32,488 research outputs found

    Observational data formats and identification of supplementary documentation for the National Geodetic Satellite Program

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    Observational formats for geodetic tracking data and supporting documentation for data reductio

    Higher dimensional models of light Majorana neutrinos confronted by data

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    We discuss experimental and observational constraints on certain models of higher dimensional light Majorana neutrinos. Models with flavor blind brane-bulk couplings plus three or four flavor diagonal light Majorana neutrinos on the brane, with subsequent mixing induced solely by the Kaluza-Klein tower of states, are found to be excluded by data on the oscillations of solar, atmospheric and reactor neutrinos, taken together with the WMAP upper bound on the sum of neutrino masses. Extra dimensions, if relevant to neutrino mixing, need to discriminate between neutrino flavors.Comment: 5 pages, Revtex4, 2 PS figures. Fig. 2a and 2b from earlier version are now combined into one figure. Minor modifications in the text. References adde

    Modeling the Field Emission Current Fluctuation in Carbon Nanotube Thin Films

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    Owing to their distinct properties, carbon nanotubes (CNTs) have emerged as promising candidate for field emission devices. It has been found experimentally that the results related to the field emission performance show variability. The design of an efficient field emitting device requires the analysis of the variabilities with a systematic and multiphysics based modeling approach. In this paper, we develop a model of randomly oriented CNTs in a thin film by coupling the field emission phenomena, the electron-phonon transport and the mechanics of single isolated CNT. A computational scheme is developed by which the states of CNTs are updated in time incremental manner. The device current is calculated by using Fowler-Nordheim equation for field emission to study the performance at the device scale.Comment: 4 pages, 5 figure

    Folding model analysis of proton radioactivity of spherical proton emitters

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    Half lives of the decays of spherical nuclei away from proton drip line by proton emissions are estimated theoretically. The quantum mechanical tunneling probability is calculated within the WKB approximation. Microscopic proton-nucleus interaction potentials are obtained by single folding the densities of the daughter nuclei with M3Y effective interaction supplemented by a zero-range pseudo-potential for exchange along with the density dependence. Strengths of the M3Y interaction are extracted by fitting its matrix elements in an oscillator basis to those elements of the G-matrix obtained with the Reid-Elliott soft-core nucleon-nucleon interaction. Parameters of the density dependence are obtained from the nuclear matter calculations. Spherical charge distributions are used for calculating the Coulomb interaction potentials. These calculations provide reasonable estimates for the observed proton radioactivity lifetimes of proton rich nuclei for proton emissions from 26 ground and isomeric states of spherical proton emitters.Comment: 6 page

    Acoustic Integrity Codes: Secure Device Pairing Using Short-Range Acoustic Communication

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    Secure Device Pairing (SDP) relies on an out-of-band channel to authenticate devices. This requires a common hardware interface, which limits the use of existing SDP systems. We propose to use short-range acoustic communication for the initial pairing. Audio hardware is commonly available on existing off-the-shelf devices and can be accessed from user space without requiring firmware or hardware modifications. We improve upon previous approaches by designing Acoustic Integrity Codes (AICs): a modulation scheme that provides message authentication on the acoustic physical layer. We analyze their security and demonstrate that we can defend against signal cancellation attacks by designing signals with low autocorrelation. Our system can detect overshadowing attacks using a ternary decision function with a threshold. In our evaluation of this SDP scheme's security and robustness, we achieve a bit error ratio below 0.1% for a net bit rate of 100 bps with a signal-to-noise ratio (SNR) of 14 dB. Using our open-source proof-of-concept implementation on Android smartphones, we demonstrate pairing between different smartphone models.Comment: 11 pages, 11 figures. Published at ACM WiSec 2020 (13th ACM Conference on Security and Privacy in Wireless and Mobile Networks). Updated reference

    Prevalensi Dan Keberadaan Vektor Malaria Di Desa Teluk Limau, Kecamatan Jebus, Kabupaten Bangka Barat, Provinsi Bangka Belitung

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    . Malaria elimination in Indonesia need necessary data as a foundation for planning and implementation activities. The purpose of this study was to estimate the malaria prevalence and the presence of potential mosquito vectors. To find out malaria endemicity, blood of sampling group was examined in the study area on 24-30 November 2010. Suspected vector mosquitoes collection was carried out by human landing method on the inside and outside of the house for 12 hours from 18:00 until 06:00. Positive SD percentage from inspection reached 4.21% (18 of 428 SD). Gametocytes SD percentage reached 18.75%, where 3 of 18 positives SD has a gametocytes. Two mosquitoes Anopheles spp. found were an An. sundaicus and An. letifer. The number of An. sundaicus trapped outdoors were five, An. letifer trapped in the house were three and An. letifer trapped outdoors were eight. This result showed malaria transmission potential in the study site and malaria surveillance should be done. It is recommended to distribute insecticide-treated nets and suggest the residents not to stayed outside the house at night to often

    Random-phase reservoir and a quantum resistor: The Lloyd model

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    We introduce phase disorder in a 1D quantum resistor through the formal device of `fake channels' distributed uniformly over its length such that the out-coupled wave amplitude is re-injected back into the system, but with a phase which is random. The associated scattering problem is treated via invariant imbedding in the continuum limit, and the resulting transport equation is found to correspond exactly to the Lloyd model. The latter has been a subject of much interest in recent years. This conversion of the random phase into the random Cauchy potential is a notable feature of our work. It is further argued that our phase-randomizing reservoir, as distinct from the well known phase-breaking reservoirs, induces no decoherence, but essentially destroys all interference effects other than the coherent back scattering.Comment: 4 pages,5 figure
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