496 research outputs found

    Stretching the capacity of Hardware Transactional Memory in IBM POWER architectures

    Full text link
    The hardware transactional memory (HTM) implementations in commercially available processors are significantly hindered by their tight capacity constraints. In practice, this renders current HTMs unsuitable to many real-world workloads of in-memory databases. This paper proposes SI-HTM, which stretches the capacity bounds of the underlying HTM, thus opening HTM to a much broader class of applications. SI-HTM leverages the HTM implementation of the IBM POWER architecture with a software layer to offer a single-version implementation of Snapshot Isolation. When compared to HTM- and software-based concurrency control alternatives, SI-HTM exhibits improved scalability, achieving speedups of up to 300% relatively to HTM on in-memory database benchmarks

    The detection of non-thermal radio continuum spokes and the study of star formation in the Cartwheel

    Full text link
    New sensitive Very Large Array 20 cm continuum observations of the Cartwheel, the prototypical collisional ring galaxy, were carried out with the principal aim of tracing supernova remnants that are expected to lie in the wake of the expanding ring and in the ring itself. We detect predominantly non-thermal radio continuum emission from regions associated with 13 ring HII complexes. The emission interior to the ring is confined to structures that resemble spokes of the wheel. The spokes start near bright HII complexes, and extend to around 6 arcsec (4 kpc) inward in the direction of the geometrical center of the ring. There is no apparent positional coincidence between the radio continuum and optical spokes. Radial distribution of intensity along the spokes suggests that the past star formation rate (SFR) in the Cartwheel was much lower than the current SFR. New Halpha observations were used to revise the current SFR in the Cartwheel. The revised value is 18 Msun/yr, which is a factor of 4 lower than the value reported previously, but is in good agreement with the SFR estimated from far infrared luminosity. About 30% of the observed 20 cm continuum non-thermal emission seems to originate in processes that are not related to star formation. Revised SFR in the Cartwheel is comparable to that in the rest of the ring galaxies.Comment: 6 pages, uses emulateapj.cls. Scheduled to appear in ApJL February 10, 200

    Bandwidth-Aware Page Placement in NUMA

    Full text link
    Page placement is a critical problem for memoryintensive applications running on a shared-memory multiprocessor with a non-uniform memory access (NUMA) architecture. State-of-the-art page placement mechanisms interleave pages evenly across NUMA nodes. However, this approach fails to maximize memory throughput in modern NUMA systems, characterised by asymmetric bandwidths and latencies, and sensitive to memory contention and interconnect congestion phenomena. We propose BWAP, a novel page placement mechanism based on asymmetric weighted page interleaving. BWAP combines an analytical performance model of the target NUMA system with on-line iterative tuning of page distribution for a given memory-intensive application. Our experimental evaluation with representative memory-intensive workloads shows that BWAP performs up to 66% better than state-of-the-art techniques. These gains are particularly relevant when multiple co-located applications run in disjoint partitions of a large NUMA machine or when applications do not scale up to the total number of cores.Comment: Accepted at 34th IEEE International Parallel & Distributed Processing Symposium (IPDPS), 202

    Avaliação da rotulagem e informação nutricional de suplementos proteicos importados no Brasil

