Plataforma de software empotrado para la implementación de algoritmos de audio y video en el DSP de la arquitectura OMAP-L138

Proyecto de Graduación (Licenciatura en Ingeniería Electrónica) Instituto Tecnológico de Costa Rica. Escuela de Ingeniería Electrónica, 2010.procesamiento digital de señales (DSP) han impulsado el desarrollo de nuevas tecnologías enfocadas en el procesamiento de audio digital y procesamiento de gráficos de alta calidad, entre otras funciones. Dichos sistemas empotrados han logrado expandirse en el mercado mundial de los dispositivos electrónicos gracias a su amplio rango de aplicación. Es por este motivo que fabricantes de circuitos electrónicos como Texas Instruments (TI) se han dado a la tarea de desarrollar dispositivos destinados específicamente al procesamiento digital de señales (DSP). RidgeRun, la empresa para la cual se desarrolla el proyecto descrito en esta tésis, provee soluciones de software para diversas plataformas que integran Sistemas en Chip (SoC) de la familia DaVinci™ y OMAP™ diseñados y producidos por Texas Instruments™ y se encuentra interesada en el desarrollo de herramientas de software basadas en la tecnología DSP. En este trabajo se crea una herramienta destinada a la construcción de aplicaciones DSP. Se seleccionó la micro-arquitectura OMAP-L138, específicamente la tarjeta ZoomEvm como plataforma de desarrollo. Antes de la realización de este proyecto no existía un marco de trabajo que vinculara el conjunto de herramientas, ya existentes, para construir aplicaciones multimedia en la micro-arquitectura del Sistema en Chip (SoC) OMAPL138 que aprovechen las capacidades de procesamiento digital de señales (DSP) disponibles para audio y video, a través de algoritmos diseñados especialmente para este tipo de dispositivos. El conjunto de herramientas implementadas se basa en componentes de software libre, provistos por la comunidad GNU/Linux y adaptados a la tecnología OMAP por Texas Instruments. Los elementos son unificados en un kit de desarrollo de software empotrado, encargado de automatizar los procesos de construcción y compilación de componentes de software dentro de los cuales se destaca un gestor de arranque, el kernel de GNU/Linux y un sistema de archivos, así como como mecanismos de instalación del software en una tarjeta de desarrollo.Instituto Tecnológico de Costa Rica. Escuela de Ingeniería en Electrónica

Werner’s syndrome: understanding the phenotype of premature aging—First case described in Colombia

Pacientes con Síndrome de WernerWerner’s syndrome (WS) is an autosomal recessive genetic disease, which is mainly characterized by scleroderma-like skin changes, juvenile cataracts, short stature, and signs of premature aging. We report a case of a 48-year-old male patient, who presents with cardinal signs of WS including high-pitched voice, sclerotic skin lesions mainly on feet, premature greying of scalp hair, bilateral cataracts, and “bird-like” facial appearance. In addition, the patient presents other clinical characteristics observed in patients with WS such as short stature, type 2 diabetes mellitus, hypogonadism, parental consanguinity, and a history of a sibling with similar clinical characteristics. WRN gene sequencing identified the homozygous pathogenic variant NM_00553.4: c.2581C>T (NP_000544.2: pGln861Ter). This is the first case of WS reported in the Colombian population. We report this case to avoid misdiagnosis of this infrequent condition and allow timely identification of potential complications associated with premature aging, especially malignancies, cardiovascular and metabolic diseases.https://orcid.org/0000-0002-1903-9621https://orcid.org/0000-0001-6336-5347https://orcid.org/0000-0002-9784-188XRevista Internacional - IndexadaN

Finding the optimal time window for increased classification accuracy during motor imagery

Motor imagery classification using electroencephalography is based on feature extraction over a length of time, and different configurations of settings can alter the performance of a classifier. Nevertheless, there is a lack of standardized settings for motor imagery classification. This work analyzes the effect of age on motor imagery training performance for two common spatial pattern-based classifier pipelines and various configurations of timing parameters, such as epochs, windows, and offsets. Results showed significant (p ≤ 0.01) inverse correlations between performance and feature quantity, as well as between performance and epoch/window ratio.info:eu-repo/semantics/publishedVersio

Transgression forms and extensions of Chern-Simons gauge theories

A gauge invariant action principle, based on the idea of transgression forms, is proposed. The action extends the Chern-Simons form by the addition of a boundary term that makes the action gauge invariant (and not just quasi-invariant). Interpreting the spacetime manifold as cobordant to another one, the duplication of gauge fields in spacetime is avoided. The advantages of this approach are particularly noticeable for the gravitation theory described by a Chern-Simons lagrangian for the AdS group, in which case the action is regularized and finite for black hole geometries in diverse situations. Black hole thermodynamics is correctly reproduced using either a background field approach or a background-independent setting, even in cases with asymptotically nontrivial topologies. It is shown that the energy found from the thermodynamic analysis agrees with the surface integral obtained by direct application of Noether's theorem.Comment: 28 pages, no figures. Minor changes in the introduction, final comments and reference

Impact of age, VR, immersion, and spatial resolution on classifier performance for a MI-based BCI

There are many factors outlined in the signal processing pipeline that impact brain–computer interface (BCI) performance, but some methodological factors do not depend on signal processing. Nevertheless, there is a lack of research assessing the effect of such factors. Here, we investigate the impact of VR, immersiveness, age, and spatial resolution on the classifier performance of a Motor Imagery (MI) electroencephalography (EEG)-based BCI in naïve participants. We found significantly better performance for VR compared to non-VR (15 electrodes: VR 77.48 ± 6.09%, non-VR 73.5 ± 5.89%, p = 0.0096; 12 electrodes: VR 73.26 ± 5.2%, non-VR 70.87 ± 4.96%, p = 0.0129; 7 electrodes: VR 66.74 ± 5.92%, non-VR 63.09 ± 8.16%, p = 0.0362) and better performance for higher electrode quantity, but no significant differences were found between immersive and non immersive VR. Finally, there was not a statistically significant correlation found between age and classifier performance, but there was a direct relation found between spatial resolution (electrode quantity) and classifier performance (r = 1, p = 0.0129, VR; r = 0.99, p = 0.0859, non-VR).info:eu-repo/semantics/publishedVersio

