2,563 research outputs found

    Towards concept identification using a knowledge-intensive approach

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    This paper presents a method for identifying concepts in microposts and classifying them into a predefined set of categories. The method relies on the DBpedia knowledge base to identify the types of the concepts detected in the messages. For those concepts that are not classified in the ontology we infer their types via the ontology properties which characterise the type

    Langevin theory of absorbing phase transitions with a conserved magnitude

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    The recently proposed Langevin equation, aimed to capture the relevant critical features of stochastic sandpiles, and other self-organizing systems is studied numerically. This equation is similar to the Reggeon field theory, describing generic systems with absorbing states, but it is coupled linearly to a second conserved and static (non-diffusive) field. It has been claimed to represent a new universality class, including different discrete models: the Manna as well as other sandpiles, reaction-diffusion systems, etc. In order to integrate the equation, and surpass the difficulties associated with its singular noise, we follow a numerical technique introduced by Dickman. Our results coincide remarkably well with those of discrete models claimed to belong to this universality class, in one, two, and three dimensions. This provides a strong backing for the Langevin theory of stochastic sandpiles, and to the very existence of this new, yet meagerly understood, universality class.Comment: 4 pages, 3 eps figs, submitted to PR

    The importance of perceived service quality in banking loyalty for large business customers

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    El comportamiento de las grandes empresas no financieras a la hora de seleccionar aquel que será su banco principal y el grado de fidelidad al mismo, es una cuestión a la que se ha prestado hasta ahora muy poca atención. La mayor parte de las empresas portuguesas que componen nuestra muestra, señala que trabaja con más de 5 bancos y se observa una relación positiva entre tamaño de la empresa y el número de bancos con los que opera, por lo que la competencia por el cliente aumenta, de ahí la relevancia de profundizar en la justificación de la elección del banco principal. Demostramos que el grado de fidelización al banco principal depende de la calidad percibida que se tenga del mismo, que es de carácter unidimensional, y es explicada por la variedad de productos, fiabilidad del servicio y la relación con el responsable de la sucursal que lleva su cuenta. En cambio, ni las condiciones de precio, de capacidad de respuesta de los empleados, ni el tipo de sucursal, intervienen significativamente. Este resultado puede ayudar a orientar eficazmente las estrategias de fidelización de las entidades financieras hacía sus clientes corporativos de mayor dimensió

    Desarrollo de un modelo de los datos logico de abastecimiento de apoyo a la gestion, para hospitales publicos basado en el Hospital Base de Curico

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    106 p.A continuación, esta memoria presentara los pasos que se deben realizar para llegar a obtener un Modelo de Datos Lógico del gran Sistema de Abastecimiento que poseen los Hospitales Públicos, para el cual se tomo como entidad de referencia al Hospital Base de Curico. Esta organización deposito su confianza y fe en este Proyecto, y tuvo la gentileza de abrir sus puertas para poder incursionar en un área muy importante como la de Abastecimiento. De este modo, gracias al Hospital Base de Curico, al Servicio de Salud del Maule y al Hospital Regional de Talca, se logro el desenlace de este Proyecto. La colaboración de los funcionarios de los establecimientos antes mencionados fue crucial para poder captar una realidad mas amplia de lo que ocurre en la actualidad con los procesos de Abastecimiento y su gestión dado que, si bien es cierto, los procesos deben ser los mismos, ya que, están regidos por las Normas de la Contraloría General de la Repdblica1. Sin embargo, la forma en que cada Hospital hace efectiva la labor de Abastecimiento es distinta, puesto que cada establecimiento realiza su gestión de la manera que cree mas conveniente para la organización. Fue así como a través del análisis y evaluación de estas gestiones, se propone en esta Memoria un Modelo que unificara a los distintos posibles métodos que existen, para cumplir con la misión de Abastecimiento, de modo que este modelo constaría con parte de ambas realidades y podría ser aplicado por cada Hospital de acuerdo a su propio estilo de Gestión

    Semejanzas y diferencias entre dos estaciones aerobiológicas

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    XV lnternational A.P.L.E. Symposium of Palynolog

    The colored Hanbury Brown--Twiss effect

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    The Hanbury Brown--Twiss effect is one of the celebrated phenomenologies of modern physics that accommodates equally well classical (interferences of waves) and quantum (correlations between indistinguishable particles) interpretations. The effect was discovered in the late thirties with a basic observation of Hanbury Brown that radio-pulses from two distinct antennas generate signals on the oscilloscope that wiggle similarly to the naked eye. When Hanbury Brown and his mathematician colleague Twiss took the obvious step to propose bringing the effect in the optical range, they met with considerable opposition as single-photon interferences were deemed impossible. The Hanbury Brown--Twiss effect is nowadays universally accepted and, being so fundamental, embodies many subtleties of our understanding of the wave/particle dual nature of light. Thanks to a novel experimental technique, we report here a generalized version of the Hanbury Brown--Twiss effect to include the frequency of the detected light, or, from the particle point of view, the energy of the detected photons. In addition to the known tendencies of indistinguishable photons to arrive together on the detector, we find that photons of different colors present the opposite characteristic of avoiding each others. We postulate that fermions can be similarly brought to exhibit positive (boson-like) correlations by frequency filtering.Comment: 18 pages, includes supplementary material of the derivation

    Evolutionary Computation on Road Safety

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    This study examines the psychological research that focuses on road safety in Smart Cities as proposed by the Vulnerable Road Users (VRUs) sphere. It takes into account qualities such as VRUs’ personal information, their habits, environmental measurements and things data. With the goal of seeing VRUs as active and proactive actors with differentiated feelings and behaviours, we are committed to integrating the social factors that characterize each VRU into our social machinery. As a result, we will focus on the development of a VRU Social Machine to assess VRUs’ behaviour in order to improve road safety. The formal background will be to use Logic Programming to define its architecture based on a Deep Learning approach to Knowledge Representation and Reasoning, complemented with an Evolutionary approach to Computing

    Sandpiles with height restrictions

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    We study stochastic sandpile models with a height restriction in one and two dimensions. A site can topple if it has a height of two, as in Manna's model, but, in contrast to previously studied sandpiles, here the height (or number of particles per site), cannot exceed two. This yields a considerable simplification over the unrestricted case, in which the number of states per site is unbounded. Two toppling rules are considered: in one, the particles are redistributed independently, while the other involves some cooperativity. We study the fixed-energy system (no input or loss of particles) using cluster approximations and extensive simulations, and find that it exhibits a continuous phase transition to an absorbing state at a critical value zeta_c of the particle density. The critical exponents agree with those of the unrestricted Manna sandpile.Comment: 10 pages, 14 figure

    Identifying Topics in Social Media Posts using DBpedia

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    This paper describes a method for identifying topics in text published in social media, by applying topic recognition techniques that exploit DBpedia. We evaluate such method for social media in Spanish and we provide the results of the evaluation performed
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