Daniele Vigo | Università di Bologna (original) (raw)

Papers by Daniele Vigo

We consider problems requiring to allocate a set of rectangular items to larger rectangular stand... more We consider problems requiring to allocate a set of rectangular items to larger rectangular standardized units by minimizing the waste. In two-dimensional bin packing problems these units are finite rectangles, and the objective is to pack all the items into the minimum number of units, while in two-dimensional strip packing problems there is a single standardized unit of given width, and the objective is to pack all the items within the minimum height.

The quantification of the freight movements occurring in each traffic zone disaggregated by suppl... more The quantification of the freight movements occurring in each traffic zone disaggregated by supply chain and of the corresponding Origin-Destination trip tables connected with the urban delivery of goods, is essential to evaluate the effects of any city logistic policy in terms of vehicle congestion and polluting emissions, based on the assignment of truck flows to the road network. To this end in this paper we propose two innovative demand models: the first one for movement generation, the second one for trip distribution.

Proc. of Transputers, Jan 1, 1992

Transportation Science, Jan 1, 2011

Multi-echelon distribution systems are quite common in supply-chain and logistic systems. They ar... more Multi-echelon distribution systems are quite common in supply-chain and logistic systems. They are used by public administrations in their transportation and traffic planning strategies as well as by companies to model their distribution systems. In the literature, most of the studies address issues related to the movement of flows throughout the system from their origins to their final destinations. A recent trend is to also focus on the management of the vehicle fleets required to provide transportation among the different echelons of the system. The aim of this paper is twofold. First, it introduces the family of Multi-Echelon Vehicle Routing Problems, a term which broadly covers such settings, where the delivery from one or more depots to customers is managed by routing and consolidating freight through intermediate depots. Second, it considers in detail the basic version of Multi-Echelon Vehicle Routing Problems, the Two-Echelon Capacitated Vehicle Routing Problem, which is an extension of the classical VRP where the delivery is compulsory delivered through intermediate depots, named satellites. A mathematical model for Two-Echelon Capacitated Vehicle Routing Problem, some valid inequalities and two math-heuristics based on the model are presented. Computational results up to 50 customers and 4 satellites show the effectiveness of the developed methods.

MIC-97: meta-heuristics international …, Jan 1, 1999

Résumé/Abstract We are given a set of rectangular small pieces which may be rotated by 90, and an... more Résumé/Abstract We are given a set of rectangular small pieces which may be rotated by 90, and an unlimited number of identical rectangular large stock pieces. We consider the problem of determining the guillotine-cuttable patterns that provide all the pieces, such that the total number of required stock pieces is minimized. We show how some classical greedy algorithms given in the literature for the case where no rotation is allowed can be adapted to our problem; in addition, an original heuristic algorithm is presented. We then introduce a ...

Operations …, Jan 1, 2005

Abstract In the three-dimensional bin packing problem the task is to orthogonally pack a given se... more Abstract In the three-dimensional bin packing problem the task is to orthogonally pack a given set of rectangular items into a minimum number of three-dimensional rectangular bins. We give a characterization of the algorithm proposed by Martello et al.(2000) for the exact solution of the problem, showing that not all orthogonal packings can be generated by the proposed algorithm. The packings, however, have the property of being robot packings, which is relevant in practical settings. References to the modified algorithm, which solves ...

Annals of Operations Research, Jan 1, 1995

Capacitated Shortest Spanning Arborescence 1 • complete and loop-free directed graph G = (V, A); ... more Capacitated Shortest Spanning Arborescence 1 • complete and loop-free directed graph G = (V, A); • V = {1, . . . , n};

Annals of Operations Research, Jan 1, 2010

Abstract The solution of a vehicle routing problem calls for the determination of a set of routes... more Abstract The solution of a vehicle routing problem calls for the determination of a set of routes, each performed by a single vehicle which starts and ends at its own depot, such that all the requirements of the customers are fulfilled and the global transportation cost is ...

European journal of …, Jan 1, 2007

In this paper we present several heuristic algorithms and a cutting-plane algorithm for the Windy... more In this paper we present several heuristic algorithms and a cutting-plane algorithm for the Windy Rural Postman Problem. This problem contains several important Arc Routing Problems as special cases and has very interesting real-life applications. Extensive computational experiments over different sets of instances are also presented.

