246 research outputs found

    Head-mounted display for interactive inspection of painted free-form surfaces

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    Cooperative Cognitive Automobiles

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    Safety requirements are among the most ambitious challenges for autonomous guidance and control of automobiles. A human-like understanding of the surrounding traffic scene is a key element to fulfill these requirements, but is a still missing capability of today's intelligent vehicles. Few recent proposals for driver assistance systems approach this issue with methods from the AI research to allow for a reasonable situation evaluation and behavior generation. While the methods proposed in this contribution are lend from cognition in order to mimic human capabilities, we argue that in the long term automated cooperation among traffic participants bears the potential to improve traffic efficiency and safety beyond the level attainable by human drivers. Both issues are major objectives of the Transregional Collaborative Research Centre 28 'cognitive automobiles,' TCRC28 that is outlined in the paper. Within this project the partners focus on systematic and interdisciplinary research on machine cognition of mobile systems as the basis for a scientific theory of automated machine behavior

    Differential cross sections for muonic atom scattering from hydrogenic molecules

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    The differential cross sections for low-energy muonic hydrogen atom scattering from hydrogenic molecules are directly expressed by the corresponding amplitudes for muonic atom scattering from hydrogen-isotope nuclei. The energy and angular dependence of these three-body amplitudes is thus taken naturally into account in scattering from molecules, without involving any pseudopotentials. Effects of the internal motion of nuclei inside the target molecules are included for every initial rotational-vibrational state. These effects are very significant as the considered three-body amplitudes often vary strongly within the energy interval ≲0.1\lesssim{}0.1 eV. The differential cross sections, calculated using the presented method, have been successfully used for planning and interpreting many experiments in low-energy muon physics. Studies of μ−\mu^{-} nuclear capture in pμp\mu and the measurement of the Lamb shift in pμp\mu atoms created in H2_2 gaseous targets are recent examples.Comment: 21 pages, 13 figures, submitted to Phys. Rev.

    Flexible Sandwich Piezoelectric Nanogenerators based ZnO Nanorods for Mechanical Energy Harvesting

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    We present a flexible sandwich piezoelectric nanogenerators (PENGs) device with gold-coated ZnO nanorods (Au@ ZNRs) as an efficient top electrode; this device was used to harvest energy from the human walking motion. ZNRs were synthesised on the two-piece of ZnO seed layer coated gold/flexible polyethylene terephthalate (Au/PET) substrates through a simple hydrothermal method of low temperature and low cost at molar concentration (0.01M). X-ray diffraction and field emission scanning electron microscopy images revealed that the as-grown ZNRs have high crystallinity and apparent vertical growth with hexagonal shapes, the average diameter of NRs is 120 nm. Flexible sandwich PENGs based ZNRs was fabricated with gold-coated one piece of ZNRs by DC-sputtering method as an efficient top electrode, which was placed on the uncoated ZNRs as-grown on another piece of substrate. The maximum output potential voltage (Vmax) under a periodic of pressing and releasing of human walking is 5.76 V. The results confirmed the top efficient electrode has created more contact area with uncoated NR when it is pressed, which increases the transfer efficiency effectively of piezoelectric potential that generated from uncoated ZNRs

    The explanation of unexpected temperature dependence of the muon catalysis in solid deuterium

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    It is shown that due to the smallness of the inelastic cross-section of the dμd\mu-atoms scattering in the crystal lattice at sufficiently low temperatures the ddμdd\mu-mesomolecules formation from the upper state of the hyperfine structure dμ(F=3/2)d\mu (F=3/2) starts earlier than the mesoatoms thermolization. It explains an approximate constancy of the ddμdd\mu-mesomolecule formation rate in solid deuterium.Comment: 6 pages, 2 jpeg-figure

    Vision-based path-planning in unstructured environments

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    Muon Catalyzed Fusion in 3 K Solid Deuterium

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    Muon catalyzed fusion in deuterium has traditionally been studied in gaseous and liquid targets. The TRIUMF solid-hydrogen-layer target system has been used to study the fusion reaction rates in the solid phase of D_2 at a target temperature of 3 K. Products of two distinct branches of the reaction were observed; neutrons by a liquid organic scintillator, and protons by a silicon detector located inside the target system. The effective molecular formation rate from the upper hyperfine state of μd\mu d and the hyperfine transition rate have been measured: λ~(3/2)=2.71(7)stat.(32)syst.μ/s\tilde{\lambda}_(3/2)=2.71(7)_{stat.}(32)_{syst.} \mu/s, and λ~(3/2)(1/2)=34.2(8)stat.(1)syst.μ/s\tilde{\lambda}_{(3/2)(1/2)} =34.2(8)_{stat.}(1)_{syst.} \mu /s. The molecular formation rate is consistent with other recent measurements, but not with the theory for isolated molecules. The discrepancy may be due to incomplete thermalization, an effect which was investigated by Monte Carlo calculations. Information on branching ratio parameters for the s and p wave d+d nuclear interaction has been extracted.Comment: 19 pages, 11 figures, submitted to PRA Feb 20, 199

    Measurement of the Positive Muon Lifetime and Determination of the Fermi Constant to Part-per-Million Precision

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    We report a measurement of the positive muon lifetime to a precision of 1.0 parts per million (ppm); it is the most precise particle lifetime ever measured. The experiment used a time-structured, low-energy muon beam and a segmented plastic scintillator array to record more than 2 x 10^{12} decays. Two different stopping target configurations were employed in independent data-taking periods. The combined results give tau_{mu^+}(MuLan) = 2196980.3(2.2) ps, more than 15 times as precise as any previous experiment. The muon lifetime gives the most precise value for the Fermi constant: G_F(MuLan) = 1.1663788 (7) x 10^-5 GeV^-2 (0.6 ppm). It is also used to extract the mu^-p singlet capture rate, which determines the proton's weak induced pseudoscalar coupling g_P.Comment: Accepted for publication in Phys. Rev. Let

    Measurement of the Resonant dμtd\mu t Molecular Formation Rate in Solid HD

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    Measurements of muon-catalyzed dt fusion (dμt→4He+n+μ−d\mu t \to ^4He+n+\mu^-) in solid HD have been performed. The theory describing the energy dependent resonant molecular formation rate for the reaction μt\mu t + HD →[(dμt)pee]∗\to [(d\mu t)pee]^* is compared to experimental results in a pure solid HD target. Constraints on the rates are inferred through the use of a Monte Carlo model developed specifically for the experiment. From the time-of- flight analysis of fusion events in 16 and 37 μg⋅cm−2\mu g\cdot cm^{-2} targets, an average formation rate consistent with 0.897±\pm(0.046)stat±_{stat}\pm (0.166)syst_{syst} times the theoretical prediction was obtained.Comment: 4 pages, 5 figure
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