165 research outputs found

    Análisis de sentiminetos de un corpus de redes sociales.

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    El análisis de sentimientos de textos en las redes sociales se ha convertido en un área de investigación cada vez más relevante debido a la influencia que las opiniones expresadas tienen en potenciales usuarios. De acuerdo con una clasificación conceptual de sentimientos y basándonos en un corpus de diversos dominios comerciales, hemos trabajado en la confección de reglas que permitan la clasificación de dichos textos según el sentimiento expresado con respecto a una marca, empresa o producto. Con la ayuda de una base de datos de colocaciones (Badele3000) y un gestor de corpus (Calíope) se han creado 200 reglas en español que han puesto de manifiesto algunas consideraciones a tener en cuenta en la siguiente fase del trabajo

    Determination of lifetimes of nuclear excited states using the Recoil Distance Doppler Shift Method in combination with magnetic spectrometers

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    The current work presents the determination of lifetimes of nuclear excited states using the Recoil Distance Doppler Shift Method, in combination with spectrometers for ion identification, normalizing the intensity of the peaks by the ions detected in the spectrometer as a valid technique that produces results comparable to the ones obtained by the conventional shifted-to-unsifted peak ratio method. The technique has been validated using data measured with the γ \gamma -ray array AGATA, the PRISMA spectrometer and the Cologne plunger setup. In this paper a test performed with the AGATA-PRISMA setup at LNL and the advantages of this new approach with respect to the conventional Recoil Distance Doppler Shift Method are discussed

    Study of Microscopic Residual Stresses in an Extruded Aluminium Alloy Sample after Thermal Treatment

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    Abstract: A method is proposed to calculate the microscopic residual stresses in extruded cylindrical samples of non-ageing aluminium alloy 5083 (Al–Mg), arising from quenching in fresh water from 530°C. We start from the premise that the alloy is single-phase and non-isotropic on a microscopic scale; it consists of many grains that exhibit different mechanical response depending on their crystallographic orientation and neighboring grains. Microscopic residual stresses depend on the applied heat treatment, microstructure and mechanical strength of the individual grains. The stresses were calculated from neutron diffraction data. Genetic programming algorithms were used to calculate microscopic residual stresses, considering that each diffraction peak describes the stress distribution of a group of grains having a certain orientation, size and environment. The algorithm assigns a stress value to each grain according to the distribution of the diffraction peaks and the microstructural parameters of these grains.This work was supported by the Madrid Regional Government-FEDER grant Y2018/NMT-4668 (Micro-Stress-MAP-CM) and the project MAT2017-83825-C4-1-R. We would also like to express our gratitude to FLNR-JINP for the beam time allocated on the FSD instrument, and to the HeuristicLab Software developers

    Establishing the Maximum Collectivity in Highly Deformed N=Z Nuclei

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    The lifetimes of the first excited 2^{+} states in the N=Z nuclei ^{80}Zr, ^{78}Y, and ^{76}Sr have been measured using the γ-ray line shape method following population via nucleon-knockout reactions from intermediate-energy rare-isotope beams. The extracted reduced electromagnetic transition strengths yield new information on where the collectivity is maximized and provide evidence for a significant, and as yet unexplained, odd-odd vs even-even staggering in the observed values. The experimental results are analyzed in the context of state-of-the-art nuclear density-functional model calculations

    Spin Structure of the Proton from Polarized Inclusive Deep-Inelastic Muon-Proton Scattering

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    We have measured the spin-dependent structure function g1pg_1^p in inclusive deep-inelastic scattering of polarized muons off polarized protons, in the kinematic range 0.003<x<0.70.003 < x < 0.7 and 1GeV2<Q2<60GeV21 GeV^2 < Q^2 < 60 GeV^2. A next-to-leading order QCD analysis is used to evolve the measured g1p(x,Q2)g_1^p(x,Q^2) to a fixed Q02Q^2_0. The first moment of g1pg_1^p at Q02=10GeV2Q^2_0 = 10 GeV^2 is Γp=0.136±0.013(stat.)±0.009(syst.)±0.005(evol.)\Gamma^p = 0.136\pm 0.013(stat.) \pm 0.009(syst.)\pm 0.005(evol.). This result is below the prediction of the Ellis-Jaffe sum rule by more than two standard deviations. The singlet axial charge a0a_0 is found to be 0.28±0.160.28 \pm 0.16. In the Adler-Bardeen factorization scheme, Δg2\Delta g \simeq 2 is required to bring ΔΣ\Delta \Sigma in agreement with the Quark-Parton Model. A combined analysis of all available proton and deuteron data confirms the Bjorken sum rule.Comment: 33 pages, 22 figures, uses ReVTex and smc.sty. submitted to Physical Review

    The Spin Structure of the Nucleon

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    We present an overview of recent experimental and theoretical advances in our understanding of the spin structure of protons and neutrons.Comment: 84 pages, 29 figure

    Early B-cell Factor gene association with multiple sclerosis in the Spanish population

