10,978 research outputs found

    Grille spectrometer (grille)

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    The Grille spectrometer was designed and flown on Spaceklab 1 by two organizations: The Office National d'Etudes et de Recherches Aerospatiales in France and the Belgian Institute for Space Aeronomy in Belgium. Its purpose is to study, on a global scale, atmospheric parameters between 15 and 150 km altitude. The investigation uses high-resolution (better than 0.1/cm) spectroscopic observations of the earth's limb in the wavelength range characteristic of the vibrational-rotational lines of the relevant atmospheric constituents. Characteristics and proposed modifications of the grille spectrometer are described. This instrument will be part of the atmospheric science research payload flown on the Atmospheric Laboratory for Applications and Science (ATLAS 1) NASA mission planned for late 1990

    From vertex detectors to inner trackers with CMOS pixel sensors

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    The use of CMOS Pixel Sensors (CPS) for high resolution and low material vertex detectors has been validated with the 2014 and 2015 physics runs of the STAR-PXL detector at RHIC/BNL. This opens the door to the use of CPS for inner tracking devices, with 10-100 times larger sensitive area, which require therefore a sensor design privileging power saving, response uniformity and robustness. The 350 nm CMOS technology used for the STAR-PXL sensors was considered as too poorly suited to upcoming applications like the upgraded ALICE Inner Tracking System (ITS), which requires sensors with one order of magnitude improvement on readout speed and improved radiation tolerance. This triggered the exploration of a deeper sub-micron CMOS technology, Tower-Jazz 180 nm, for the design of a CPS well adapted for the new ALICE-ITS running conditions. This paper reports the R&D results for the conception of a CPS well adapted for the ALICE-ITS.Comment: 4 pages, 4 figures, VCI 2016 conference proceeding

    Dual use of budgeting in uncertainty contexts: Explorative study of senior sales and marketing managers

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    Based on prior accounting literature and Simons’ framework (1990, 1995), the authors explore the use of budgets in PEU situations in a qualitative study. They conducted a field-based study and interviewed 14 senior sales and marketing managers from various industries, using projective techniques imported from psychological research.budgeting; uncertainty; perceived environmental uncertainty (PEU); interactive control system (ICS); sales and marketing managers

    Interface Engineering to Create a Strong Spin Filter Contact to Silicon

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    Integrating epitaxial and ferromagnetic Europium Oxide (EuO) directly on silicon is a perfect route to enrich silicon nanotechnology with spin filter functionality. To date, the inherent chemical reactivity between EuO and Si has prevented a heteroepitaxial integration without significant contaminations of the interface with Eu silicides and Si oxides. We present a solution to this long-standing problem by applying two complementary passivation techniques for the reactive EuO/Si interface: (ii) an insituin\:situ hydrogen-Si (001)(001) passivation and (iiii) the application of oxygen-protective Eu monolayers --- without using any additional buffer layers. By careful chemical depth profiling of the oxide-semiconductor interface via hard x-ray photoemission spectroscopy, we show how to systematically minimize both Eu silicide and Si oxide formation to the sub-monolayer regime --- and how to ultimately interface-engineer chemically clean, heteroepitaxial and ferromagnetic EuO/Si (001)(001) in order to create a strong spin filter contact to silicon.Comment: 11 pages of scientific paper, 10 high-resolution color figures. Supplemental information on the thermodynamic problem available (PDF). High-resolution abstract graphic available (PNG). Original research (2016

    Charm meson resonances in DPνD \to P \ell \nu decays

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    Motivated by recent experimental results we reconsider semileptonic DPνD \to P \ell \nu_{\ell} decays within a model which combines heavy quark symmetry and properties of the chiral Lagrangian. We include excited charm meson states, some of them recently observed, in our Lagrangian and determine their impact on the charm meson semileptonic form factors. We find that the inclusion of excited charm meson states in the model leads to a rather good agreement with the experimental results on the q2q^2 shape of the F+(q2)F_+(q^2) form factor. We also calculate branching ratios for all DPνD \to P \ell \nu_{\ell} decays.Comment: 9 pages, 4 figures; minor corrections, added some discussion, version as publishe

