2,650 research outputs found

    Policy Analysis Tool Applied to Colombian Needs: PATACON Model Description

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    In this document we lay out the microeconomic foundations of a dynamic stochastic general equilibrium model designed to forecast and to advice monetary policy authorities in Colombia. The model is called Policy Analysis Tool Applied to Colombian Needs (PATACON). In companion documents we present other aspects of the model and its platform, including the estimation of the parameters that affect the dynamics and the impulse responses functions.Monetary Policy, DSGE, Small open economy. Classification JEL: E32, E52, F41.

    Silent speech: restoring the power of speech to people whose larynx has been removed

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    Every year, some 17,500 people in Europe and North America lose the power of speech after undergoing a laryngectomy, normally as a treatment for throat cancer. Several research groups have recently demonstrated that it is possible to restore speech to these people by using machine learning to learn the transformation from articulator movement to sound. In our project articulator movement is captured by a technique developed by our collaborators at Hull University called Permanent Magnet Articulography (PMA), which senses the changes of magnetic field caused by movements of small magnets attached to the lips and tongue. This solution, however, requires synchronous PMA-and-audio recordings for learning the transformation and, hence, it cannot be applied to people who have already lost their voice. Here we propose to investigate a variant of this technique in which the PMA data are used to drive an articulatory synthesiser, which generates speech acoustics by simulating the airflow through a computational model of the vocal tract. The project goals, participants, current status, and achievements of the project are discussed below.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Renormalization on noncommutative torus

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    We study a self-interacting scalar φ4 theory on the d-dimensional noncommutative torus. We determine, for the particular cases d= 2 and d= 4 , the counterterms required by one-loop renormalization. We discuss higher loops in two dimensions and two-loop contributions to the self-energy in four dimensions. Our analysis points toward the absence of any problems related to the ultraviolet/infrared mixing and thus to renormalizability of the theory. However, we find another potentially troubling phenomenon which is a wild behavior of the two-point amplitude as a function of the noncommutativity matrix θ.Instituto de Física La Plat

    Método numérico para la calibración de un modelo dsge

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    En este artículo se propone un método numérico para la calibración de un modelo de equilibrio general dinámico y estocástico (dsge). Esencialmente, este consiste en utilizar un algoritmo híbrido de optimización, primero para encontrar un estado estacionario del modelo y luego para minimizar una función objetivo que se define según el propósito que tenga el investigador con el proceso de calibración. El algoritmo propuesto consiste en una aplicación del algoritmo de simulated annealing, seguida de métodos tradicionales de optimización. Las bondades del algoritmo se analizan mediante simulaciones de Monte Carlo, usando un modelo de economía cerrada cuyo estado estacionario no tiene solución analítica. Los resultados de este ejercicio muestran que el algoritmo propuesto genera resultados más precisos y que utiliza menos recursos computacionales que las alternativas tradicionales. Además, se presentan los resultados de la calibración de un modelo para la economía colombiana que consta de 179 ecuaciones y que se ajusta a cincuenta razones con cincuenta parámetros. La máxima desviación porcentual entre las razones del modelo y los valores correspondientes de la economía colombiana es de 7,9% y, en veintinueve de los cincuenta casos, esta desviación es menor o igual a 1%.simulated annealing, calibración, dsge, estado estacionario.

    Non-Parallel Articulatory-to-Acoustic Conversion Using Multiview-based Time Warping

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    This work was supported in part by the Spanish State Research Agency (SRA) grant number PID2019-108040RB-C22/SRA/10.13039/501100011033, and the FEDER/Junta de AndalucíaConsejería de Transformación Económica, Industria, Conocimiento y Universidades project no. B-SEJ-570-UGR20.In this paper, we propose a novel algorithm called multiview temporal alignment by dependence maximisation in the latent space (TRANSIENCE) for the alignment of time series consisting of sequences of feature vectors with different length and dimensionality of the feature vectors. The proposed algorithm, which is based on the theory of multiview learning, can be seen as an extension of the well-known dynamic time warping (DTW) algorithm but, as mentioned, it allows the sequences to have different dimensionalities. Our algorithm attempts to find an optimal temporal alignment between pairs of nonaligned sequences by first projecting their feature vectors into a common latent space where both views are maximally similar. To do this, powerful, nonlinear deep neural network (DNN) models are employed. Then, the resulting sequences of embedding vectors are aligned using DTW. Finally, the alignment paths obtained in the previous step are applied to the original sequences to align them. In the paper, we explore several variants of the algorithm that mainly differ in the way the DNNs are trained. We evaluated the proposed algorithm on a articulatory-to-acoustic (A2A) synthesis task involving the generation of audible speech from motion data captured from the lips and tongue of healthy speakers using a technique known as permanent magnet articulography (PMA). In this task, our algorithm is applied during the training stage to align pairs of nonaligned speech and PMA recordings that are later used to train DNNs able to synthesis speech from PMA data. Our results show the quality of speech generated in the nonaligned scenario is comparable to that obtained in the parallel scenario.Spanish State Research Agency (SRA) PID2019-108040RB-C22/SRA/10.13039/501100011033FEDER/Junta de AndalucíaConsejería de Transformación Económica, Industria, Conocimiento y Universidades project no. B-SEJ-570-UGR20

    Laparoscopic surgery of vesicovaginal fistula: results of a multi institutional experience

