7,292 research outputs found
Mining web data for competency management
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+ production in coherent hadron - hadron interactions at LHC energies
In this paper we study the ( and )
production in coherent hadron - hadron interactions at LHC energies.
Considering the ultrarelativistic protons as a source of photons, we estimate
the 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 cross sections and rapidity distributions at
and 14 TeV demonstrate that the experimental analysis of the
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
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 CrNbS[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
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 collisions
The exclusive processes in electron-proton () 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- 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
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.
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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