645 research outputs found
Experiencias con el uso del GHQ en un dispensario de reumatología
A partir de nuestra experiencia con la administración sistemática de un cuestionario en una consulta de una especialidad médica exponemos en esta comunicación en primer lugar los resultados de dicha administración y las conclusiones clinicas que creemos poder extraer de ellos y en segundo lugar los efectos de dicha administración en la relación medico-enfermo (incluidos los aspectos de dinámica del equipo médico y relación médico-institución y enfermo-institución) y las ventajas y peligros que creemos que pueden de- ducirse de nuestra experiencia. Desde hace cinco años uno de nosotros colabora con un equipo de reumatólogos en el Hospital de la Cruz Roja de Barcelona (Servicio de Reuma- tologia, Dir. Dr. M. Casademont) en la atención de 10s pacientes que acuden a la consulta de reumatologia de dicho hospital
Clearing algorithms and network centrality
I show that the solution of a standard clearing model commonly used in
contagion analyses for financial systems can be expressed as a specific form of
a generalized Katz centrality measure under conditions that correspond to a
system-wide shock. This result provides a formal explanation for earlier
empirical results which showed that Katz-type centrality measures are closely
related to contagiousness. It also allows assessing the assumptions that one is
making when using such centrality measures as systemic risk indicators. I
conclude that these assumptions should be considered too strong and that, from
a theoretical perspective, clearing models should be given preference over
centrality measures in systemic risk analyses
On the Computational Complexity of Measuring Global Stability of Banking Networks
Threats on the stability of a financial system may severely affect the
functioning of the entire economy, and thus considerable emphasis is placed on
the analyzing the cause and effect of such threats. The financial crisis in the
current and past decade has shown that one important cause of instability in
global markets is the so-called financial contagion, namely the spreading of
instabilities or failures of individual components of the network to other,
perhaps healthier, components. This leads to a natural question of whether the
regulatory authorities could have predicted and perhaps mitigated the current
economic crisis by effective computations of some stability measure of the
banking networks. Motivated by such observations, we consider the problem of
defining and evaluating stabilities of both homogeneous and heterogeneous
banking networks against propagation of synchronous idiosyncratic shocks given
to a subset of banks. We formalize the homogeneous banking network model of
Nier et al. and its corresponding heterogeneous version, formalize the
synchronous shock propagation procedures, define two appropriate stability
measures and investigate the computational complexities of evaluating these
measures for various network topologies and parameters of interest. Our results
and proofs also shed some light on the properties of topologies and parameters
of the network that may lead to higher or lower stabilities.Comment: to appear in Algorithmic
A High Dynamic Range ASIC for Time of Flight PET with monolithic crystals
The HRFlexToT is a 16-channel ASIC for SiPM anode readout designed for Positron Emission Tomography (PET) applications that features high dynamic range (>8 bits), low input impedance, common cathode connection, high speed and low power (~3.5 mW/ch). The ASIC has been manufactured using XFAB 0.18 mm CMOS technology. The main characteristics of the HRFlexToT, compared to its predecessor, are a new energy measurement readout providing a linear Time Over Threshold (ToT) with an extended dynamic range, lower power consumption and better timing response. Initial measurements show a linearity error below 3%. Single Photon Time Resolution (SPTR) measurements performed using a Hamamatsu MPPC S13360-3050CS (3x3 mm2 pixel, 50 umm cell) shows 30% improvement with respect to the previous version of the ASIC, setting this specification in the order of 141 ps FWHM and reducing 3 times power consumption. It is important to highlight that an SPTR of 141 ps FWHM is, according to the best of our knowledge, the best resolution achieved so far for this sensor. Coincidence Time Resolution (CTR) measurements are expected to be performed during 2018
The Cherenkov Telescope Array Large Size Telescope
The two arrays of the Very High Energy gamma-ray observatory Cherenkov
Telescope Array (CTA) will include four Large Size Telescopes (LSTs) each with
a 23 m diameter dish and 28 m focal distance. These telescopes will enable CTA
to achieve a low-energy threshold of 20 GeV, which is critical for important
studies in astrophysics, astroparticle physics and cosmology. This work
presents the key specifications and performance of the current LST design in
the light of the CTA scientific objectives.Comment: 4 pages, 5 figures, In Proceedings of the 33rd International Cosmic
Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at
arXiv:1307.223
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