15,233 research outputs found

    Infrared (IR) Sensors applied to Fire detection and to people’s safety

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    The IR Imaging and Remote Sensing Laboratory – LIR-UC3M of Universidad Carlos III, has developed IR multi and hyper spectral analysis techniques for passive (no emitters) and reliable (low false alarm rate) threat sensing. Specifically, they are based on sensors development and spectral processing for classifying the scene to optimize the discrimination of threats from backgrounds, decoys or other spurious emitting sources, for a dramatic decrease of false alarm rate

    Multi and Hyper-spectral passive Infrared (IR) Sensors for reliable detection of threats

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    The IR Imaging and Remote Sensing Laboratory – LIR-UC3M of Universidad Carlos III, has developed IR multi and hyper spectral analysis techniques for passive (no emitters) and reliable (low false alarm rate) threat sensing. Specifically, they are based on sensors development and spectral processing for classifying the scene to optimize the discrimination of threats from backgrounds, decoys or other spurious emitting sources, for a dramatic decrease of false alarm rate

    Flux switching alternators for small wind generation

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    This paper considers the application of flux switching alternators for small wind generation. First, after a brief presentation of the small wind energy systems, a description and the fundamentals of flux switching machines is given, then the state of art of flux switching generators is presented. Finally a critical assessment is shown, considering the main advantages and drawbacks of this type of machines as alternator for use in small wind generation systems.Peer ReviewedPostprint (published version

    Amenability and paradoxicality in semigroups and C*-algebras

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    We analyze the dichotomy amenable/paradoxical in the context of (discrete, countable, unital) semigroups and corresponding semigroup rings. We consider also F{\o}lner's type characterizations of amenability and give an example of a semigroup whose semigroup ring is algebraically amenable but has no F{\o}lner sequence. In the context of inverse semigroups SS we give a characterization of invariant measures on SS (in the sense of Day) in terms of two notions: domaindomain measurabilitymeasurability and localizationlocalization. Given a unital representation of SS in terms of partial bijections on some set XX we define a natural generalization of the uniform Roe algebra of a group, which we denote by RX\mathcal{R}_X. We show that the following notions are then equivalent: (1) XX is domain measurable; (2) XX is not paradoxical; (3) XX satisfies the domain F{\o}lner condition; (4) there is an algebraically amenable dense *-subalgebra of RX\mathcal{R}_X; (5) RX\mathcal{R}_X has an amenable trace; (6) RX\mathcal{R}_X is not properly infinite and (7) [0][1][0]\not=[1] in the K0K_0-group of RX\mathcal{R}_X. We also show that any tracial state on RX\mathcal{R}_X is amenable. Moreover, taking into account the localization condition, we give several C*-algebraic characterizations of the amenability of XX. Finally, we show that for a certain class of inverse semigroups, the quasidiagonality of Cr(X)C_r^*\left(X\right) implies the amenability of XX. The converse implication is false.Comment: 29 pages, minor corrections. Mistake in the statement of Proposition 4.19 from previous version corrected. Final version to appear in Journal of Functional Analysi

    The contrastive value of lexical stress in visual word recognition: Evidence from spanish

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    Resumen tomado de la publicaciónEl valor contrastivo del acento léxico en el reconocimiento visual de palabras: evidencia del español. Antecedentes: muchos pares de palabras en español, en particular muchas formas verbales, difieren solo en la sílaba acentuada, tal como aNImo y aniMÓ. Así el acento puede adquirir un valor contrastivo que fue confirmado por Dupoux, Pallier, Sebastian y Mehler (1997) en español, pero no en francés, en percepción auditiva. Método: este estudio contrasta el efecto de primado en pares de palabras que difieren en su patrón de acentuación con el efecto de repetición, el primado solo de acento (sin relación ortográfica) y el primado morfológico en reconocimiento visual de palabras. Resultados: usando priming enmascarado se obtuvo facilitación para los pares con diferente acento (rasGÓ/RASgo) comparando con los pares sin relación (dorMÍ/RASgo), pero no se produjo comparando con los no relacionados de igual acento (PERsa/RASgo). Sin embargo, los pares idénticos (RASgo-RASgo) produjeron facilitación comparando con ambas condiciones ortográficamente relacionadas. Con un SOA largo los pares con diferente acento (ortográficamente iguales) produjeron una facilitación significativa, como ocurrió con los pares relacionados morfológicos (RASga/RASgo), sobre los pares ortográficamente diferentes (PERsa/RASgo). Conclusión: estos resultados confirman la importancia del procesamiento temprano y preléxico del acento para la selección léxica en español, como ocurre con las características ortográficas y fonológicas de las palabras.Universidad de Oviedo. Biblioteca de Psicología; Plaza Feijoo, s/n.; 33003 Oviedo; Tel. +34985104146; Fax +34985104126; [email protected]

