An artifact in fits to conic-based surfaces

It is common in Physiological Optics to fit the corneal and the lens surfaces to conic-based surfaces (usually ellipse-based surfaces), obtaining their characteristic radius of curvature and asphericity. Here we show that the variation in radius and asphericity due to experimental noise is strongly correlated. This correlation is seen both in experimental data of the corneal topographer Pentacam and in simulations. We also show that the effect is a characteristic of the geometry of ellipses, and not restricted to any experimental device or fitting procedure.Comment: 5 pages, 5 figure

Towards a Reliable Comparison and Evaluation of Network Intrusion Detection Systems Based on Machine Learning Approaches

Presently, we are living in a hyper-connected world where millions of heterogeneous devices are continuously sharing information in different application contexts for wellness, improving communications, digital businesses, etc. However, the bigger the number of devices and connections are, the higher the risk of security threats in this scenario. To counteract against malicious behaviours and preserve essential security services, Network Intrusion Detection Systems (NIDSs) are the most widely used defence line in communications networks. Nevertheless, there is no standard methodology to evaluate and fairly compare NIDSs. Most of the proposals elude mentioning crucial steps regarding NIDSs validation that make their comparison hard or even impossible. This work firstly includes a comprehensive study of recent NIDSs based on machine learning approaches, concluding that almost all of them do not accomplish with what authors of this paper consider mandatory steps for a reliable comparison and evaluation of NIDSs. Secondly, a structured methodology is proposed and assessed on the UGR'16 dataset to test its suitability for addressing network attack detection problems. The guideline and steps recommended will definitively help the research community to fairly assess NIDSs, although the definitive framework is not a trivial task and, therefore, some extra effort should still be made to improve its understandability and usability further

The Languages at Home and at School in Irun

It is survey about the diversity of languages spoken at school & at home in Irun

Special issue: Bio-inspired algorithms with structured populations

International audienceThe advantages of using structured populations in Evolutionary Algorithms (EAs) and other metaheuristicas are well known today, not only for parallelization purposes, but also for enhancing the performance of the algorithm with respect to the equivalent algorithm with panmictic population, even for sequential executions. The use of an appropriate population structure will allow us to create a higher efficiency and efficacy algorithm once structured, both numerically and in real time (e.g. parallelism). The articles composing this special issue represent excellent novel contributions in this direction. We collected six high-quality papers out of the 43 received ones. These finally selected papers deal with different aspects related to the topic of this special issue, such as theoretical studies, identification of current challenges in the field, novel population structure designs, and empirical validation on highly complex problems

Experiments on PMMA model to predict the impact of corneal refractive surgery on corneal shape: Reply

2 pages.-- OCIS codes: 120.6650, 140.3390, 170.1020, 170.3890, 330.4460, 330.5370.A reply to the comment by Jiménez et al. on the paper "Experiments on PMMA model to predict the impact of corneal refractive surgery on corneal shape" by Dorronsoro et al., Opt. Express, 14, 6142-6156 (2006).Peer reviewe