Recursos de colección

Archivo Digital UPM (117.876 recursos)

This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Matemáticas

Mostrando recursos 1 - 20 de 102

  1. Modelo matemático de reconstrucción del sistema inmune posterior a la quimioterapia

    Portillo Garrigues, Pablo María
    El objetivo de este trabajo es la modelización del proceso de reconstrucción del sistema inmune de un paciente. El sistema inmune del paciente ha sido eliminado tras recibir radio o químioterapia, a continuación se procede a re- alizar transplante de células blancas. Con el objetivo de modelizar el proceso, se consideran cuatro ecuaciones diferenciales del modelo propuesto en Szymanska [R.4] y una quinta ecuación del modelo propuesto en de Colijn et al [R.2]. Ésta última ecuación contiene seis parámetros desconocidos, para esti- marlos se ha implementado el método de los mínimos cuadrados utilizando un algoritmo de optimización, conocido como Algoritmo de la colonia de hormi- gas (Ant colony Optimization)....

  2. Resolución numérica de la ecuación de Reynolds y aplicaciones a la teoría de la lubricación

    Soriano del Pino, Lucas
    Se presenta un modelo de resolución numérica de la ecuación de Reynolds, basado en el método de los elementos finitos. El primer paso consiste en la derivación de la propia ecuación a partir de las ecuaciones de Navier-Stokes mediante análisis dimensional. A esto le sigue la demostraci ón de que la ecuación obtenida tiene solución única aplicando el teorema de Lax-Milgram. Siguiendo los pasos del análisis por elementos finitos se reduce el problema a resolver un sistema de ecuaciones lineales. La elección del método de resolución del sistema permite incorporar al modelo el fenómeno de la cavitación. Se obtienen resultados para distintas geometrías inducidas por la variación en la...

  3. Spatial dispersion and clustering of soil structure through lacunarity of X-ray CT images of soil macropore volumes

    San Jose Martinez, Fernando; Caniego Monreal, Francisco; García-Gutiérrez Baez, Carlos
    Lacunarity functions have been revealed as means to measure the deviation of object?s geometrical structure from transltional invariance beyond self-similarity and fractal geometry. In this work, we will explore how lacunarity quantifies ifferent patterns of dispersion and clustering of different geometrical structures of soil macropore volumes imaged by X-ray computed tomography.

  4. Distribution of zeros of the Husimi function in a realistic Hamiltonian molecular system

    Arranz Saiz, Francisco Javier; Borondo Rodríguez, Florentino; Benito Zafrilla, Rosa Maria
    In this paper we numerically check the validity of a theory on the distribution of zeros of the Husimi function due to Leboeuf and Voros [J. Phys. A 23, 1765 (1990)] for the integrability or chaoticity of a dynamical system in conditions which are not covered in the original proof. Our results for a generic Hamiltonian model for the LiCN molecule indicate also that in this case the conclusions of these authors hold. We have also found that this criterion is related to that proposed by Stratt, Handy and Miller based on the nodal complexity of the wave function [J....

  5. A protocol for wide range porosity data image aquisition

    García-Gutiérrez Baez, Carlos; San Jose Martinez, Fernando; Caniego Monreal, Francisco
    A protocol for obtaining soil digital images with a wide range of pore sizes, intended for fractal studies of the porosity, using a photo- camera and a confocal microscope images is proposed

  6. Transition from Order to Chaos in Molecular Wave Functions and Spectra

    Arranz Saiz, Francisco Javier; Borondo Rodríguez, Florentino; Benito Zafrilla, Rosa María
    In this Communication we describe how the transition from regularity to classical chaos in molecular Hamiltonian systems shows up at the quantum level in the structure of the corresponding wave functions and spectra. By changing the value of hbar we show how the scars result from combinations of regular wave functions.

  7. Reduction of Discrete Dynamical Systems with Applications to Dynamics Population Models

    Bravo de la Parra, Rafael; Marvá, M.; Sánchez., E.; Sanz Lorenzo, Luis
    In this work we review the aggregation of variables method for discrete dynamical systems. These methods consist of describing the asymptotic behaviour of a complex system involving many coupled variables through the asymptotic behaviour of a reduced system formulated in terms of a few global variables. We consider population dynamics models including two processes acting at different time scales. Each process has associated a map describing its effect along its specific time unit. The discrete system encompassing both processes is expressed in the slow time scale composing the map associated to the slow one and the k-th iterate of the...