Trade-off modeling of superconducting levitation machines: theory and experiment

Based on the critical state model for the superconducting components, we develop a set of theoretical tools that allow to extract relevant engineering parameters of a superconducting levitation machine. We provide a number of analytical and numerical expressions for the evaluation of the electromagnetic quantities, energies and forces in 2D problems. This assumption includes: (i) rotational symmetric systems as those in bearings and motors, and also the case of (ii) translational symmetry as in long transportation lines. The theory, that trades off simplicity and predictive power builds on the vector potential/current density formulation of the Maxwell equations (A, J) and is validated by comparison against experimental tension-compression data in our universal test machine. As shown, very simple computer coding is required to implement the method.Funding of this research by Spanish MINECO and the European FEDER Program (Projects MAT2011-22719 and ENE2011-29741) and by Gobierno de Aragon (Research group T12) is gratefully acknowledged.Peer Reviewe

Preparation of Palladium-Supported Periodic Mesoporous Organosilicas and their Use as Catalysts in the Suzuki Cross-Coupling Reaction

Three periodic mesoporous materials, i.e., two organosilicas with either ethylene or phenylene bridges and one silica, have been used as supports for Pd nanoparticles. All Pd-supported samples (1.0 wt%) were prepared by the incipient wetness method and subsequently reduced in an H2 stream at 200 °C. Both hydrogen chemisorption and temperature programmed reduction experiments revealed significant differences depending on the support. Pd2+ species were more reducible on the mesoporous organosilicas than on their silica counterpart. Also, remarkable differences on the particle morphology were observed by transmission electron microscopy. All Pd-supported samples were active in the Suzuki cross-coupling reaction between bromobenzene and phenylboronic aci

A fluorescence-activatable reporter of flavivirus NS2B–NS3 protease activity enables live imaging of infection in single cells and viral plaques

The genus Flavivirus in the family Flaviviridae comprises many medically important viruses, such as dengue virus (DENV), Zika virus (ZIKV), and yellow fever virus. The quest for thera- peutic targets to combat flavivirus infections requires a better understanding of the kinetics of virus–host interactions during infections with native viral strains. However, this is precluded by limitations of current cell-based systems for monitoring flavivi- rus infection in living cells. In the present study, we report the construction of fluorescence-activatable sensors to detect the activities of flavivirus NS2B–NS3 serine proteases in living cells. The system consists of GFP-based reporters that become fluo- rescent upon cleavage by recombinant DENV-2/ZIKV proteases in vitro. A version of this sensor containing the flavivirus inter- nal NS3 cleavage site linker reported the highest fluorescence activation in stably transduced mammalian cells upon DENV-2/ ZIKV infection. Moreover, the onset of fluorescence correlated with viral protease activity. A far-red version of this flavivirus sensor had the best signal-to-noise ratio in a fluorescent Dulbec- co’s plaque assay, leading to the construction of a multireporter platform combining the flavivirus sensor with reporter dyes for detection of chromatin condensation and cell death, enabling studies of viral plaque formation with single-cell resolution. Finally, the application of this platform enabled the study of cell-population kinetics of infection and cell death by DENV-2, ZIKV, and yellow fever virus. We anticipate that future studies of viral infection kinetics with this reporter system will enable basic investigations of virus–host interactions and facilitate future applications in antiviral drug research to manage flavivi- rus infections.International Centre for Genetic Engineering and Biotechnology Grant CRP/CRI18-02.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí

Análisis modal comparado entre modelos virtuales 2d y 3d aplicado a un Cube Sat

El siguiente trabajo presenta un análisis modal comparado entre modelos virtuales 2D y 3D, para validar la sistematización de una metodología de análisis completo de Ingeniería Asistida por Computadora, ejemplificada en la aplicación a un modelo de nano satélite tipo Cube Sat. Se detallan los requerimientos de las especificaciones técnicas, condiciones estructurales, cargas, restricciones y frecuencias de vibración, que sufre este satélite al momento de su despegue y durante su órbita. Posteriormente se aplica al Diseño Asistido por Computadora la solicitud del análisis de respuesta dinámica al modelo de su estructura principal simplificada, utilizando el Método de los Elementos Finitos. Las simulaciones incluyen el análisis dinámico de frecuencias naturales y modos de vibración libre. La comparación se lleva a cabo con las herramientas de un Sistema de Ingeniería Basada en el Conocimiento que permiten optimizar la elaboración de diseños mecánicos y reducir tiempos de solución ante nuevos retos de simulación

Preparation of palladium-supported periodic mesoporous organosilicas and their use as catalysts in the Suzuki cross-coupling reaction

Three periodic mesoporous materials, i.e., two organosilicas with either ethylene or phenylene bridges and one silica, have been used as supports for Pd nanoparticles. All Pd-supported samples (1.0 wt%) were prepared by the incipient wetness method and subsequently reduced in an H2 stream at 200 °C. Both hydrogen chemisorption and temperature programmed reduction experiments revealed significant differences depending on the support. Pd2+ species were more reducible on the mesoporous organosilicas than on their silica counterpart. Also, remarkable differences on the particle morphology were observed by transmission electron microscopy. All Pd-supported samples were active in the Suzuki cross-coupling reaction between bromobenzene and phenylboronic acid