20,403 research outputs found
FURY: Fuzzy unification and resolution based on edit distance
We present a theoretically founded framework for fuzzy
unification and resolution based on edit distance over trees.
Our framework extends classical unification and resolution
conservatively. We prove important properties of the framework
and develop the FURY system, which implements the
framework efficiently using dynamic programming. We
evaluate the framework and system on a large problem in
the bioinformatics domain, that of detecting typographical
errors in an enzyme name databas
Optical links in the angle-data assembly of the 70-meter antennas
In the precision-pointing mode the 70 meter antennas utilize an optical link provided by an autocollimator. In an effort to improve reliability and performance, commercial instruments were evaluated as replacement candidates, and upgraded versions of the existing instruments were designed and tested. The latter were selected for the Neptune encounter, but commercial instruments with digital output show promise of significant performance improvement for the post-encounter period
Kinetic Roughening in Growth Models with Diffusion in Higher Dimensions
We present results of numerical simulations of kinetic roughening for a
growth model with surface diffusion (the Wolf-Villain model) in 3+1 and
4+1~dimensions using lattices of a linear size up to in 3+1~D and
in 4+1~D. The effective exponents calculated both from the surface width and
from the height--height correlation function are much larger than those
expected based on results in lower dimensions, due to a growth instability
which leads to the evolution of large mounded structures on the surface. An
increase of the range for incorporation of a freshly deposited particle leads
to a decrease of the roughness but does not suppress the instability.Comment: 8 pages, LaTeX 2.09, IC-DDV-93-00
Photoelasticity of sodium silicate glass from first principles
Based on density-functional perturbation theory we have computed the
photoelastic tensor of a model of sodium silicate glass of composition
(NaO)(SiO) (NS3). The model (containig 84 atoms) is
obtained by quenching from the melt in combined classical and Car-Parrinello
molecular dynamics simulations. The calculated photoelastic coefficients are in
good agreement with experimental data. In particular, the calculation
reproduces quantitatively the decrease of the photoelastic response induced by
the insertion of Na, as measured experimentally.
The extension to NS3 of a phenomenological model developed in a previous work
for pure a-SiO indicates that the modulation upon strain of other
structural parameters besides the SiOSi angles must be invoked to explain the
change in the photoelstic response induced by Na
Scaling of Local Slopes, Conservation Laws and Anomalous Roughening in Surface Growth
We argue that symmetries and conservation laws greatly restrict the form of
the terms entering the long wavelength description of growth models exhibiting
anomalous roughening. This is exploited to show by dynamic renormalization
group arguments that intrinsic anomalous roughening cannot occur in local
growth models. However some conserved dynamics may display super-roughening if
a given type of terms are present.Comment: To appear in Phys. Rev. Lett., 4 pages in RevTeX style, no fig
Counter Rotating Open Rotor Animation using Particle Image Velocimetry
This article describes the two accompanying fluid dynamics videos for the
"Counter rotating open rotor flow field investigation using stereoscopic
Particle Image Velocimetry" presented at the 64th Annual Meeting of the APS
Division of Fluid Dynamics in Baltimore, Maryland, November 20-22, 2011.Comment: Videos are include
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