693 research outputs found

    Arquitectura Computacional para la Inferencia deuna CNN Cuantizada para Detectar FibrilaciónAuricular

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    Atrial Fibrillation is a common cardiac arrhythmia, which is characterized by an abnormal heartbeat rhythm that can be life-threatening. Recently, researchers have proposed several Convolutional Neural Networks (CNNs) to detect Atrial Fibrillation. CNNs have high requirements on computing and memory resources, which usually demand the use of High Performance Computing (eg, GPUs). This high energy demand is a challenge for portable devices. Therefore, efficient hardware implementations are required. We propose a computational architecture for the inference of a Quantized Convolutional Neural Network (Q-CNN) that allows the detection of the Atrial Fibrillation (AF). The architecture exploits data-level parallelism by incorporating SIMD-based vector units, which is optimized in terms of computation and storage and also optimized to perform both the convolutional and fully connected layers. The computational architecture was implemented and tested in a Xilinx Artix-7 FPGA. We present the experimental results regarding the quantization process in a different number of bits, hardware resources, and precision. The results show an accuracy of 94% accuracy for 22-bits. This work aims to be the basis for the future implementation of a portable, low-cost, and high-reliability device for the diagnosis of Atrial Fibrillation.La fibrilación auricular es una arritmia cardíaca común, que se caracte-riza por un ritmo cardíaco anormal que puede poner en peligro la vida.Recientemente, se han propuesto varias Redes Neuronales Convoluciona-les (CNNs, por sus siglas en inglés) para detectar la fibrilación auricular.Las CNN tienen altos requisitos de recursos informáticos y de memoria,lo que generalmente demanda el uso Computación de Altro Rendimientocomo por ejemplo GPUs. Esta alta demanda de energía es un desafío pa-ra los dispositivos portátiles. Por lo tanto, se requieren implementacionesde hardware eficientes. Proponemos una arquitectura computacional pa-ra la inferencia de una Red Neural Convolucional Cuantizada (Q-CNN)que permite la detección de la Fibrilación Auricular (FA). La arquitecturaaprovecha el paralelismo a nivel de datos, incorporando unidades vecto-riales basadas en SIMD, que están optimizadas en términos de cálculoy almacenamiento. El diseño también se optimizó para realizar tanto lascapas convolucionales como las capas completamente conectadas. La ar-quitectura computacional se implementó y probó en una FPGA XilinxArtix-7. Presentamos los resultados experimentales con respecto al proce-so de cuantización en un número diferente de bits, recursos de hardwarey precisión. Los resultados muestran una precisión del 94 % para 22 bits.Este trabajo pretende ser la base para la futura implementación de undispositivo portátil, de bajo costo y alta confiabilidad para el diagnósticode Fibrilación Auricular

    A machine-learning data set prepared from the NASA solar dynamics observatory mission

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    In this paper, we present a curated data set from the NASA Solar Dynamics Observatory (SDO) mission in a format suitable for machine-learning research. Beginning from level 1 scientific products we have processed various instrumental corrections, down-sampled to manageable spatial and temporal resolutions, and synchronized observations spatially and temporally. We illustrate the use of this data set with two example applications: forecasting future extreme ultraviolet (EUV) Variability Experiment (EVE) irradiance from present EVE irradiance and translating Helioseismic and Magnetic Imager observations into Atmospheric Imaging Assembly observations. For each application, we provide metrics and baselines for future model comparison. We anticipate this curated data set will facilitate machine-learning research in heliophysics and the physical sciences generally, increasing the scientific return of the SDO mission. This work is a direct result of the 2018 NASA Frontier Development Laboratory Program. Please see the Appendix for access to the data set, totaling 6.5TBs

    Hybrid System of Photovoltaic and Solar Thermal Technologies for Industrial Process Heat

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    Process heating is the activity with the most energy consumption in the industrial sector. Solar heating (SH) systems are a promising alternative to provide renewable thermal energy to industrial processes. However, factors such as high investment costs and area limitations in industrial facilities hinder their utilization; therefore, hybrid systems that combine two different solar thermal or photovoltaic technologies where each technology operates under conditions that allow a higher overall performance than conventional configurations have been proposed. In this review, we discuss the limitations of conventional SH systems and the potential of hybrid configurations to overcome them. First, the current literature about conventional and hybrid systems is presented. Then, the application of common performance indicators to evaluate hybrid configurations is analyzed. Finally, the limitation, advantages, and potential applications of conventional and hybrid systems are discussed. This work shows that conventional systems are the most promising alternatives in low and high-temperature industrial applications. At the same time, in medium and processes, hybrid configurations have great potential to increase the performance of SH systems and help to boost their adoption in the industrial sector. There are few studies about hybrid systems in industrial applications, and further research is required to determine their potential

