Recursos de colección

Archivo Digital UPM (120.672 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 132

  1. The numerical analysis of fault-induced mine water inrush using the extended finite element method and fracture mechanics

    Zhou, Qinglong; Herrera Herbert, Juan; Hidalgo López, Arturo
    Fault activation caused by construction, earthquakes, or mining can produce disastrous water-inrush episodes in underground mines. Fault activation is generally caused by stress concentration at the fault tip, so in this study, a computational model of a typical underground stope with a hidden fault was established for quantitatively assessing the magnitude of the stress concentration of the stress fields of the fault-tip. Numerical simulation was performed using the extended finite element method and fracture mechanics. The stress intensity factors, which represent the magnitude of the stress concentration, were obtained using the interaction integral method to quantitatively evaluate the tip fields...

  2. Aggregation operators on type-2 fuzzy sets

    Torres Blanc, Carmen; Cubillo Villanueva, Susana; Hernández, Pablo
    Cubillo et al. in 2015 established the axioms that an operation must fulfill to be an aggregation operator on a bounded poset (partially ordered set), in particular onM (set of fuzzy membership degrees of T2FSs, which are the functions from [0,1] to [0,1]). Previously, Takáˇc in 2014 had applied Zadeh's extension principle to obtain a set of operators on M which are, under some conditions, aggregation operators on L*, the set of strongly normal and convex functions of M. In this paper, we introduce a more general set of operators on M than were given by Takáˇc, and we study,...

  3. Regresión logística basada en distancias para detección de fraude en el IRPF

    Moreno Palenzuela, Jorge
    El fraude es uno de los mayores problemas en la sociedad actual. Dentro de la Agencia Tributaria Espa~nola existe una gran preocupación por la identificación y prevención de fraude en la declaración de impuestos de las diferentes entidades y personas físicas, que alcanza cotas de pérdidas de varios miles de millones de euros sobre las arcas públicas. Tras un acuerdo con la agencia, varias tesis de fin de grado y finn de máster de estos últimos a~nos en la Escuela se han centrado en el intento de explotación de los datos que ésta proporciona, con el objetivo de poder obtener un modelo de predicción adecuado que nos...

  4. Eye evolution simulation with a genetic algorithm based on the hypothesis of Nilsson and Pelger

    Salas Machado, R.; Castellanos Peñuela, Angel Luis; Lahoz-Beltra, Rafael
    The present work addresses for the first time the simulation of the evolution of an elemental eye by means of a simple genetic algorithm. The problem of the gradual evolution of a structure as complex as the eye was raised by Darwin, being still at the beginning of the 21st century a source of controversy between creationists and evolutionists. Taking as a starting point the paper of Nilsson and Pelger and their hypothesis that the evolution of the eye can be studied if we limit ourselves to its optical geometry, we show how eye evolution could take place gradually applying...

  5. Predicting the risk of fault-induced water inrush using the adaptive neuro-fuzzy inference system

    Zhou, Qinglong; Herrera Herbert, Juan; Hidalgo Lopez, Arturo
    Sudden water inrush has been a deadly killer in underground engineering for decades. Currently, especially in developing countries, frequent water inrush accidents still kill a large number of miners every year. In this study, an approach for predicting the probability of fault-induced water inrush in underground engineering using the adaptive neuro-fuzzy inference system (ANFIS) was developed. Six parameters related to the aquifer, the water-resisting properties of the aquifuge and the mining-induced stresses were extracted as the major parameters to construct the ANFIS model. The constructed ANFIS was trained with twenty reported real fault-induced water inrush cases, and another five new...

  6. Latent force models for earth observation time series prediction

    Luengo García, David; Campos-Taberner, Manuel; Camps-Valls, Gustau
    We introduce latent force models for Earth observation time series analysis. The model uses Gaussian processes and differential equations to combine data driven modelling with a physical model of the system. The LFM presented here performs multi-output structured regression, adapts to the signal characteristics, it can cope with missing data in the time series, and provides explicit latent functions that allow system analysis and evaluation. We successfully illustrate the performance in challenging scenarios of crop monitoring from space, providing time-resolved time series predictions.

  7. Estudio y análisis de algoritmos de optimización para la obtención de cadenas de cruce óptimas en trasplantes cruzados

    Revuelta del Campo, Fernando
    El trasplante renal es, actualmente, la mejor solución para las personas que sufren de insuficiencia renal crónica. El otro método, menos eficiente, para paliar las consecuencias de esta enfermedad es la diálisis. Éste se utiliza cuando no se dispone de una persona capaz de donar uno de sus riñones debido a diferentes causas. La principal causa por la cual no es posible realizar un trasplante es la incompatibilidad, tanto sanguínea como del sistema inmunológico o inmunitario. Se puede decir que encontrar dos personas compatibles en grupo sanguíneo no es tan difícil como encontrar a dos personas que compartan un sistema...

