34 research outputs found

    A Tool for automated design of sigma-delta modulators using statistical optimization

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    A tool is presented which starting from high level specifications of SC σδ modulators (resolution, bandwidth and oversampling ratio) calculates first optimum specifications for the building blocks (op-amps, comparator, etc.), and then, optimum sizes for their schematics. At both design levels (high-level synthesis and cell dimensioning), optimization is performed via using statistical techniques and innovative heuristics, which allow global design (independent on the initial conditions) and increased computer efficiency as compared to conventional statistical optimization techniques. The tool has been conceived to be flexible at the high-level part(via the use of an architecture independent, behaviourable modeling approach) and completely open at the cell-design part. Performance of the tool is demonstrated via the automatic design of a 16bit-dynamic range, 8Khz second-order SC σδ modulator in 1.2 μm CMOS technology, for which measurements on a fabricated prototype are reported

    Modeling OpAmp-induced harmonic distortion for switched-capacitor ΣΔ modulator design

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    This communication reports a new modeling of opamp-induced harmonic distortion in SC ΣΔ modulators, which is aimed to optimum design of this kind of circuit for high-performance applications. We analyze incomplete transfer of charge in a SC integrator and use power expansion and nonlinear fitting to obtain analytical models to represent harmonic distortion as function of the opamp finite gain-bandwidth (GB), slew-rate (SR) and nonlinear DC gain. Calculated models apply for all modulator architectures where harmonic distortion is dominated by the first integrator in the chain. We show that results provided by the new analytical models fit well to that obtained by simulation in time domain and have accuracy levels much larger than that provided by previously reported modeling approaches

    Cooperative learning at the Analytical Chemistry laboratory

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    [SPA] El aprendizaje cooperativo es un sistema de organización del trabajo y de motivación, en el que el alumno es responsable de su aprendizaje y el de sus compañeros. A diferencia de los sistemas individualista y competitivo, las metas son grupales. La aplicación sistemática de este sistema da respuesta a tres principios básicos del Espacio Europeo de Educación Superior (EEES): participación y autonomía del estudiante, utilización de metodologías activas y papel del profesorado como agente facilitador del aprendizaje. Brevemente, con esta metodología se divide la clase en pequeños equipos, que reciben unas consignas de actuación a partir de las cuales planifican el trabajo del grupo. Cada miembro del grupo será responsable de áreas específicas que será necesario realizar satisfactoriamente para el éxito del grupo. En esta comunicación se plantea la aplicación del aprendizaje cooperativo para el aprovechamiento efectivo de las clases prácticas de laboratorio de análisis químico, dirigido a alumnos de último curso de la titulación de Ingeniería Química. La práctica en concreto consiste en la verificación de un equipo de HPLC-UV/Vis, para comprobar la conformidad con las especificaciones del fabricante. Además, esta metodología permite trabajar competencias transversales como razonamiento crítico, trabajo en equipo, gestión de proyectos y comunicación entre otras. [ENG] Cooperative learning is a work organizational system to motivate students, who become responsible for their own and their team mates learning. Unlike the individualistic and competitive learning styles, in cooperative learning student achievements occurs only when the other students in the group also achieve the objectives and rewards. Systematic application of this methodology helps reaching three basic principles of the European Higher Education Area (EHEA): student participation and autonomy, active methodologies application and lecturer role as facilitator in the learning process. In short, this methodology involves splitting up the class into small teams, which have to organize their self-workload to complete assignments and reach objectives previously established. Each team member is responsible for specific tasks that must be properly completed for the final success of the group. In this communication we propose the cooperative learning for effective laboratory lessons of analytical chemistry, aimed to last year students of chemical engineering. The specific assignment involves the verification of a whole equipment of liquid chromatography (HPLC) with spectrophotometric detection (UV-Vis) to check compliance with supplier specifications. In addition to specific competences, applying cooperative learning approach, students develop generic competences such as critical thinking, working with other, project management and communication among others