    Power Quality Indices Estimation Platform

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    En este artículo se presenta una plataforma interactiva para la estimación de índices de calidad de la potencia de sistemas eléctricos monofásicos, en conformidad con el estándar IEEE 1459-2010. La plataforma PQanalizador se desarrolló con el objetivo de apoyar actividades de docencia e investigación en calidad de la energía eléctrica. La plataforma estima los índices a partir de señales de voltaje y corriente usando tres diferentes algoritmos basados en la transformada rápida de Fourier (FFT), la transformada Wavelet Packet (WPT) y la metodología de mínimos cuadrados. Los resultados muestran que los algoritmos implementados son eficientes para la estimación de los índices de calidad de la potencia y que la plataforma puede ser usada según los objetivos propuestos.An interactive platform for estimating the quality indices in single phase electric power systems is presented. It meets the IEEE 1459-2010 standard recommendations. The platform was developed in order to support teaching and research activities in electric power quality. The platform estimates the power quality indices from voltage and current signals using three different algorithms based on fast Fourier transform (FFT), wavelet packet transform (WPT) and least squares method. The results show that the algorithms implemented are efficient for estimating the quality indices of the power and the platform can be used according to the objectives established.

    Nanomechanical Characterization of the Deformation Response of Orthotropic Ti–6Al–4V

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    The nanoindentation‐induced mechanical deformation response is applied to identify the orthotropic elastic moduli using the Delafargue and Ulm method as well as to validate the asymmetric orthotropic CPB06 nonlinear plasticity model required in simulations of nonuniform macroscopic mechanical response of the Ti–6Al–4V alloy. Scanning electron microscope (SEM) technique allows to select the maximum penetration depth for the indentation in the deformed alpha phase and alpha–beta interphase, α and α/β, respectively. The apparent macromechanical response can be successfully derived from several residual imprints conducted at micro‐ and/or submicrometric length scale and distributed throughout samples of the investigated bulk alloy, as demonstrated by correlation with finite element simulations based on the orthotropic elastoplastic model. The accurate numerical response obtained validates the material model and the Delafargue and Ulm approach, opening a window for next generation identification methods of macromechanical plasticity models with hybrid experimental–numerical method based on instrumented indentation and the use of SEM technique

    Recommendations for enterovirus diagnostics and characterisation within and beyond Europe.

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    Enteroviruses (EV) can cause severe neurological and respiratory infections, and occasionally lead to devastating outbreaks as previously demonstrated with EV-A71 and EV-D68 in Europe. However, these infections are still often underdiagnosed and EV typing data is not currently collected at European level. In order to improve EV diagnostics, collate data on severe EV infections and monitor the circulation of EV types, we have established European non-polio enterovirus network (ENPEN). First task of this cross-border network has been to ensure prompt and adequate diagnosis of these infections in Europe, and hence we present recommendations for non-polio EV detection and typing based on the consensus view of this multidisciplinary team including experts from over 20 European countries. We recommend that respiratory and stool samples in addition to cerebrospinal fluid (CSF) and blood samples are submitted for EV testing from patients with suspected neurological infections. This is vital since viruses like EV-D68 are rarely detectable in CSF or stool samples. Furthermore, reverse transcriptase PCR (RT-PCR) targeting the 5'noncoding regions (5'NCR) should be used for diagnosis of EVs due to their sensitivity, specificity and short turnaround time. Sequencing of the VP1 capsid protein gene is recommended for EV typing; EV typing cannot be based on the 5'NCR sequences due to frequent recombination events and should not rely on virus isolation. Effective and standardized laboratory diagnostics and characterisation of circulating virus strains are the first step towards effective and continuous surveillance activities, which in turn will be used to provide better estimation on EV disease burden