    Get PDF
    A prática esportiva possui benefícios claros à saúde, desde que em níveis moderados. Entretanto, a busca por otimização do rendimento e aprimoramento estético tem oportunizado a venda e consumo de diversos produtos ditos ergogênicos. Consumidores geralmente não demonstram interesse nas informações a respeito destes produtos, fator que contribui com o crescimento indiscriminado do mercado de suplementação. Foi objetivo deste estudo avaliar as adequações na informação nutricional de suplementos protéicos para atletas frente ao rótulo do produto no país de origem e às legislações nacionais que se referem aos suplementos e produtos embalados. A verificação das informações obrigatórias de rotulagem foi baseada nas Resoluções RDC Nº 18/2010 e RDC nº 259/2002, do Ministério da Saúde. Foram coletadas informações apenas de alimentos protéicos comercializados em estabelecimentos especializados no Município de Niterói, RJ. Foram obtidos e analisados 27 rótulos. Dentre os produtos, 89% (n=24) apresentaram informação nutricional na língua portuguesa, e 11% (n=3) em sua língua original. Quanto as irregularidades, apenas 7,4% (n=2) apresentaram-se em total acordo com as Resoluções de referência, enquanto 92,6% (n=25) continham alguma incorreção. Os resultados permitem concluir que a rotulagem dos suplementos protéicos importados, no que tange à informação nutricional, não possui a padronização devida, desobedecendo em grande parte dos casos, a um ou mais requesitos estabelecidos pela Resolução nacional vigente. ABSTRACTAssessment of the labeling and nutrition facts of imported protein supplements in BrazilSports practice has clear health benefits in moderate levels. However, the goal for optimization of performance and aesthetic enhancement has favored the selling and intake of various products said to be performance enhancers. Consumers generally don’t show interest on acquiring information concerning supplement intake, and end up becoming supporters of the growing market of dietary supplements. This study main purpose was to evaluate the adequacy of nutrition facts from imported protein supplements to its original information and the national laws regarding supplements and packaged products. The verification of mandatory labeling information was based on RDC Nº 18/2010 and RDC nº 259/2002 resolutions from the Ministry of Health. We collected information only from protein supplements sold in specialized stores in the city of Niterói, Rio de Janeiro. A total of 27 labels were analyzed. Among the evaluated products, 89% (n=24) had its nutrition facts written in Portuguese and 11%(n=3) in their original language. Regarding irregularities, only 7,4% (n=2) of the products were in full accordance with the resolutions of reference, whereas 92,6% (n=25) contained some inaccuracies at their labels. Our results indicate that the labeling of imported protein supplements, regarding nutrition facts, has no proper standardization, disobeying in most cases one or more requisites established by existing national resolutions

    Real-Time State Estimation of the EPFL-Campus Medium-Voltage Grid by Using PMUs

    Get PDF
    We describe the real-time monitoring infrastructure of the smart-grid pilot on the EPFL campus. We experimentally validate the concept of a real-time state-estimation for a 20 kV active distribution network. We designed and put into operation the whole infrastructure composed by the following main elements: (1) dedicated PMUs connected on the medium-voltage side of the network secondary substations by means of specific current/voltage transducers; (2) a dedicated communication network engineered to support stringent time limits and (3) an innovative state estimation process for real-time monitoring that incorporates phasor-data concentration and state estimation processes. Special care was taken to make the whole chain resilient to cyber-attacks, equipment failures and power outages. The achieved latency is within 65ms. The refresh rate of the estimated state is 20ms. The real-time visualization of the state estimator output is made publicly available, as well as the historical data (PMU measurements and estimated states). To the best of our knowledge, the work presented here is the first operational system that provides low-latency real-time state estimation by using PMU measurements of a real active distribution network

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

    Get PDF
    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

    Get PDF
    A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

    Get PDF
    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Sigh in patients with acute hypoxemic respiratory failure and acute respiratory distress syndrome: the PROTECTION pilot randomized clinical trial

    Get PDF
    Background: Sigh is a cyclic brief recruitment manoeuvre: previous physiological studies showed that its use could be an interesting addition to pressure support ventilation to improve lung elastance, decrease regional heterogeneity and increase release of surfactant. Research question: Is the clinical application of sigh during pressure support ventilation (PSV) feasible? Study design and methods: We conducted a multi-center non-inferiority randomized clinical trial on adult intubated patients with acute hypoxemic respiratory failure or acute respiratory distress syndrome undergoing PSV. Patients were randomized to the No Sigh group and treated by PSV alone, or to the Sigh group, treated by PSV plus sigh (increase of airway pressure to 30 cmH2Ofor 3 seconds once per minute) until day 28 or death or successful spontaneous breathing trial. The primary endpoint of the study was feasibility, assessed as non-inferiority (5% tolerance) in the proportion of patients failing assisted ventilation. Secondary outcomes included safety, physiological parameters in the first week from randomization, 28-day mortality and ventilator-free days. Results: Two-hundred fifty-eight patients (31% women; median age 65 [54-75] years) were enrolled. In the Sigh group, 23% of patients failed to remain on assisted ventilation vs. 30% in the No Sigh group (absolute difference -7%, 95%CI -18% to 4%; p=0.015 for non-inferiority). Adverse events occurred in 12% vs. 13% in Sigh vs. No Sigh (p=0.852). Oxygenation was improved while tidal volume, respiratory rate and corrected minute ventilation were lower over the first 7 days from randomization in Sigh vs. No Sigh. There was no significant difference in terms of mortality (16% vs. 21%, p=0.342) and ventilator-free days (22 [7-26] vs. 22 [3-25] days, p=0.300) for Sigh vs. No Sigh. Interpretation: Among hypoxemic intubated ICU patients, application of sigh was feasible and without increased risk
    corecore