207 research outputs found

    Fast multi-dimensional scattered data approximation with Neumann boundary conditions

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    An important problem in applications is the approximation of a function ff from a finite set of randomly scattered data f(xj)f(x_j). A common and powerful approach is to construct a trigonometric least squares approximation based on the set of exponentials {e2πikx}\{e^{2\pi i kx}\}. This leads to fast numerical algorithms, but suffers from disturbing boundary effects due to the underlying periodicity assumption on the data, an assumption that is rarely satisfied in practice. To overcome this drawback we impose Neumann boundary conditions on the data. This implies the use of cosine polynomials cos(πkx)\cos (\pi kx) as basis functions. We show that scattered data approximation using cosine polynomials leads to a least squares problem involving certain Toeplitz+Hankel matrices. We derive estimates on the condition number of these matrices. Unlike other Toeplitz+Hankel matrices, the Toeplitz+Hankel matrices arising in our context cannot be diagonalized by the discrete cosine transform, but they still allow a fast matrix-vector multiplication via DCT which gives rise to fast conjugate gradient type algorithms. We show how the results can be generalized to higher dimensions. Finally we demonstrate the performance of the proposed method by applying it to a two-dimensional geophysical scattered data problem

    Precise measurement of the W-boson mass with the CDF II detector

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    We have measured the W-boson mass MW using data corresponding to 2.2/fb of integrated luminosity collected in proton-antiproton collisions at 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470126 W->enu candidates and 624708 W->munu candidates yield the measurement MW = 80387 +- 12 (stat) +- 15 (syst) = 80387 +- 19 MeV. This is the most precise measurement of the W-boson mass to date and significantly exceeds the precision of all previous measurements combined

    CMS physics technical design report : Addendum on high density QCD with heavy ions

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    Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

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    Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

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    A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

    stairs and fire

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    Management of small agricultural cooperation and corporatization

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    The possibility of applying the principles of corporate governance in the practice of small agricultural businesses is considered. The authors believe that cooperative associations of small market participants can transform into corporate associations at a certain stage of development. The scientific novelty is represented by an improved economic mechanism of two-level cooperation of small agricultural enterprises with the financial participation of municipalities, regional and Federal authorities and the formation of their own cooperative Bank. The mechanism recommended by the authors is aimed at motivating small business participants to cooperate by the possibility of subsequent corporatization. The implementation of the cooperation development plan will require temporary exemption of its participants from the tax burden, while the state should practice joint construction of processing, logistics and other necessary facilities in the agricultural sector, with the subsequent transfer of its shares to consumer cooperatives of small businesses

    Studying the effect of fire retardant coating on the fire hazard characteristics of wood using infrared thermography

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    This paper represents a study concerning the effect of fire retardant treatment «FUKAM» on the fire hazard characteristics of pine, aspen and larch. The front of model ground fire was investigated to estimate its effect on the surface of wood samples. Infrared thermography was used as a diagnostic method. The surface temperature distribution was obtained for the test wood samples after exposure to a fire front that was modeled using pine needles. The probability of ignition was estimated for the chosen experimental parameters for each kind of wood. The fire hazard characteristics of wood after fire retardant treatment showed a significant reduction in the surface temperature and the resistance to fire for the chosen parameters of the experiment compared to the same untreated samples

    Experimental research of penetration hearth of burning in the peat layer

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    В статье Grishin M
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