  8. Bases teóricas de los robots rígidos actuados por cables

    Aguarón de Blas, Juan
    Capítulo sobre teoría de robots accionados por cables en base a variables de fuerza, configuración articular y longitud de cable. Incluye diagramas de flujo para su identificación.

  9. Sticky proposal densities for adaptive MCMC methods

    Martino, Luca; Casarin, R.; Luengo García, David
    Monte Carlo (MC) methods are commonly used in Bayesian signal processing to address complex inference problems. The performance of any MC scheme depends on the similarity between the proposal (chosen by the user) and the target (which depends on the problem). In order to address this issue, many adaptive MC approaches have been developed to construct the proposal density iteratively. In this paper, we focus on adaptive Markov chain MC (MCMC) algorithms, introducing a novel class of adaptive proposal functions that progressively stick to the target. This proposed class of sticky MCMC methods converge very fast to the target, thus...

  10. Multiple importance sampling with overlapping sets of proposals

    Elvira Arregui, Víctor; Martino, Luca; Luengo Garcia, David; Bugallo, Mónica F.
    In this paper, we introduce multiple importance sampling (MIS) approaches with overlapping (i.e., non-disjoint) sets of proposals. We derive a novel weighting scheme, based on the deterministic mixture methodology, that leads to unbiased estimators. The proposed framework can be seen as a generalization of other well-known MIS algorithms available in the literature. Furthermore, it allows us to achieve any desired trade-off between the variance of the estimators and the computational complexity through the definition of the sets of proposals. Simulations using a bimodal target density show the good performance of the proposed approach.

  11. Domain Reduction Strategy for Stability Analysis of a NACA0012 airfoil

    Sanvido, Silvia; Abruzzese, Gennaro; Vicente Buendia, Javier de; Valero Sánchez, Eusebio
    A new reduction domain strategy is applied in the framework of stability analysis for industrial applications. The aim of this work is to investigate if the geometrical approach proposed could be used as alternative or in combination with the numerical techniques that are currently employed for alleviating the prohibitive computational costs associated to the study of the stability of complex aerodynamic ows.Global linear stability analysis has been applied to a NACA0012 airfoil to study the transient bu�et phenomenon. The leading disturbance associated to bu�eting remains located in a inner región of the computational domain, making this problem a perfect test case for...

  12. An evolutionary scheduling approach for trading-off accuracy vs. verifiable energy in multicore processors

    Liqat, Umer; Bankovic, Zorana; López García, Pedro; Hermenegildo, Manuel V.
    This work addresses the problem of energy-efficient scheduling and allocation of tasks in multicore environments, where the tasks can allow a certain loss in accuracy in the output, while still providing proper functionality and meeting an energy budget. This margin for accuracy loss is exploited by using computing techniques that reduce the work load, and thus can also result in significant energy savings. To this end, we use the technique of loop perforation, that transforms loops to execute only a subset of their original iterations, and integrate this technique into our existing optimization tool for energy-efficient scheduling. To verify that...

  13. Computationally efficient simulation of unsteady aerodynamics using POD on the fly

    Moreno Ramos, Ruben; Vega de Prada, José Manuel; Varas Merida, Fernando
    Modern industrial aircraft design requires a large amount of sufficiently accurate aerodynamic and aeroelastic simulations. Current computational fluid dynamics (CFD) solvers with aeroelastic capabilities, such as the NASA URANS unstructured solver FUN3D, require very large computational resources. Since a very large amount of simulation is necessary, the CFD cost is just unaffordable in an industrial production environment and must be significantly reduced. Thus, a more inexpensive, yet sufficiently precise solver is strongly needed. An opportunity to approach this goal could follow some recent results (Terragni and Vega 2014 SIAM J. Appl. Dyn. Syst. 13 330–65; Rapun et al 2015 Int....

  14. Multiobjective simulated annealing for collision avoidance in ATM accounting for three admissible maneuvers

    Mateos Caballero, Alfonso; Jiménez Martín, Antonio
    Technological advances are required to accommodate air traffic control systems for the future growth of air traffic. Particularly, detection and resolution of conflicts between aircrafts is a problem that has attracted much attention in the last decade becoming vital to improve the safety standards in free flight unstructured environments. We propose using the archive simulated annealing- based multiobjective optimization algorithm to deal with such a problem, accounting for three admissible maneuvers (velocity, turn, and altitude changes) in a multiobjective context. The minimization of the maneuver number and magnitude, time delays, or deviations in the leaving points are considered for analysis. The optimal values for the...