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    Indexación: Web of Science; Scielo.Introduction: Vesico-vaginal fistula is a rare complication of gynecologic surgery, with a high rate of surgical resolution O'Conor open technique. Aim: To report the results of a multi-institutional experience in laparoscopic repair of vesico-vaginal fistula. Material and Methods: Between January 2006 and June 2011, 21 laparoscopic vesico-vaginal fistula were performed. The surgical technique, demographic variables and results are described. Results: The mean age was 45.6 years. The average time between the diagnosis of the fistula and the laparoscopic repair was 15.23 months. The mean total operative time (bladder and laparoscopic) was 153.12 minutes and the average hospital stay was 2.7 days. The average time of bladder catheter was 9.4 days. There was a minimal recurrence of a fistula, repaired by a vaginal approach. Urethrocystography revealed indemnity of the repair in the other 20 cases. The overall success rate was 95.2% (20 out of 21 patients) Conclusions: The laparoscopic approach follows all principles for repair of a vesico-vaginal fistulas. It look like a good alternative in the hands of experienced surgeons. Key words: Vesicovaginal fistula, hysterectomy, complications, laparoscopy, O'Conor.Introducción: La fístula vesico-vaginal es una complicación infrecuente de la cirugía ginecológica, con alta tasa de resolución quirúrgica con la técnica abierta tradicional de O'Conor. Objetivo: Comunicar los resultados de una experiencia multi-institucional en la reparación laparoscópica de las fístulas vesico-vaginales. Material y Método: Entre enero de 2006 y junio de 2011 se realizaron 21 reparaciones de fístulas vesico-vaginales por vía laparoscópica. Se describe la técnica quirúrgica y se analizan las variables demográficas, quirúrgicas y resultados de la serie. Resultados: La edad media de las pacientes fue de 45,6 años. El tiempo promedio transcurrido entre el diagnóstico de la fistula y su reparación laparoscópica fue de 15,23 meses. El tiempo quirúrgico medio total (vesical y laparoscópico) fue de 153,12 min y el de hospitalización 2,7 días. El tiempo promedio de catéter uretro-vesical fue de 9,4 días. Hubo una mínima recidiva de una fístula, la cual fue reparada por vía vaginal. El control radiológico mediante cistografía reveló indemnidad de la reparación en el resto de los casos. La tasa global de éxito fue de 95,2% (20 de 21 pacientes) Conclusiones: El abordaje laparoscópico permite cumplir con todos los principios para la reparación de las fístulas vesico-vaginales. La reducción de la morbilidad y la eficacia del procedimiento, lo transforman en una excelente alternativa en manos de cirujanos experimentados. Palabras clave: Fístula vesico-vaginal, histerectomía, complicaciones, laparoscopia, O'Conor.http://ref.scielo.org/f3vxt

    On the algebraic structure of rotationally invariant two-dimensional Hamiltonians on the noncommutative phase space

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    We study two-dimensional Hamiltonians in phase space with noncommutativity both in coordinates and momenta. We consider the generator of rotations on the noncommutative plane and the Lie algebra generated by Hermitian rotationally invariant quadratic forms of noncommutative dynamical variables. We show that two quantum phases are possible, characterized by the Lie algebras sl (2, ℝ) or su(2) according to the relation between the noncommutativity parameters, with the rotation generator related with the Casimir operator. From this algebraic perspective, we analyze the spectrum of some simple models with nonrelativistic rotationally invariant Hamiltonians in this noncommutative phase space, such as the isotropic harmonic oscillator, the Landau problem and the cylindrical well potential.Instituto de Física La Plat

    Multi-view Temporal Alignment for Non-parallel Articulatory-to-Acoustic Speech Synthesis

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    Articulatory-to-acoustic (A2A) synthesis refers to the generation of audible speech from captured movement of the speech articulators. This technique has numerous applications, such as restoring oral communication to people who cannot longer speak due to illness or injury. Most successful techniquesso far adopt a supervised learning framework, in which timesynchronousarticulatory-and-speech recordings are used to train a supervised machine learning algorithm that can be used later to map articulator movements to speech. This, however, prevents the application of A2A techniques in cases where parallel data is unavailable, e.g., a person has already lost her/his voice and only articulatory data can be captured. In this work, we propose a solution to this problem based on the theory of multi-view learning. The proposed algorithm attempts to find an optimal temporal alignment between pairs of nonaligned articulatory-and-acoustic sequences with the same phonetic content by projecting them into a common latent space where both views are maximally correlated and then applying dynamic time warping. Several variants of this idea are discussed and explored. We show that the quality of speech generated in the non-aligned scenario is comparable to that obtained in the parallel scenario.This work was funded by the Spanish State Research Agency (SRA) under the grant PID2019-108040RBC22/ SRA/10.13039/501100011033. Jose A. Gonzalez-Lopez holds a Juan de la Cierva-Incorporation Fellowship from the Spanish Ministry of Science, Innovation and Universities (IJCI-2017-32926)

    On the algebraic structure of rotationally invariant two-dimensional Hamiltonians on the noncommutative phase space

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    We study two-dimensional Hamiltonians in phase space with noncommutativity both in coordinates and momenta. We consider the generator of rotations on the noncommutative plane and the Lie algebra generated by Hermitian rotationally invariant quadratic forms of noncommutative dynamical variables. We show that two quantum phases are possible, characterized by the Lie algebras sl (2, ℝ) or su(2) according to the relation between the noncommutativity parameters, with the rotation generator related with the Casimir operator. From this algebraic perspective, we analyze the spectrum of some simple models with nonrelativistic rotationally invariant Hamiltonians in this noncommutative phase space, such as the isotropic harmonic oscillator, the Landau problem and the cylindrical well potential.Instituto de Física La Plat
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