371 research outputs found

    An SVM-based solution for fault detection in wind turbines

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    Research into fault diagnosis in machines with a wide range of variable loads and speeds, such as wind turbines, is of great industrial interest. Analysis of the power signals emitted by wind turbines for the diagnosis of mechanical faults in their mechanical transmission chain is insufficient. A successful diagnosis requires the inclusion of accelerometers to evaluate vibrations. This work presents a multi-sensory system for fault diagnosis in wind turbines, combined with a data-mining solution for the classification of the operational state of the turbine. The selected sensors are accelerometers, in which vibration signals are processed using angular resampling techniques and electrical, torque and speed measurements. Support vector machines (SVMs) are selected for the classification task, including two traditional and two promising new kernels. This multi-sensory system has been validated on a test-bed that simulates the real conditions of wind turbines with two fault typologies: misalignment and imbalance. Comparison of SVM performance with the results of artificial neural networks (ANNs) shows that linear kernel SVM outperforms other kernels and ANNs in terms of accuracy, training and tuning times. The suitability and superior performance of linear SVM is also experimentally analyzed, to conclude that this data acquisition technique generates linearly separable datasets.Projects, CENIT-2008-1028, TIN2011-24046, IPT-2011-1265-020000 and DPI2009-06124-E/DPI of the Spanish Ministry of Economy and Competitivenes

    Estado de salud y barreras en la atención de niños con defectos congénitos nacidos entre el 2011 y el 2017 en dos instituciones de salud de Cali

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    Introduction: Birth defects affect 2-3% of births contributing an important load to the causes of infant morbidity and mortality during the first five years of life. In Colombia, they are the second cause of infant mortality according to reports from the Departamento Administrativo Nacional de Estadística (DANE) 2011.Objective: To describe the state of health and barriers in the health care of children with congenital defects born between 2011 and 2017 in two institutions of Cali.Materials and methods: We conducted a descriptive cross-sectional observational study. We included babies born between January, 2011, and December, 2017, with at least one congenital defect who were followed up by telephone.Results: Out of 54,193 births during the period, 1,389 (2.56%) newborns had at least one congenital defect. All cases were classified according to the prognostic scale and 881 were included in the follow-up. The most frequent congenital defect was congenital cardiac malformation with 88 cases (9.99%), followed by malformation/defect of the kidney with 73 cases (8.29%), Down syndrome with 72 cases (8.17%), and testicular abnormalities with 56 cases (6.36%). Out of the 454 cases with effective follow-up, 161 (35.46%) of the caregivers stated that they had experienced at least one type of barrier during health care.Conclusion: Follow-up programs should be implemented for patients with birth defects to contribute to reducing morbidity and mortality.Introducción. Los defectos congénitos afectan entre el 2 y el 3 % de los recién nacidos, y son una carga importante entre las causas de morbilidad y mortalidad infantil en los primeros cinco años de vida. En Colombia, fueron la segunda causa de mortalidad infantil según los reportes del Departamento Administrativo Nacional de Estadística (DANE) para el 2011.Objetivo. Describir el estado de salud y las barreras en la atención de niños con defectos congénitos nacidos entre el 2011 y el 2017 en dos instituciones de salud de Cali.Materiales y métodos. Se hizo un estudio observacional descriptivo de corte transversal. Se incluyeron los nacidos entre enero de 2011 y diciembre de 2017 con, al menos, un defecto congénito, a quienes se les hizo seguimiento telefónico.Resultados. De 54.193 nacidos en el período analizado, 1.389 (2,56 %) tenían, por lo menos, un defecto congénito. Todos los casos se clasificaron según la escala de pronóstico y se incluyeron 881 en el seguimiento. El defecto congénito más frecuente fue la malformación congénita cardíaca, con 88 (9,99 %) casos; en segundo lugar, las malformaciones o defectos del riñón, con 73 (8,29 %) casos; en tercer lugar, el síndrome de Down, con 72 (8,17 %) casos, y en cuarto lugar, las anormalidades testiculares, con 56 (6,36 %). Ciento sesenta y uno (35,46 %) de los cuidadores de los 454 casos con seguimiento efectivo, manifestaron haber encontrado, por lo menos, un tipo de barrera en la atención.Conclusión. Se deben implementar programas de seguimiento de los pacientes con defectos congénitos, que contribuyan a disminuir la morbimortalidad

