Entorno de soporte al aprendizaje activo en procesamiento de lenguaje

El procesamiento de lenguaje es una competencia central en disciplinas relacionadas tanto con Informática como con Lingüística Computacional. Su carácter constructivo aconseja la adopción de una estrategia activa para su enseñanza, según la cual el alumno aprende definiendo lenguajes y construyendo sus procesadores: los programas que procesan las frases de dichos lenguajes. Bajo esta hipótesis, y en el contexto del programa de Proyectos de Innovación y Mejora de la Calidad Docente 2005-2006 de la UCM, estamos desarrollando un entorno informático orientado a facilitar dicho aprendizaje activo. En este artículo motivamos y describimos dicho entorno

Retailing farmed fish In southern Europe: supermarkets lead other seafood retailers.

Seafood retail channels in Southern Europe include four main classes: traditional fish markets and fishmongers, supermarkets and hypermarkets. Location, primary products and typical level of interaction with customers vary among the formats. In a survey in Spain, price was much more important for customers of supermarkets and hypermarkets than for those of the traditional channels, who rated quality more important. The empathy and reliability of vendors were scored higher for the traditional stores

Coding Prony's method in MATLAB and applying it to biomedical signal filtering

Background:The response of many biomedical systems can be modelled using a linear combination of damped exponential functions. The approximation parameters, based on equally spaced samples, can be obtained using Prony's method and its variants (e.g. the matrix pencil method). This paper provides a tutorial on the main polynomial Prony and matrix pencil methods and their implementation in MATLAB and analyses how they perform with synthetic and multifocal visual-evoked potential (mfVEP) signals. This paper briefly describes the theoretical basis of four polynomial Prony approximation methods: classic, least squares (LS), total least squares (TLS) and matrix pencil method (MPM). In each of these cases, implementation uses general MATLAB functions. The features of the various options are tested by approximating a set of synthetic mathematical functions and evaluating filtering performance in the Prony domain when applied to mfVEP signals to improve diagnosis of patients with multiple sclerosis (MS). Results:The code implemented does not achieve 100%-correct signal approximation and, of the methods tested, LS and MPM perform best. When filtering mfVEP records in the Prony domain, the value of the area under the receiver-operating-characteristic (ROC) curve is 0.7055 compared with 0.6538 obtained with the usual filtering method used for this type of signal (discrete Fourier transform low-pass filter with a cut-off frequency of 35 Hz). Conclusions:This paper reviews Prony's method in relation to signal filtering and approximation, provides the MATLAB code needed to implement the classic, LS, TLS and MPM methods, and tests their performance in biomedical signal filtering and function approximation. It emphasizes the importance of improving the computational methods used to implement the various methods described above.Universidad de AlcaláSecretaría de Estado de Investigación, Desarrollo e Innovació

Dirac neutrinos from flavor symmetry

We present a model where Majorana neutrino mass terms are forbidden by the flavor symmetry group Delta(27). Neutrinos are Dirac fermions and their masses arise in the same way as those of the charged fermions, due to very small Yukawa couplings. The model fits current neutrino oscillation data and correlates the octant of the atmospheric angle theta(23) with the magnitude of the lightest neutrino mass, with maximal mixing excluded for any neutrino mass hierarchy

Frequency measurement under non-sinusoidal conditions

Frequency measurement is an important issue in electrical engineering. Electric power systems have become increasing complex over the last decade. The use of distributed generation, the connection of non-linear loads and the presence of unexpected system faults are the main causes of frequency variations. In addition, power quality includes frequency as an important index. From a hardware instrumentation point of view, frequency measurement has different requirements: i.) Large power systems have slow frequency variation due to the high inertia of the overall network. This kind of problem requires frequency measuring methods capable of detecting small and also slow frequency variations. ii.) Small power systems can have frequency variation due to their reduced short-circuit power capacity. This type of problem requires fast methods with the capacity to detect large frequency variations. There are different groups of methods intended for frequency measurement. The methods can be compared in terms of computation and dynamic response, especially when the main voltage is disturbed. This research work focuses on frequency measurement under non-sinusoidal conditions. The paper studies the behaviour of a modified version of Sezi's method and its hardware implementation using a microcontroller. This system can be used for frequency measurement or as a synchronized sampling source in harmonic measurement (e.g. EN 61000-4-7) The fast time response of the system enables it to be used in almost all kinds of application: small and slow frequency variations; frequency triggering in power system protection and power quality index characterisation

Geodetic Study of the 2006–2010 Ground Deformation in La Palma (Canary Islands): Observational Results

