variable to branch on. Generalized strong branching extends the … Read more

Substitution-based Equipment Balancing in Service Networks with Multiple Equipment Types

We investigate substitution-based equipment balancing for a package express carrier operating multiple equipment types in its service network. The weekly schedule of movements used to transport packages through the service network leads to changes in equipment inventory at the facilities in the network. We seek to reduce this change, i.e., the equipment imbalance associated with … Read more

Multivariable branching: A 0-1 knapsack problem case study

We explore the benefits of multi-variable branching strategies for linear programming based branch and bound algorithms for the 0-1 knapsack problem, i.e., of branching on sets of variables rather than on a single variable (the current default in integer programming solvers). We present examples where multi-variable branching shows advantage over single-variable branching, and partially characterize … Read more