1,260 research outputs found

    Alu logarítmica

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    Ingeniero (a) ElectrónicoPregrad

    Nonuniversal large-size asymptotics of the Lyapunov exponent in turbulent globally coupled maps

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    Globally coupled maps (GCMs) are prototypical examples of high-dimensional dynamical systems. Interestingly, GCMs formed by an ensemble of weakly coupled identical chaotic units generically exhibit a hyperchaotic “turbulent” state. A decade ago, Takeuchi et al. [Phys. Rev. Lett. 107, 124101 (2011)] theorized that in turbulent GCMs the largest Lyapunov exponent (LE), λ(N), depends logarithmically on the system size N: λ∞−λ(N)≃c/lnN. We revisit the problem and analyze, by means of analytical and numerical techniques, turbulent GCMs with positive multipliers to show that there is a remarkable lack of universality, in conflict with the previous prediction. In fact, we find a power-law scaling λ∞−λ(N)≃c/Nγ, where γ is a parameter-dependent exponent in the range 0<γ≤1. However, for strongly dissimilar multipliers, the LE varies with N in a slower fashion, which is here numerically explored. Although our analysis is only valid for GCMs with positive multipliers, it suggests that a universal convergence law for the LE cannot be taken for granted in general GCMs.D.V. acknowledges support by Agencia Estatal de Investigación (Spain), and European Social Fund (EU) under Grant No. BES-2017-081808 of the FPI Programme. We acknowledge support by Agencia Estatal de Investigación (Spain), and European Regional Development Fund (EU) under Project No. FIS2016-74957-P (AEI/FEDER, EU)

    Maximizing the statistical diversity of an ensemble of bred vectors by using the geometric norm

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    It is shown that the choice of the norm has a great impact on the construction of ensembles of bred vectors. The geometric norm maximizes (in comparison with other norms such as the Euclidean one) the statistical diversity of the ensemble while at the same time it enhances the growth rate of the bred vector and its projection on the linearly most unstable direction (i.e., the Lyapunov vector). The geometric norm is also optimal in providing the least fluctuating ensemble dimension among all the spectrum of norms studied. The results are exemplified with numerical integrations of a toy model of the atmosphere (the Lorenz-96 model), but these findings are expected to be generic for spatially extended chaotic systems.D.P. acknowledges support by CSIC under the Junta de Ampliación de Estudios Programme (JAE-Doc). Financial support from the Ministerio de Ciencia e Innovacioón (Spain) under Projects FIS2009-12964-C05-05 and CGL2010-21869 is acknowledged

    Spatio-temporal evolution of perturbations in ensembles initialized by bred, Lyapunov and singular vectors

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    We study the evolution of finite perturbations in the Lorenz ?96 model, a meteorological toy model of the atmosphere. The initial perturbations are chosen to be aligned along different dynamic vectors: bred, Lyapunov, and singular vectors. Using a particular vector determines not only the amplification rate of the perturbation but also the spatial structure of the perturbation and its stability under the evolution of the flow. The evolution of perturbations is systematically studied by means of the so-called mean-variance of logarithms diagram that provides in a very compact way the basic information to analyse the spatial structure. We discuss the corresponding advantages of using those different vectors for preparing initial perturbations to be used in ensemble prediction systems, focusing on key properties: dynamic adaptation to the flow, robustness, equivalence between members of the ensemble, etc. Among all the vectors considered here, the so-called characteristic Lyapunov vectors are possibly optimal, in the sense that they are both perfectly adapted to the flow and extremely robust.DP acknowledges the support by CSIC under the Junta de Ampliación de Estudios Programme (JAE-Doc). Financial support from the Ministerio de Educación y Ciencia (Spain) under projects FIS2006-12253-C06-04 and CGL2007-64387/CLI is acknowledged

