Moreno G.,UCLM |
Penabad J.,UCLM |
Riaza J.A.,UCLM |
Vidal G.,Polytechnic University of Valencia
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017
Fuzzy logic programming is a growing declarative paradigm aiming to integrate fuzzy logic into logic programming. One of the most difficult tasks when specifying a fuzzy logic program is determining the right weights for each rule, as well as the most appropriate fuzzy connectives and operators. In this paper, we introduce a symbolic extension of fuzzy logic programs in which some of these parameters can be left unknown, so that the user can easily see the impact of their possible values. Furthermore, given a number of test cases, the most appropriate values for these parameters can be automatically computed. Finally, we show some benchmarks that illustrate the usefulness of our approach. © Springer International Publishing AG 2017.
Gavete L.,Technical University of Madrid |
Benito J.J.,Spanish University for Distance Education (UNED) |
Applied Mathematical Modelling | Year: 2014
The generalized finite difference method (GFDM) is a meshfree method that can be applied for solving problems defined over irregular clouds of points. The GFDM uses the Taylor series development and the moving least squares approximation to obtain explicit formulae for the partial derivatives.In this paper, this meshfree method is used for solving elliptic and parabolic partial differential equations in 3-D. The influence of the main parameters involved in the approximation and the treatment of the Neumann boundary condition are shown. Parabolic equations have been solved using an explicit method and the criterion for stability has been improved taking into account the irregularity of the cloud of points. The numerical results show the high accuracy obtained. © 2015 Elsevier Inc.
Tapiador F.J.,UCLM |
Turk F.J.,Jet Propulsion Laboratory |
Petersen W.,NASA |
Hou A.Y.,NASA |
And 8 more authors.
Atmospheric Research | Year: 2012
This paper explores the many aspects of precipitation measurement that are relevant to providing an accurate global assessment of this important environmental parameter. Methods discussed include ground data, satellite estimates and numerical models. First, the methods for measuring, estimating, and modeling precipitation are discussed. Then, the most relevant datasets gathering precipitation information from those three sources are presented. The third part of the paper illustrates a number of the many applications of those measurements and databases, namely hydropower, data assimilation and validation of Regional Climate Models (RCM). The aim of the paper is to organize the many links and feedbacks between precipitation measurement, estimation and modeling, indicating the uncertainties and limitations of each technique in order to identify areas requiring further attention, and to show the limits within which datasets can be used. Special emphasis is put on the central role of the upcoming Global Precipitation Measurement (GPM) mission in precipitation science. © 2011.
Guerrero A.R.,UC |
CEUR Workshop Proceedings | Year: 2015
The objective of this study was to identify the specialization profiles which are most required by companies and organizations in Lima, through the analysis of job postings published in the Internet. Text Mining techniques were used to extract relevant information and to identify some generic skills for the Peruvian statisticians. For purposes of this study, we analyzed 2,809 job postings published in the Blog "Estadísticos de Perú" , between 2009 and 2014. We have identified many requirements, knowledge and specific skills that companies and organizations were looking for. After that, job postings were segmented using Singular Value Decomposition (SVD) of the Terms and Documents Matrix. In addition, five segments were discovered, corresponding to specific competency profiles of statisticians, where each one has different types of knowledge and specific skills.
Cuadra Troncoso J.M.,Spanish University for Distance Education (UNED) |
Alvarez-Sanchez J.R.,Spanish University for Distance Education (UNED) |
De La Paz Lopez F.,Spanish University for Distance Education (UNED) |
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011
When using raw 2D range measures to delimit the border for the free area sensed by a robot, the noise makes the sensor to yield a cloud of points, which is an imprecise border. This vagueness pose some problems for robot navigation using area center methods, due to free area split points locations. The basic method, when locating split points, does not take into account environmental features, only the raw cloud of points. In order to determine accurately such environmental features we use a novel range scan segmentation method. This method has the interesting characteristic of being adaptive to environment noise, in the sense that we do not need to fix noise standard deviation, even different areas of the same scan can have different deviations, e. g. a wall besides a hedge. Procedure execution time is in the order of milliseconds for modern processors. Information about interesting navigational features is used to improve area center navigation by means of determining safer split points and developing the idea of dynamic split point. A dynamic split point change its position to a new feature if this new feature is considered more dangerous than the one marked by the split point. © 2011 Springer-Verlag Berlin Heidelberg.
Jimenez-Borja C.,UCLM |
Brosda S.,University of Patras |
Makri M.,University of Patras |
Sapountzi F.,University of Patras |
And 3 more authors.
Solid State Ionics | Year: 2012
Electrochemical investigations have been carried out on Pd/YSZ catalyst-electrodes for deep oxidation of methane in excess of oxygen. A wet impregnation technique has been used to achieve highly active Pd catalyst films. It was found that co-feeding of ethylene in oxidizing gas mixtures enhances the rate of methane conversion and allows for electrochemical promotion of methane oxidation at temperatures as low as 320 °C. The electrochemical promotion behavior has been studied with long term potentiostatic transients together with AC impedance measurements during polarization. © 2012 Elsevier B.V.