Transportation …, Jan 1, 2007

T he fleet size and mix vehicle routing problem with time windows (FSMVRPTW) is the problem of de... more T he fleet size and mix vehicle routing problem with time windows (FSMVRPTW) is the problem of determining, at the same time, the composition and the routing of a fleet of heterogeneous vehicles aimed to serve a given set of customers. The routing problem requires us to design a set of minimum-cost routes originating and terminating at a central depot and serving customers with known demands, within given time windows. This paper develops a constructive insertion heuristic and a metaheuristic algorithm for FSMVRPTW. Extensive computational experiments on benchmark instances show that the proposed method is robust and efficient, and outperforms the previously published results.

Journal of the Operational …, Jan 1, 2007

Almost all heuristic optimization procedures require the presence of a well-tuned set of paramete... more Almost all heuristic optimization procedures require the presence of a well-tuned set of parameters. The tuning of these parameters is usually a critical issue and may entail intensive computational requirements. We propose a fast and effective approach composed of two distinct stages. In the first stage, a genetic algorithm is applied to a small subset of representative problems to determine a few robust parameter sets. In the second stage, these sets of parameters are the starting points for a fast local search procedure, able to more deeply investigate the space of parameter sets for each problem to be solved. This method is tested on a parametric version of the Clarke and Wright algorithm and the results are compared with an enumerative parameter setting approach previously proposed in the literature. The results of our computational testing show that our new parameter-setting procedure produces results of the same quality as the enumerative approach, but requires much shorter computational time.

Top, Jan 1, 1997

Abstract In this paper we consider the minimum makespan Open Shop problem without preemption. It ... more Abstract In this paper we consider the minimum makespan Open Shop problem without preemption. It is well-known that the case with only two machines can be optimally solved in linear time, whereas the problem with an arbitrary number of machines is NP-hard in the ...

Annals of Operations Research, Jan 1, 2004

We present a computer code that implements a general Tabu Search technique for the solution of tw... more We present a computer code that implements a general Tabu Search technique for the solution of two-and three-dimensional bin packing problems, as well as virtually any of their variants requiring the minimization of the number of bins. The user is only requested to provide a procedure that gives an approximate solution to the actual variant to be solved.

4OR: A Quarterly Journal of Operations …, Jan 1, 2007

5 Comparison of various VRP relaxations 6 Branch-and-cut methods Separation algorithms Branching ... more 5 Comparison of various VRP relaxations 6 Branch-and-cut methods Separation algorithms Branching strategies 7 Branch-and-cut-and-price method R. Baldacci (DEIS) Exact Algorithms for the VRP May 12, 2008 2 / 66 Outline (2) Pricing and cut generation 8 Set partitioning with additional cuts Finding an optimal VRP solution Bounding procedure Route generation algorithm 9 Summary of the computational experiments 10 Appendix 11 References R. Baldacci (DEIS) Exact Algorithms for the VRP May 12, 2008 3 / 66 Problem description

ACM Transactions on …, Jan 1, 2007

We consider the problem of orthogonally packing a given set of rectangular-shaped boxes into the ... more We consider the problem of orthogonally packing a given set of rectangular-shaped boxes into the minimum number of three-dimensional rectangular bins. The problem is NP-hard in the strong sense and extremely difficult to solve in practice. We characterize relevant subclasses of packing and present an algorithm which is able to solve moderately large instances to optimality. Extensive computational experiments compare the algorithm for the three-dimensional bin packing when solving general orthogonal packings and when restricted to robot packings.

Electronic notes in discrete …, Jan 1, 1999

Constraint Programming techniques have been successfully applied to several combinatorial optimiz... more Constraint Programming techniques have been successfully applied to several combinatorial optimization problems. One of their advantages is the availability of complex global constraints performing efficient propagation and interacting with each other through shared variables. However, Constraint Programming techniques have shown their limitations in dealing with objective functions, since they are usually able to prune only few levels of the search tree when most decision variables have been already instantiated. In ...

Discrete Applied Mathematics, Jan 1, 2002

Given a set of rectangular items, and an unlimited number of identical rectangular bins, we consi... more Given a set of rectangular items, and an unlimited number of identical rectangular bins, we consider the problem of allocating, without overlapping, all the items to the minimum number of bins. We assume that the items may be rotated by 90

The vehicle routing problem, Jan 1, 2002

Chapter 8 VRP with Backhauls Paolo Toth Daniele Vigo 8.1 Introduction In this chapter we consider... more Chapter 8 VRP with Backhauls Paolo Toth Daniele Vigo 8.1 Introduction In this chapter we consider the VRP with Backhauls (VRPB), also known as the linehaul-backhaul problem, an extension of the Capacitated VRP (CVRP) where the customer set is partitioned into two subsets. ...