    Evaluación geológica - minera del ANAP Colca : Prospectos Colca y Huallpachaca

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    El Instituto Geológico Minero y Metalúrgico a través de las Dirección de Recursos Mineros Energéticos y la Actividad de Área de No Adminsión de Petitorios (ANAP), desarrolló la evaluación geológico económica de del ANAP Colca. El ANAP Colca está ubicado en la región Apurímac, dentro de la provincia de Cotabambas (hoja topográfica 28-r), en los distritos de Cotabambas y Tambobamba, comprendiendo las comunidades de Colca, Pamparki, Paruro, Huañec y Huamancharpa. Tiene un área de 14100 hectáreas y se encuentra a una altura promedio de 2900 m.s.n.m. Dentro del ANAP Colca se ha reconocido dos prospectos que según su importancia económica son: Colca (6200 has) y Hualpachaca (5600 has). La geología está mayormente conformada por rocas del Grupo Tacaza, de edad Paleógeno – Neógeno, que consisten de lavas andesíticas afaníticas y porfiríticas en menor proporción, moderadamente alteradas, con irregular presencia de minerales de cobre, zinc, plomo y oro; rocas intrusivas conformado por dioritas, tonalitas y granodioritas que corresponden al Plutón Cotabambas y Plutón Colca expuestas en el sector sur del ANAP de edad Paleógeno – Neógeno. Las alteraciones hidrotermales observadas en el ANAP Colca son la alteración propilítica y argílica presentándose de manera moderada a débil. La alteración propilítica (clr- ep- ser- calc) ha sido observada mayormente al norte del poblado de Cutuctuy principalmente en la carretera que desciende de Cutuctuy al río Apurímac. La alteración argílica (ser- Arcs - spe - ep) es la que prevalece en el Prospecto Colca no se evidencia alteración filica por la ausencia de cuarzo y pirita por lo que se presume que el yacimiento mineral podría encontrase en el nivel alto del sistema quizás a mayor profundidad se encuentre las asociaciones mineralógicas típicas de esta alteración. La mineralización en ambos prospectos se manifiestan como vetas epitermales de intermedia sulfuración debido a la presencia de óxidos de Fe como jarosita, goethita, especularita; carbonatos (malaquita) y sulfuros como pirita, calcopirita, pirrotita, arsenopirita en trazas. En particular en las zonas de Ninaraura, Cutuctuy y Callapunco del Prospecto Colca con los datos de prospección geofísica mediante la aplicación de Inducción polarizada (IP) con valores altos en cargabilidad (>20 mV/V) y altos en resistividad de 110 -2200 Ohm*m. conducen a direccionar un posible emplazamiento de un depósito tipo pórfido de Cu-Au tanto en la andesita y en el contacto con el intrusivo diorítico. En un recorrido realizado en las cabeceras del río Aquilano, el contacto del intrusivo diorítico y las calizas de la formación Arcurquina (Ferrobamba) forman un skarn donde actualmente realizan labores de minería informal en las comunidades de Pamparki y Colca. Se recolectaron 445 muestras de esquirlas de roca de las cuales tenemos el resultado geoquímico con los valores de Au, destacando los sectores de: Ninaraura con 04 muestras anómalas cuyos valores oscilan de 859 ppb (Rocol-602) a 3063 ppb (Rocol-417), Marangallay con una muestra anómala de 975 ppb (Rocol-547), faldas del cerro Huayllaje en la margen izquierda del río Aquilano con una muestra anómala de 2200 ppb (Rocol-482) y en la zona de Pamparki (Margen izquierda del río Apurímac) una muestra anómala de 1594 ppb (Rocol-523). Estos valores son interesantes en una etapa de exploración (prospección). Es importante mencionar que el prospecto Huallpachaca se encuentra ubicado en el mismo corredor estructural de orientación NE – SO a una distancia horizontal de ± 3 kilómetros en línea recta del pórfido Cotabambas (Cu-Au) de propiedad de Panoro Minerals Ltd

    Admixture in Latin America: Geographic Structure, Phenotypic Diversity and Self-Perception of Ancestry Based on 7,342 Individuals

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    The current genetic makeup of Latin America has been shaped by a history of extensive admixture between Africans, Europeans and Native Americans, a process taking place within the context of extensive geographic and social stratification. We estimated individual ancestry proportions in a sample of 7,342 subjects ascertained in five countries (Brazil, Chile, Colombia, México and Perú). These individuals were also characterized for a range of physical appearance traits and for self-perception of ancestry. The geographic distribution of admixture proportions in this sample reveals extensive population structure, illustrating the continuing impact of demographic history on the genetic diversity of Latin America. Significant ancestry effects were detected for most phenotypes studied. However, ancestry generally explains only a modest proportion of total phenotypic variation. Genetically estimated and self-perceived ancestry correlate significantly, but certain physical attributes have a strong impact on self-perception and bias self-perception of ancestry relative to genetically estimated ancestry

    Regulation of Intestinal Immune Response by Selective Removal of the Anterior, Posterior, or Entire Pituitary Gland in Trichinella spiralis Infected Golden Hamsters

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    The influence of anterior pituitary hormones on the gastrointestinal tract of humans and animals has been previously reported. Hypophysectomy (HYPOX) in the rat causes atrophy of the intestinal mucosa, and reduction of gastric secretion and intestinal absorption, as well as increased susceptibility to bacterial and viral infections. However, to our knowledge, no findings have been published concerning the immune response following HYPOX during worm infection, particularly that which is caused by the nematode Trichinella spiralis. The aim of this work was to analyze the effects of total or partial HYPOX on colonization of T. spiralis in the intestinal lumen, together with duodenal and splenic cytokine expression. Our results indicate that 5 days post infection, only neurointermediate pituitary lobectomy (NIL) reduces the number of intestinally recovered T. spiralis larvae. Using semiquantitative inmunofluorescent laser confocal microscopy, we observed that the mean intensity of all tested Th1 cytokines was markedly diminished, even in the duodenum of infected controls. In contrast, a high level of expression of these cytokines was noted in the NIL infected hamsters. Likewise, a significant decrease in the fluorescence intensity of Th2 cytokines (with the exception of IL-4) was apparent in the duodenum of control and sham infected hamsters, compared to animals with NIL surgeries, which showed an increase in the expression of IL-5 and IL-13. Histology of duodenal mucosa from NIL hamsters showed an exacerbated inflammatory infiltrate located along the lamina propria, which was related to the presence of the parasite. We conclude that hormones from each pituitary lobe affect the gastrointestinal immune responses to T. spiralis through various mechanisms
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