We consider a particular pick-up and delivery vehicle routing
problem, with unit vehicle capacity and possible compatibility
constraints between consecutive operations. The problem arises
in the collection and disposal of bulky recyclable waste, where
containers of different types, used to collect different waste
materials, must be picked-up to be emptied at suitable disposal
plants and replaced by empty bins alike. Disposal plants depend
on the material and are located in different sites. Here we provide
a bipartite graph model based on an Asymmetric Vehicle Routing
formulation and discuss heuristic algorithms.
Slides presentation
Collaborators
Roberto Aringhieri, Maurizio Bruglieri, Maddalena Nonato.
The case of a long haul freight ransportation company is considered.
Goods are collected nationalwise and have to be transported towards
foreign destinations. The strategic problem addressed here is
to find the best location and dimension for the national deposits
(hubs), to allocate local customers to the activated hubs, and
to assign them international. On the basis of the average annual
traffic, the objective is to minimize the installation and managing
costs. A detailed analysis of the cost functions is made, and
a couple of mathematical models are presented. Managing costs
are typically concave. A preliminary computational study is carried
out on real data.
Slides presentation
Collaborators
Alessandro Cavallet, Roberto Wolfler Calvo (Université de Troyes).
The problem of planning the daily transportation between the main depots of an express courrier is considered. Mathematical models that take into account the fleet size, the trucks redistribution, the possible exchange of goods between trucks in intermediate centers, are considered.
Collaborators
Renato De Leone (Dipartimento di Matematica e Fisica, Università di Camerino)
Maddalena Nonato (DIEI, Università di Perugia)
Daniele Pretolani (Dipartimento di Matematica e Fisica, Università di Camerino)
A particular periodic scheduling problem arising when designing
timetables in the railway freight transportation setting is addressed.
Given a railway network, a set of commodities to be transported
in the network, and a set of train services with their frequencies,
the problem consists in determining the departure times for each
train and the route for each commodity to minimize the total delay
time incurred by the commodities at the stations. Two alternative
models are proposed, which are used to obtain both lower bounds
and heuristic solutions.
Collaborators
Giorgio Gallo (Dipartimento di Informatica, Università di Pisa)
Angel Marin (Departamento de Matematica Aplicada y Estadistica, Universitad Politecnica de Madrid)
Papers: