OR Seminar

Date: 22/03/2017
Hour: 14h30
Venue: Sala 1.4 - edifício VII, FCT NOVA

A multi-item inventory distribution problem: a Hospital case study

Adelaide Cerveira (DM - UTAD)

A multi-item inventory distribution problem motivated by a practical case occurring in the logistic operations of a hospital is considered. There, a single warehouse supplies several nursing wards. The goal is to define a weekly distribution plan of medical products that minimizes the visits to wards, while respecting inventory capacities and safety stock levels.
A mathematical formulation is introduced and several improvements such as tightening constraints, valid inequalities and an extended reformulation.

A general view on the Minimum Weighted Tree Reconstruction problem

Cristina Requejo (DM - UA)

The Minimum Weighted Tree Reconstruction (MWTR) problem is considered. This problem consists of constructing a tree connecting a set of terminal nodes and of associating weights to the edges such that the weight of the path between each pair of terminals is greater than or equal to a given distance between these terminals and the total weight of the tree is minimized. This problem has applications in several areas, namely, the inference of phylogenetic trees, the modeling of traffic networks and the analysis of internet infrastructures. We present mixed-integer linear programming models for the MWTR problem and discuss computational results obtained with two different sets of instances, one from the phylogenetic area and another from the telecommunications area. Robust optimization models will also be addressed.