996 resultados para text-dependent speaker verification


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In this paper, the scales of Raven's Progressive Matrices Test, General Scale and Advanced Scale, Series II, for the student population (third cycle of EGB and Polimodal ) in the city of La Plata are presented. Considerations are made as regards both the increase in scores (Flynn effect) observed in relation to the previous scale (1964) and the different mean scores according to two age groups (13-16 and 17-18 years of age) and education mode. The findings enabled inferences related to the significance of the increase, particularly in the case of the higher scores in the population attending a special kind of educational institution.

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The majority of marine benthic invertebrates protect themselves from predators by producing calcareous tubes or shells that have remarkable mechanical strength. An elevation of CO2 or a decrease in pH in the environment can reduce intracellular pH at the site of calcification and thus interfere with animal's ability to accrete CaCO3. In nature, decreased pH in combination with stressors associated with climate change may result in the animal producing severely damaged and mechanically weak tubes. This study investigated how the interaction of environmental drivers affects production of calcareous tubes by the serpulid tubeworm, Hydroides elegans. In a factorial manipulative experiment, we analyzed the effects of pH (8.1 and 7.8), salinity (34 and 27), and temperature (23°C and 29°C) on the biomineral composition, ultrastructure and mechanical properties of the tubes. At an elevated temperature of 29°C, the tube calcite/aragonite ratio and Mg/Ca ratio were both increased, the Sr/Ca ratio was decreased, and the amorphous CaCO3 content was reduced. Notably, at elevated temperature with decreased pH and reduced salinity, the constructed tubes had a more compact ultrastructure with enhanced hardness and elasticity compared to decreased pH at ambient temperature. Thus, elevated temperature rescued the decreased pH-induced tube impairments. This indicates that tubeworms are likely to thrive in early subtropical summer climate. In the context of climate change, tubeworms could be resilient to the projected near-future decreased pH or salinity as long as surface seawater temperature rise at least by 4°C.

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We analyzed strontium/calcium ratios (Sr/Ca) in four colonies of the Atlantic coral genus Montastrea with growth rates ranging from 2.3 to 12.6 mm/a. Derived Sr/Ca-sea surface temperature (SST) calibrations exhibit significant differences among the four colonies that cannot be explained by variations in SST or seawater Sr/Ca. For a single coral Sr/Ca ratio of 8.8 mmol/mol, the four calibrations predict SSTs ranging from 24.0° to 30.9°C. We find that differences in the Sr/Ca-SST relationships are correlated systematically with the average annual extension rate (ext) of each colony such that Sr/Ca (mmol/mol) = 11.82 (±0.13) - 0.058 (±0.004) * ext (mm/a) - 0.092 (±0.005) * SST (°C). This observation is consistent with previous reports of a link between coral Sr/Ca and growth rate. Verification of our growth-dependent Sr/Ca-SST calibration using a coral excluded from the calibration reconstructs the mean and seasonal amplitude of the actual recorded SST to within 0.3°C. Applying a traditional, nongrowth-dependent Sr/Ca-SST calibration derived from a modern Montastrea to the Sr/Ca ratios of a conspecific coral that grew during the early Little Ice Age (LIA) (400 years B.P.) suggests that Caribbean SSTs were >5°C cooler than today. Conversely, application of our growth-dependent Sr/Ca-SST calibration to Sr/Ca ratios derived from the LIA coral indicates that SSTs during the 5-year period analyzed were within error (±1.4°C) of modern values.

