Evolutionary design of nearest prototype classifiers

In pattern classification problems, many works have been carried out with the aim of designing good classifiers from different perspectives. These works achieve very good results in many domains. However, in general they are very dependent on some crucial parameters involved in the design. These parameters have to be found by a trial and error process or by some automatic methods, like heuristic search and genetic algorithms, that strongly decrease the performance of the method. For instance, in nearest prototype approaches, main parameters are the number of prototypes to use, the initial set, and a smoothing parameter. In this work, an evolutionary approach based on Nearest Prototype Classifier (ENPC) is introduced where no parameters are involved, thus overcoming all the problems that classical methods have in tuning and searching for the appropiate values. The algorithm is based on the evolution of a set of prototypes that can execute several operators in order to increase their quality in a local sense, and with a high classification accuracy emerging for the whole classifier. This new approach has been tested using four different classical domains, including such artificial distributions as spiral and uniform distibuted data sets, the Iris Data Set and an application domain about diabetes. In all the cases, the experiments show successfull results, not only in the classification accuracy, but also in the number and distribution of the prototypes achieved.Publicad

Local feature weighting in nearest prototype classification

The distance metric is the corner stone of nearest neighbor (NN)-based methods, and therefore, of nearest prototype (NP) algorithms. That is because they classify depending on the similarity of the data. When the data is characterized by a set of features which may contribute to the classification task in different levels, feature weighting or selection is required, sometimes in a local sense. However, local weighting is typically restricted to NN approaches. In this paper, we introduce local feature weighting (LFW) in NP classification. LFW provides each prototype its own weight vector, opposite to typical global weighting methods found in the NP literature, where all the prototypes share the same one. Providing each prototype its own weight vector has a novel effect in the borders of the Voronoi regions generated: They become nonlinear. We have integrated LFW with a previously developed evolutionary nearest prototype classifier (ENPC). The experiments performed both in artificial and real data sets demonstrate that the resulting algorithm that we call LFW in nearest prototype classification (LFW-NPC) avoids overfitting on training data in domains where the features may have different contribution to the classification task in different areas of the feature space. This generalization capability is also reflected in automatically obtaining an accurate and reduced set of prototypes.Publicad

Forgetting complex propositions

This paper uses possible-world semantics to model the changes that may occur in an agent's knowledge as she loses information. This builds on previous work in which the agent may forget the truth-value of an atomic proposition, to a more general case where she may forget the truth-value of a propositional formula. The generalization poses some challenges, since in order to forget whether a complex proposition $\pi$ is the case, the agent must also lose information about the propositional atoms that appear in it, and there is no unambiguous way to go about this. We resolve this situation by considering expressions of the form $[\boldsymbol{\ddagger} \pi]\varphi$, which quantify over all possible (but minimal) ways of forgetting whether $\pi$. Propositional atoms are modified non-deterministically, although uniformly, in all possible worlds. We then represent this within action model logic in order to give a sound and complete axiomatization for a logic with knowledge and forgetting. Finally, some variants are discussed, such as when an agent forgets $\pi$ (rather than forgets whether $\pi$) and when the modification of atomic facts is done non-uniformly throughout the model

Derivation of the spin Hamiltonians for Fe in MgO

A method to calculate the effective spin Hamiltonian for a transition metal impurity in a non- magnetic insulating host is presented and applied to the paradigmatic case of Fe in MgO. In a first step we calculate the electronic structure employing standard density functional theory (DFT), based on generalized-gradient approximation (GGA), using plane waves as a basis set. The corresponding basis of atomic-like maximally localized Wannier functions is derived and used to represent the DFT Hamiltonian, resulting in a tight-binding model for the atomic orbitals of the magnetic impurity. The third step is to solve, by exact numerical diagonalization, the N electron problem in the open shell of the magnetic atom, including both effect of spin-orbit and Coulomb repulsion. Finally, the low energy sector of this multi-electron Hamiltonian is mapped into effective spin models that, in addition to the spin matrices S, can also include the orbital angular momentum L when appropriate. We successfully apply the method to Fe in MgO, considering both, the undistorted and Jahn-Teller (JT) distorted cases. Implications for the influence of Fe impurities on the performance of magnetic tunnel junctions based on MgO are discussed.Comment: 10 pages, 7 Figure

Heat waves and human well-being in Madrid (Spain)

Heat waves pose additional risks to urban spaces because of the additional heat provided by urban heat islands (UHIs) as well as poorer air quality. Our study focuses on the analysis of UHIs, human thermal comfort, and air quality for the city of Madrid, Spain during heat waves. Heat wave periods are defined using the long-term records from the urban station Madrid-Retiro. Two types of UHI were studied: the canopy layer UHI (CLUHI) was evaluated using air temperature time-series from five meteorological stations; the surface UHI (SUHI) was derived from land surface temperature (LST) images from MODIS (Moderate Resolution Imaging Spectroradiometer) products. To assess human thermal comfort, the Physiological Equivalent Temperature (PET) index was applied. Air quality was analyzed from the records of two air quality networks. More frequent and longer heat waves have been observed since 1980; the nocturnal CLUHI and both the diurnal and nocturnal SUHI experience an intensification, which have led to an increasing number of tropical nights. Conversely, thermal stress is extreme by day in the city due to the lack of cooling by winds. Finally, air quality during heat waves deteriorates because of the higher than normal amount of particles arriving from Northern AfricaThis research was funded by the research project number CGL2016-80154-R “Análisis y modelización de eventos climáticos extremos en Madrid: olas de calor e inversiones térmicas” funded by Convocatoria 2016 de Proyectos de I+D+I, correspondientes al programa estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad, from the Spanish Ministry of Educatio

