12,771 research outputs found

    Test-bed of a real time detection system for L/H and H/L transitions implemented with the ITMS platform

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    A basic requirement of the data acquisition systems used in long pulse fusion experiments is to detect events of interest in the acquired signals in real time. Developing such applications is usually a complex task, so it is necessary to develop a set of hardware and software tools that simplify their implementation. An example of these tools is the Intelligent Test and Measurement System (ITMS), which offers distributed data acquisition, distribution and real time processing capabilities with advanced, but easy to use, software tools that simplify application development and system setup. This paper presents the application of the ITMS platform to solve the problem of detecting L/H and H/L transitions in real time based on the use of efficient pattern recognition algorithms

    Ley chilena de tolerancia cero al alcohol: fortalezas, falencias y carencias que no deben ser obviadas.

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    Carnevali, R (Carnevali, Raul).Univ Talca, Ctr Estudios Derecho Penal, Fac Ciencias Jurid & Sociales, Santiago, ChileChile has recently entered into force Act No. 20.580, which modifies the legal limits of blood alcohol concentration in drivers and increases the penalties for driving under the influence of alcohol, narcotics or psychotropic substances. The aim of this review was to give an account of the strengths of this new law but, at the same time, to alert the scientific and legal community about its flaws. We also present some shortcomings of Chilean regulatory framework that remain uncorrected, those that should be considered in the design of public policies for improving road safety and the criteria that judges should ponder during judgment, to determine either conviction or acquittal. (Rev Med Chile 2012; 140: 939-945)

    No surviving evolved companions to the progenitor of supernova SN 1006

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    Type Ia supernovae are thought to occur as a white dwarf made of carbon and oxygen accretes sufficient mass to trigger a thermonuclear explosion1^{1}. The accretion could occur slowly from an unevolved (main-sequence) or evolved (subgiant or giant) star2,3^{2,3}, that being dubbed the single-degenerate channel, or rapidly as it breaks up a smaller orbiting white dwarf (the double- degenerate channel)3,4^{3,4}. Obviously, a companion will survive the explosion only in the single-degenerate channel5^{5}. Both channels might contribute to the production of type Ia supernovae6,7^{6,7} but their relative proportions still remain a fundamental puzzle in astronomy. Previous searches for remnant companions have revealed one possible case for SN 15728,9^{8,9}, though that has been criticized10^{10}. More recently, observations have restricted surviving companions to be small, main-sequence stars11,12,13^{11,12,13}, ruling out giant companions, though still allowing the single-degenerate channel. Here we report the result of a search for surviving companions to the progenitor of SN 100614^{14}. None of the stars within 4' of the apparent site of the explosion is associated with the supernova remnant, so we can firmly exclude all giant and subgiant companions to the progenitor. Combined with the previous results, less than 20 per cent of type Iae occur through the single degenerate channel.Comment: Published as a letter in Nature (2012 September 27

    No surviving companion in Kepler's supernova

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    We have surveyed Kepler's supernova remnant in search of the companion star of the explosion. We have gone as deep as 2.6 solar luminosities in the stars within 20% of the radius of the remnant. We use FLAMES at the VLT-UT2 telescope to obtain high resolution spectra of the stellar candidates selected from HST images. The resulting set of stellar parameters suggests that these stars come from a rather ordinary mixture of field stars (mostly giants). A few of the stars seem to have low [Fe/H] (< -1) and they are consistent with being metal-poor giants. The radial velocities and rotational velocities vrot sin i are very well determined. There are no fast rotating stars as vrot sin i < 20 km/s. The radial velocities from the spectra and the proper motions determined from HST images are compatible with those expected from the Besan\c{c}on model of the Galaxy. The strong limits placed on luminosity suggest that this supernova could have arisen either from the core-degenerate scenario or from the double-degenerate scenario.Comment: ApJ accepted, 7 figures and 7 table

    Analysis of CMB maps with 2D wavelets

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    We consider the 2D wavelet transform with two scales to study sky maps of temperature anisotropies in the cosmic microwave background radiation (CMB). We apply this technique to simulated maps of small sky patches of size 12.8 \times 12.8 square degrees and 1.5' \times 1.5' pixels. The relation to the standard approach, based on the cl's is established through the introduction of the scalogram. We consider temperature fluctuations derived from standard, open and flat-Lambda CDM models. We analyze CMB anisotropies maps plus uncorrelated Gaussian noise (uniform and non-uniform) at idfferent S/N levels. We explore in detail the denoising of such maps and compare the results with other techniques already proposed in the literature. Wavelet methods provide a good reconstruction of the image and power spectrum. Moreover, they are faster than previously proposed methods.Comment: latex file 7 pages + 5 postscript files + 1 gif file; accepted for publication in A&A
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