The Nutritious Supply Chain: Optimizing Humanitarian Food Aid

The World Food Programme (WFP) is the largest humanitarian agency fighting hunger worldwide, reaching around 90 million people with food assistance in 80 countries each year. To deal with the operational complexities inherent in its mandate, WFP has been developing tools to assist its decision makers with integrating supply chain decisions across departments and functional … Read more

An Efficient Algorithm for Computing Robust Minimum Capacity s-t Cuts

The Minimum Capacity s-t Cut Problem (Min Cut) is an intensively studied problem in combinatorial optimization. In this paper, we study Min Cut when arc capacities are uncertain but known to exist in pre-specified intervals. This framework can be used to model many real-world applications of Min Cut under data uncertainty such as in open-pit … Read more

Rapidly Solving an Online Sequence of Maximum Flow Problems

We investigate how to rapidly solve an online sequence of maximum flow problems. Sequences of maximum flow problems arise in a diverse collection of settings, including stochastic network programming and real-time scheduling of jobs on a two-processor computer. In this paper, we formulate solving an online sequence of maximum flow problems as the Maximum Flow … Read more

The Maximum Flow Network Interdiction Problem: Valid Inequalities, Integrality Gaps, and Approximability

We study the Maximum Flow Network Interdiction Problem (MFNIP). We present two classes of polynomially separable valid inequalities for Cardinality MFNIP. We also prove the integrality gap of the LP relaxation of Wood’s (1993) integer program is not bounded by a constant factor, even when the LP relaxation is strengthened by our valid inequalities. Finally, … Read more