Jimenez-Borja C.,UCLM |
Brosda S.,University of Patras |
Matei F.,Petroleum Gas University of Ploiesti |
Makri M.,University of Patras |
And 6 more authors.
Applied Catalysis B: Environmental | Year: 2012
The catalytic activity of Pd/YSZ and Pd-CeO2/YSZ catalysts prepared via organometallic paste calcination or via wet impregnation has been investigated under conditions of excess in oxygen and at temperatures from 250 to 450°C. The catalyst-electrodes were characterized via XRD, SEM, in situ electrical conductivity measurements, electrochemical current-potential curves and catalytic kinetic measurements. The impregnated Pd films were found to be more active with light-off temperatures of 270°C vs. 320°C for metal paste catalysts. Only the impregnated catalyst could be electropromoted at temperatures above 320°C. The Pd-CeO2/YSZ catalyst exhibited high catalytic activity but could not be electropromoted.Co-feeding of ethylene or pre treatment in oxidizing ethylene-oxygen gas mixtures enhances the rate of methane conversion in comparison to non-treated samples and allows electrochemical promotion of the methane oxidation at temperatures as low as 320. °C. The reason for this behavior is discussed in view of detailed pre and post surface characterization and in situ electrochemical measurements. © 2012 Elsevier B.V.
Carrion M.C.,Organica y Bioquimica |
Ruiz-Castaneda M.,Organica y Bioquimica |
Espino G.,University of Burgos |
Aliende C.,University of Burgos |
And 5 more authors.
ACS Catalysis | Year: 2014
The new complex [(η6-p-cym)RuCl(κ2-N,N- dmbpy)](BF4) (p-cym = p-cymene; dmbpy = 4,4′-dimethyl-2, 2′-bipyridine) is water-soluble and active in the catalytic transfer hydrogenation (TH) of different ketones (cyclohexanone, 2-cyclohexenone, and 3-pentanone) to the corresponding alcohols using aqueous HCOONa/HCOOH as the hydrogen source at pH 4.4. A higher activity was found for the TH of the imine N-benzylideneaniline under the same conditions. Excellent results have been obtained for catalyst recycling. Aqua, formato, and hydrido species were detected by 1H NMR experiments in D2O. Importantly, when the catalytic reaction was carried out in D2O, selective deuteration at the Cα of the alcohols was observed due to a rapid Ru-H/D+ exchange, which was also deduced theoretically. This process involves a reversal of polarity of the D+ ion, which is transformed into a Ru-D function ("umpolung"). Negligible deuterium labeling was observed for the imine, possibly due to the high activity in the TH process and also to the decrease in the hydrido complex concentration due to the stability of a hydrido-imine intermediate. Both facts should ensure that the TH reaction will compete favorably with the Ru-H/D+ exchange. The basic nature of the imine hydrogenation product can also hinder the stated Ru-H/D+ exchange. On the basis of DFT calculations, all these hypotheses are discussed. In addition, calculations at this level also support the participation of the stated aqua, formato, and hydrido intermediates in the catalytic reaction and provide a detailed microscopic description of the full catalytic cycle. In the case of the imine TH process, the formation of the hydrido complex (decarboxylation step) is clearly the limiting step of the cycle. On the contrary, in the hydrogenation of cyclohexanone, both decarboxylation and reduction steps exhibit similar barriers, and due to the limitations of the solvent model employed, a definitive conclusion on the rate-determining step cannot be inferred. © 2014 American Chemical Society.
Guerrero-Gomez-Olmedo R.,GRAM |
Lopez-Sastre R.J.,GRAM |
Maldonado-Bascon S.,GRAM |
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013
We address the problem of vehicle detection and tracking for traffic monitoring in Smart City applications. We introduce a novel approach for vehicle tracking by simultaneous detection and viewpoint estimation. An Extended Kalman Filter (EKF) is adapted to describe the vehicle's motion when not only the pose of the object is measured, but also its viewpoint with respect to the camera. Specifically, we enhance the motion model with observations of the vehicle viewpoint jointly extracted by the detection step. The approach is evaluated on a novel and challenging dataset with different video sequences recorded at urban environments, which is released with the paper. Our experimental validation confirms that the integration of an EKF with both detections and viewpoint estimations results beneficial. © 2013 Springer-Verlag.
Carrion M.,UCLM |
Energy | Year: 2015
This paper aims to study the operational consequences of the integration of a large number of plug-in electric vehicles in a renewable-dominated power system. The coordination between the power system operator and the charging process of plug-in electric vehicles under a smart-grid environment is modeled using several approaches. The operation of the power system is modeled by means of a network-constrained stochastic economic dispatch. This problem is formulated using a two-stage stochastic programming model in which the uncertainties associated with the charging process of plug-in electric vehicles and with the availability of the renewable sources are characterized as stochastic processes. Numerical results on a realistic case based on the Iberian Peninsula power system are provided and analyzed. © 2015 Elsevier Ltd.