    Hormigones autocompactables reforzados con fibras

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    La incorporación de fibras cortas dispersas en la matriz del hormigón favorece el control de la fisuración y aumenta la tenacidad. Se reconoce al hormigón reforzado con fibras (HRF) como un material de alta performance para la fabricación de elementos premoldeados, revestimientos de túneles, pavimentos o tableros de puentes. También es posible sustituir o combinar las armaduras transversales con el refuerzo de fibras para mejorar la capacidad resistente al corte y lograr un comportamiento más dúctil, lo que es de interés en elementos estructurales de alma delgada. Aunque las fibras de acero han sido las más utilizadas para reforzar al hormigón, en la actualidad se han desarrollado fibras sintéticas estructurales que pueden competir en ocasiones con las anteriores. La fabricación de HRF de alta resistencia y más recientemente Hormigones Autocompactables Reforzados con Fibras (HACRF) dan lugar a nuevas alternativas de aplicación, entre las que se destacan la realización de reparaciones y refuerzos. Este trabajo muestra las primeras experiencias desarrolladas con el fin de explorar ¡as posibilidades de elaboración y propiedades de HACRF, los estudios se orientaron a la valoración de elementos estructurales de aplicación en la ingeniería vial incluyendo tanto fibras de acero como sintéticas.The incorporation of short fibers dispersed in the matrix of concrete enhances the control of cracks growth and increases the tenacity. It is recognized that fiber reinforced concrete (FRC) is a material of high performance for the manufacture of precast elements, coatings of tunnels, pavements or boards of bridges. Also it is possible to replace or to combine the cross-sectional steel bars with the fiber reinforcement to improve the shear stress capacity and to obtain a more ductile behavior, which is of interest in structural elements of thin soul. Although the steel fibers have been the most used to reinforce concrete, at the present time have been developed structural synthetic fibers that can compete sometimes with the previous ones. The development of high strength FRC and more recently Fiber Reinforced Self-compacting Concrete (FRSCC) give rise to new alternatives of application; the most important being repairs and reinforcements of old structures. This work shows the first experiences developed with the purpose of exploring the elaboration possibilities and properties of FRSCC, the studies were oriented to the evaluation of structural elements of application in road engineering including both steel and synthetic fibers

    Diseño e implementación de un vehículo aéreo no tripulado con sistema de despegue y aterrizaje vertical utilizando tecnologías de manufactura aditiva para el sector agrícola

