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Curriculum Vitae Download PDF file

Research interests

On the practical side my work is mainly focused on metaheuristic methods to solve combinatorial optimization problems arising, for example, in telecommunications or in the context of scheduling. On the theoretical side, I'm especially interested in improving our understanding of algorithm behaviour. My main contributions are concerning the metaheuristic ant colony optimization (ACO).

Some current and past projects

• Developing ACO algorithms for a very general class of shop scheduling problems called group shop scheduling (GSS) (download a paper). The set of all GSS instances (including some job shop scheduling (JSS) and most of the existing open shop scheduling (OSS) benchmark instances, which are special cases of GSS) can be downloaded here.

• The hyper-cube framework for ant colony optimization. The benefits that are coming with this framework are twofold. First, the framework provides an automatic scaling of the pheromone values in ACO algorithms. Second, this framework allows to prove nice properties of the behaviour of Ant System (AS), which was the first ACO algorithm proposed in the literature (download).

• Studying the influence of the pheromone model on the algorithm performace. In particular, I study the reasons of why ACO algorithms may go wrong in certain settings. See this paper for an example.

• Developing hybridizations of ACO with more classical OR techniques. As an example, see the current state-of-the-art algorithm for open shop scheduling, which is a hybrid between ACO and beam search (download).

• Developing metaheuristic algorithms for the k-cardinality tree (KCT) problem (download).

• Developing iterated local search (ILS) algorithms for problems arising in telecommnications, i.e., the problem of error correcting code design

Research jobs

From 2000 until 2004 I was funded by the Metaheuristics Network, a Research Training Network funded by the Improving Human Potential program of the CEC. The main goal of the project was to achieve a better understanding of the different metaheuristics and to learn more about the behaviour of the different methods on different combinatorial optimization problems.

In 2004 I was funded by SegraVis, another Research Training Network funded by the Improving Human Potential program of the CEC.

Since December 2004 I have a "Juan de la Cierva" post-doctoral fellowship from the Spanish Ministry of Science and Technology. Goal of my project is to explore possible hybridizations between ant colony optimization and more classical techniques for optimization such as, for example, operations research and artificial intelligence methods.