A GPU-based Evolution Strategy for Optic Disk Detection in Retinal Images

La ejecución paralela de aplicaciones usando unidades de procesamiento gráfico (gpu) ha ganado gran interés en la comunidad académica en los años recientes. La computación paralela puede ser aplicada a las estrategias evolutivas para procesar individuos dentro de una población, sin embargo, las estrategias evolutivas se caracterizan por un significativo consumo de recursos computacionales al resolver problemas de gran tamaño o aquellos que se modelan mediante funciones de aptitud complejas. Este artículo describe la implementación de una estrategia evolutiva para la detección del disco óptico en imágenes de retina usando Compute Unified Device Architecture (cuda). Los resultados experimentales muestran que el tiempo de ejecución para la detección del disco óptico logra una aceleración de 5 a 7 veces, comparado con la ejecución secuencial en una cpu convencional.Parallel processing using graphic processing units (GPUs) has attracted much research interest in recent years. Parallel computation can be applied to evolution strategy (ES) for processing individuals in a population, but evolutionary strategies are time consuming to solve large computational problems or complex fitness functions. In this paper we describe the implementation of an improved ES for optic disk detection in retinal images using the Compute Unified Device Architecture (CUDA) environment. In the experimental results we show that the computational time for optic disk detection task has a speedup factor of 5x and 7x compared to an implementation on a mainstream CPU

Comparative analysis between Sir Gawain and the Green Knight and The Lord of the Rings: a thematic comparison

Trabajo de fin de Grado. Grado en Estudios Ingleses. Curso académico 2015-2016[EN]This project attempts to show the thematic relation which exists between Sir Gawain and the Green Knight (15th Century) and The Lord of the Rings (20th Century). Even though both pieces are five centuries far from each other, they share different themes with their similarities and their differences. Sir Gawain and the Green Knight could be seen as the most representative work in which we can learn quite about knights, their traditions, and their time in England. Meanwhile, The Lord of the Rings can be considered the perfect trilogy where we can find, apart from knights, different races and different problems which knights and everybody else will have to face in Middle-Earth. Only three main themes will be discussed and analysed in which we will be able to see their similarities in both stories, and their differences about how the same theme can be explored from different perspectives. [ES]Este Trabajo de Fin de Grado trata de mostrar la relación temática que existe entre Sir Gawain and the Green Knight (Siglo XV) y The Lord of the Rings (Siglo XX). A pesar de ser obras que están separadas por cinco siglos comparten diferentes temas con sus semejanzas y sus diferencias. Sir Gawain and the Green Knight podría ser visto como el trabajo más representativo en el cual podemos aprender bastante sobre caballeros, sus tradiciones y su tiempo en Inglaterra. Mientras tanto, The Lord of the Rings puede ser considerada la perfecta trilogía donde podemos encontrar, además de caballeros, diferentes razas y diferentes problemas que caballeros y todos los demás deberán hacer frente en la Tierra Media. Solamente tres temas principales serán discutidos y analizados en los cuales seremos capaces de ver sus semejanzas en ambas historias y sus diferencias, sobre cómo el mismo tema puede ser explorado desde diferentes perspectivas

Origin of passivation in hole-selective transition metal oxides for crystalline silicon heterojunction solar cells

Transition metal oxides (TMOs) have recently demonstrated to be a good alternative to boron/phosphorous doped layers in crystalline silicon heterojunction solar cells. In this work, the interface between n-type c-Si (n-Si) and three thermally evaporated TMOs (MoO3, WO3, and V2O5) was investigated by transmission electron microscopy, secondary ion-mass, and x-ray photoelectron spectroscopy. For the oxides studied, surface passivation of n-Si was attributed to an ultra-thin (1.9–2.8 nm) SiOx~1.5 interlayer formed by chemical reaction, leaving oxygen-deficient species (MoO, WO2, and VO2) as by-products. Carrier selectivity was also inferred from the inversion layer induced on the n-Si surface, a result of Fermi level alignment between two materials with dissimilar electrochemical potentials (work function difference ¿¿ = 1 eV). Therefore, the hole-selective and passivating functionality of these TMOs, in addition to their ambient temperature processing, could prove an effective means to lower the cost and simplify solar cell processing.Postprint (author's final draft

Superior performance of V2O5 as hole selective contact over other transition metal oxides in silicon heterojunction solar cells

