9,490 research outputs found
Recover Subjective Quality Scores from Noisy Measurements
Simple quality metrics such as PSNR are known to not correlate well with
subjective quality when tested across a wide spectrum of video content or
quality regime. Recently, efforts have been made in designing objective quality
metrics trained on subjective data (e.g. VMAF), demonstrating better
correlation with video quality perceived by human. Clearly, the accuracy of
such a metric heavily depends on the quality of the subjective data that it is
trained on. In this paper, we propose a new approach to recover subjective
quality scores from noisy raw measurements, using maximum likelihood
estimation, by jointly estimating the subjective quality of impaired videos,
the bias and consistency of test subjects, and the ambiguity of video contents
all together. We also derive closed-from expression for the confidence interval
of each estimate. Compared to previous methods which partially exploit the
subjective information, our approach is able to exploit the information in
full, yielding tighter confidence interval and better handling of outliers
without the need for z-scoring or subject rejection. It also handles missing
data more gracefully. Finally, as side information, it provides interesting
insights on the test subjects and video contents.Comment: 16 pages; abridged version appeared in Data Compression Conference
(DCC) 201
Hindered magnetic dipole transitions between P-wave bottomonia and coupled-channel effects
In the hindered magnetic dipole transitions of heavy quarkonia, the
coupled-channel effects originating from the coupling of quarkonia to a pair of
heavy and anti-heavy mesons can play a dominant role. Here, we study the
hindered magnetic dipole transitions between two -wave bottomonia, and , with . In these processes the
coupled-channel effects are expected to lead to partial widths much larger than
the quark model predictions. We estimate these partial widths which, however,
are very sensitive to unknown coupling constants related to the vertices
. A measurement of the hindered M1 transitions can shed
light on the coupled-channel dynamics in these transitions and hence on the
size of the coupling constants. We also suggest to check the coupled-channel
effects by comparing results from quenched and fully dynamical lattice QCD
calculations.Comment: 10 pages, 2 figures, version accepted for publication in Physics
Letters
Lorentz violation dispersion relation and its application
We derive a modified dispersion relation (MDR) in the Lorentz violation
extension of quantum electrodynamics (QED) sector in the standard model
extension (SME) framework. Based on the extended Dirac equation and
corresponding MDR, we observe the resemblance of the Lorentz violation coupling
with spin-gravity coupling. We also develop a neutrino oscillation mechanism
induced by the presence of nondiagonal terms of Lorentz violation couplings in
2-flavor space in a 2-spinor formalism by explicitly assuming neutrinos to be
Marjorana fermions. We also obtain a much stringent bound ()
on one of the Lorentz violation parameters by applying MDR to the ultrahigh
energy cosmic ray (UHECR) problem.Comment: 22 Latex pages, final version in publicatio
Analysis of the vertex with the light-cone QCD sum rules
In this article, we analyze the vertex with the light-cone QCD
sum rules. The strong coupling constant is an important
parameter in evaluating the charmonium absorption cross sections in searching
for the quark-gluon plasmas. Our numerical value for the is
consistent with the prediction of the effective SU(4) symmetry and vector meson
dominance theory.Comment: 6 pages, 1 figure, revised versio
Stability of parallel/perpendicular domain boundaries in lamellar block copolymers under oscillatory shear
We introduce a model constitutive law for the dissipative stress tensor of
lamellar phases to account for low frequency and long wavelength flows. Given
the uniaxial symmetry of these phases, we argue that the stress tensor must be
the same as that of a nematic but with the local order parameter being the
slowly varying lamellar wavevector. This assumption leads to a dependence of
the effective dynamic viscosity on orientation of the lamellar phase. We then
consider a model configuration comprising a domain boundary separating
laterally unbounded domains of so called parallel and perpendicularly oriented
lamellae in a uniform, oscillatory, shear flow, and show that the configuration
can be hydrodynamically unstable for the constitutive law chosen. It is argued
that this instability and the secondary flows it creates can be used to infer a
possible mechanism for orientation selection in shear experiments.Comment: 26 pages, 10 figure
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