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    En este proyecto se realiza el diseño e implementación de un VANT con tecnología VTOL que permita en un futuro reemplazar labores humanas en el campo. Se integra la tecnología VTOL que facilita el despegue y aterrizaje de aeronaves en topografía montañosa ya que no necesita de una pista. El diseño de la aeronave se realiza en el software CAD Autodesk Inventor, algunas de las características de la aeronave son el perfil alar NACA 0012 y tiene un ala de forma trapezoidal para brindar una mayor maniobrabilidad. La construcción de la aeronave se hace en impresión 3D y el material es PLA, para el sistema de autopiloto se utiliza la pixhawk 2.4.8 ya tiene un software open source y una gran comunidad que implementa distintos tipos de firmware personalizables. Se ensamblan las piezas de la aeronave y se añaden perfiles de aluminio para mejorar la resistencia de la aeronave, posteriormente se hacen todas las conexiones eléctricas y electrónicas, se realiza la configuración del autopiloto y se realizan pruebas de laboratorio de las piezas móviles, motores brushless y modos de vuelo.This project involves the design and implementation of an UAV with VTOL technology that will allow in the future to replace human labor in the field. It integrates VTOL technology that facilitates the take-off and landing of aircrafts in mountainous topography because it doesn't need a runway. The design of the aircraft is made in Autodesk Inventor CAD software, some of the characteristics of the aircraft are the NACA 0012 airfoil and has a trapezoidal wing to provide greater maneuverability. The construction of the aircraft is made in 3D printing and the material is PLA, for the autopilot system used is pixhawk 2.4.8 already has an open source software and a large community that implements different types of customizable firmware. The parts of the aircraft are assembled and aluminum profiles are added to improve the strength of the aircraft, then all electrical and electronic connections are made, the autopilot configuration is done and laboratory tests of moving parts, brushless motors and flight modes are performed.PregradoIngeniero(a) Mecatrónico(a)CONTENIDO CAPÍTULO I.............................................................................................................1 1. Definición de la propuesta................................................................................1 1.1. Introducción ...............................................................................................1 1.2. Definición del problema .............................................................................1 1.2.1. Planteamiento del problema................................................................1 1.2.2. Formulación del problema...................................................................2 1.2.3. Sistematización ...................................................................................2 1.3. Delimitación ...............................................................................................2 1.4. Objetivos....................................................................................................3 1.4.1. Objetivo general ..................................................................................3 1.4.2. Objetivos específicos ..........................................................................3 1.5. Justificación ...............................................................................................3 CAPÍTULO 2............................................................................................................5 2. Fundamentación teórica de la aeronautica, los vehículos aéreos no tripulados e impresión 3D .....................................................................................................5 2.1. Generalidades de la aeronáutica ...............................................................5 2.1.1. Aerodinámica ......................................................................................5 2.2. Los VANT y RPAS (drones).....................................................................13 2.2.1. Clasificación según el tipo de aplicación ...........................................13 2.2.2. Clasificación según la disposición del perfil alar ...............................15 2.2.3. Componentes de un VANT ...............................................................16 2.3. Diseño asistido por computador (CAD)....................................................24 2.3.1. Solidworks.........................................................................................24 2.3.2. Inventor .............................................................................................25 2.3.3. CATIA................................................................................................26 2.3.4. Fusion 360 ........................................................................................26 2.4. Manufactura aditiva (MA).........................................................................27 2.4.1. Orígenes ...........................................................................................27 2.4.2. Clasificación de los procesos de MA.................................................29 2.4.3. Proceso general ................................................................................34 2.4.4. Slicer 3D............................................................................................36 2.4.5. Parámetros de impresión ..................................................................38 2.4.6. La MA en la aeronáutica ...................................................................42 CAPITULO III.........................................................................................................44 3. Diseño de la aeronave ...................................................................................44 3.1. Antecedentes de los drones ....................................................................44 3.1.1. Antecedentes internacionales ...........................................................44 3.1.2. Antecedentes nacionales ..................................................................46 3.2. Características de las piezas ...................................................................47 3.3. Creación de las piezas.............................................................................48 3.3.1. Alas ...................................................................................................48 3.3.2. Fuselaje.............................................................................................52 3.3.3. Empenaje ..........................................................................................54 3.3.4. Accesorios.........................................................................................57 3.4. Construcción y ensamblaje......................................................................59 3.5. Componentes de los sistemas de control y electrónico ...........................63 3.5.1. Autopiloto PIXHAWK 2.4.8................................................................63 3.5.2. Motores brushless .............................................................................65 3.5.3. Servomotores....................................................................................65 3.5.4. Speed Control (Controlador de velocidad) ........................................67 3.5.5. Módulo 3DR ......................................................................................67 3.5.6. UBEC ................................................................................................68 3.5.7. Batería Li-Po .....................................................................................68 3.5.8. Control remoto...................................................................................68 3.5.9. GPS...................................................................................................69 3.6. Conexiones del sistema electrónico ........................................................70 3.6.1. Sensores y periféricos.......................................................................70 3.6.2. Comunicación con el radio control (RC)............................................71 3.6.3. Alimentación del autopiloto ...............................................................72 3.7. Configuración del autopiloto ....................................................................73 3.7.1. Carga del firmware............................................................................74 3.7.2. Calibración del radiocontrol RC.........................................................76 3.7.3. Calibración del acelerómetro.............................................................77 3.7.4. Configuración del drone como Tricopter ...........................................78 3.7.5. Configuración de las salidas del autopiloto .......................................79 3.7.6. Configuración de los modos de vuelo ...............................................83 CAPÍTULO IV.........................................................................................................85 4. Resultados .....................................................................................................85 4.1. Diseño mecánico del VANT con tecnología VTOL ..................................85 4.2. Conexión de los sistemas electrónicos y de control ................................87 4.3. Validación de la configuración del autopiloto ...........................................89 5. Conclusiones..................................................................................................93 6. Recomendaciones..........................................................................................94 7. Referencias ....................................................................................................95 8. Anexos .........................................................................................................10

    Representation of Working-Class Housing at the Beginning of the Twentieth Century. From the Daily Solutions to the Competition for Cartagena’s Working-Class Quarters in 1902

