71 research outputs found

    Self-tuning Personalized Information Retrieval in an Ontology-Based Framework

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    Reliability is a well-known concern in the field of personalization technologies. We propose the extension of an ontology-based retrieval system with semantic-based personalization techniques, upon which automatic mechanisms are devised that dynamically gauge the degree of personalization, so as to benefit from adaptivity but yet reduce the risk of obtrusiveness and loss of user control. On the basis of a common domain ontology KB, the personalization framework represents, captures and exploits user preferences to bias search results towards personal user interests. Upon this, the intensity of personalization is automatically increased or decreased according to an assessment of the imprecision contained in user requests and system responses before personalization is applied

    Optically Active Defects Induced by 10 MeV Electron Beam in Transparent MgAl2O4 Ceramics

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    In the synthesized MgAl2O4 ceramics, Raman scattering modes were detected due to the presence of random distribution of cations over structural positions (structural reversal effects). Irradiation by 10 MeV electron beam caused intensity redistribution of the fundamental bands in Raman spectrum. New optical absorption bands were registered. Observed features were attributed to the effect of radiation-induced ‘ionic mixing’ in cation sublattice. This effect is the formation of additional [Al

    ON POSSIBILITY OF USING OF Al2O3/MgO CERAMIC COMPOSITE TO DETECT PULSED ELECTRON BEAMS

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    The Al2O3/MgO composite was synthesized under a high temperature in vacuum. The TL curve was obtained. The dependence of the TL peak intensity at 200 oC on the dose irradiation by pulsed electron beam with energy of 130 keV was determined. It was found that the dose response in the range from 1.5 to 10kGy is superlinear

    Optical and luminescent properties of ceria nanoparticles produced by gas phase method

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    The study on luminescent and optical properties of ceria nanoparticles allow one to indirectly assess the defectiveness of the material crystal lattice. The decomposition of the luminescence spectrum in the Gaussian bands shows the presence of Ce3+ ions in the CeO2 crystal lattice, as well as optical active centers, probably associated with oxygen vacancies. These characteristics permit us to estimate the relative amount of Ce3+ ions in the crystal lattice and could be considered as an important prerequisite for the use of nanoparticles as redox agents in industry and medicine. © 2020 IOP Publishing Ltd.Russian Science Foundation, RSF: 18-72-00041The work was supported by Russian Science Foundation project № 18-72-00041

    Observation of narrow baryon resonance decaying into pKs0pK^0_s in pA-interactions at 70GeV/c70 GeV/c with SVD-2 setup

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    SVD-2 experiment data have been analyzed to search for an exotic baryon state, the Θ+\Theta^+-baryon, in a pKs0pK^0_s decay mode at 70GeV/c70 GeV/c on IHEP accelerator. The reaction pApKs0+XpA \to pK^0_s+X with a limited multiplicity was used in the analysis. The pKs0pK^0_s invariant mass spectrum shows a resonant structure with M=1526±3(stat.)±3(syst.)MeV/c2M=1526\pm3(stat.)\pm 3(syst.) MeV/c^2 and Γ<24MeV/c2\Gamma < 24 MeV/c^2. The statistical significance of this peak was estimated to be of 5.6σ5.6 \sigma. The mass and width of the resonance is compatible with the recently reported Θ+\Theta^+- baryon with positive strangeness which was predicted as an exotic pentaquark (uuddsˉuudd\bar{s}) baryon state. The total cross section for Θ+\Theta^+ production in pN-interactions for XF0X_F\ge 0 was estimated to be (30÷120)μb(30\div120) \mu b and no essential deviation from A-dependence for inelastic events (A0.7)(\sim A^{0.7}) was found.Comment: 8 pages, 7 figures, To be submitted to Yadernaya Fizika. v3-v5 - Some references added, minor typos correcte

    INFLUENCE OF HIGH-TEMPERATURE PROCESSING ON LUMINESCENT PROPERTIES OF MONOCLINIC ZIRCONIUM OXIDE

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    The cathodo- and thermoluminescence of samples of monoclinic zirconium oxide (ZrO2) under the influence of annealing in a reducing carbon medium was studied. As a result, it can be seen that this annealing leads to an increase in the luminescence intensity. The results may indicate an increase of the number of oxygen vacancies
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