Tutte Colloquium - Fernando Afonso Santos

Friday, December 11, 2015 3:30 pm - 3:30 pm EST (GMT -05:00)

Title: A branch-and-cut-and-price algorithm for the pollution routing problem

Speaker: Fernando Afonso Santos
Affiliation: University of Waterloo
Room: MC 5501

Abstract: A classical combinatorial optimization problem is the Vehicle
Routing Problem with Time-windows (VRPTW). In such problem, a fleet of
identical vehicles must visit customers to deliver goods such that the
total amount of delivered goods is no more than the truck's capacity and
each customer is served within its pre-specified time-window. The aim is
to minimize the cost of visiting all customers exactly once. The Pollution
Routing Problem (PRP) is a variant of the VRPTW where in addition to the
routes, the speeds on which the vehicle will travel can also be determined.
The main motivation in the PRP is that speeds will affect the amount of
pollution that is generated. The goal of the PRP then is to minimize the
total cost as a (nonlinear) function of the speeds and the routes. This
talk is to introduce a Branch-and-cut-and-price algorithm for the PRP. We
propose a dynamic programming algorithm to price out negative reduced cost routes that derives novel dominance rules in order to prune out
unpromising labels and perform faster. Extensive computational experiments are conducted to assess the performance of the proposed algorithm.