1,354 research outputs found

    Aprender cooperando en aulas universitarias de informática

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    En este artículo se describe cómo es posible conjugar la docencia tradicional con la puesta en práctica de otras metodologías alternativas en materias tecnológicas. En concreto esta experiencia se ha llevado a la práctica en la asignatura Estructura y Tecnología de Computadores II. Se trata de una asignatura obligatoria de primer curso de la Ingeniería Técnica en Informática de Gestión de la Universidad de Sevilla, en la que cada grupo tiene, de media, 80 alumnos matriculados. Se conjugan técnicas de aprendizaje cooperativo con algunas herramientas de evaluación como las rúbricas (o listas de comprobación) y el portafolio electrónico. Se ha comprobado que, con la combinación de estas metodologías, los alumnos encuentran más satisfactorio el proceso de aprendizaje, se comprometen en ese proceso y, además, fomentan el desarrollo de muchas de las competencias transversales que demanda el EEES.Peer Reviewe

    Use of 3D Printing in Model Manufacturing for Minor Surgery Training of General Practitioners in Primary Care

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    In order to increase the efficiency of the Spanish health system, minor surgery programs are currently carried out in primary care centers. This organizational change has led to the need to train many general practitioners (GPs) in this discipline on a practical level. Due to the cost of the existing minor surgery training models in the market, pig’s feet or chicken thighs are used to practice the removal of figured lesions and the suture of wounds. In the present work, the use of 3D printing is proposed, to manufacture models that reproduce in a realistic way the most common lesions in minor surgery practice, and that allow doctors to be trained in an adequate way. Four models with the most common dermal lesions have been designed and manufactured, and then evaluated by a panel of experts. Face validity was demonstrated with four items on a five-point Likert scale that was completed anonymously. The models have obtained the following results: aesthetic recreation, 4.6 ± 0.5; realism during anesthesia infiltration, 4.8 ± 0.4; realism during lesion removal, 2.8 ± 0.4; realism during surgical wound closure, 1.2 ± 0.4. The score in this last section could be improved if a more elastic skin-colored filament were found on the market

    Localized oscillations in nonlinear hamiltonian Klein-Gordon lattices. Breathers and Anderson modes

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    PósterThere are two different sources of localization in discrete lattices: • Anderson modes in disordered harmonic lattices [1] • Discrete breathers in homogeneous nonlinear lattices [2

    Solving random homogeneous linear second-order differential equations: a full probabilistic description

