239 research outputs found

    Glottal Source Cepstrum Coefficients Applied to NIST SRE 2010

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    Through the present paper, a novel feature set for speaker recognition based on glottal estimate information is presented. An iterative algorithm is used to derive the vocal tract and glottal source estimations from speech signal. In order to test the importance of glottal source information in speaker characterization, the novel feature set has been tested in the 2010 NIST Speaker Recognition Evaluation (NIST SRE10). The proposed system uses glottal estimate parameter templates and classical cepstral information to build a model for each speaker involved in the recognition process. ALIZE [1] open-source software has been used to create the GMM models for both background and target speakers. Compared to using mel-frequency cepstrum coefficients (MFCC), the misclassification rate for the NIST SRE 2010 reduced from 29.43% to 27.15% when glottal source features are use

    Clinical Cysticercosis epidemiology in Spain based on the hospital discharge database: What's new?

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    BACKGROUND: Cysticercosis (CC) is a tissue infection caused by the larval cysts of the pork tapeworm Taenia solium. It is usually acquired by eating contaminated food or drinking water. CC Cysts can develop in the muscles, the eyes, the brain, and/or the spinal cord. T. solium is found worldwide, but its prevalence has decreased in developed countries due to stricter meat inspection and better hygiene and sanitation. Nevertheless, CC is still a leading cause of seizures and epilepsy. In Spain, The disease is not nationally reportable and data on CC infected animals are also missing, despite the European Directive 2003/99/EC. METHODOLOGY/PRINCIPAL FINDINGS: We performed a retrospective descriptive study using the Spanish Hospitalization Minimum Data Set (CMBD). Data with ICD-9 CM cysticercosis code ("123.1") placed in first or second diagnostic position from 1997 to 2014 were analyzed. Hospitalization rates were calculated and clinical characteristics were described. Spatial distribution of cases and their temporal behavior were also assessed. A total of 1,912 hospital discharges with clinical cysticercosis were identified. From 1998 to 2008, an increasing trend in the number of CC hospitalizations was observed, decreasing afterwards, in parallel with a decrease in the external migration rate. The Murcia region had the highest median hospitalization rate (13.37 hospitalizations/100,000 population), followed by Navarra and Madrid. The 16-44 age group was the most represented (63.6%). The three most frequent associated diagnoses were epilepsy and convulsions (49.5%), hydrocephalus (11.8%) and encephalitis/myelitis/meningitis (11.6%). CONCLUSIONS/SIGNIFICANCE: There is a need for a common strategy on data collection, monitoring and reporting, which would facilitate a more accurate picture on the CC epidemiological scenario. Even if most cases might be imported, improving the human and animal CC surveillance will result useful both in gaining extended disease knowledge and reducing morbidity and related-costs.The authors received no specific funding for this work.S

    Bio-inspired broad-class phonetic labelling

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    Recent studies have shown that the correct labeling of phonetic classes may help current Automatic Speech Recognition (ASR) when combined with classical parsing automata based on Hidden Markov Models (HMM).Through the present paper a method for Phonetic Class Labeling (PCL) based on bio-inspired speech processing is described. The methodology is based in the automatic detection of formants and formant trajectories after a careful separation of the vocal and glottal components of speech and in the operation of CF (Characteristic Frequency) neurons in the cochlear nucleus and cortical complex of the human auditory apparatus. Examples of phonetic class labeling are given and the applicability of the method to Speech Processing is discussed

    Glottal-Source Spectral Biometry for Voice Characterization

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    The biometric signature derived from the estimation of the power spectral density singularities of a speaker’s glottal source is described in the present work. This consists in the collection of peak-trough profiles found in the spectral density, as related to the biomechanics of the vocal folds. Samples of parameter estimations from a set of 100 normophonic (pathology-free) speakers are produced. Mapping the set of speaker’s samples to a manifold defined by Principal Component Analysis and clustering them by k-means in terms of the most relevant principal components shows the separation of speakers by gender. This means that the proposed signature conveys relevant speaker’s metainformation, which may be useful in security and forensic applications for which contextual side information is considered relevant

    Análisis dinámico in situ de transmisores de presión capacitivos

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    Los sensores de presión capacitivos tipo Rosemount son ampliamente utilizados en las centrales nucleares para la medida de la presión, el caudal y el nivel. Están unidos a las líneas de proceso de la central mediante líneas sensoras siendo el mantenimiento del sistema sensor-línea fundamental para mantener la seguridad en la planta. La vigilancia in situ del sistema en su conjunto, sensor-línea, se suele realizar mediante la medida del tiempo de respuesta del transmisor de presión con las técnicas de análisis de ruido. Sin embargo, determinadas averías como la pérdida de aceite de su cámara interna no son detectables por medio de la medida del tiempo de respuesta, ya que éste apenas varía su valor en una fase incipiente del síndrome. No obstante, la mejora de la descripción dinámica del sensor podría servir para detectar dichas averías. En laboratorio se ha demostrado que la función de transferencia del sistema sensor-línea puede tener más de un polo real, y en consecuencia, el modelo de tres polos (dos polos complejos conjugados y uno real) utilizado hasta ahora en otros trabajos podría sustituirse por uno de cuatro o incluso cinco. En este trabajo se propone utilizar técnicas de vigilancia in situ basadas en el análisis de ruido y en el Dynamic Data System para ampliar la descripción dinámica del sensor y con ello mejorar las posibilidades de diagnóstico de averías como el síndrome de la pérdida de aceite del sensor en fases incipientes. Se han analizado varias medidas de planta con la metodología propuesta y se muestran los resultados obtenidos

