9,332 research outputs found
Digital system detects binary code patterns containing errors
System of square loop magnetic cores associated with code input registers to react to input code patterns by reference to a group of control cores in such a manner that errors are canceled and patterns containing errors are accepted for amplification and processing. This technique improves reception capabilities in PCM telemetry systems
Shuttle unified navigation filter, revision 1
Equations designed to meet the navigation requirements of the separate shuttle mission phases are presented in a series of reports entitled, Space Shuttle GN and C Equation Document. The development of these equations is based on performance studies carried out for each particular mission phase. Although navigation equations have been documented separately for each mission phase, a single unified navigation filter design is embodied in these separate designs. The purpose of this document is to present the shuttle navigation equations in a form in which they would most likely be coded-as the single unified navigation filter used in each mission phase. This document will then serve as a single general reference for the navigation equations replacing each of the individual mission phase navigation documents (which may still be used as a description of a particular navigation phase)
Democratic Dissent and the Politics of Rescue during the Twenty-first Century’s “Inhospitable” EU Migration “Crisis”
This article uses critical approaches to examine the ways in which dissenters have objected to the European Union’s current “politics of rescue.” The authors argue that the term “hospitality” has been a key term in liberal theorizing about mobility since the Enlightenment, but that various neo-liberal “pull” theories, worries about securitization and the militarization of rescue efforts in the Mediterranean have converged in ways that have turned Europe into an “inhospitable” place for foreigners. The authors use three short case studies—of maritime captains’ and sailors’ rescue efforts, academic critiques of FRONTEX, and vernacular reactions to the iconic Kurdi image—to put on display the contradictions that exist when illiberal decisions are made by EU communities that are supposed to be democratically governed by hospitality principles. They also argue that the focus on the social agency of “traffickers” deflects attention away from the structural and colonial facets of these migration “crises.
An Automatic Algorithm for Minimizing Anomalies and Discrepancies in Point Clouds Acquired by Laser Scanning Technique
An Improved Description of the Dielectric Breakdown in Oxides Based on a Generalized Weibull distribution
In this work, we address modal parameter fluctuations in statistical
distributions describing charge-to-breakdown and/or
time-to-breakdown during the dielectric breakdown regime of
ultra-thin oxides, which are of high interest for the advancement of electronic
technology. We reobtain a generalized Weibull distribution (-Weibull), which
properly describes data when oxide thickness fluctuations are
present, in order to improve reliability assessment of ultra-thin oxides by
time-to-breakdown extrapolation and area scaling. The incorporation
of fluctuations allows a physical interpretation of the -Weibull
distribution in connection with the Tsallis statistics. In support to our
results, we analyze data of SiO-based MOS devices obtained
experimentally and theoretically through a percolation model, demonstrating an
advantageous description of the dielectric breakdown by the -Weibull
distribution.Comment: 5 pages, 3 figure
N=2 Conformal Superspace in Four Dimensions
We develop the geometry of four dimensional N=2 superspace where the entire
conformal algebra of SU(2,2|2) is realized linearly in the structure group
rather than just the SL(2,C) x U(2)_R subgroup of Lorentz and R-symmetries,
extending to N=2 our prior result for N=1 superspace. This formulation
explicitly lifts to superspace the existing methods of the N=2 superconformal
tensor calculus; at the same time the geometry, when degauged to SL(2,C) x
U(2)_R, reproduces the existing formulation of N=2 conformal supergravity
constructed by Howe.Comment: 43 pages; v2 references added, acknowledgments update
Surface-Barrier Effects in the Microwave Second-Harmonic Response of Superconductors in the Mixed State
We report on transient effects in the microwave second-order response of
different type of superconductors in the mixed state. The samples have
contemporarily been exposed to a dc magnetic field, varying with a constant
rate of 60 Oe/s, and a pulsed microwave magnetic field. The time evolution of
the signal radiated at the second-harmonic frequency of the driving field has
been measured for about 500 s from the instant in which the dc-field sweep has
been stopped, with sampling time of about 0.3 s. We show that the
second-harmonic signal exhibits two relaxation regimes; an initial exponential
decay, which endures roughly 10 s, and a logarithmic decay in the time scale of
minutes. Evidence is given that the decay in the time scale of minutes is ruled
by magnetic relaxation over the surface barrier.Comment: 6 pages, 6 embedded figure
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