5,628 research outputs found

    Assessment of Temperature-Dependent Regression Model Terms of a RUAG Six-Component Block-Type Balance

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    A metric called the percent contribution was applied to regression models of temperature-dependent calibration data of a RUAG six-component block-type balance in order to assess the influence of temperature-dependent regression model terms on the balance load prediction. Regression models were examined that are needed if either the Iterative or the Non-Iterative Method is used for the load prediction. Computed values of the percent contribution confirmed that the cross-product term defined by a primary load and the temperature difference is the most influential temperature-dependent term of the regression model of a primary output that the Iterative Method needs. Similarly, the analysis showed that the cross-product term defined by a primary output and the temperature difference is the most influential temperature-dependent term of the regression model of a primary load that the Non-Iterative Method needs. Computed results support conclusions that were reported in an earlier theoretical study. This study asserted that the cross-product term defined by a primary load or output and the temperature difference models the temperature-dependent shift of the gage sensitivity. The influence of other temperature-dependent terms used in the regression models of the calibration data of RUAG's balance was negligible. This observation may be explained by the fact that RUAG's block-type balances have highly linear characteristics. Overall, the percent contribution has proven itself to be a reliable and easy-to-implement metric that may also be used for the assessment of the influence of temperature-dependent regression model terms on the load prediction of a six-component strain-gage balance

    N=2 central charge superspace and a minimal supergravity multiplet

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    We extend the notion of central charge superspace to the case of local supersymmetry. Gauged central charge transformations are identified as diffeomorphisms at the same footing as space-time diffeomorphisms and local supersymmetry transformations. Given the general structure we then proceed to the description of a particular vector-tensor supergravity multiplet of 24+24 components, identified by means of rather radical constraints

    Invariant Subspaces of Nilpotent Linear Operators. I

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    Let kk be a field. We consider triples (V,U,T)(V,U,T), where VV is a finite dimensional kk-space, UU a subspace of VV and T V→VT \:V \to V a linear operator with Tn=0T^n = 0 for some nn, and such that T(U)⊆UT(U) \subseteq U. Thus, TT is a nilpotent operator on VV, and UU is an invariant subspace with respect to TT. We will discuss the question whether it is possible to classify these triples. These triples (V,U,T)(V,U,T) are the objects of a category with the Krull-Remak-Schmidt property, thus it will be sufficient to deal with indecomposable triples. Obviously, the classification problem depends on nn, and it will turn out that the decisive case is n=6.n=6. For n<6n < 6, there are only finitely many isomorphism classes of indecomposables triples, whereas for n>6n > 6 we deal with what is called ``wild'' representation type, so no complete classification can be expected. For n=6n=6, we will exhibit a complete description of all the indecomposable triples.Comment: 55 pages, minor modification in (0.1.3), to appear in: Journal fuer die reine und angewandte Mathemati

    An overview of new supersymmetric gauge theories with 2-form gauge potentials

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    An overview of new 4d supersymmetric gauge theories with 2-form gauge potentials constructed by various authors during the past five years is given. The key role of three particular types of interaction vertices is emphasized. These vertices are used to develop a connecting perspective on the new models and to distinguish between them. One example is presented in detail to illustrate characteristic features of the models. A new result on couplings of 2-form gauge potentials to Chern-Simons forms is presented.Comment: 11 pages; to appear in the proceedings of NATO ARW "Noncommutative structures in mathematics and physics" (Kiev 09/00); table in section 3 correcte

    Hortibot: Feasibility study of a plant nursing robot performing weeding operations – part IV

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    Based on the development of a robotic tool carrier (Hortibot) equipped with weeding tools, a feasibility study was carried out to evaluate the viability of this innovative technology. The feasibility was demonstrated through a targeted evaluation adapted to the obtainable knowledge on the system performance in horticulture. A usage scenario was designed to set the implementation of the robotic system in a row crop of seeded bulb onions considering operational and functional constraints in organic crop, production. This usage scenario together with the technical specifications of the implemented system provided the basis for the feasibility analysis, including a comparison with a conventional weeding system. Preliminary results show that the automation of the weeding tasks within a row crop has the potential of significantly reducing the costs and still fulfill the operational requirements set forth. The potential benefits in terms of operational capabilities and economic viability have been quantified. Profitability gains ranging from 20 to 50% are achievable through targeted applications. In general, the analyses demonstrate the operational and economic feasibility of using small automated vehicles and targeted tools in specialized production settings

    Hawking radiation from decoherence

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    It is argued that the thermal nature of Hawking radiation arises solely due to decoherence. Thereby any information-loss paradox is avoided because for closed systems pure states remain pure. The discussion is performed for a massless scalar field in the background of a Schwarzschild black hole, but the arguments should hold in general. The result is also compared to and contrasted with the situation in inflationary cosmology.Comment: 6 pages, to appear in Class. Quantum Gra

    Herstellung und Charakterisierung von menschlichen Oligodendrozyten-VorlÀuferzellinien

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    Bei der Multiplen Sklerose kommen im Verlauf der Erkrankung das Myelin und die Oligodendrozyten zu Schaden. Zu Beginn der Erkrankung kann man RemyelinisierungsvorgĂ€nge beobachten. Hier scheinen die Oligodendrozyten-VorlĂ€uferzellen eine entscheidende Rolle zu spielen. In der Arbeit wurde mit Hilfe eines retroviralen Transfer des LTAg auf humane Oligodendrozyten-VorlĂ€uferzellen drei Zelllinien hergestellt die ein Markerprofil aufweisen welches fĂŒr Oligdodenrozyten-VorlĂ€uferzellen typisch ist

    Dynamic charge inhomogenity in cuprate superconductors

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    The inelastic x-ray scattering spectrum for phonons of Δ1\Delta_{1}-symmetry including the CuO bond-stretching phonon dispersion is analyzed by a Lorentz fit in HgBa2_{2}CuO4_{4} and Bi2_{2}Sr2_{2}CuO6_{6}, respectively, using recently calculated phonon frequencies as input parameters. The resulting mode frequencies of the fit are almost all in good agreement with the calculated data. An exception is the second highest Δ1\Delta_{1}-branch compromising the bond-stretching modes which disagrees in both compounds with the calculations. This branch unlike the calculations shows an anomalous softening with a minimum around the wavevector \vc{q}=\frac{2\pi}{a}(0.25, 0, 0). Such a disparity with the calculated results, that are based on the assumption of an undisturbed translation- and point group invariant electronic structure of the CuO plane, indicates some {\it static} charge inhomogenities in the measured probes. Most likely these will be charge stripes along the CuO bonds which have the strongest coupling to certain longitudinal bond-stretching modes that in turn selfconsistently induce corresponding {\it dynamic} charge inhomogenities. The symmetry breaking by the mix of dynamic and static charge inhomogenities can lead to a reconstruction of the Fermi surface into small pockets.Comment: 7 pages, 4 figure
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