245 research outputs found

    Lo intentan pero no es fácil: como reinterpretan niños y niñas los contenidos televisivos actuales

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    La televisión sigue suponiendo para el público infantil una herramienta de ocio de primera línea, compaginándose con las nuevas tecnologías de un modo óptimo. Los niños y niñas actualmente muestran un papel activo con respecto a sus opciones de entretenimiento disponibles en el hogar, siendo cada vez más partícipes tanto en la elección de medios como de contenidos. La manera en la que éstos decodifican lo que consumen se percibe con ejes comunes que pueden ser analizados cualitativamente. Y esta percepción en todo caso estará influenciada por los contextos en los que están inmersos tanto a nivel micro como macrosocia

    Non-intrusive load monitoring techniques for activity of daily living recognition

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    Esta tesis nace con la motivación de afrontar dos grandes problemas de nuestra era: la falta de recursos energéticos y el envejecimiento de la población. Respecto al primer problema, nace en la primera década de este siglo el concepto de Smart Grids con el objetivo de alcanzar la eficiencia energética. Numerosos países comienzan a realizar despliegues masivos de contadores inteligentes ("Smart Meters"), lo que despierta el interés de investigadores que comienzan a desarrollar nuevas técnicas para predecir la demanda. Así, los sistemas NILM (Non-Intrusive Load Monitoring) tratan de predecir el consumo individual de los dispositivos conectados a partir de un único sensor: el contador inteligente. Por otra parte, los grandes avances en la medicina moderna han permitido que nuestra esperanza de vida aumente considerablemente. No obstante, esta longevidad, junto con la baja fertilidad en los países desarrollados, tiene un efecto secundario: el envejecimiento de la población. Unos de los grandes avances es la incorporación de la tecnología en la vida cotidiana, lo que ayuda a los más mayores a llevar una vida independiente. El despliegue de una red de sensores dentro de la vivienda permite su monitorización y asistencia en las tareas cotidianas. Sin embargo, son intrusivos, no escalables y, en algunas ocasiones, de alto coste, por lo que no están preparados para hacer frente al incremento de la demanda de esta comunidad. Esta tesis doctoral nace de la motivación de afrontar estos problemas y tiene dos objetivos principales: lograr un modelo de monitorización sostenible para personas mayores y, a su vez, dar un valor añadido a los sistemas NILM que despierte el interés del usuario final. Con este objetivo, se presentan nuevas técnicas de monitorización basadas en NILM, aunando lo mejor de ambos campos. Esto supone un ahorro considerable de recursos en la monitorización, ya que únicamente se necesita un sensor: el contador inteligente; lo cual da escalabilidad a estos sistemas. Las contribuciones de esta tesis se dividen en dos bloques principales. En el primero se proponen nuevas técnicas NILM optimizadas para la detección de la actividad humana. Así, se desarrolla una propuesta basada en detección de eventos (conexiones de dispositivos) en tiempo real y su clasificación a un dispositivo. Con el objetivo de que pueda integrarse en contadores inteligentes. Cabe destacar que el clasificador se basa en modelos generalizados de dispositivos y no necesita conocimiento específico de la vivienda. El segundo bloque presenta tres nuevas técnicas de monitorización de personas mayores basadas en NILM. El objetivo es proporcionar una monitorización básica pero eficiente y altamente escalable, ahorrando en recursos. Los procesos Cox, log Gaussian Cox Processes (LGCP), monitorizan un único dispositivo si la rutina está estrechamente ligada a este. Así, se propone un sistema de alarmas si se detectan cambios en el comportamiento. LGCP tiene la ventaja de poder modelar periodicidades e incertidumbres propias del comportamiento humano. Cuando la rutina no depende de un único dispositivo, se proponen dos técnicas: una basada en gaussianas mixtas, Gaussian Mixture Models (GMM); y la otra basada en la Teoría de la Evidencia de Dempster-Shafer (DST). Ambas monitorizan y detectan deterioros en la actividad, causados por enfermedades como la demencia y el alzhéimer. Únicamente DST usa incertidumbres que simulan mejor el comportamiento humano y, por tanto, permite alarmas en caso de un repentino desvío. Finalmente, todas las propuestas han sido validadas mediante la evaluación de métricas y la obtención de resultados experimentales. Para ello, se han usado medidas de escenarios reales que han sido recopiladas en bases de datos. Los resultados obtenidos han sido satisfactorios, demostrando que este tipo de monitorización es posible y muy beneficioso para nuestra sociedad. Además, se ha dado a lugar nuevas propuestas que serán desarrolladas en el futuro. Códigos UNESCO: 120320 - sistemas de control medico, 332201 – distribución de la energía, 120701 – análisis de actividades, 120304 – inteligencia artificial, 120807 – plausibilidad, 221402 – patrones

    From farmers to bioengineers: Sowing genes, harvesting molecules

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    Twenty-first-century agriculture faces major challenges that urgently need to be answered. In the last decade, new breeding technologies have been developed that can help meet these challenges. These technologies are not only more accurate and efficient, but are also simpler and more accessible, which will facilitate the progressive democratisation of agricultural biotechnology. In this text we discuss future agricultural development in terms of technological democratisation and regulatory relaxation. In this scenario one would expect an increase in the diversity of cultivated varieties and species, the strong development of biofactory crops and, in the long term, the emergence of increasingly fit «smart» crops

    Using genetic variability available in the breeder's pool to engineer fruit quality