Normativa y espacio doméstico. Hacia una nueva metodología del proyecto de vivienda protegida: texto y póster

El póster es el resultado de una investigación en torno al tema del espacio doméstico, investigación basada en la búsqueda de las claves para conocer qué es actualmente un PROGRAMA de vivienda colectiva, es decir, cómo podemos hacer hoy un programa a través de situaciones reales no codificadas. Se trata de un acercamiento desde la escala de la célula -la CULTURA DOMÉSTICA, lo que podríamos denominar la TERAPIA-, sin olvidar la escala de la agrupación -la CULTURA EDIFICATORIA, para nosotros SOPORTE-, a través de la parametrización de una serie de CONDICIONES, frente a la clasificación en funciones de la normativa actual. Los 50 artículos para una nueva Normativa de Vivienda Protegida surgen a partir de una revisión de las normas de diseño contempladas en la normativa estatal de Viviendas de Protección Oficial, reguladas por el Real Decreto 3148/1978, de 10 de noviembre, por el que se desarrolla el Real Decreto-Ley 31/1978, de 31 de octubre, sobre política de vivienda, así como la normativa de carácter autonómico vigente en la Comunidad de Madrid (PGOUM) y la normativa desarrollada por la Empresa Municipal de la Vivienda y Suelo de Madrid (EMVS). A partir de estas tres "escalas legislativas" -nacional, autonómica y municipal- se han seleccionado los artículos u ordenanzas referidos expresamente a normas de diseño del ESPACIO DOMÉSTICO, obviando aquellos otros relacionados con parámetros urbanísticos, normas técnicas de calidad en la construcción o aspectos administrativos

The pros and cons of Journalism: the profession’s negative image in ten American films and its perception by the media in the United States and Spain

El cine sobre periodistas y medios de comunicación es un filón muy rico de la cultura cinematográfica norteamericana que casi se ha convertido en un subgénero. Para la docencia en las titulaciones de Periodismo donde se introducen es una excelente herramienta con la que mostrar a los futuros periodistas las grandezas y la miseria de la profesión que han grano menudo. Este artículo es fruto de la investigación que sobre el tratamiento de la profesión periodística en el cine, ha llevado a cabo el Observatorio de medios de comunicación de la Universidad Complutense de Madrid, bajo la dirección del autor. Analiza una selección de películas norteamericanas significativas, estrenadas entre 1937 y 1988, en las que el periodista y el medio aparecen retratados como villanos y no como unos héroes sociales. Se ocupa después del tratamiento que la prensa les dio en la última década del siglo XX y de cómo el periodista villano existe en la actualidad.The movies about journalists and media is a very rich mother lode of American film culture it has almost become a subgenus. For the teaching in the various degrees of Journalism is an excellent tool with which to show to future journalists the greatness and the misery of the profession they have chosen. This article is the result of the research on the treatment of the journalistic profession in the film, he has carried out the Observatory of means of communication from the Universidad Complutense de Madrid, under the direction of the author. Analyzes a selection of significant American films, which were released between 1937 and 1988 in which the journalist and the media portrayed as villains appear and not as some social heroes. After dealing with the treatment that the press gave them in the last decade of the twentieth century and how the journalist villain exists today

Valores y contravalores del periodismo: la imagen ética de la profesión en nueve películas americanas

El cine sobre periodistas y medios de comunicación es un filón muy rico de la cultura cinematográfica norteamericana que casi se ha convertido en un subgénero. Para la docencia en las titulaciones de Periodismo donde se introducen es una excelente herramienta con la que mostrar a los futuros periodistas las grandezas y la miseria de la profesión que han elegido. Este artículo es fruto de la investigación que sobre el tratamiento de la profesión periodística en el cine, ha llevado a cabo el Observatorio de medios de comunicación de la Universidad Complutense de Madrid , bajo la dirección del autor. Analiza una selección de películas norteamericanas significativas, estrenadas entre 1952 y 2008 en las que el periodista y el medio aparecen retratados como ideales, incluso como héroes sociales, bien siendo los protagonistas, bien dando réplica a un periodista o a un medio villano.The movies about journalists and media is a very rich mother lode of American film culture it has almost become a subgenus. For the teaching on the degree of journalism where entered is an excellent tool with which to show to future journalists the greatness and the misery of the profession they have often grain. This article is the result of the research on the treatment of the journalistic profession in the film, he has carried out the Observatory of Media, in the Universidad Complutense de Madrid , under the direction of the author. Analyzes a selection of significant American films, which were released between 1952 and 2008 in which the journalist and the media are portrayed as ideals, even as social heroes, well being the protagonists, either by giving reply to a journalist or a medium villain