7,292 research outputs found

    Mining web data for competency management

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    We present CORDER (COmmunity Relation Discovery by named Entity Recognition) an un-supervised machine learning algorithm that exploits named entity recognition and co-occurrence data to associate individuals in an organization with their expertise and associates. We discuss the problems associated with evaluating unsupervised learners and report our initial evaluation experiments

    Quarkonium+γ\gamma production in coherent hadron - hadron interactions at LHC energies

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    In this paper we study the H+γH + \gamma (H=J/ΨH = J/\Psi and Υ\Upsilon) production in coherent hadron - hadron interactions at LHC energies. Considering the ultrarelativistic protons as a source of photons, we estimate the γ+pH+γ+X\gamma + p \rightarrow H + \gamma + X cross section using the non-relativistic QCD (NRQCD) factorization formalism and considering different sets of values for the matrix elements. Our results for the total p+pp+H+γ+X p + p \rightarrow p + H + \gamma + X cross sections and rapidity distributions at s=7\sqrt{s} = 7 and 14 TeV demonstrate that the experimental analysis of the J/Ψ+γJ/\Psi + \gamma production at LHC is feasible.Comment: 6 pages, 3 figures, 1 table. Improved version with a new figure. Version to be published in European Physical Journal

    Theory of standing spin waves in finite-size chiral spin soliton lattice

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    We present a theory of standing spin wave (SSW) in a monoaxial chiral helimagnet. Motivated by experimental findings on the magnetic field-dependence of the resonance frequency in thin films of Cr{}Nb3_{3} S6{}_{6}[Goncalves et al., Phys. Rev. B95, 104415 (2017)], we examine the SSW over a chiral soliton lattice (CSL) excited by an ac magnetic field applied parallel and perpendicular to the chiral axis. For this purpose, we generalize Kittel-Pincus theories of the SSW in ferromagnetic thin films to the case of non-collinear helimagnet with the surface end spins which are softly pinned by an anisotropy field. Consequently, we found there appear two types of modes. One is a Pincus mode which is composed of a long-period Bloch wave and a short-period ripple originated from the periodic structure of the CSL. Another is a short-period Kittel ripple excited by space-periodic perturbation which exists only in the case where the ac field is applied perpendicular the chiral axis. We demonstrate that the existence of the Pincus mode and the Kittel ripple is consistent with experimentally found double resonance profile.Comment: 17 pages, 14 figure

    UN Ocean Conference needs transparent and science-based leadership on ocean conservation

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    The United Nations Ocean conference convened in June 2022. Heads of state, businesses, and civil society organizations met in Lisbon to discuss how to scale up ocean action to achieve SDG 14 goals. In the face of the existential challenges of the climate emergency and species extinction crisis, bold and decisive action on ocean conservation through a shift in the protection paradigm is needed now. Recognizing existing barriers (e.g., political, organizational, social, economic) that operate at various scales (e.g., international, regional and national) and that are precluding achieving a healthy ocean is key and has to be addressed with strong leadership and sound commitments. A roadmap with clear steps and achievements including metrics assessing protection levels, stages of establishment, management effectiveness and equity is now needed to guarantee the success of marine conservation goals. Portugal can and should help lead the way by adopting such a roadmap and approach, but post-2020 decisions need to incorporate, beyond area goals, both the quality and effectiveness of ocean protection through metrics and standards such as those provided by the MPA Guide, Green List and Blue Parks.Fundação para a Ciência e a Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

    Non-linear QCD dynamics and exclusive production in epep collisions

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    The exclusive processes in electron-proton (epep) interactions are an important tool to investigate the QCD dynamics at high energies as they are in general driven by the gluon content of proton which is strongly subject to parton saturation effects. In this paper we compute the cross sections for the exclusive vector meson production as well as the deeply virtual Compton scattering (DVCS) relying on the color dipole approach and considering the numerical solution of the Balitsky-Kovchegov equation including running coupling corrections. We show that the small-xx evolution given by this evolution equation is able to describe the DESY-HERA data and is relevant for the physics of the exclusive observables in future electron-proton colliders and in photoproduction processes to be measured in coherent interactions at the LHC.Comment: 6 pages, 4 figure

    Dipole model for double meson production in two-photon interactions at high energies

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    In this work the double vector meson production in two-photon interactions at high energies is investigated considering saturation physics. We extend the color dipole picture for this process and study the energy and virtuality dependence of the forward differential cross section. Comparison with previous results is presented and the contribution of the different photon polarizations is estimated.Comment: 20 pages, 8 figures, 1 table. Version to be published in European Physical Jornal

    Decomposição de resíduos de milho e soja em função do tempo e do manejo do solo.

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    A evolução da decomposição dos resíduos culturais é um aspecto muito complexo, ainda pouco conhecido e estudado, porém de grande importância na compreensão de processos como a formação da matéria orgânica e a manutenção da fertilidade e sustentabilidade dos solos. A sua velocidade de decomposição determina o tempo de permanência da cobertura morta na superfície do solo, sendo variável conforme a constituição dos diferentes tecidos vegetais. O objetivo deste trabalho foi a obtenção de equações matemáticas, que expliquem a evolução da dinâmica de decomposição de resíduos de milho e soja, em semeadura direta e convencional, utilizando- se dados de um ensaio de longa duração (12 anos) conduzido no campo experimental da Embrapa Soja, em Londrina, PR. Foram obtidas equações exponenciais, que mostraram semelhanças na velocidade de decomposição dos resíduos de milho e soja e níveis de decomposição mais elevados em semeadura convencional,tanto para o milho quanto para a soja.bitstream/item/31179/1/Boletim-PD-3.pd
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