1,261 research outputs found
Impact of anaerobic digestion and centrifugation/decanting processes in bacterial communities fractions
Tsunami hazard at the Western Mediterranean Spanish coast from seismic sources
Spain represents an important part of the tourism
sector in theWestern Mediterranean, which has been affected
in the past by tsunamis. Although the tsunami risk at the
Spanish coasts is not the highest of the Mediterranean, the
necessity of tsunami risk mitigation measures should not be
neglected. In the Mediterranean area, Spain is exposed to
two different tectonic environments with contrasting characteristics.
On one hand, the Alboran Basin characterised
by transcurrent and transpressive tectonics and, on the other
hand, the North Algerian fold and thrust belt, characterised
by compressive tectonics. A set of 22 seismic tsunamigenic
sources has been used to estimate the tsunami threat over the
Spanish Mediterranean coast of the Iberian peninsula and
the Balearic Islands. Maximum wave elevation maps and
tsunami travel times have been computed by means of numerical
modelling and we have obtained estimations of threat
levels for each source over the Spanish coast. The sources on
the Western edge of North Algeria are the most dangerous,
due to their threat to the South-Eastern coast of the Iberian
Peninsula and to theWestern Balearic Islands. In general, the
Northern Algerian sources pose a greater risk to the Spanish
coast than the Alboran Sea sources, which only threaten
the peninsular coast. In the Iberian Peninsula, the Spanish
provinces of Almeria and Murcia are the most exposed, while
all the Balearic Islands can be affected by the North Algerian
sources with probable severe damage, specially the islands of
Ibiza and Minorca. The results obtained in this work are useful
to plan future regional and local warning systems, as well
as to set the priority areas to conduct research on detailed
tsunami risk
Diffusion Maps for dimensionality reduction and visualization of meteorological data
This is the author’s version of a work that was accepted for publication in Neurocomputing. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Neurocomputing, VOL 163, (2015) DOI 10.1016/j.neucom.2014.08.090The growing interest in big data problems implies the need for unsupervised methods for data visualization and dimensionality reduction. Diffusion Maps (DM) is a recent technique that can capture the lower dimensional geometric structure underlying the sample patterns in a way which can be made to be independent of the sampling distribution. Moreover, DM allows us to define an embedding whose Euclidean metric relates to the sample's intrinsic one which, in turn, enables a principled application of k-means clustering. In this work we give a self-contained review of DM and discuss two methods to compute the DM embedding coordinates to new out-of-sample data. Then, we will apply them on two meteorological data problems that involve time and spatial compression of numerical weather forecasts and show how DM is capable to, first, greatly reduce the initial dimension while still capturing relevant information in the original data and, also, how the sample-derived DM embedding coordinates can be extended to new patterns.The authors acknowledge partial support from Spain's grant TIN2010-21575-C02-01 and the UAM{ADIC Chair for Machine Learning. The first author is also supported by an FPI{UAM grant and kindly thanks the Applied Mathematics Department of Yale University for receiving her during her visits
A common framework for the robust design of tuned mass damper techniques to mitigate pedestrian-induced vibrations in lively footbridges
The dynamic response of modern slender footbridges is usually sensitive to both the pedestrian actions and the
uncertainties associated with their inherent structural behavior. Thus, tuned mass dampers have been widely
integrated in the design of these structures to guarantee the fulfillment of the vibration serviceability limit state
during their overall life cycle. Three different techniques of tuned mass dampers (active, semi-active and passive)
are usually considered for this purpose. Although there are algorithms for the robust design of each particular
technique, however, this specificity makes difficult the implementation of all these techniques in practical en gineering applications. Herein, the motion-based design method under uncertainty conditions is proposed and
further implemented to create a common framework for the robust design of all these techniques when they are
employed to mitigate pedestrian-induced vibrations in slender footbridges. According to this method, the design
problem may be transformed into the combination of two sequential sub-problems: (i) a reliability multi objective optimization sub-problem; and (ii) a decision-making sub-problem. Subsequently, the performance
of this proposal has been validated through a numerical case study in which the dynamic response of a steel