  15. Estudio de la generación de emulsiones en microfluidos mediante simulación numérica

    Hurtado de Mendoza, Aurelio
    El Trabajo de Fin de Grado que se presenta aquí es el resultado de seis meses de prácticas del alumno, como becario en el laboratorio de Mecánica y Modelización de Procesos Propios de Marsella, Francia. El laboratorio M2P2 participa en un gran número de proyectos de investigación en los ámbitos de la Ingeniería Química y de la Dinámica de Fluidos Computacional (CFD, por sus siglas en inglés), algunos de ellos dirigidos por expertos de reconocido prestigio internacional. Dentro de este laboratorio, el equipo PROMETHEE se centra en el estudio de los microfluidos y los nanofluidos, es decir, del comportamiento de los fluidos a escalas por debajo...

  16. Proyecto de un edificio "Unidad Judicial en Ambato-Ecuador"

    Cortez Castedo, Luis Fernando
    El edificio se sitúa en la ciudad ecuatoriana de Ambato, región que se encuentra a 2580 msnm y es declarada zona de alto riesgo sísmico; la superficie aproximada de construcción es de 4355.00m2. La función o uso del edificio es de tipo judicial, se considera un espacio público como edificio público. La estructura se diseña con necesidad de tener una libertad en la organización espacial interna del edificio, delimitados mediante tabiquería montada en seco; por lo que se proyecta un módulo tipo de acero de dimensiones similares en ambos ejes, procurando una distribución uniforme y simétrica de rigideces que varíen gradualmente en...

  17. Uso de los métodos de cálculo diferencial de Leibniz y Newton en los libros de texto de la Biblioteca Histórica de la UCM en torno al siglo XVIII

    Palma Villalon, Emilia
    Investigación en curso sobre los libros de texto de cálculo diferencial en el siglo XVIII. En esta ponencia se presenta el uso de las terminologías del cálculo de fluxiones de Newton y el cálculo diferencial de Leibniz en los libros del siglo XVIII.

  18. Wind power probabilistic forecast in the reproducing Kernel Hilbert space

    Gallego Castillo, Cristobal Jose; Cuerva Tejero, Alvaro; Bessa, Ricardo J.; Cavalcante, Laura
    Wind power probabilistic forecast is a key input in decision-making problems under risk, such as stochastic unit commitment, operating reserve setting and electricity market bidding. While the majority of the probabilistic forecasting methods are based on quantile regression, the associated limitations call for new approaches. This paper described a new quantile regression model based on the Reproducing Kernel Hilbert Space (RKHS) framework. In particular, two versions of the model, off-line and on-line, were implemented and tested for a real wind farm. Results showed the superiority of the on-line approach in terms of performance, robustness and computational cost. Additionally, it was observed that, in the...

  19. Multiple solutions and numerical analysis to the dynamic and stationary models coupling a delayed energy balance model involving latent heat and discontinuous albedo with a deep ocean

    Hidalgo López, Arturo; Tello Del Castillo, María Lourdes; Díaz Díaz, Jesús Ildefonso
    We study a climatologically important interaction of two of the main components of the geophysical system by adding an energy balance model for the averaged atmospheric temperature as dynamic boundary condition to a diagnostic ocean model having an additional spatial dimension. In this work, we give deeper insight than previous papers in the literature, mainly with respect to the 1990 pioneering model by Watts and Morantine. We are taking into consideration the latent heat for the two phase ocean as well as a possible delayed term. Non uniqueness for the initial boundary value problem, uniqueness under a non-degeneracy condition, and...

  20. Approximate controllability of coupled 1-d wave equations onstar-shaped graphs

    Dager Salomon, Rene
    In this Note, we study the approximate controllability of a cascade system of two 1-d wave equations defined on a star-shaped planar graph. Only the first equation is controlled, with controls applied at the simple vertices. The controls act on the second equation through the coupling at the multiple vertex. We give a necessary and sufficient condition for the approximate controllability of the system: all the ratios of the lengths of any two different edges of the graph should be irrational numbers. The result implies that, under these conditions, the approximate desensitizing controllability of a star-shaped network of strings holds,...

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