6,643 research outputs found

    DC-Prophet: Predicting Catastrophic Machine Failures in DataCenters

    Full text link
    When will a server fail catastrophically in an industrial datacenter? Is it possible to forecast these failures so preventive actions can be taken to increase the reliability of a datacenter? To answer these questions, we have studied what are probably the largest, publicly available datacenter traces, containing more than 104 million events from 12,500 machines. Among these samples, we observe and categorize three types of machine failures, all of which are catastrophic and may lead to information loss, or even worse, reliability degradation of a datacenter. We further propose a two-stage framework-DC-Prophet-based on One-Class Support Vector Machine and Random Forest. DC-Prophet extracts surprising patterns and accurately predicts the next failure of a machine. Experimental results show that DC-Prophet achieves an AUC of 0.93 in predicting the next machine failure, and a F3-score of 0.88 (out of 1). On average, DC-Prophet outperforms other classical machine learning methods by 39.45% in F3-score.Comment: 13 pages, 5 figures, accepted by 2017 ECML PKD

    Characterizing stellar populations in spiral disks

    Full text link
    It is now possible to measure detailed spectral indices for stellar populations in spiral disks. We propose to interpret these data using evolutionary synthesis models computed from the Star Formation Histories obtained from chemical evolutionary models. We find that this technique is a powerful tool to discriminate between old and young stellar populations. We show an example of the power of Integral Field spectroscopy in unveiling the spatial distribution of populations in a barred galaxy.Comment: 5 pages, to be published in "Science Perspectives for 3D Spectroscopy", Eds. M. Kissler-Patig, M.M. Roth and J.R. Walsh (Springer-Verlag, ESO astrophysics symposia series

    New objects in old structures: The Iron Age hoard of the Palacio III megalithic funerary complex (Almadén de la Plata, Seville, Spain)

    Get PDF
    Cultural contact, exchange and interaction feature high in the list of challenging topics of current research on European Prehistory. Not far off is the issue of the changing role of monuments in the making and maintaining of key cultural devices such as memory and identity. Addressing both these highly-debated issues from a science-based perspective, in this paper we look at an unusual case study set in southern Iberia and illustrate how these archaeological questions can benefit from robust materials-science approaches.We present the contextual, morphological and analytical study of an exceptional Early Iron Age hoard composed of a number of different (and mostly exotic) materials such as amber, quartz, silver and ceramic. This hoard, found under the fallen orthostat of a megalithic structure built at least 2000 years earlier, throws new light on long-distance exchange networks and the effect they could have had on the cultural identities and social relations of local Iberian Early Iron Age communities. Moreover, the archaeometric study reveals how diverse and distant the sources of these item are (Northern Europe to Eastern and Western Mediterranean raw materials, as well as local and eastern technologies), therefore raising questions concerning the social mechanisms used to establish change and resistance in contexts of colonial encounter

    The Offline Software Framework of the Pierre Auger Observatory

    Full text link
    The Pierre Auger Observatory is designed to unveil the nature and the origins of the highest energy cosmic rays. The large and geographically dispersed collaboration of physicists and the wide-ranging collection of simulation and reconstruction tasks pose some special challenges for the offline analysis software. We have designed and implemented a general purpose framework which allows collaborators to contribute algorithms and sequencing instructions to build up the variety of applications they require. The framework includes machinery to manage these user codes, to organize the abundance of user-contributed configuration files, to facilitate multi-format file handling, and to provide access to event and time-dependent detector information which can reside in various data sources. A number of utilities are also provided, including a novel geometry package which allows manipulation of abstract geometrical objects independent of coordinate system choice. The framework is implemented in C++, and takes advantage of object oriented design and common open source tools, while keeping the user side simple enough for C++ novices to learn in a reasonable time. The distribution system incorporates unit and acceptance testing in order to support rapid development of both the core framework and contributed user code.Comment: 4 pages, 2 figures, presented at IEEE NSS/MIC, 23-29 October 2005, Puerto Ric

    A note on the rare decay of a Higgs boson into photons and a ZZ boson

    Full text link
    We have calculated the width of the rare decay H→γγZH\to\gamma\gamma Z at one-loop level in the standard model for Higgs boson masses in the range 115GeV≤mH≤160GeV115 {\rm GeV} \leq m_H \leq 160 {\rm GeV} . For this range of Higgs boson masses we find that ZZ boson is predominantly longitudinally polarized, and the photons have the same helicity. A comparison of the decay width Γ(H→γγZ)\Gamma(H\to \gamma\gamma Z) to those of H→γγH\to\gamma\gamma and H→γZH\to\gamma Z shows that, for the Higgs boson mass of mH∼135GeVm_H \sim 135 \rm{GeV}, the ratios of the decay widths are Γ(H→γγZ)/Γ(H→γγ)∼Γ(H→γγZ)/Γ(H→γZ)∼10−5−10−6\Gamma(H\to\gamma\gamma Z) / \Gamma(H\to\gamma\gamma) \sim \Gamma(H\to\gamma\gamma Z) / \Gamma(H\to\gamma Z) \sim 10^{-5}-10^{-6}.Comment: 4 pages, 5 figures, RevTe

    The involvement of Nrf2 in depression: systematic review of preclinical studies

    Get PDF
    Increased levels of pro-inflammatory cytokines and decreased antioxidant defenses are likely to be linked to the development of depressive symptoms. Nrf2 plays an important role in cellular defense against oxidative stress and binds to ARE, which is located in the promoter region of several phase II antioxidant enzymes and associated stress-responsive enzymes. Reduced Keap1-Nrf2 signaling is implicated in the pathogenesis of mood disorders such as Major Depressive Disorder (MDD).info:eu-repo/semantics/publishedVersio
    • …
    corecore