    Percepção de incongruências no contorno entonacional de frases e de melodias por crianças com, ou sem, treino musical

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    A prosódia está relacionada com a materialização da linguagem enquanto estímulo acústico. Constituem aspectos da prosódia a entoação, o ritmo, a intensidade e as pausas linguísticas (Ladefoged, 1982). Alguns destes aspectos são comuns à música. No caso da entoação da fala, esta é análoga à melodia em música. A prosódia de uma frase falada e a melodia de um trecho musical apresentam componentes estruturais muito semelhantes. O presente estudo aborda esta questão do ponto de vista psicológico. Trata-se de um estudo sobre a percepção de melodias e de prosódia, realizado no seguimento de Schön et al (2002), cuja problemática está centrada no contorno da frequência fundamental ( fo) da entoação em fala e da melodia em música. Pretendese averiguar se há ou não uma correlação entre a percepção prosódica e a percepção melódica; e se a aprendizagem musical pode potenciar o desenvolvimento da capacidade de percepção prosódica, nomeadamente no que diz respeito ao contorno entonacional. A metodologia empregue é comportamental (medida dos tempos de reacção, percentagem de repostas correctas e sensibilidade, d’). Os participantes do estudo são dois grupos de crianças do 4.º ano de escolaridade: um com aprendizagem musical desde o 1.º ano de escolaridade e outro sem aprendizagem musical formal. Os resultados indicaram que não existem diferenças significativas entre os dois grupos de crianças. Contudo, as crianças com melhor performance na tarefa musical, independentemente do grupo a que pertencem, são as que têm melhor performance na tarefa de linguagem. Este facto pode ser indicador de uma predisposição musical que pode influenciar o desenvolvimento da percepção das características entonacionais da linguagem

    On the Determination of a1a_1 and a2a_2 from Hadronic Two Body BB Decays

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    {}From Class I decays : B^o \ra \pi^+ ( \rho^+ ) + D^- ( {D^*}^- ), we determine a1a_1, and from Class III decays : B^+ \ra \pi^+ ( \rho^+ ) + \ol{D}^o ( {\ol{D}^*}^o ), we determine an allowed domain in the (a1,a2)( a_1, a_2 ) plane. We find that within one standard deviation errors, the allowed band of a1a_1 from Class I decays is at least three standard deviations removed from the allowed domain (a1,a2)( a_1, a_2 ) from Class III decays.If we expand the experimental errors to two standard deviations we do find a small intersection between the a1a_1 band and the allowed (a1,a2)( a_1, a_2 ) domain. The results usually quoted in the literature lie in this intersection. We suggest : (1) an independent measurement of the branching ratio for the Class III decay, B^+ \ra \rho^+ \ol{D}^o , (2) a high-statistics measurement of the branching ratio of the Class I decay, B \ra \ol{D} ( \ol{D}^* ) + D_s ( D_s^* ) in both charged states, and (3) a measurement of the longitudinal polarization fraction in the Class III decay B^+ \ra \rho^+ {\ol{D}^*}^o to shed more light on the questions involved .Comment: 9pages(Latex)+4 figures(PS file appended), PAR/LPTHE/94-2

    Statistical region-based active contours for segmentation: an overview

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    International audienceIn this paper we propose a brief survey on geometric variational approaches and more precisely on statistical region-based active contours for medical image segmentation. In these approaches, image features are considered as random variables whose distribution may be either parametric, and belongs to the exponential family, or non-parametric estimated with a kernel density method. Statistical region-based terms are listed and reviewed showing that these terms can depict a wide spectrum of segmentation problems. A shape prior can also be incorporated to the previous statistical terms. A discussion of some optimization schemes available to solve the variational problem is also provided. Examples on real medical images are given to illustrate some of the given criteria
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