Colloquium on Advances in OR Transportation Applications (AORTA)
This one-day event will host four global leaders in the application of Operational Research to transportation.
The inaugural AORTA colloquium takes place at the University of Bath on 1 April 2019. This one-day event will host four global leaders in the application of Operational Research to transportation. Attendance is free, but registration is mandatory.
09:00 - 09:45 Registration
09:45 - 10:00 Introductory remarks
10:00 - 11:00 Prof Gilbert Laporte - Vehicle Routing in the Post-Brexit Age
I will briefly review the history of the vehicle routing problem, starting from the Dantzig and Ramser paper in 1959. The talk will cover classical and modern heuristics as well as old and new exact algorithms. I will offer come critical comments on some of these methods, and I will touch upon stochastic and dynamic problems. I will finally mention some recent research trends that are likely to mark the field of vehicle routing in the post-Brexit age.
11:00 - 11:15 Coffee break
11:15 - 12:15 Prof Daniele Vigo - Real time conflict resolution in railway applications
We consider the real-time resolution of conflicts arising in real-world train management applications. More precisely, given a nominal timetable for a set of trains and a set of modifications due to delays or other resources unavailability, we are aiming at defining a set of actions which must be implemented to grant safety, e.g., to avoid potential conflicts such as train collisions or headway violations, and restore quality by reducing the delays. To be compatible with real-time management, the required actions must be determined in a few seconds, hence specialized fast heuristics must be used. Moreover, the driving of the trains in response to the proposed actions must be optimised to reduce the energy consumption associated with unforeseen speed changes.
12:15 - 13:30 Lunch break
13:30 - 14:30 Prof Harilaos Psaraftis - Speed Optimization vs Speed Reduction in Maritime Transport: the Speed Limit Debate.
Speed optimization and speed reduction are included in the set of candidate short-term measures under discussion at the International Maritime Organization (IMO), in the quest to reduce greenhouse gas (GHG) emissions from ships. However, there is much confusion on what either speed optimization or speed reduction may mean, and some stakeholders have proposed mandatory speed limits as a measure to achieve GHG emissions reduction. The purpose of this talk is to shed some light into the speed limit debate, and specifically whether reducing speed by imposing a speed limit is better than doing the same by imposing a bunker levy. To that effect, some models that optimize ship speed are presented, and the two options are compared under various criteria. The main result of the analysis is that the speed limit option exhibits a number of deficiencies as an instrument to reduce GHG emissions, at least vis-à-vis the bunker levy option.
14:30 - 14:45 Coffee break
14:45 - 15:45 Prof Kjetil Fagerholt - Routing and Scheduling in Maritime Transportation
The problem of routing and scheduling a fleet of ships to transport a set of (partially optional) bulk cargoes is a complicated task. A basic version of this problem can be formulated as a Pickup and Delivery Problem with Time Windows. However, practical problems often pose additional complexities and opportunities that are not considered in this basic version. The purpose of this talk is to show how some of these practical extensions can be incorporated (such as flexible cargo quantities, split cargoes, and sailing speed optimization) and to show that, although the problems become harder to solve when introducing these extensions, significantly better solutions can sometimes be obtained. Thus, fleet operators have the possibility to significantly improve the financial results of their operation.
15:45 - 16:00 Closing remarks