Feature Extraction for Murmur Detection Based on Support Vector Regression of Time-Frequency Representations

This paper presents a nonlinear approach for time-frequency representations (TFR) data analysis, based on a statistical learning methodology - support vector regression(SVR), that being a nonlinear framework, matches recent findings on the underlying dynamics of cardiac mechanic activity and phonocardiographic (PCG) recordings. The proposed methodology aims to model the estimated TFRs, and extract relevant features to perform classification between normal and pathologic PCG recordings (with murmur). Modeling of TFR is done by means of SVR, and the distance between regressions is calculated through dissimilarity measures based on dot product. Finally, a k-nn classifier is used for the classification stage, obtaining a validation performance of 97.85%

Focalization of Acoustic Vortices Using Phased Array Systems

AbstractAcoustic vortices (AV) are helical wavefronts that exhibit a screw-type dislocation and a phase singularity along its principal axis of propagation, at which the pressure of the field is zero. AV can be generated using various methods among which stands out the use of phased array systems because they allow us to electronically control the acoustic beam by means of the application of a given delay law to the array elements. Little research has been reported regarding the focalization of AV to obtain a higher pressure distribution. In view of this, this work presents the study of different delay laws for generating and focusing AV. The analysis of the resultant geometry and pressure distribution of the focused beams is included. We demonstrate that it is possible to increase the pressure amplitude up to 3 times with respect to a non-focalized, at the focal distance. Experimental tests were carried out using a hexagonal multitransducer of 30 elements at 40kHz. A good agreement between simulations and experimental results was obtained

Emergence of competing magnetic interactions induced by Ge doping in the semiconductor FeGa3

ABSTRACT: FeGa3 is an unusual intermetallic semiconductor that presents intriguing magnetic responses to the tuning of its electronic properties. When doped with Ge, the system evolves from diamagnetic to paramagnetic to ferromagnetic ground states that are not well understood. In thiswork,we have performed a joint theoretical and experimental study of FeGa3−xGex using density functional theory and magnetic susceptibility measurements. For low Ge concentrations we observe the formation of localized moments on some Fe atoms and, as the dopant concentration increases, a more delocalized magnetic behavior emerges. The magnetic configuration strongly depends on the dopant distribution, leading even to the appearance of antiferromagnetic interactions in certain configurations

Efectos de varias dosis de magnesio aplicadas al suelo sobre el crecimiento de plántulas de cacao (Theobroma cacao L.).

Cacao-Theobroma caca

Time-Frequency based Feature Selection for Discrimination of non stationary Biosignals.

This research proposes a generic methodology for dimensionality reduction upon time-frequency representations applied to the classification of different types of biosignals. The methodology directly deals with the highly redundant and irrelevant data contained in these representations, combining a first stage of irrelevant data removal by variable selection, with a second stage of redundancy reduction using methods based on linear transformations. The study addresses two techniques that provided a similar performance: the first one is based on the selection of a set of the most relevant time?frequency points, whereas the second one selects the most relevant frequency bands. The first methodology needs a lower quantity of components, leading to a lower feature space; but the second improves the capture of the time-varying dynamics of the signal, and therefore provides a more stable performance. In order to evaluate the generalization capabilities of the methodology proposed it has been applied to two types of biosignals with different kinds of non-stationary behaviors: electroencephalographic and phonocardiographic biosignals. Even when these two databases contain samples with different degrees of complexity and a wide variety of characterizing patterns, the results demonstrate a good accuracy for the detection of pathologies, over 98%.The results open the possibility to extrapolate the methodology to the study of other biosignals

Validación de la escala de ansiedad al coronavirus en una muestra colombiana

El coronavirus del síndrome respiratorio agudo severo 2 (SARS CoV 2) tuvo su origen en los murciélagos y se transmitió a los seres humanos a través del contacto con animales exóticos en los mercados de Wuhan, provincia de Hubei ( en noviembre de 2019 ( 2020). Dicho virus se transmite por inhalación o por contacto con gotas infectadas y el periodo de incubación oscila entre 2 y 14 días, con un promedio de 5 6 días, y un promedio de manifestación de los síntomas de 11.5 días (Liu et al., 2020), aun cuando se calcula que un 30% de las personas contagiadas son asintomáticas (Lauer et al., 2020)

El espacio como instrumento de formación. Arquitectura como estrategia educativa aplicado a un Jardín Infantil

Artículo de GradoEl proyecto se desarrolla como ejercicio académico en un contexto real donde se propone adoptar y entender la transformación de la idea de diseño en las instalaciones educacionales en el país con base en la petición que la secretaria de educación le hizo a el Arq. Frank Locker, donde el arquitecto debe establecer criterios de diseño en búsqueda de cambiar la forma de aprender, todo esto basado en la relación entre el tipo de educación y la arquitectura como lugar de aprendizaje, enfocado en lo que la educación Colombiana busca.1. Resumen 2. Abstract 3. Contenido 4. Introducción 5. Hipótesis 6. Objetivo General 7. Objetivos Específicos 8. Marco teórico 9. Metodología 10. Resultados 11. La relación entre equipamiento y la transformación de espacio público en un entorno urbano no consolidado 12. Espacio para la enseñanza 13. Disposición de elementos estructurales para mayor eficiencia formal y sismo resistente 14. Discusión basada en comparación con particularidades similares 15. Conclusión 16. ReferenciasPregradoArquitect

Análisis bibliométrico sobre metodologías de costeo de proyectos de la industria creativa

Objective. To analyze the research trends in relation to the costing of creative economy projects. Methods. A bibliometric analysis was developed from the Scopus database, applying a search equation and calculating bibliometric indicators such as quantity, quality and identification of emerging topics from documents published between 1970 and 2020. Results. The creative industries has been a topic of interest to researchers since 1997; however, it is possible to observe a continuous growth from the year 2001, date that coincides with the first publications made by Professor John Howkins, in the same way it is identified that from the social sciences show a greater interest in the subject. Conclusions. There is evidence of an impact and growth in the area of study, which validates the convenience of research projects oriented to costing methodologies for creative industry projects.Objetivo. Analizar las tendencias investigativas en relación con el costeo de proyectos de la economía creativa. Métodos. Se desarrolló un análisis bibliométrico a partir de la base de datos Scopus, aplicando una ecuación de búsqueda y calculando indicadores de tipo bibliométricos como cantilidad, calidad e identificación de temas emergentes a partir de los documentos publicados entre 1970 y 2020. Resultados. Las industrias creativas ha sido un tema de interés de los investigadores desde el año 1997; sin embargo, se logra observar un crecimiento continuo a partir del año 2001, fecha que coincide con las primeras publicaciones realizadas por el profesor John Howkins, de igual forma se identifica que desde las ciencias sociales demuestran un mayor interés por la temática Conclusiones. Se evidencia un impacto y crecimiento del área de estudio, lo que valida la conveniencia de los proyectos de investigación orientados a las metodologías de costeo de proyectos de la industria creativa