For heavy tails, classical extreme value index estimators, like the Hill estimator, are usually asymptotically biased. Consequently those estimators are quite sensitive to the number of top order statistics used in the estimation. The recent minimum-variance reduced-bias extreme value index estimators enable us to remove the dominant component of asymptotic bias and keep the asymptotic variance of the new estimators equal to the asymptotic variance of the Hill estimator. In this paper a new minimum-variance reduced-bias extreme value index estimator is introduced, and its non degenerate asymptotic behaviour is studied. A comparison with another important minimum-variance reduced-bias extreme value index estimator is also provided.For heavy tails, classical extreme value index estimators, like the Hill estimator, are usually asymptotically biased. Consequently those estimators are quite sensitive to the number of top order statistics used in the estimation. The recent minimum-variance reduced-bias extreme value index estimators enable us to remove the dominant component of asymptotic bias and keep the asymptotic variance of the new estimators equal to the asymptotic variance of the Hill estimator. In this paper a new minimum-variance reduced-bias extreme value index estimator is introduced, and its non degenerate asymptotic behaviour is studied. A comparison with another important minimum-variance reduced-bias extreme value index estimator is also provided.

Apresentam-se e analisam-se um conjunto de ensaios realizados em vigas de betão armado reforçadas com armaduras pós-instaladas de aço ou de FRP, incluindo os referentes a uma nova técnica (CREatE) desenvolvida na FCT NOVA, tendo-se concluído que a técnica CREatE possibilita aumentos de resistência e ductilidade consideráveis face às técnicas tradicionais.

http://docentes.fct.unl.pt/lblm/files/jacs-2016-138-8834.pdf

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The focus of the following article is on the use of new robotic systems in the manufacturing industry with respect to the social dimension. Since “intuitive” human–machine interaction (HMI) in robotic systems becomes a significant objective of technical progress, new models of work organization are needed. This hypothesis will be investigated through the following two aims: The first aim is to identify relevant research questions related to the potential use of robotic systems in different systems of work organization at the manufacturing shop-floor level. The second aim is to discuss the conceptualization of (old) organizational problems of human–robot interaction (HRI). In this context, the article reflects on the limits of cognitive and perceptual workload for robot operators in complex working systems. This will be particularly relevant whenever more robots with different “roles” are to be increasingly used in the manufacturing industry. The integration of such complex socio-technical systems needs further empirical and conceptual research with regard to “social” aspects of the technical dimension. Future research should, therefore, also integrate economic and societal issues to understand the full dimensions of new human–robot interaction in industry today.

Large-area electronics for applications in environments with radioactive contamination or medical X-ray detectors require materials and devices resistant to continuous ionizing radiation exposure. Here the superior X-ray radiation hardness of oxide thin film transistors (TFTs) based on gallium-indium-zinc oxide is demonstrated, when compared to organic ones. In the experiments both TFTs are subjected to X-ray radiation and their performances are monitored as a function of total ionizing dose. Flexible oxide TFTs maintain a constant mobility of 10 cm2 V−1 s−1 even after exposure to doses of 410 krad(SiO2), whereas organic TFTs lose 55% of their transport performance. The exceptional resistance of oxide semiconductors ionization damage is attributed to their intrinsic properties such as independence of transport on long-range order and large heat of formation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Presentamos en este trabajo un estudio realizado en dos escuelas públicas, una en Brasil y otra en Portugal, sobre el potencial integrador de la robótica virtual y tangible. El enfoque metodológico se mezcló y se basó en dos talleres de capacitación de profesores sobre el potencial integrador de estas dos herramientas. Los participantes fueron cuatro profesores y cuatro estudiantes con necesidades educativas especiales. Se aplicó un cuestionario a los estudiantes y profesores que participaron en los talleres de formación y se procedió a la descripción de las actividades. Los resultados indicaron que las dos herramientas obtuvieron evaluaciones similares, que tienen potencial educativo e integrador, ya que permiten suavizar las diferencias y promover la cooperación y el aprendizaje de modo activo y significativo, a través de actividades lúdicas y divertidas para los estudiantes.

Physica Scripta, 90(2015) 054009. doi:10.1088/0031-8949/90/5/054009

In this article, we revisit Feuerverger and Halls maximum likelihood estimation of the extreme value index. Based on those estimators we propose new estimators that have the smallest possible asymptotic variance, equal to the asymptotic variance of the Hill estimator. The full asymptotic distributional properties of the estimators are derived under a general third-order framework for heavy tails. Applications to a real data set and to simulated data are also presented.In this article, we revisit Feuerverger and Halls maximum likelihood estimation of the extreme value index. Based on those estimators we propose new estimators that have the smallest possible asymptotic variance, equal to the asymptotic variance of the Hill estimator. The full asymptotic distributional properties of the estimators are derived under a general third-order framework for heavy tails. Applications to a real data set and to simulated data are also presented.

The present work reports a simple and easy wet chemistry synthesis of cuprous oxide (Cu2O) nanospheres at room temperature without surfactants and using different precursors. Structural characterization was carried out by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy coupled with focused ion beam and energy-dispersive X-ray spectroscopy. The optical band gaps were determined from diffuse reflectance spectroscopy. The photoluminescence behavior of the as-synthesized nanospheres showed significant differences depending on the precursors used. The Cu2O nanospheres were constituted by aggregates of nanocrystals, in which an on/off emission behavior of each individual nanocrystal was identified during transmission electron microscopy observations. The thermal behavior of the Cu2O nanospheres was investigated with in situ X-ray diffraction and differential scanning calorimetry experiments. Remarkable structural differences were observed for the nanospheres annealed in air, which turned into hollow spherical structures surrounded by outsized nanocrystals. FAU - Nunes, Daniela

In this paper we consider various classes of monoids of transformations of a finite chain,
including those of transformations that preserve or reverse either the order or the orientation.
In line with Howie and McFadden (1990),
we complete the study of the ranks (and of idempotent ranks, when applicable) of all their ideals.