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Research so far has provided little evidence that benthic biogeochemical cycling is affected by ocean acidification under realistic climate change scenarios. We measured nutrient exchange and sediment community oxygen consumption (SCOC) rates to estimate nitrification in natural coastal permeable and fine sandy sediments under pre-phytoplankton bloom and bloom conditions. Ocean acidification, as mimicked in the laboratory by a realistic pH decrease of 0.3, significantly reduced SCOC on average by 60% and benthic nitrification rates on average by 94% in both sediment types in February (pre-bloom period), but not in April (bloom period). No changes in macrofauna functional community (density, structural and functional diversity) were observed between ambient and acidified conditions, suggesting that changes in benthic biogeochemical cycling were predominantly mediated by changes in the activity of the microbial community during the short-term incubations (14 days), rather than by changes in engineering effects of bioturbating and bio-irrigating macrofauna. As benthic nitrification makes up the gross of ocean nitrification, a slowdown of this nitrogen cycling pathway in both permeable and fine sediments in winter, could therefore have global impacts on coupled nitrification-denitrification and hence eventually on pelagic nutrient availability.

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Voice biometry is classically based on the parameterization and patterning of speech features mainly. The present approach is based on the characterization of phonation features instead (glottal features). The intention is to reduce intra-speaker variability due to the `text'. Through the study of larynx biomechanics it may be seen that the glottal correlates constitute a family of 2-nd order gaussian wavelets. The methodology relies in the extraction of glottal correlates (the glottal source) which are parameterized using wavelet techniques. Classification and pattern matching was carried out using Gaussian Mixture Models. Data of speakers from a balanced database and NIST SRE HASR2 were used in verification experiments. Preliminary results are given and discussed.

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Current text-to-speech systems are developed using studio-recorded speech in a neutral style or based on acted emotions. However, the proliferation of media sharing sites would allow developing a new generation of speech-based systems which could cope with spontaneous and styled speech. This paper proposes an architecture to deal with realistic recordings and carries out some experiments on unsupervised speaker diarization. In order to maximize the speaker purity of the clusters while keeping a high speaker coverage, the paper evaluates the F-measure of a diarization module, achieving high scores (>85%) especially when the clusters are longer than 30 seconds, even for the more spontaneous and expressive styles (such as talk shows or sports).

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Basándonos en la recopilación inicial de preposiciones, locuciones preposicionales, términos con preposición dependiente y phrasal verbs utilizados en el texto técnico realizada en otros proyectos anteriores del Departamento de Lingüística Aplicada a la Ciencia y a la Tecnología, el objetivo de este trabajo es completar, organizar, actualizar y dar visibilidad a esta información inicial. Tras realizar un proceso exhaustivo de verificación, unificación, clasificación y ampliación de la información existente, en caso necesario, el listado resultante se utiliza para elaborar un glosario de términos con preposición. El objetivo final de este proyecto es que este glosario esté a disposición de los usuarios, a través de una consulta on-line, en la página del ILLLab (http://illlab.euitt.upm.es/wordpress/), dependiente del Departamento de Lingüística Aplicada a la Ciencia y a la Tecnología. Para incluir en el glosario ejemplos actualizados de textos técnicos, se ha recopilado un corpus lingüístico de textos técnicos, tomando como base diferentes números de la revista IEEE Spectrum, en su edición digital, publicados entre los años 2009 y 2012. El objetivo de esta recopilación es la de ofrecer al consultante diferentes ejemplos de uso en el texto técnico de los distintos términos con preposición que componen el glosario, de manera que pueda acceder de manera rápida y sencilla a ejemplos de uso real de los términos que está buscando, con objeto de clarificar aspectos relacionados con su uso o, en su caso, facilitar su aprendizaje. Toda esta información, tanto el listado de términos con preposición como las frases pertenecientes al corpus recopilado, se incorpora a una base de datos, alojada dentro de la misma página web del ILLLab. A través de un formulario de consulta, a disposición del usuario en dicha página, se pueden obtener todos los términos recopilados que coincidan con los criterios de búsqueda introducidos. El usuario puede realizar dos tipos de búsqueda principales: por preposición o por término completo. Además, puede elegir una búsqueda global (entre todos los términos que integran el glosario) o parcial (en una sola de las categorías en las que se han dividido los diferentes términos, de acuerdo con su función gramatical). Por último, se presentan unas estadísticas de uso de los términos recopilados dentro de los diferentes textos que integran el corpus lingüístico, de manera que pueda establecerse una relación de los que aparecen con más frecuencia en el texto técnico. ABSTRACT. Based on the initial collection of prepositions, prepositional phrases, dependent prepositions and phrasal verbs used in technical texts collected on previous projects in the Department of Applied Linguistics to Science and Technology, the aim of this project is to improve, organize, update and provide visibility to this initial information. Following a process of verification, unification, classification and extension of existing information, if necessary, a glossary of terms with preposition is built. The ultimate objective of this project is to make this glossary available to users through an online consultation in the ILLLab webpage (http://illlab.euitt.upm.es/wordpress/). The administration of tis webpage depends of the Department of Applied Linguistics in Science and Technology. A linguistic corpus of technical texts has been compiled, based on different numbers of the IEEE Spectrum magazine, in its online edition, published between the years 2009 and 2012. The aim of this collection is to provide different examples of use in the technical text for the terms included in the glossary, so that examples of the actual use of the terms consulted can be easily and quickly accessed, in order to clarify doubts regarding their meaning or translation into Spanish and facilitate learning. All this information, both the list of terms with prepositional phrases as well as the corpus developed, is incorporated in a database. Through a searching form, the ILLLab's user may obtain all the terms matching the search criteria entered. The user can perform two types of main search: by preposition or by full term. Additionally, a global search can be selected (including all terms included in the glossary) or a partial one (including only one of the glossary's categories). Finally, some statistics of use are presented according to the various texts included in the corpus, so a relation of the most frequent prepositions in the technical text can be established.