    Financial Market Models for the Grid

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    The existing network of computing devices around the world created by the Internet gives the possibility of establishing a global market for computing power, where anybody connected to this network can acquire computing power or sell his own spare computing resources in exchange for real money. This potential global market for computing power, which does not exist yet, is what we study in this thesis. Specifically, we study the market with both analytic and simulated models. This thesis predicts how a future global market for Grid computing will behave. We give arguments that such a large market, together with its potential indefinite growth, would not be able to scale if it were organized with a central server, and therefore we study a peer-to-peer market model in our simulations. We create a high-level model with the most relevant characteristics of the market, where buyers and sellers trade a single commodity. In our simulations, the parameters of the volume of contracts, proportion of satisfied agents and number of messages in the network achieve stable values in the long run. We also derive analytically the conditions that make the price get stable over time; we then implement these conditions in the simulation as local mechanisms of the market participants, which make the whole system achieve a stable price evolution. We are also confident that, as soon as the Grid market emerges, a parallel market of derivatives will be created as well. This market of derivatives will be important due to the non-storability nature of computing power. We develop a futures market for computing power based on Markov chains, where we initially model the behaviour of each participant with a particular Markov chain, and then we derive a global transition probability matrix that models the market as a whole. Furthermore, we analyse the performance of a futures trader operating in such a market, and we obtain an optimal trading strategy with the use of Markov Decision Processes. We finally develop a stochastic differential equation model that captures the essence of the spot price evolution of computing power observed in our market simulations. This model is based on a previously one proposed for the electricity market, and consists of the use of a Markov regime-switching mechanism in order to model the existence of spikes in the spot price. We then estimate the parameters in the model with the output data of our simulation program; the estimation is carried out both by maximum likelihood and the generalised method of moments

    On the testability of WCAG 2.0 for beginners

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    Web accessibility for people with disabilities is a highly visible area of research in the field of ICT accessibility, including many policy activities across many countries. The commonly accepted guidelines for web accessibility (WCAG 1.0) were published in 1999 and have been extensively used by designers, evaluators and legislators. W3C-WAI published a new version of these guidelines (WCAG 2.0) in December 2008. One of the main goals of WCAG 2.0 was testability, that is, WCAG 2.0 should be either machine testable or reliably human testable. In this paper we present an educational experiment performed during an intensive web accessibility course. The goal of the experiment was to assess the testability of the 25 level-A success criteria of WCAG 2.0 by beginners. To do this, the students had to manually evaluate the accessibility of the same web page. The result was that only eight success criteria could be considered to be reliably human testable when evaluators were beginners. We also compare our experiment with a similar study published recently. Our work is not a conclusive experiment, but it does suggest some parts of WCAG 2.0 to which special attention should be paid when training accessibility evaluator

    Debiasing EQ-5D Tariffs. New estimations of the spanish EQ-5D value set under nonexpected utility

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    Este proyecto tiene como objetivo estimar las utilidades asociadas a los estados de salud definidos mediante el sistema EuroQol-5D a partir de la medición directa de las preferencias de una muestra de la población andaluza. Los valores obtenidos serán susceptibles de ser utilizados en el marco de estudios de evaluación económica de políticas sanitarias (análisis coste-utilidad) realizados en la comunidad andaluza y en el conjunto del estado. Para la valoración directa de un subconjunto de estados de salud se realizará una encuesta personal asistida por ordenador a una muestra representativa por sexo y cuotas de edad de la población española, extraída de la población residente en Andalucía. Los métodos que se aplicarán para obtener las preferencias y calcular las utilidades tratarán de corregir algunos de los sesgos que pueden afectar a las estimaciones existentes. Así, se adoptarán enfoques teóricos alternativos a los habitualmente empleados que permitirán relajar algunos de los supuestos que han sido puestos en cuestión a la luz de la evidencia empírica, como es el caso de la linealidad de la función de utilidad del tiempo de vida, la validez descriptiva de la teoría de la utilidad esperada o la separabilidad multiplicativa de las preferencias por cantidad y calidad de vida.EQ-5D, social tariff, utility curvature, probability weighting, rank-dependent utility, time trade-off, value lottery equivalence, certainlty equivalence

    Improved electromagnetic compatibility standards for the interconnected wireless world

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    © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The future is wireless, a world where everything is interconnected. However, the current standards for ensuring the electromagnetic compatibility (EMC) and the coexistence of such wireless systems urge for a major update. It is shown how novel statistical approaches based on the amplitude probability distribution detector and time-domain measurements are better suited for estimating the degradation caused by electromagnetic interferences on digital communication systems than the established practice of determining compliance according to the quasi-peak detector levels using a pass/fail criterion. Therefore, a redefinition of the test methods and of the compliance requirements in terms of EMC standards must be a priority of the international standardization bodies. Finally, a discussion of the fundamental challenges involved in this standardization breakthrough for EMC is delivered.Postprint (author's final draft
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