    Quadratic approximate dynamic programming for scheduling water resources: a case study

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    We address the problem of scheduling water resources in a power system via approximate dynamic programming.To this goal, we model a finite horizon economic dispatch problemwith convex stage cost and affine dynamics, and consider aquadratic approximation of the value functions. Evaluating theachieved policy entails solving a quadratic program at each timestep, while value function fitting can be cast as a semidefiniteprogram. We test our proposed algorithm on a simplified versionof the Uruguayan power system, achieving a four percent costreduction with respect to the myopic polic

    Bio-inspired Dynamic Formant Tracking for Phonetic Labelling

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    It is a known fact that phonetic labeling may be relevant in helping current Automatic Speech Recognition (ASR) when combined with classical parsing systems as HMM's by reducing the search space. Through the present paper a method for Phonetic Broad-Class Labeling (PCL) based on speech perception in the high auditory centers is described. The methodology is based in the operation of CF (Characteristic Frequency) and FM (Frequency Modulation) neurons in the cochlear nucleus and cortical complex of the human auditory apparatus in the automatic detection of formants and formant dynamics on speech. Results obtained informant detection and dynamic formant tracking are given and the applicability of the method to Speech Processing is discussed

    A Hybrid Parameterization Technique for Speaker Identification

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    Classical parameterization techniques for Speaker Identification use the codification of the power spectral density of raw speech, not discriminating between articulatory features produced by vocal tract dynamics (acoustic-phonetics) from glottal source biometry. Through the present paper a study is conducted to separate voicing fragments of speech into vocal and glottal components, dominated respectively by the vocal tract transfer function estimated adaptively to track the acoustic-phonetic sequence of the message, and by the glottal characteristics of the speaker and the phonation gesture. The separation methodology is based in Joint Process Estimation under the un-correlation hypothesis between vocal and glottal spectral distributions. Its application on voiced speech is presented in the time and frequency domains. The parameterization methodology is also described. Speaker Identification experiments conducted on 245 speakers are shown comparing different parameterization strategies. The results confirm the better performance of decoupled parameterization compared against approaches based on plain speech parameterization

    Curva de aprendizaje en cistoscopia flexible en residentes y urólogos de América Latina.

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    La cistoscopia es esencial en urología para diagnosticar patologías vesicales, especialmente el cáncer. La cistoscopia flexible ofrece ciertas ventajas como la disponibilidad en el consultorio. El aprendizaje de esta técnica requiere diversos grados de habilidad endoscópica. A menudo se asume que la competencia en el procedimiento se logra en los primeros años de formación urológica o dentro de un número limitado de procedimientos. Nuestro objetivo en el presente trabajo fue conocer la curva de aprendizaje en dicha técnica entre los urólogos de América Latina. Para el estudio se realizó una encuesta entre urólogos de Latinoamérica, donde se preguntaba si habían recibido capacitación durante su residencia y cómo había sido su curva de aprendizaje. En el estudio participaron 83 colegas, incluyendo residentes, urólogos recién graduados y aquellos con más de un año de experiencia. El 70% se sintió competente para realizar cistoscopias sin supervisión. El 57% recibió capacitación en su centro de residencia. En cuanto a la curva de aprendizaje un 86% de los encuestados refirieron la autopercepción de competencia entre las primeras 15 cistoscopias. El estudio incluyó a residentes, urólogos con más de un año de experiencia y recién graduados. La disponibilidad de cistoscopia flexible durante la residencia fue mayor para los residentes (77%) en comparación con los urólogos con experiencia. La mayoría se sintió competente entre los 6-10 procedimientos. En el análisis de capacitación en la residencia, el 74% de los residentes la recibió. Cuando se analizan por separado residentes, urólogos recién graduados y los que tienen más de un año de experiencia, se observan diferencias generacionales. La cistoscopia flexible es más común en las nuevas generaciones y la capacitación también está más extendida en ellas. La curva de aprendizaje es corta, con un 86% alcanzando competencia en 15 procedimientos

    1.8-THz-wide optical frequency comb emitted from monolithic passively mode-locked semiconductor quantum-well laser

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    We report on an optical frequency comb with 14 nm (∼1.8 THz) spectral bandwidth at a −3 dB level that is generated using a passively mode-locked quantum-well laser in photonic integrated circuits fabricated through an InP generic photonic integration technology platform. This 21.5-GHz colliding-pulse mode-locked laser cavity is defined by on-chip reflectors incorporating intracavity phase modulators followed by an extracavity semiconductor optical amplifier as a booster amplifier. A 1.8-THz-wide optical comb spectrum is presented with an ultrafast pulse that is 0.35 ps wide. The radio frequency beat note has a 3-dB linewidth of 450 kHz and 35-dB SNR.Horizon 2020 Framework Programme (H2020) (642355); Spanish Ministerio de Economía y Competitividad (MINECO) DiDACTIC (TEC2013-47753-C3-3-R); Consejería de Educación, Juventud y Deporte of Comunidad de Madrid (P2013/ICE-3004)
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