Alfredo
Marin (Universidad de de
Murcia,
Spain)
Short Biography
Alfredo
Marin studied Mathematics in
He is a laureate of the EURO Summer Institute on Location (1995) and a member of the EWGLA, the Spanish Group on Location GELOCA, the SADERYL projects and the Spanish Network on Location. He has authored or coauthored 20 scientific articles in combinatorial optimization, mostly in the area of discrete location and several chapters on books.
Lecture to be presented in EWI 2007
Title
Location
of Hubs
Abstract
In this talk we shall deal with the multiple allocation hub location problems family. A set of points, which are both origins and destinations, is given. From each point to each other point, a certain amount of a single product must be sent. The cost of sending a unit of product between each pair of points is also known. Some of the points are to be chosen to install hubs (transhipment points) on them. The effect is that the cost of sending a unit from one hub to another hub is reduced, multiplying it by a given constant between 0 and 1. All the product must go from the origin to some hub (if the origin is not a hub itself) and then perhaps to another hub and then to the destination (if the destination is not the second hub). Multiple allocation means that the product with origin in one point can follow totally different routes depending on the destination to be reached (the opposite case, single allocation, arises when the first hub is the same for all the product generated in one origin). The goal is to find the set of hubs and the set of routes with the minimum total cost in two cases: when the number of hubs is limited and the case in which a fixed cost must be paid when some given point is chosen to be a hub. We will study the evolution of the integer programming formulations developed to solve this problem when the capacity of the hubs is not limited and also when it is limited, as well as some specific solution methods, most of them based on the given formulations.