    Estimating Adaptive Setpoint Temperatures Using Weather Stations

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    [Abstract] Reducing both the energy consumption and CO2 emissions of buildings is nowadays one of the main objectives of society. The use of heating and cooling equipment is among the main causes of energy consumption. Therefore, reducing their consumption guarantees such a goal. In this context, the use of adaptive setpoint temperatures allows such energy consumption to be significantly decreased. However, having reliable data from an external temperature probe is not always possible due to various factors. This research studies the estimation of such temperatures without using external temperature probes. For this purpose, a methodology which consists of collecting data from 10 weather stations of Galicia is carried out, and prediction models (multivariable linear regression (MLR) and multilayer perceptron (MLP)) are applied based on two approaches: (1) using both the setpoint temperature and the mean daily external temperature from the previous day; and (2) using the mean daily external temperature from the previous 7 days. Both prediction models provide adequate performances for approach 1, obtaining accurate results between 1 month (MLR) and 5 months (MLP). However, for approach 2, only the MLP obtained accurate results from the 6th month. This research ensures the continuity of using adaptive setpoint temperatures even in case of possible measurement errors or failures of the external temperature probe

    Cytotoxic cell populations developed during treatment with tyrosine kinase inhibitors protect autologous CD4+ T cells from HIV-1 infection

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    Factor de impacto: 5,858 Q1Tyrosine kinase inhibitors (TKIs) are successfully used in clinic to treat chronic myeloid leukemia (CML). Our group previously described that CD4+ T cells from patients with CML on treatment with TKIs such as dasatinib were resistant to HIV-1 infection ex vivo. The main mechanism for this antiviral activity was primarily based on the inhibition of SAMHD1 phosphorylation, which preserves the activity against HIV-1 of this innate immune factor. Approximately 50% CML patients who achieved a deep molecular response (DMR) may safely withdraw TKI treatment without molecular recurrence. Therefore, it has been speculated that TKIs may induce a potent antileukemic response that is maintained in most patients even one year after treatment interruption (TI). Subsequent to in vitro T-cell activation, we observed that SAMHD1 was phosphorylated in CD4+ T cells from CML patients who withdrew TKI treatment more than one year earlier, which indicated that these cells were now susceptible to HIV-1 infection. Importantly, these patients were seronegative for HIV-1 and seropositive for cytomegalovirus (CMV), but without CMV viremia. Although activated CD4+ T cells from CML patients on TI were apparently permissive to HIV-1 infection ex vivo, the frequency of proviral integration was reduced more than 12-fold on average when these cells were infected ex vivo in comparison with cells isolated from untreated, healthy donors. This reduced susceptibility to infection could be related to an enhanced NK-dependent cytotoxic activity, which was increased 8-fold on average when CD4+ T cells were infected ex vivo with HIV-1 in the presence of autologous NK cells. Enhanced cytotoxic activity was also observed in CD8 + T cells from these patients, which showed 8-fold increased expression of TCRγδ and more than 18-fold increased production of IFNγ upon activation with CMV peptides. In conclusion, treatment with TKIs induced a potent antileukemic response that may also have antiviral effects against HIV-1 and CMV, suggesting that transient use of TKIs in HIV-infected patients could develop a sustained antiviral response that would potentially interfere with HIV-1 reservoir dynamics.This work was supported by NIH grant R01AI143567; the Spanish Ministry of Economy and Competitiveness (SAF2016-78480-R); the Spanish AIDS Research Network RD16CIII/0002/0001 that is included in Acción Estratégica en Salud, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2016-2020, Instituto de Salud Carlos III, European Region Development Fund (ERDF). The work of María Rosa López-Huertas and Sara Rodríguez-Mora is financed by NIH grant R01AI143567. The work of Lorena Vigón is supported by a pre-doctoral grant from Instituto de Salud Carlos III (FIS PI16CIII/00034-ISCIII-FEDER). The work of Elena Mateos is supported by the Spanish Ministry of Economy and Competitiveness SAF2016-78480-R.S

    El proceso penal del siglo XXI, Quo vadis iustitia?