    A simple but efficient voice activity detection algorithm through Hilbert transform and dynamic threshold for speech pathologies

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    A simple but efficient voice activity detector based on the Hilbert transform and a dynamic threshold is presented to be used on the pre-processing of audio signals -- The algorithm to define the dynamic threshold is a modification of a convex combination found in literature -- This scheme allows the detection of prosodic and silence segments on a speech in presence of non-ideal conditions like a spectral overlapped noise -- The present work shows preliminary results over a database built with some political speech -- The tests were performed adding artificial noise to natural noises over the audio signals, and some algorithms are compared -- Results will be extrapolated to the field of adaptive filtering on monophonic signals and the analysis of speech pathologies on futures works20th Argentinean Bioengineering Society Congress, SABI 2015 (XX Congreso Argentino de Bioingeniería y IX Jornadas de Ingeniería Clínica)28–30 October 2015, San Nicolás de los Arroyos, Argentin

    Safety and efficacy of Lactobacillus plantarum NCIMB 42150 as a silage additive for all animal species

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    The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of a specific strain of Lactobacillus plantarum when used as a technological additive intended to improve ensiling at a proposed application rate of 1 9 108 colony forming unit (CFU)/kg fresh material. L. plantarum is considered by EFSA to be suitable for the qualified presumption of safety approach to safety assessment and not to require specific demonstration of safety other than demonstrating the absence of resistance to antibiotics of human and veterinary significance. As the identity of the strain was clearly established and as no antibiotic resistance was detected, the use of the strain in the production of silage is presumed safe for livestock species, consumers of products from animals fed treated silage and the environment. In the absence of data, no conclusion can be drawn on the skin and eye irritancy or skin sensitisation of the additive. The additive should be considered as a potential respiratory sensitiser. Five studies with laboratory-scale silos were made using forage of differing water-soluble carbohydrate content. Replicate silos containing forages treated at the proposed application rate were compared to identical silos containing the same but untreated forage. In addition, in four studies, formic acid was included as positive control. The mini-silos were then stored for 90\u2013103 days at 20\u201324\ub0C. After opening, the contents of the silos were analysed. Results showed that this strain of L. plantarum has the potential to improve the production of silage from easy, moderately difficult and difficult to ensile forage species by increasing the production of lactic acid, reducing the pH and increasing the preservation of dry matter when used at an application rate of 1 9 108 CFU/kg

    Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP

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    Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~ events. Spin correlations are favoured by data, and found to agree with the Standard Model predictions. In addition, correlations between the W-boson decay planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events. Decay-plane correlations, consistent with zero and with the Standard Model predictions, are measured

    Ultrarelativistic sources in nonlinear electrodynamics

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    The fields of rapidly moving sources are studied within nonlinear electrodynamics by boosting the fields of sources at rest. As a consequence of the ultrarelativistic limit the delta-like electromagnetic shock waves are found. The character of the field within the shock depends on the theory of nonlinear electrodynamics considered. In particular, we obtain the field of an ultrarelativistic charge in the Born-Infeld theory.Comment: 10 pages, 3 figure

    Measurement of the Cross Section for Open-Beauty Production in Photon-Photon Collisions at LEP

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    The cross section for open-beauty production in photon-photon collisions is measured using the whole high-energy and high-luminosity data sample collected by the L3 detector at LEP. This corresponds to 627/pb of integrated luminosity for electron-positron centre-of-mass energies from 189GeV to 209GeV. Events containing b quarks are identified through their semi-leptonic decay into electrons or muons. The e+e- -> e+e-b b~X cross section is measured within our fiducial volume and then extrapolated to the full phase space. These results are found to be in significant excess with respect to Monte Carlo predictions and next-to-leading order QCD calculations

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

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    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

    Standalone vertex finding in the ATLAS muon spectrometer

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    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

    Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

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    A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction
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