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    [EN] The problem of the Working-class houses in Spain was taking shape during decades due to different socio-economical causes. The promulgation of the 1st ‘Casas Baratas’ Act in 1911 was the first response of the State as an awareness of this serious social problem, but in the meanwhile, different solutions for the Workingclass dwelling were proposed by a variety of agents (private companies, building societies, public administration, etc.). This paper collects some significant projects in the area of Cartagena and contrasts their graphic proposals, from the simplest works to the outstanding solution provided by the project of the first Spanish competition of social housing in the twentieth century, approaching the construction of two Working-class quarters in Cartagena. Finally, some most common aspects and features of this kind of representation for housing production are shown.[ES] El problema de la vivienda obrera en España se estuvo generando durante décadas debido a diferentes causas socioeconómicas. La promulgación de la 1ª Ley de Casas Baratas en 1911 fue la primera respuesta del Estado como toma de conciencia de este grave problema social, pero en tanto se gestaba, las distintas soluciones para el alojamiento obrero fueron propuestas por múltiples agentes (privados, cooperativas, administración, etc.). Este artículo ofrece un recorrido por algunos proyectos significativos de vivienda obrera en la comarca de Cartagena analizando sus propuestas gráficas, desde las obras más sencillas y cotidianas, hasta la solución excepcional del proyecto para el primer concurso de vivienda social en la España del siglo XX, que propone la construcción de dos barrios obreros en Cartagena. Finalmente se exponen los aspectos y pautas identificadas en este tipo de representaciones para la producción de vivienda.Fundación Séneca. Agencia de Ciencia y Tecnología de la Región de MurciaRódenas-López, MA.; Juan-Vidal, F.; Ros-Mcdonnell, D.; Jiménez-Vicario, PM. (2021). Representación de la vivienda obrera a principios del siglo XX. De las soluciones cotidianas al Concurso de Barrios Obreros para Cartagena de 1902. EGA Expresión Gráfica Arquitectónica. 26(41):150-163. https://doi.org/10.4995/ega.2021.14177OJS1501632641RÓDENAS ROZAS, F. J. 1986. El proceso de transformación espacial del municipio de La Unión, (1840-1960) / dir. José Luis Sarasa Andrés. Tesis Lic -Universidad de Murcia, 1986.ORTEGA ORTEGA, M., MANTECA MARTÍNEZ, J. I. & CALVO LÓPEZ, J. Vivienda obrera minera en Cartagena-La Unión. In: UPCT, C., ed. IV Congreso Nacional de Etnografía del Campo de Cartagena, 22-24 Octubre 2015 2015 Cartagena (España). 574.ARIAS GONZÁLEZ, L. 2003. El socialismo y la vivienda obrera en España (1926-1939) : (la cooperativa socialista de casas baratas "Pablo Iglesias") / Luis Arias González, Salamanca, Ediciones Universidad de Salamanca.INSTITUTO DE REFORMAS SOCIALES (ESPAÑA) 1907. Preparación de las bases para un proyecto de ley de casas para obreros : casas baratas, Madrid, Imprenta de la Sucesora de M. Minuesa de los Ríos

    Integration of multisensor hybrid reasoners to support personal autonomy in the smart home.

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    The deployment of the Ambient Intelligence (AmI) paradigm requires designing and integrating user-centered smart environments to assist people in their daily life activities. This research paper details an integration and validation of multiple heterogeneous sensors with hybrid reasoners that support decision making in order to monitor personal and environmental data at a smart home in a private way. The results innovate on knowledge-based platforms, distributed sensors, connected objects, accessibility and authentication methods to promote independent living for elderly people. TALISMAN+, the AmI framework deployed, integrates four subsystems in the smart home: (i) a mobile biomedical telemonitoring platform to provide elderly patients with continuous disease management; (ii) an integration middleware that allows context capture from heterogeneous sensors to program environment¿s reaction; (iii) a vision system for intelligent monitoring of daily activities in the home; and (iv) an ontologies-based integrated reasoning platform to trigger local actions and manage private information in the smart home. The framework was integrated in two real running environments, the UPM Accessible Digital Home and MetalTIC house, and successfully validated by five experts in home care, elderly people and personal autonomy
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