14,117 research outputs found

    The advanced receiver 2: Telemetry test results in CTA 21

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    Telemetry tests with the Advanced Receiver II (ARX II) in Compatibility Test Area 21 are described. The ARX II was operated in parallel with a Block-III Receiver/baseband processor assembly combination (BLK-III/BPA) and a Block III Receiver/subcarrier demodulation assembly/symbol synchronization assembly combination (BLK-III/SDA/SSA). The telemetry simulator assembly provided the test signal for all three configurations, and the symbol signal to noise ratio as well as the symbol error rates were measured and compared. Furthermore, bit error rates were also measured by the system performance test computer for all three systems. Results indicate that the ARX-II telemetry performance is comparable and sometimes superior to the BLK-III/BPA and BLK-III/SDA/SSA combinations

    Spatial and temporal aspects of visual backward masking in children and young adolescents

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    We thank Marc Repnow for his help setting up the experiments. In addition, we thank two anonymous reviewers for their very thoughtful and helpful comments. This work was supported by the Volkswagen Foundation project ā€œBetween Europe and the Orientā€”A Focus on Research and Higher Education in/on Central Asia and the Caucasusā€ and by the VELUX Foundation project ā€œPerception, Cognition and Healthy Brain Aging.ā€Peer reviewedPublisher PD

    Generalized Attractor Points in Gauged Supergravity

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    The attractor mechanism governs the near-horizon geometry of extremal black holes in ungauged 4D N=2 supergravity theories and in Calabi-Yau compactifications of string theory. In this paper, we study a natural generalization of this mechanism to solutions of arbitrary 4D N=2 gauged supergravities. We define generalized attractor points as solutions of an ansatz which reduces the Einstein, gauge field, and scalar equations of motion to algebraic equations. The simplest generalized attractor geometries are characterized by non-vanishing constant anholonomy coefficients in an orthonormal frame. Basic examples include Lifshitz and Schrodinger solutions, as well as AdS and dS vacua. There is a generalized attractor potential whose critical points are the attractor points, and its extremization explains the algebraic nature of the equations governing both supersymmetric and non-supersymmetric attractors.Comment: 31 pages, LaTeX; v2, references fixed; v3, minor changes, version to appear in Phys. Rev.
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