On the Completeness of Spider Diagrams Augmented with Constants

Diagrammatic reasoning can be described formally by a number of diagrammatic logics; spider diagrams are one of these, and are used for expressing logical statements about set membership and containment. Here, existing work on spider diagrams is extended to include constant spiders that represent specific individuals. We give a formal syntax and semantics for the extended diagram language before introducing a collection of reasoning rules encapsulating logical equivalence and logical consequence. We prove that the resulting logic is sound, complete and decidable

Theoretical highlights of neutrino-nucleus interactions

The recent theoretical developments in the field of neutrino-nucleus interactions in the few-GeV region are reviewed based on the presentations made at the NuInt09 Workshop. The topics of electron scattering and its connections with neutrino interactions, neutrino induced quasielastic scattering and pion production (coherent and incoherent) are covered, with special emphasis on the challenges that arise in the comparison with new experimental data.Comment: Plenary talk at NuFact09, Chicago, July 20-25, 200

Starting from scratch: experimenting with computer science in Flemish secondary education

In the Flemish secondary education curriculum, as in many countries and regions, computer science currently only gets an extremely limited coverage. Recently, in Flanders (and elsewhere), it has been proposed to change this, and try-outs are undertaken, both in and outside of schools. In this paper, we discuss some of those efforts, and in particular take a closer look at the preliminary results of one experiment involving different approaches to programming in grade 8. These experiments indicate that many students from secondary schools would welcome a more extensive treatment of computer science. Planning and implementing such a treatment, however, raises a number of issues, from which in this paper, we formulate a handful as calls for action for the computer science education research community

An enhanced classifier system for autonomous robot navigation in dynamic environments

In many cases, a real robot application requires the navigation in dynamic environments. The navigation problem involves two main tasks: to avoid obstacles and to reach a goal. Generally, this problem could be faced considering reactions and sequences of actions. For solving the navigation problem a complete controller, including actions and reactions, is needed. Machine learning techniques has been applied to learn these controllers. Classifier Systems (CS) have proven their ability of continuos learning in these domains. However, CS have some problems in reactive systems. In this paper, a modified CS is proposed to overcome these problems. Two special mechanisms are included in the developed CS to allow the learning of both reactions and sequences of actions. The learning process has been divided in two main tasks: first, the discrimination between a predefined set of rules and second, the discovery of new rules to obtain a successful operation in dynamic environments. Different experiments have been carried out using a mini-robot Khepera to find a generalised solution. The results show the ability of the system to continuous learning and adaptation to new situations.Publicad