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    [EN] In this paper a complete probabilistic description for the solution of random homogeneous linear second-order differential equations via the computation of its two first probability density functions is given. As a consequence, all unidimensional and two-dimensional statistical moments can be straightforwardly determined, in particular, mean, variance and covariance functions, as well as the first-order conditional law. With the aim of providing more generality, in a first step, all involved input parameters are assumed to be statistically dependent random variables having an arbitrary joint probability density function. Second, the particular case that just initial conditions are random variables is also analysed. Both problems have common and distinctive feature which are highlighted in our analysis. The study is based on random variable transformation method. As a consequence of our study, the well-known deterministic results are nicely generalized. Several illustrative examples are included.This work has been partially supported by the Spanish M. C. Y. T. Grant MTM2013-41765-P.Casabán, M.; Cortés, J.; Romero, J.; Roselló, M. (2016). Solving random homogeneous linear second-order differential equations: a full probabilistic description. Mediterranean Journal of Mathematics. 13(6):3817-3836. https://doi.org/10.1007/s00009-016-0716-6S38173836136Øksendal B.: Stochastic Differential Equations: An Introduction with Applications, 6th edn. Springer, Berlin (2007)Soong T.T.: Random Differential Equations in Science and Engineering. Academic Press, New York (1973)Neckel, T., Rupp, F.: Random Differential Equations in Scientific Computing. Versita, London (2013)Nouri, K., Ranjbar, H.: Mean square convergence of the numerical solution of random differential equations. Mediterr. J. Math. 1–18 (2014). doi: 10.1007/s00009-014-0452-8Villafuerte, L., Chen-Charpentier, B.M.: A random differential transform method: theory and applications. Appl. Math. Lett. 25(10), 1490–1494 (2012). doi: 10.1016/j.aml.2011.12.033Licea, J.A., Villafuerte, L., Chen-Charpentier, B.M.: Analytic and numerical solutions of a Riccati differential equation with random coefficients. J. Comput. Appl. Math. 239, 208–219 (2013). doi: 10.1016/j.cam.2012.09.040Casabán, M.C., Cortés, J.C., Romero, J.V., Roselló, M.D.: Probabilistic solution of random homogeneous linear second-order difference equations. Appl. Math. Lett. 34, 27–32 (2014). doi: 10.1016/j.aml.2014.03.010Santos, L.T., Dorini, F.A., Cunha, M.C.C.: The probability density function to the random linear transport equation. Appl. Math. Comput. 216 (5), 1524–1530 (2010). doi: 10.16/j.amc.2010.03.001El-Tawil, M., El-Tahan, W., Hussein, A.: Using FEM-RVT technique for solving a randomly excited ordinary differential equation with a random operator. Appl. Math. Comput. 187(2), 856–867 (2007). doi: 10.1016/j.amc.2006.08.164Hussein, A., Selim, M.M.: Solution of the stochastic radiative transfer equation with Rayleigh scattering using RVT technique. Appl. Math. Comput. 218(13), 7193–7203 (2012). doi: 10.1016/j.amc.2011.12.088Casabán, M.C., Cortés, J.C., Romero, J.V., Roselló, M.D.: Probabilistic solution of random SI-type epidemiological models using the random variable transformation technique. Commun. Nonlinear Sci. Numer. Simul. 24(1–3), 86–97 (2015). doi: 10.1016/j.cnsns.2014.12.016Casabán, M.C., Cortés, J.C., Romero, J.V., Roselló, M.D.: Determining the first probability density function of linear random initial value problems by the random variable transformation (RVT) technique: a comprehensive study. In: Abstract and Applied Analysis 2014-ID248512, pp. 1–25 (2014). doi: 10.1155/2013/248512Casabán, M.C., Cortés, J.C., Navarro-Quiles, A., Romero, J.V., Roselló, M.D., Villanueva, R.J.: A comprehensive probabilistic solution of random SIS-type epidemiological models using the random variable transformation technique. Commun. Nonlinear Sci. Numer. Simul. 32, 199–210 (2016). doi: 10.1016/j.cnsns.2015.08.009El-Wakil, S.A., Sallah, M., El-Hanbaly, A.M.: Random variable transformation for generalized stochastic radiative transfer in finite participating slab media. Phys. A 435 66–79 (2015). doi: 10.1016/j.physa.2015.04.033Dorini, F.A., Cunha, M.C.C.: On the linear advection equation subject to random fields velocity. Math. Comput. Simul. 82, 679–690 (2011). doi: 10.16/j.matcom.2011.10.008Dhople, S.V., Domínguez-García, D.: A parametric uncertainty analysis method for Markov reliability and reward models. IEEE Trans. Reliab. 61(3), 634–648 (2012). doi: 10.1109/TR.2012.2208299Williams, M.M.R.: Polynomial chaos functions and stochastic differential equations. Ann. Nucl. Energy 33(9), 774–785 (2006). doi: 10.1016/j.anucene.2006.04.005Chen-Charpentier, B.M., Stanescu, D.: Epidemic models with random coefficients. Math. Comput. Model. 52(7/8), 1004–1010 (2009). doi: 10.1016/j.mcm.2010.01.014Papoulis A.: Probability, Random Variables and Stochastic Processes. McGraw-Hill, New York (1991

    Experimental infection of encapsulated and free larvae of Anisakis larvae type I in Wistar rats

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    En este trabajo se realiza un estudio sobre el papel patógeno de las larvas de Anisakis encapsuladas en las vísceras del pez y las que se encuentran libres en la cavidad corporal del mismo, mediante la estimación de las lesiones causadas en el tracto digestivo de ratas Wistar. Los resultados muestran que el porcentaje de lesiones fue mayor (92,9%) en las ratas infectadas con larvas libres que en aquellas a las cuales se les administraron las larvas encapsuladas (35,7%), además, ninguna de ellas se encontró en la cavidad corporal del animal.In this study we performed a research on the pathogenic role of encapsulated Anisakis larvae in the viscera of the fish and free larvae in the body cavity of the fish, through the evaluation of the lesions induced in the digestive tract of Wistar rats. The results show that the percentage of lesions was higher (92.9%) in rats infected with free larvae than in those receiving encapsulated larvae (35.7%), besides, none of the larvae was found in the body cavity of the animals.Trabajo financiado por el proyecto: P07-CVI-0324

    Quasi-particle Lifetimes in a d_{x^2-y^2} Superconductor

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    We consider the lifetime of quasi-particles in a d-wave superconductor due to scattering from antiferromagnetic spin-fluctuations, and explicitly separate the contribution from Umklapp processes which determines the electrical conductivity. Results for the temperature dependence of the total scattering rate and the Umklapp scattering rate are compared with relaxation rates obtained from thermal and microwave conductivity measurements, respectively.Comment: 14 pages, 4 figure

    Second Screen Interactions for Automatically Web-Enriched Broadcast Video

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    Including hypermedia in broadcast video combines content formatted for a lean-forward medium (the Web) with a lean-back one (TV) to form a hybrid medium. We identify four challenges for interacting with and experiencing this new medium. We discuss the role a second screen may play in addressing these challenges
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