Transition metal oxides (TMOs) have recently been proved to efficiently serve as hole-selective contacts in crystalline silicon (c-Si) heterojunction solar cells. In the present work, two TMO/c-Si heterojunctions are explored using MoO3 (reference) and V2O5 as an alternative candidate. It has been found that V2O5 devices present larger (16% improvement) power conversion efficiency mainly due to their higher open-circuit voltage. While V2O5/c-Si devices with textured front surfaces exhibit larger short-circuit currents, it is also observed that flat solar cell architectures allow for passivation of the V2O5/n-Si interface, giving significant carrier lifetimes of 200 µs (equivalent to a surface recombination velocity of Seff ~140 cm s-1) as derived from impedance analysis. As a consequence, a significant open-circuit voltage of 662 mV is achieved. It is found that, at the TMO/c-Si contact, a TMO work function enhancement ¿FTMO occurs during the heterojunction formation with the consequent dipole layer enlargement ¿’=¿+¿FTMO. Our results provide new insights into the TMO/c-Si contact energetics, carrier transport across the interface and surface recombination allowing for further understanding of the nature of TMO/c-Si heterojunctions.Peer ReviewedPostprint (published version

FPGA-based embedded system for ultrasonic positioning

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. A. Sánchez, Á. de Castro, G. Gonzalez-de-Rivera, and J. Garrido, "FPGA-based embedded system for ultrasonic positioning", 2010 IEEE International Symposium on Industrial Electronics, ISIE, Bari (Italy), 2010, pp. 3051 - 3056This paper presents an FPGA-based ultrasonic location system. This system uses low-cost FPGAs and ultrasonic transducers to provide 3-D location to mobile nodes in an indoor environment. Synchronization is reached using the radiofrequency transducers that mobile nodes usually include. FPGAs have been used to sample ultrasonics and radiofrequency inside a custom peripheral which is attached to a MicroBlaze soft-processor. The calculus of the position of the mobile node is accomplished inside this processor.This work has been partially supported by the CCG08-UAM/TIC-4258 project of the Comunidad de Madrid and UAM and by the TEC2009-09871 project of the Ministerio de Ciencia e Innovacion of Spai

Tumor de células de Leydig: revisión de la literatura a propósito de un caso.

En este trabajo presentamos el caso de un tumor de células de Leydig estudiado en el HCU Lozano Blesa. Explicamos sus características macroscópicas, microscópicas e inmunohistoquímicas más relevantes y comparamos nuestros hallazgos con los descritos en la literatura.<br /

Structural health monitoring using the Firefly optimization algorithm and finite elements

In this study, a novel technique for multiple damage detection of structures using modal characterization to evaluate the dynamic response of the structure given a damage model is investigated. The damage identification problem is seen as an optimization problem to be solved using a firefly optimization algorithm. The objective function is based on a numerical damage model that considers the modal response of the structures. We show some implementation details and discuss the obtained results for a benchmark problem used to assess the performance of the method and its advantages for structural health monitoring.En este estudio, se investiga una técnica novedosa para la detección de daños múltiples de estructuras mediante la caracterización modal para evaluar la respuesta dinámica de la estructura dado un modelo de daño. El problema de identificación de daños se plantea como un problema de optimización que se resuelve utilizando un algoritmo de optimización tipo firefly. La función objetivo se basa en un modelo de daño numérico que considera la respuesta modal de las estructuras. Mostramos algunos detalles de implementación y discutimos los resultados obtenidos para un problema de referencia utilizado para evaluar el rendimiento del método y sus ventajas para el monitoreo de la salud estructural

Análisis de nuevos mercados para la exportación de muebles modulares por parte de la empresa Kandecor hacia el mercado común CentroAmericano

El principal propósito de esta monografía es estudiar y analizar las posibilidades de la empresa Kandecor para lograr su objetivo futuro de exportar muebles modulares de madera a los principales países de Centroamérica. Este trabajo se basa en información relevante que permita a Kandecor en el corto plazo cumplir con su propósito de expandir su mercado para este tipo de productos. La empresa KANDECOR en su interés de incrementar sus negocios hacia el mercado externo ha visto la posibilidad de exportar hacia el Mercado Común Centroamericano sus muebles modulares de madera bajo la modalidad de sistema 32.Incluye bibliografí