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    BACKGROUND: The etiology of multiple sclerosis (MS) is at present not fully elucidated, although it is considered to result from the interaction of environmental and genetic susceptibility factors. In this work we aimed at testing the Early B-cell Factor (EBF1) gene as a functional and positional candidate risk factor for this neurological disease. Axonal damage is a hallmark for multiple sclerosis clinical disability and EBF plays an evolutionarily conserved role in the expression of proteins essential for axonal pathfinding. Failure of B-cell differentiation was found in EBF-deficient mice and involvement of B-lymphocytes in MS has been suggested from their presence in cerebrospinal fluid and lesions of patients. METHODS: The role of the EBF1 gene in multiple sclerosis susceptibility was analyzed by performing a case-control study with 356 multiple sclerosis patients and 540 ethnically matched controls comparing the EBF1 polymorphism rs1368297 and the microsatellite D5S2038. RESULTS: Significant association of an EBF1-intronic polymorphism (rs1368297, A vs. T: p = 0.02; OR = 1.26 and AA vs. [TA+TT]: p = 0.02; OR = 1.39) was discovered. This association was even stronger after stratification for the well-established risk factor of multiple sclerosis in the Major Histocompatibility Complex, DRB1*1501 (AA vs. [TA+TT]: p = 0.005; OR = 1.78). A trend for association in the case-control study of another EBF1 marker, the allele 5 of the very informative microsatellite D5S2038, was corroborated by Transmission Disequilibrium Test of 53 trios (p = 0.03). CONCLUSION: Our data support EBF1 gene association with MS pathogenesis in the Spanish white population. Two genetic markers within the EBF1 gene have been found associated with this neurological disease, indicative either of their causative role or that of some other polymorphism in linkage disequilibrium with them

    Legal linked data ecosystems and the rule of law

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    This chapter introduces the notions of meta-rule of law and socio-legal ecosystems to both foster and regulate linked democracy. It explores the way of stimulating innovative regulations and building a regulatory quadrant for the rule of law. The chapter summarises briefly (i) the notions of responsive, better and smart regulation; (ii) requirements for legal interchange languages (legal interoperability); (iii) and cognitive ecology approaches. It shows how the protections of the substantive rule of law can be embedded into the semantic languages of the web of data and reflects on the conditions that make possible their enactment and implementation as a socio-legal ecosystem. The chapter suggests in the end a reusable multi-levelled meta-model and four notions of legal validity: positive, composite, formal, and ecological

    Evidence for octupole collectivity in Pt-172

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    Excited states in the extremely neutron-deficient nucleus Pt-172 were populated via Ru-96(Kr-78, 2p) and Mo-92(Kr-83, 3n) reactions. The level scheme has been extended up to an excitation energy of approximate to 5MeV and tentative spin-parity assignments up to I-pi = 18(+). Linear polarization and angular distribution measurements were used to determine the electromagnetic E1 character of the dipole transitions connecting the positive-parity ground-state band with an excited side-band, firmly establishing it as a negativeparity band. The lowestmember of this negative-parity structure was firmly assigned spin-parity 3(-). In addition, we observed an E3 transition from this 3(-) state to the ground state, providing direct evidence for octupole collectivity in Pt-172. Large-scale shell model (LSSM) and total Routhian surface (TRS) calculations have been performed, supporting the interpretation of the 3(-) state as a collective octupole-vibrational state.Peer reviewe

    Lifetime measurement of neutron-rich even-even molybdenum isotopes

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    Background: In the neutron-rich A approximate to 100 mass region, rapid shape changes as a function of nucleon number as well as coexistence of prolate, oblate, and triaxial shapes are predicted by various theoretical models. Lifetime measurements of excited levels in the molybdenum isotopes allow the determination of transitional quadrupole moments, which in turn provides structural information regarding the predicted shape change. Purpose: The present paper reports on the experimental setup, the method that allowed one to measure the lifetimes of excited states in even-even molybdenum isotopes from mass A = 100 up to mass A = 108, and the results that were obtained. Method: The isotopes of interest were populated by secondary knock-out reaction of neutron-rich nuclei separated and identified by the GSI fragment separator at relativistic beam energies and detected by the sensitive PreSPEC-AGATA experimental setup. The latter included the Lund-York-Cologne calorimeter for identification, tracking, and velocity measurement of ejectiles, and AGATA, an array of position sensitive segmented HPGe detectors, used to determine the interaction positions of the gamma ray enabling a precise Doppler correction. The lifetimes were determined with a relativistic version of the Doppler-shift-attenuation method using the systematic shift of the energy after Doppler correction of a gamma-ray transition with a known energy. This relativistic Doppler-shift-attenuation method allowed the determination of mean lifetimes from 2 to 250 ps. Results: Even-even molybdenum isotopes from mass A = 100 to A = 108 were studied. The decays of the low-lying states in the ground-state band were observed. In particular, two mean lifetimes were measured for the first time: tau = 29.7(-9.1)(+11.3) ps for the 4(+) state of Mo-108 and tau = 3.2(-0.7)(+ 0.7) ps for the 6(+) state of Mo-102. Conclusions: The reduced transition strengths B(E2), calculated from lifetimes measured in this experiment, compared to beyond-mean-field calculations, indicate a gradual shape transition in the chain of molybdenum isotopes when going from A = 100 to A = 108 with a maximum reached at N = 64. The transition probabilities decrease for Mo-108 which may be related to its well-pronounced triaxial shape indicated by the calculations
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