Computer Science

Abstract. Given the high expressivity of the Web Ontology Language OWL 2, there is a potential for great diversity in the logical content of OWL ontologies. The fact that many naturally occurring entailments of such ontologies have multiple justifications indicates that ontologies often overdetermine their consequences, suggesting a diversity in supporting reasons.

Abstract. FishBase is an important species data collection produced by the FishBase Information and Research Group Inc (FIN), a not-forprofit NGO with the aim of collecting comprehensive information (from the taxonomic to the ecological) about all the world's finned fish species. FishBase is exposed as a MySQL backed website (supporting a range of canned, although complex queries) and serves over 33 million hits per month. FishDelish is a transformation of FishBase into LinkedData weighing in at 1.38 billion triples.

Abstract. Given the high expressivity of modern ontology languages, such as OWL, there is the possibility for great diversity in the logical content of ontologies. Informally, this can be seen by the constant evolution of reasoners to deal with new sorts of content and the range of optimisations reasoners need in order to be competitive.

In this paper, we present an approach to determining the cognitive complexity of justifications for entailments of OWL ontologies. We introduce a simple cognitive complexity model and present the results of validating that model via experiments involving OWL users. The validation is based on test data derived from a large and diverse corpus of naturally occurring justifications.

Current ontology development tools offer debugging support by presenting justifications for entailments of OWL ontologies. While these minimal subsets have been shown to support debugging and understanding tasks, the occurrence of multiple justifications presents a significant cognitive challenge to users. In many cases even a single entailment may have many distinct justifications, and justifications for distinct entailments may be critically related.

Abstract. The canonical standard description logic reasoning service is classification, that is, the generation of the set of atomic subsumptions which are entailed by some ontology. While this consequence relation is well defined and finite, there is significant variance in the composition of that set. For example, it is common (in tools and in discussion) to exclude some tautologies (eg, A⊑, A⊑ A).

Abstract. Current ontology development tools offer debugging support by presenting justifications for entailments of OWL ontologies. In many cases even a single entailment may have many distinct justifications, and justifications for distinct entailments may be critically related. We call the set of relations between multiple justifications the justificatory structure of an ontology.

The DM Sense group, as it was called, met several times during the Dagstuhl Seminar to discuss intelligent user interactions in decision support with an emphasis on the need to create dialogues between decision makers and their decision support tools which explained the process and the underlying reasoning so bringing understanding and insight to the decision makers. The challenge was to develop dialogues that facilitated the user's thinking.

Abstract This report documents the programme and outcomes of the Dagstuhl Seminar 12041 Learning in Multiobjective Optimization. The purpose of the seminar was to bring together researchers from the two main communities studying multiobjective optimization, Multiple Criteria Decision Making and Evolutionary Multiobjective Optimization, to take part in a wide-ranging discussion of what constitutes learning in multiobjective optimization, how it can be facilitated, and how it can be measured.

Comparatively few studies have addressed directly the question of quantifying the benefits to be had from using molecular genetic markers in experimental breeding programmes (eg for improved crops and livestock), nor the question of which organisms should be mated with each other to best effect. We argue that this requires in silico modelling, an approach for which there is a large literature in the field of evolutionary computation (EC), but which has not really been applied in this way to experimental breeding programmes.

A b stract All around us, impacting on all aspects of life, we are witnessing the storage and processing of increasingly large amounts of data as available computing power continues its inexorable rise. In order to fully benefit from all these data, the development of novel and improved techni q ues for both data analysis and data visualisation is imperative. Currently, two of the main driving forces in this respect are the research fields of document retrieval and bioinformatics.

Abstract. Ant-based clustering and sorting is a nature-inspired heuristic for general clustering tasks. It has been applied variously, from problems arising in commerce, to circuit design, to text-mining, all with some promise. However, although early results were broadly encouraging, there has been very limited analytical evaluation of the algorithm. Toward this end, we first propose a scheme that enables unbiased interpretation of the clustering solutions obtained, and then use this to conduct a full evaluation of the algorithm.

Abstract Most popular evolutionary algorithms for multiobjective optimisation maintain a population of solutions from which individuals are selected for reproduction. In this paper, we introduce a simpler evolution scheme for multiobjective problems, called the Pareto archived evolution strategy (PAES). We argue that PAES may represent the simplest possible non-trivial algorithm capable of generating diverse solutions in the Pareto optimal set.

The main goal of this paper is to attempt an unbiased comparison of the performance of straightforward implementations of five different metaheuristics on a university course timetabling problem. In particular, the metaheuristics under consideration are Evolutionary Algorithms, Ant Colony Optimization, Iterated Local Search, Simulated Annealing, and Tabu Search. To attempt fairness, the implementations of all the algorithms use a common solution representation, and a common neighbourhood structure or local search.

Abstract The probabilistic traveling salesman problem concerns the best way to visit a set of customers located in some metric space, where each customer requires a visit only with some known probability. A solution to this problem is an a priori tour which visits all customers, and the objective is to minimize the expected length of the a priori tour over all customer subsets, assuming that customers in any given subset must be visited in the same order as they appear in the a priori tour.

Abstract This report documents the programme and outcomes of the Dagstuhl Seminar 12041" Learning in Multiobjective Optimization". The purpose of the seminar was to bring together researchers from the two main communities studying multiobjective optimization, Multiple Criteria Decision Making and Evolutionary Multiobjective Optimization, to take part in a wide-ranging discussion of what constitutes learning in multiobjective optimization, how it can be facilitated, and how it can be measured.

Abstract O-line routing in backbone communications networks is an important combinatorial optimisation problem. It has three main uses: rst, o-line routing provides reference benchmark results for dynamic (on-line) routing strategies. Second, and more interestingly, o-line routing is becoming more and more investigated and employed in its own right as a way of quickly nding signi cantly improved routings for live networks which can then be imposed on the network to o er a net improvement in quality of service.

Abstract: Three problems in exploratory data analysis, clustering, feature selection and semi-supervision, are considered in this paper. We discuss how multiobjective optimization provides a flexible means to overcome some of the fundamental difficulties that arise in each of these problems, and refer to recent experimental work that has demonstrated its practical performance benefits compared to traditional single-objective approaches.