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    Actas de la Jornada "EL PROCESO PENAL DEL SIGLO XXI: QUO VADIS IUSTITIA?", celebrada en la Facultad de Derecho de Jerez de la Frontera, de la Universidad de Cádiz, el 24 de Abril de 2015.Quo vadis iustitia? La pregunta persigue que tanta reforma como se persigue se detenga un momento para responder y, con ello, para pensar sobre el modelo de justicia que se está diseñando. Ya han sido muchas las voces que han hablado de la legislación “galopante” o “motorizada”, o que han usado variados calificativos para referirse al frenesí en la productividad de nuestras cámaras legislativas. Si esto es algo que puede llegar a provocar inseguridad jurídica, debemos pensar que, cuando de lo que se trata es de las normas que afectan a la justicia (orgánicas y procesales) lo que se puede llegar a provocar es una alteración en el equilibrio de los poderes del Estado. No se puede dejar de lado que el funcionamiento de la justicia tiene que ver con uno de los poderes del Estado, el cual, precisamente, debe constituir el fiel que refleje el equilibrio entre los demás, aunque Montesquieu ya no esté muy de moda. La jornada s centra en algunos aspectos de la reforma del proceso penal.Área de Derecho Procesal, Facultad de Derecho Universidad de Cádiz Casa de Iberoamérica (Ayunatmiento de Cádiz) Gestiona: FUECA Proyecto Investigación MINECO DER 2011-26954Documento PDF con 232 páginas

    5to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

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    El V Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2019, realizado del 6 al 8 de febrero de 2019 y organizado por la Universidad Politécnica Salesiana, ofreció a la comunidad académica nacional e internacional una plataforma de comunicación unificada, dirigida a cubrir los problemas teóricos y prácticos de mayor impacto en la sociedad moderna desde la ingeniería. En esta edición, dedicada a los 25 años de vida de la UPS, los ejes temáticos estuvieron relacionados con la aplicación de la ciencia, el desarrollo tecnológico y la innovación en cinco pilares fundamentales de nuestra sociedad: la industria, la movilidad, la sostenibilidad ambiental, la información y las telecomunicaciones. El comité científico estuvo conformado formado por 48 investigadores procedentes de diez países: España, Reino Unido, Italia, Bélgica, México, Venezuela, Colombia, Brasil, Estados Unidos y Ecuador. Fueron recibidas un centenar de contribuciones, de las cuales 39 fueron aprobadas en forma de ponencias y 15 en formato poster. Estas contribuciones fueron presentadas de forma oral ante toda la comunidad académica que se dio cita en el Congreso, quienes desde el aula magna, el auditorio y la sala de usos múltiples de la Universidad Politécnica Salesiana, cumplieron respetuosamente la responsabilidad de representar a toda la sociedad en la revisión, aceptación y validación del conocimiento nuevo que fue presentado en cada exposición por los investigadores. Paralelo a las sesiones técnicas, el Congreso contó con espacios de presentación de posters científicos y cinco workshops en temáticas de vanguardia que cautivaron la atención de nuestros docentes y estudiantes. También en el marco del evento se impartieron un total de ocho conferencias magistrales en temas tan actuales como la gestión del conocimiento en la universidad-ecosistema, los retos y oportunidades de la industria 4.0, los avances de la investigación básica y aplicada en mecatrónica para el estudio de robots de nueva generación, la optimización en ingeniería con técnicas multi-objetivo, el desarrollo de las redes avanzadas en Latinoamérica y los mundos, la contaminación del aire debido al tránsito vehicular, el radón y los riesgos que representa este gas radiactivo para la salud humana, entre otros

    Marco activo de recursos de innovación docente: Madrid

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    Una guía de espacios e instituciones para actividades educativas complementarias en enseñanza secundaria y Formación Profesional
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