footbridge has been controlled by three different tuned mass damper techniques designed according to the
proposed common framework.Ministerio de Economía y Competitividad ( España) RTI2018-094945-B-C21Ministerio de Ciencia, Innovación y Universidades (España) RTI2018-099639-B-I0
La propuesta de Master en Ingeniería Informática de las Universidades Públicas de la Comunidad de Madrid
Versión electrónica de la ponencia presentada en Simposio Internacional de Informática Educativa (SIIE 2004), celebrado en Cáceres en 2004En noviembre de 2002, las universidades públicas madrileñas iniciaron
una propuesta de Plan de Estudios de Master en Ingeniería Informática resultado de la
convocatoria de Master, regulada por orden 6534/2002, de 26 de noviembre. En el
presente documento se resume el resultado del equipo de trabajo constituido por
miembros representantes de las seis universidades públicas de la Comunidad de Madrid
con los que han colaborado miembros de universidades extranjeras invitadas en
calidad de participantes
Diffusion maps and local models for wind power prediction
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-33266-1_70Proceedings of 22nd International Conference on Artificial Neural Networks, Lausanne, Switzerland, September 11-14, 2012In this work we will apply Diffusion Maps (DM), a recent technique for dimensionality reduction and clustering, to build local models for wind energy forecasting. We will compare ridge regression models for K–means clusters obtained over DM features, against the models obtained for clusters constructed over the original meteorological data or principal components, and also against a global model. We will see that a combination of the DM model for the low wind power region and the global model elsewhere outperforms other options.With partial support from grant TIN2010-21575-C02-01
of Spain’s Ministerio de Economía y Competitividad and the UAM–ADIC Chair for Machine Learning in Modelling and Prediction. The first author is also supported by an FPI-UAM grant and kindly thanks the Applied Mathematics Department
of Yale University for receiving her during a visit. The second author is
supported by the FPU-MEC grant AP2008-00167. We also thank Red Eléctrica de España, Spain’s TSO, for providing historic wind energy dat
First application of carbon-based screen-printed electrodes for the voltammetric determination of the organic UV filters oxybenzone and octocrylene
A new voltammetric methodology is proposed for the simultaneous determination of the organic UV filters oxybenzone (benzophenone 3, BP3) and octocrylene (OC) in personal care products and in wastewater extracts.It is based on previous adsorptive stripping voltammetric (AdSV) methods developed for hanging mercury drop electrodes, adapted to the special characteristics of carbon-based screen-printed electrodes. Among the carbon substrates tested, regular carbon screen-printed devices exhibited the best performance, with detection limits of 4.8 and 6.6 μmol L−1 and linearity ranges of 16-400 and 22-400 μmol L−1 for BP3 and OC, respectively, and, as compared to mercury electrodes, with the advantages of environmental safety, easy of use, low cost and compatibility with automation and flow measurements. The methodology has been successfully tested in real samples and compared to the standard methodology by liquid chromatography - tandem mass spectrometry (LCMS/MS)
Different involvement of medial prefrontal cortex and dorso-lateral striatum in automatic and controlled processing of a future conditioned stimulus
Recent studies support the idea that stimulus processing in latent inhibition can vary during the course of preexposure. Controlled attentional mechanisms are said to be important in the early stages of preexposure, while in later stages animals adopt automatic processing of the stimulus to be used for conditioning. Given this distinction, it is possible that both types of processing are governed by different neural systems, affecting differentially the retrieval of information about the stimulus. In the present study we tested if a lesion to the dorso-lateral striatum or to the medial prefrontal cortex has a selective effect on exposure to the future conditioned stimulus (CS). With this aim, animals received different amounts of exposure to the future CS. The results showed that a lesion to the medial prefrontal cortex enhanced latent inhibition in animals receiving limited preexposure to the CS, but had no effect in animals receiving extended preexposure to the CS. The lesion of the dorso-lateral striatum produced a decrease in latent inhibition, but only in animals with an extended exposure to the future conditioned stimulus. These results suggest that the dorsal striatum and medial prefrontal cortex play essential roles in controlled and automatic processes. Automatic attentional processes appear to be impaired by a lesion to the dorso-lateral striatum and facilitated by a lesion to the prefrontal cortex.Ministerio de Economía, Industria y Competitividad PSI2015-65500-
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