  8. Statistical study of the sound coverage in façade sound insulation measurement using different types of loudspeakers

    Pedrero González, Antonio; Iglesias Martínez, Luis; Sánchez Bote, José Luis; Díaz Sanchidrián, César; Navacerrada Saturio, María de los Ángeles
    The international standard ISO 16283-3: 2016 provides procedures to determine the airborne sound insulation of building facades, both for whole facades (global methods) and for facade elements (element methods), such as for doors, windows, etc. In both cases, the standard offers the possibility of using environmental noise as the sound source (road traffic noise, railway noise and aircraft noise) or, alternatively, a loudspeaker that emits broadband noise as an artificial sound source. When using an artificial sound source, the loudspeaker directivity requirements have been established to ensure uniform sound coverage across the facade area. This work analyzes the distribution of...

  9. The water-land-food-energy-climate nexus for a resource efficient Europe.

    Lapisdou, Chrisy; Witmer, Maria; Vamvakeridou Lyroudia, Lydia; Domingo, Xavier; Brouwer, Floor; Howells, Mark; Susnik, Janez; Blanco Fonseca, Maria; Bonazountas, Marc; Fournier, Maite; Papadopoulou, Maria
    Α novel methodology for addressing policy inconsistencies and knowledge gaps that hinder the transition to a greater resource efficiency Europe is proposed. We focus on the integration of all different sectors that interact and influence each other, namely the “water- energy- food- land use- climate nexus” and we develop tools for identifying and quantifying their complex interlinkages under the influence of climate change. In order to achieve this, we employ a series of sophisticated models (referred to as “thematic models”), each of which addresses a different nexus dimension, or a combination of a few, while none addresses all nexus dimensions in an integrative manner. We use dynamic systems modeling and other complexity science...

  10. Tratamiento estadístico de interferencia múltiple en sistemas de comunicación móviles

    Crespo Pérez, Carlos
    Este Proyecto estudia la modelización de la interferencia múltiple en sistemas de comunicaciones móviles, especialmente en los primeros estándares avanzados (GSM, DCS 1800) en los distintos escenarios posibles de propagación radioeléctrica. Retomando trabajos iniciados incipientemente en 1949 aplica metodología de procesos estocásticos matemáticos para el modelado, desarrollando herramientas informáticas que permiten el cálculo de los efectos de dichas interferencias a la hora de diseñar redes móviles de esta naturaleza. El trabajo constituye un base interesante desde el punto de vista del tratamiento matemático (es inédito en la fecha de realización) y que coincide con el momento histórico de desarrollo para la...

  11. Detrended fluctuation analysis for spatial characterisation of landscapes

    Castellanos Moncho, Maria Teresa; Morato Izquierdo, M. del Carmen; Aguado Cortijo, Pedro Luis; Monte Diaz de Guereñu, Juan Pablo del; Tarquis Alfonso, Ana Maria
    The interactions among abiotic, biotic, and anthropic factors and their influence at different scales create a complex dynamic in landscape evolution. Scaling and multifractal analysis have the potential to characterise landscapes in terms of the statistical signature of the selected measure, in this case, altitude. This work evaluates the multifractality of altitude data points along transects that are obtained in several directions using Detrended Fluctuation Analysis (DFA) in a protected area adjacent to Madrid. The study data set consist of a matrix 2048 � 2048 pixels obtained at a 5 m resolution and extracted from a digital terrain model (DTM) using a Geographic Information System (GIS). We...

  12. Optimización, mediante simulación Monte-Carlo, del receptor paramétrico recortador con ruido Hankel en entorno Radar

    Casas Regidor, Juan
    El Proyecto consistirá en el estudio del detector recortador en función del número de muestras integradas, el factor de forma del ruido Hankel y la probabilidad de falsa alarma deseada con el objetivo de optimizar el parámetro “A” de la expresión matemática del detector. La optimización se realizará mediante simulación Monte-Carlo en entorno Matlab. El parámetro “A” óptimo será aquel que nos proporcione mejor probabilidad de detección, para una determinada relación señal a ruido, siempre y cuando nos mantenga la probabilidad de falsa alarma por debajo de un valor máximo prefijado. ABSTRACT. The Project consists of the study of the trimmer detector based...

  13. Security analysis of cache replacement policies

    Cañones Martín, Pablo; Köpf, Boris; Reineke, Jan
    Modern computer architectures share physical resources between different programs in order to increase area-, energy-, and cost- efficiency. Unfortunately, sharing often gives rise to side channels that can be exploited for extracting or transmitting sensitive information. We currently lack techniques for systematic reasoning about this interplay between security and efficiency. In particular, there is no established way for quantifying security properties of shared caches. In this paper, we propose a novel model that enables us to characterize important security properties of caches. Our model encompasses two aspects: (1) The amount of information that can be absorbed by a cache, and...