La Palma is one of the youngest of the Canary Islands, and historically the most active. The recent activity and unrest in the archipelago, the moderate seismicity observed in 2017 and 2018 and the possibility of catastrophic landslides related to the Cumbre Vieja volcano have made it strongly advisable to ensure a realistic knowledge of the background surface deformation on the island. This will then allow any anomalous deformation related to potential volcanic unrest on the island to be detected by monitoring the surface deformation. We describe here the observation results obtained during the 2006–2010 period using geodetic techniques such as Global Navigation Satellite System (GNSS), Advanced Differential Synthetic Aperture Radar Interferometry (A-DInSAR) and microgravimetry. These results show that, although there are no significant associated variations in gravity, there is a clear surface deformation that is spatially and temporally variable. Our results are discussed from the point of view of the unrest and its implications for the definition of an operational geodetic monitoring system for the islan

Continuous‑wavelet‑transform analysis of the multifocal ERG waveform in glaucoma diagnosis

The vast majority of multifocal electroretinogram (mfERG) signal analyses to detect glaucoma study the signals’ amplitudes and latencies. The purpose of this paper is to investigate application of wavelet analysis of mfERG signals in diagnosis of glaucoma. This analysis method applies the continuous wavelet transform (CWT) to the signals, using the real Morlet wavelet. CWT coefficients resulting from the scale of maximum correlation are used as inputs to a neural network, which acts as a classifier. mfERG recordings are taken from the eyes of 47 subjects diagnosed with chronic open-angle glaucoma and from those of 24 healthy subjects. The high sensitivity in the classification (0.894) provides reliable detection of glaucomatous sectors, while the specificity achieved (0.844) reflects accurate detection of healthy sectors. The results obtained in this paper improve on the previous findings reported by the authors using the same visual stimuli and database.Ministerio de Ciencia e Innovació

Using a process-based stomatal model in olive and its potential application to deficit irrigation studies

Over the last years modeling plant transpiration has been pointed out as a powerful tool to optimize the management of irrigation in fruit trees. In this study we tested the hydromechanical model of stomata functioning proposed by Buckley et al. (2003), a model with a strong physiological basis. The great contribution of this model is that its parameters have direct physiological meaning. Firstly, the model was simplified to make its parameters estimation friendly and easy. Secondly, the model was fitted to data obtained in a hedgerow olive orchard under regulated deficit irrigation. The hydromechanical model fitted our data satisfactorily and allowed us to analyze the physiological parameters obtained.Ministerio de Ciencia e Innovación español AGL2009-11310/AGRJunta de Andalucí

Improved measurement of intersession latency in mfVEPs

Purpose: The purpose of the study is to present a method (Selfcorr) by which to measure intersession latency differences between multifocal VEP (mfVEP) signals. Methods: The authors compared the intersession latency difference obtained using a correlation method (Selfcorr) against that obtained using a Template method. While the Template method cross-correlates the subject’s signals with a reference database, the Selfcorr method cross-correlates traces across subsequent recordings taken from the same subject. Results: The variation in latency between intersession signals was 0.8 ± 13.6 and 0.5 ± 5.0 ms for the Template and Selfcorr methods, respectively, with a coefficient of variability C V_TEMPLATE = 15.83 and C V_SELFCORR = 5.68 (n = 18, p = 0.0002, Wilcoxon). The number of analyzable sectors with the Template and Selfcorr methods was 36.7 ± 8.5 and 45.3 ± 8.7, respectively (p = 0.0001, paired t test, two tailed). Conclusions: The Selfcorr method produces smaller intersession mfVEP delays and variability over time than the Template method.Ministerio de Ciencia e Innovació

Clinical Benefit of Tamsulosin and the Hexanic Extract of Serenoa Repens, in Combination or as Monotherapy, in Patients with Moderate/Severe LUTS-BPH: A Subset Analysis of the QUALIPROST Study

To investigate whether tamsulosin (TAM) and the hexanic extract of Serenoa repens (HESr) are more effective in combination than as monotherapy in men with moderate-to-severe lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH). Subset analysis of data from a 6-month, multicenter observational study. Patients received either tamsulosin (0.4 mg/day) or HESr (320 mg/day) alone or in combination. Primary endpoints were change in symptoms and quality of life. Tolerability was also assessed. Seven hundred and nine patients were available for intention to treat (ITT) analysis, 263 treated with tamsulosin, 262 with HESr, and 184 with TAM + HESr. After 6 months, International Prostate Symptom Score (IPSS) scores improved by a mean (standard deviation) of 7.2 (5.0) points in the TAM + HESr group compared to 5.7 (4.3) points with TAM alone and 5.4 (4.6) points with HESr (p < 0.001). Quality of life showed greatest improvement with combination therapy (p < 0.02). Adverse effects were reported by 1.9% of patients receiving HESr, 13.3% receiving TAM, and 12.0% receiving TAM + HESr (p < 0.001). In men with moderate/severe LUTS/BPH, combination treatment with TAM + HESr produced more effective symptom relief and greater improvement in quality of life than with either treatment alone, with acceptable tolerability