4,746,097 research outputs found
Model Predictions for Neutrino Oscillation Parameters
We have surveyed leptonic and grand unified models of neutrino masses and
mixings in the literature which are still viable and give numerical predictions
for the reactor angle, . The results are of considerable interest
in anticipation of the next generation reactor experiments and the possible
future need for neutrino factories. Of the 63 models considered which were
published or posted on the Archive before June 2006, half predict values of
\sin^2 2\theta_{13} \gsim 0.015, which should yield positive signals for
disappearance in the reactor experiments planned for the near
future. Depending upon the outcome of those experiments, half of the models can
be eliminated on the basis of the presence or absence of such an observed
disappearance signal.Comment: 23 pages including 3 figures; published versio
Identification of left ventricular model parameters
Simulations with a model of left ventricular pressure generation consisting of time-varying elastance, resistance, series-elastance, and deactivation were fitted to pressure curves measured in the isolated rabbit ventricle. For constant ejection flows, a fit with a RMS error of 2.78 mmHg was obtained provided that deactivation was actually incorporated in the model. Deactivation was assumed to depend linearly on end ejection pressure. Resistance was found to be independent of volum
Galactic longitude dependent Galactic model parameters
We present the Galactic model parameters for thin disc estimated by Sloan
Digital Sky Survey (SDSS) data of 14 940 stars with apparent magnitudes
in six intermediate latitude fields in the first Galactic
quadrant. Star/galaxy separation was performed by using the photometric
pipeline and the isodensity contours in the two colour
diagram. The separation of thin disc stars is carried out by the bimodal
distribution of stars in the histogram, and the absolute magnitudes
were evaluated by a procedure presented in the literature Bilir et al. (2005).
Exponential density law fits better to the derived density functions for the
absolute magnitude intervals and , whereas
sech/sech laws are more appropriate for absolute magnitude intervals
and . We showed that the scaleheight and
scalelength are Galactic longitude dependent. The average values and ranges of
the scaleheight and the scalelength are pc ( pc)
and pc ( pc) respectively. This result would
be useful to explain different numerical values claimed for those parameters
obtained by different authors for the fields in different directions of the
Galaxy.Comment: 28 pages, including 12 figures and 7 tables, accepted for publication
in New Astronom
Volume limited dependent Galactic model parameters
We estimated 34 sets of Galactic model parameters for three intermediate
latitude fields with Galactic longitudes l=60, l=90, and l=180, and we
discussed their dependence on the volume. Also, we confirmed the variation of
these parameters with absolute magnitude and Galactic longitude. The star
samples in two fields are restricted with bright and unit absolute magnitude
intervals, (4,5], and (5,6], whereas for the third field a larger absolute
magnitude interval is adopted, (4,10]. The limiting apparent magnitudes of star
samples are g=15 and g=22.5 mag which provide space densities within distances
in the line of sight 0.9 and 25 kpc. The Galactic model parameters for the thin
disc are not volume dependent. However, the ones for thick disc and halo do
show spectacular trends in their variations with volume, except for the
scalelength of the thick disc. The local space density of the thick disc
increases, whereas the scaleheight of the same Galactic component decreases
monotonically. However, both model parameters approach asymptotic values at
large distances. The axial ratio of the halo increases abruptly for the volumes
where thick disc is dominant, whereas it approaches an asymptotic value
gradually for larger volumes, indicating a continuous transition from disclike
structure to a spherical one at the outermost region of the Galaxy. The
variation of the Galactic model parameters with absolute magnitude can be
explained by their dependence on the stellar luminosity, whereas the variation
with volume and Galactic longitude at short distances is a bias in analysis.Comment: 12 pages, including 8 figures and 5 tables, accepted for publication
in PAS
Projecting Ising Model Parameters for Fast Mixing
Inference in general Ising models is difficult, due to high treewidth making
tree-based algorithms intractable. Moreover, when interactions are strong,
Gibbs sampling may take exponential time to converge to the stationary
distribution. We present an algorithm to project Ising model parameters onto a
parameter set that is guaranteed to be fast mixing, under several divergences.
We find that Gibbs sampling using the projected parameters is more accurate
than with the original parameters when interaction strengths are strong and
when limited time is available for sampling.Comment: Advances in Neural Information Processing Systems 201
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