  14. On the Harnack Inequality for Quasilinear Elliptic Equations With a First Order Term

    Merchán Rubira, Susana; Montoro, Luigi; Sciunzi, Berardino
    We consider weak solutions to −∆pu + a(x, u)|∇u|q = f(x, u), with p > 1, q ≥ max{p − 1, 1}. We exploit the Moser iteration technique to prove a Harnack comparison inequality for C 1 weak solutions. As a consequence we deduce a strong comparison principle.

  15. Algunas condiciones para la obtención de negaciones sobre los Conjuntos Tipo 2

    Hernández Varela, Pablo Ramón; Cubillo Villanueva, Susana; Torres Blanc, Carmen
    En Hernández et. al. (2014) se presentó, a partir del "Principio de Extensión" de Zadeh, un conjunto de operadores en [0,1], exponiendo algunas condiciones bajo las que dichas operaciones son negaciones en L (conjunto de las funciones normales y convexas de [0,1] en [0,1]. Además, L es un subconjunto del conjunto de los grados de pertenencia de los conjuntos borrosos de tipo 2). En el presente trabajo, se define un conjunto de operaciones más general que el estudiado en el referido artículo, y se establecen algunas condiciones suficientes para que sean negaciones y negaciones fuertes sobre L.

  16. Double ant colony system to improve accessibility after a disaster

    Sacristán Robles, Víctor; Jiménez Martín, Antonio; Mateos Caballero, Alfonso
    We propose a novel double ant colony system to deal with accessibility issues after a natural or man-made disaster. The aim is to maximize the number of survivors that reach the nearest regional center (center of economic and social activity in the region) in a minimum time by planning which rural roads damaged by the disaster should be repaired given the available financial and human resources. The proposed algorithm is illustrated by means of a large instance based on the Haiti natural disasters in August-September 2008.

  17. Nuevos órdenes sobre los números y cantidades borrosas

    Cubillo Villanueva, Susana; Hernández Varela, Pablo Ramón; Torres Blanc, Carmen; Guerrero, José Atilio
    En los procesos de los sistemas borrosos, comúnmente se debe comparar y elegir entre varios números borrosos para emitir una respuesta o tomar una decisión. En cierto sentido, los números y cantidades borrosas se pueden considerar como "valores reales" con grados de incertidumbre, imprecisión, o vaguedad, y por tanto se representan como conjuntos borrosos sobre la recta real. Es decir, en general, no son simplemente números reales, y no se pueden ordenar con el orden total de los mismos. En lo que sigue, para simplificar las notaciones, identificaremos un conjunto borroso F sobre la recta real con su función de...

  18. Parallel metropolis chains with cooperative adaptation

    Martino, Luca; Elvira Arregui, Víctor; Luengo García, David; Louzada, Francisco
    Monte Carlo methods, such as Markov chain Monte Carlo (MCMC) algorithms, have become very popular in signal processing over the last years. In this work, we introduce a novel MCMC scheme where parallel MCMC chains interact, adapting cooperatively the parameters of their proposal functions. Furthermore, the novel algorithm distributes the computational effort adaptively, rewarding the chains which are providing better performance and, possibly even stopping other ones. These extinct chains can be reactivated if the algorithm considers it necessary. Numerical simulations show the benefits of the novel scheme.

  19. Combinatorial bounds on connectivity for dominating sets in maximal outerplanar graphs

    Canales Cano, Santiago; Castro Delgado, Irene; Hernández Peñalver, Gregorio; Martins, Ana Mafalda
    In this article we study some variants of the domination concept attending to the connectivity of the subgraph generated by the dominant set. This study is restricted to maximal outerplanar graphs. We establish tight combinatorial bounds for connected domination, semitotal domination, independent domination and weakly connected domination for any n-vertex maximal outerplanar graph

  20. Tree-structured Bayesian networks for wrapped Cauchy directional distributions

    Leguey Vitoriano, Ignacio; Bielza Lozoya, María Concepción; Larrañaga Múgica, Pedro María
    Modelling the relationship between directional variables is a nearly unexplored field. The bivariate wrapped Cauchy distribution has recently emerged as the first closed family of bivariate directional distri- butions (marginals and conditionals belong to the same family). In this paper, we introduce a tree-structured Bayesian network suitable for mod- elling directional data with bivariate wrapped Cauchy distributions. We describe the structure learning algorithm used to learn the Bayesian net- work. We also report some simulation studies to illustrate the algorithms including a comparison with the Gaussian structure learning algorithm and an empirical experiment on real morphological data from juvenile rat somatosensory cortex cells.

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