2,854 research outputs found
Color Filtering Localization for Three-Dimensional Underwater Acoustic Sensor Networks
Accurate localization for mobile nodes has been an important and fundamental
problem in underwater acoustic sensor networks (UASNs). The detection
information returned from a mobile node is meaningful only if its location is
known. In this paper, we propose two localization algorithms based on color
filtering technology called PCFL and ACFL. PCFL and ACFL aim at collaboratively
accomplishing accurate localization of underwater mobile nodes with minimum
energy expenditure. They both adopt the overlapping signal region of task
anchors which can communicate with the mobile node directly as the current
sampling area. PCFL employs the projected distances between each of the task
projections and the mobile node, while ACFL adopts the direct distance between
each of the task anchors and the mobile node. Also the proportion factor of
distance is proposed to weight the RGB values. By comparing the nearness
degrees of the RGB sequences between the samples and the mobile node, samples
can be filtered out. And the normalized nearness degrees are considered as the
weighted standards to calculate coordinates of the mobile nodes. The simulation
results show that the proposed methods have excellent localization performance
and can timely localize the mobile node. The average localization error of PCFL
can decline by about 30.4% than the AFLA method.Comment: 18 pages, 11 figures, 2 table
Application of the light-front holographic wavefunction for heavy-light pseudoscalar meson in decays
In this paper we extend our analyses of the decay constant and distribution
amplitude with an improved holographic wavefunction to the heavy-light
pseudoscalar mesons. In the evaluations, the helicity-dependence of the
holographic wavefunction is considered; and an independent mass scale parameter
is employed to moderate the strong suppression induced by the heavy quark.
Under the constraints from decay constants and masses of pseudoscalar mesons,
the -analyses for the holographic parameters exhibit a rough
consistence with the results obtained by fitting the Regge trajectory. With the
fitted parameters, the results for the decay constants and distribution
amplitudes are presented. We then show their application in evaluating the
decays, in which the power-suppressed spectator
scattering and weak annihilation corrections are first estimated. Numerically,
the spectator scattering and weak annihilation corrections present a negative
shift of about on the branching fractions; while, the predictions are
still larger than the experimental data. Such small negative shift confirms the
estimation based on the power counting rules.Comment: 10 pages, 5 figure
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