1,971 research outputs found

    Some results on the eigenfunctions of the quantum trigonometric Calogero-Sutherland model related to the Lie algebra E6

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    The quantum trigonometric Calogero-Sutherland models related to Lie algebras admit a parametrization in which the dynamical variables are the characters of the fundamental representations of the algebra. We develop here this approach for the case of the exceptional Lie algebra E6.Comment: 17 pages, no figure

    A New Fast Motion Estimation and Mode Decision algorithm for H.264 Depth Maps encoding in Free Viewpoint TV

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    In this paper, we consider a scenario where 3D scenes are modeled through a View+Depth representation. This representation is to be used at the rendering side to generate synthetic views for free viewpoint video. The encoding of both type of data (view and depth) is carried out using two H.264/AVC encoders. In this scenario we address the reduction of the encoding complexity of depth data. Firstly, an analysis of the Mode Decision and Motion Estimation processes has been conducted for both view and depth sequences, in order to capture the correlation between them. Taking advantage of this correlation, we propose a fast mode decision and motion estimation algorithm for the depth encoding. Results show that the proposed algorithm reduces the computational burden with a negligible loss in terms of quality of the rendered synthetic views. Quality measurements have been conducted using the Video Quality Metric

    Succession : the key to company survival

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    An XMM-Newton view of FeK{\alpha} in HMXBs

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    We present a comprehensive analysis of the whole sample of available XMM-Newton observations of High Mass X-ray Binaries (HMXBs) until August, 2013, focusing on the FeK{\alpha} emission line. This line is a key tool to better understand the physical properties of the material surrounding the X-ray source within a few stellar radii (the circumstellar medium). We have collected observations from 46 HMXBs, detecting FeK{\alpha} in 21 of them. We have used the standard classification of HMXBs to divide the sample in different groups. We find that: (1) FeK{\alpha} is centred at a mean value of 6.42 keV. Considering the instrumental and fits uncertainties, this value is compatible with ionization states lower than FeXVIII. (2) The flux of the continuum is well correlated with the flux of the line, as expected. Eclipse observations show that the Fe fluorescence emission comes from an extended region surrounding the X-ray source. (3) FeK{\alpha} is narrow (width lower than 0.15keV), reflecting that the reprocessing material does not move at high speeds. We attempt to explain the broadness of the line in terms of three possible broadening phenomena: line blending, Compton scattering and Doppler shifts (with velocities of the reprocessing material V=1000-2000 km/s). (4) The equivalent hydrogen column (NH) directly correlates with the EW of FeK{\alpha}, displaying clear similarities to numerical simulations. It highlights the strong link between the absorbing and the fluorescent matter. The obtained results clearly point to a very important contribution of the donors wind in the FeK{\alpha} emission and the absorption when the donor is a supergiant massive star.Comment: Accepted for publication in A&A. 13 pages, 16 figures + Appendice

    On an approach for computing the generating functions of the characters of simple Lie algebras

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    We describe a general approach to obtain the generating functions of the characters of simple Lie algebras which is based on the theory of the quantum trigonometric Calogero-Sutherland model. We show how the method works in practice by means of a few examples involving some low rank classical algebras

    Los hospitales docentes en la España contemporånea

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    Desde el siglo XVIII se produjo un avance significativo en la función docente del hospital en Europa y en América del norte. La unificación entre la medicina y la cirugía y la integración de pråcticas clínicas en los planes de estudio médicos generaron la necesidad de vincular las facultades de medicina a uno o varios hospitales. España se incorporó a este proceso progresiva y tardíamente con sus propias particularidades. El objetivo del artículo es presentar una primera aproximación a la historia de los hospitales clínicos universitarios, haciendo especial hincapié en la etapa en la que fueron gestionados por el Ministerio de Educación. Desde un punto de vista político se podrå observar cómo se establecen y desarrollan las relaciones entre las instituciones locales y el Estado central a la hora de gestionar la estructura hospitalaria en el país, y, en concreto, los hospitales docentes.From the 18th century onwards, there were major developments in the teaching function of hospitals in Europe and North America. The unification of medicine and surgery and the integration of clinical practice into the curricula of medical studies created the need to link schools of medicine to hospitals. Spain only joined this process gradually and belatedly and with its own peculiarities. The aim of this article was to outline the history of teaching hospitals in Spain, particularly the university clinical hospitals managed by the Ministry of Education. The study also focuses on political aspects of the issue, especially the establishment and development of the relationship between local institutions and the central state in managing the country's hospital system in general and teaching hospitals in particular
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