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    8 páginas, 1 figura, 2 tablas.-- This article is open-access.We substantiate here the opinion that experts in biotechnology and natural biodiversity can work together on the production of successive waves of next-gen GM fruit crops to improve organoleptic and nutritional quality and therefore generate wider public acceptance. In this scenario genetic engineering becomes a faster and more precise way of transferring genes of interest to fruit crop plants from the same or sexually compatible species (intra- or cisgenesis) than more traditional methods, such as MASPB. The availability of complete genome sequences for an increasing number of crop plants, as well as the results from genomics studies, can assist in the identification of gene-to-trait association. The next wave of GM crops will be able to take full advantage of a Synthetic Biology-based strategy in the development of new fruit varieties by using DNA not necessarily present in the breeder's pool for a wide range of applications. There are still a number of challenges which require attention, such as identifying genes and allelic forms associated with traits of interest and improving the precision and stability of the transferred DNA, etc.Peer reviewe

    DNA assembly standards: Setting the low-level programming code for plant biotechnology

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    [EN] Synthetic Biology is defined as the application of engineering principles to biology. It aims to increase the speed, ease and predictability with which desirable changes and novel traits can be conferred to living cells. The initial steps in this process aim to simplify the encoding of new instructions in DNA by establishing low-level programming languages for biology. Together with advances in the laboratory that allow multiple DNA molecules to be efficiently assembled together into a desired order in a single step, this approach has simplified the design and assembly of multigene constructs and has even facilitated the automated construction of synthetic chromosomes. These advances and technologies are now being applied to plants, for which there are a growing number of software and wetware tools for the design, construction and delivery of DNA molecules and for the engineering of endogenous genes. Here we review the efforts of the past decade that have established synthetic biology workflows and tools for plants and discuss the constraints and bottlenecks of this emerging field.Marta Vazquez-Vilar is funded by Wageningen University & Research. Diego Orzaez is funded by the Spanish Ministry of Economy and Competitiveness [grant number BIO2016-78601-R]. Nicola Patron is funded by the UK Biotechnological and Biological Sciences Research Council (BBSRC) and Engineering and Physics Research Council (EPSRC)Synthetic Biology for Growth programme [OpenPlant Synthetic Biology Research Centre, grant number BB/L0I4130/1], and by the Earlham DNA Foundry [grant number BB/CCG1720/1].Vázquez-Vilar, M.; Orzáez Calatayud, DV.; Patron, N. (2018). DNA assembly standards: Setting the low-level programming code for plant biotechnology. Plant Science. 273:33-41. https://doi.org/10.1016/j.plantsci.2018.02.024S334127

    Computational approach to design face-milled spiral bevel gear drives with favorable conditions of meshing and contact

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    The micro-geometry of the tooth surfaces of spiral bevel and hypoid pinions has to be fine adjusted to obtain enhanced meshing and contact characteristics during the meshing process with their corresponding mating gears. In this paper, a new methodology is proposed to design face-milled spiral bevel gear drives to, firstly, derive favorable orientation and dimensions of the contact pattern between the mating surfaces of the gears and, secondly, obtain a predesigned parabolic function of negative transmission errors with limited magnitude of maximum transmission errors. The proposed approach is based on the definition of the desired topography for the active surfaces of the pinion followed by a numerical derivation of their finishing machine-tool settings through a bound-constrained optimization algorithm. Increasing mechanical strength and reducing the levels of noise and vibration of face-milled spiral bevel gear drives constitute the main objectives of the proposed design process. A numerical example is provided to illustrate the applicability of the developed theory.The work of the second author has been funded by the FPI scholarship Ref. BES-2011-045995 granted by the Spanish Ministry of Economy and Competitiveness (MINECO)

    Diseño, análisis y optimización de engranajes cilíndricos de dentadura curvilínea

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    Los principales objetivos de este Trabajo son: Análisis de las ventajas e inconvenientes que ofrece el empleo de transmisiones de engranajes cilíndricos formados por dientes con forma geométrica curvilínea frente a transmisiones de engranajes cilíndrico-rectos y cilíndrico-helicoidales.Escuela Técnica Superior de Ingeniería IndustrialUniversidad Politécnica de Cartagen

    DC Network Indoor and Outdoor LED Lighting

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    LED lighting products have become a significant revolution in this technological sector. These components are, by nature, digital emitters created with semiconductor crystals that are powered with very low voltage and direct current (DC). Under these conditions, they have become one of the most relevant actors in the present tendency that is recovering the DC as the channel to transport and distribute energy and is reinforcing the photovoltaic (PV) panels as a relevant sustainable energy source that allows to improve the efficiencies of all types of lighting installations with the local self-generated energy. An analysis of the working principles of this component and the mechanism implemented for their control as lighting equipment to be powered with both conventional alternate current (AC) and DC is presented. A specific differentiation is done upon indoor and outdoor applications where new standards and regulations, specific technical procedures, and singular experimental project descriptions are detailed. The results expose the advantages and difficulties of implementation of this new DC paradigm, the main conclusion obtained up to this moment, and trends of future evolution

    Electrical consequences of large-scale replacement of metal halide by LED luminaires

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    The recent trend for large-scale replacement of luminaires using discharge light sources with LED luminaires without any significant adjustments to the electrical installation has generated controversy. This study examines the main electrical measures in a large outdoor lighting installation before and after the replacement of a large number of metal halide floodlights with LED luminaires. The electrical parameters of both technologies are discussed in detail and compared, with special attention given to the odd-numbered harmonics of voltage and current, the generated wave deformation, currents in the neutral conductor, the wattless reactive volt amps and the peak inrush currents. At cold start-up, the LED luminaires generate large power-on currents, much larger than those generated by the metal halide lamps, despite requiring 36% less real installed power. This is a basic problem to be solved when planning a public lighting renovation with LED luminaires as the rest of electrical parameters are reduced. To address this problem, it is proposed to energise the luminaires using magneto-thermal protection circuits with slow trip curves that will tolerate the large short-term inrush currents
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