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Video-based vehicle detection is the focus of increasing interest due to its potential towards collision avoidance. In particular, vehicle verification is especially challenging due to the enormous variability of vehicles in size, color, pose, etc. In this paper, a new approach based on supervised learning using Principal Component Analysis (PCA) is proposed that addresses the main limitations of existing methods. Namely, in contrast to classical approaches which train a single classifier regardless of the relative position of the candidate (thus ignoring valuable pose information), a region-dependent analysis is performed by considering four different areas. In addition, a study on the evolution of the classification performance according to the dimensionality of the principal subspace is carried out using PCA features within a SVM-based classification scheme. Indeed, the experiments performed on a publicly available database prove that PCA dimensionality requirements are region-dependent. Hence, in this work, the optimal configuration is adapted to each of them, rendering very good vehicle verification results.

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MFCC coefficients extracted from the power spectral density of speech as a whole, seems to have become the de facto standard in the area of speaker recognition, as demonstrated by its use in almost all systems submitted to the 2013 Speaker Recognition Evaluation (SRE) in Mobile Environment [1], thus relegating to background this component of the recognition systems. However, in this article we will show that selecting the adequate speaker characterization system is as important as the selection of the classifier. To accomplish this we will compare the recognition rates achieved by different recognition systems that relies on the same classifier (GMM-UBM) but connected with different feature extraction systems (based on both classical and biometric parameters). As a result we will show that a gender dependent biometric parameterization with a simple recognition system based on GMM- UBM paradigm provides very competitive or even better recognition rates when compared to more complex classification systems based on classical features

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Histograms of Oriented Gradients (HoGs) provide excellent results in object detection and verification. However, their demanding processing requirements bound their applicability in some critical real-time scenarios, such as for video-based on-board vehicle detection systems. In this work, an efficient HOG configuration for pose-based on-board vehicle verification is proposed, which alleviates both the processing requirements and required feature vector length without reducing classification performance. The impact on classification of some critical configuration and processing parameters is in depth analyzed to propose a baseline efficient descriptor. Based on the analysis of its cells contribution to classification, new view-dependent cell-configuration patterns are proposed, resulting in reduced descriptors which provide an excellent balance between performance and computational requirements, rendering higher verification rates than other works in the literature.