17,689 research outputs found
Enabling Quality-Driven Scalable Video Transmission over Multi-User NOMA System
Recently, non-orthogonal multiple access (NOMA) has been proposed to achieve
higher spectral efficiency over conventional orthogonal multiple access.
Although it has the potential to meet increasing demands of video services, it
is still challenging to provide high performance video streaming. In this
research, we investigate, for the first time, a multi-user NOMA system design
for video transmission. Various NOMA systems have been proposed for data
transmission in terms of throughput or reliability. However, the perceived
quality, or the quality-of-experience of users, is more critical for video
transmission. Based on this observation, we design a quality-driven scalable
video transmission framework with cross-layer support for multi-user NOMA. To
enable low complexity multi-user NOMA operations, a novel user grouping
strategy is proposed. The key features in the proposed framework include the
integration of the quality model for encoded video with the physical layer
model for NOMA transmission, and the formulation of multi-user NOMA-based video
transmission as a quality-driven power allocation problem. As the problem is
non-concave, a global optimal algorithm based on the hidden monotonic property
and a suboptimal algorithm with polynomial time complexity are developed.
Simulation results show that the proposed multi-user NOMA system outperforms
existing schemes in various video delivery scenarios.Comment: 9 pages, 6 figures. This paper has already been accepted by IEEE
INFOCOM 201
Neutron-skin thickness of finite nuclei in relativistic mean-field models with chiral limits
We study several structure properties of finite nuclei using relativistic
mean-field Lagrangians constructed according to the Brown-Rho scaling due to
the chiral symmetry restoration at high densities. The models are consistent
with current experimental constraints for the equations of state of symmetric
matter at both normal and supra-normal densities and of asymmetric matter at
sub-saturation densities. It is shown that these models can successfully
describe the binding energies and charge radii of finite nuclei. Compared to
calculations with usual relativistic mean-field models, these models give a
reduced thickness of neutron skin in ^{208}Pb between 0.17 fm and 0.21 fm. The
reduction of the predicted neutron skin thickness is found to be due to not
only the softening of the symmetry energy but also the scaling property of
meson required by the partial restoration of chiral symmetry.Comment: Accepted version to appear in PRC (2007
Large-mass neutron stars with hyperonization
Within a density-dependent relativistic mean-field model using in-medium
meson-hadron coupling constants and meson masses, we explore effects of
in-medium hyperon interactions on properties of neutron stars. It is found that
the hyperonic constituents in large-mass neutron stars can not be simply ruled
out, while the recently measured mass of the millisecond pulsar J1614-2230 can
constrain significantly the in-medium hyperon interactions. Moreover, effects
of nuclear symmetry energy on hyperonization in neutron stars are also
discussed
Manufacture’s Production and Pricing Strategies With Carbon Tax Policy and Strategic Customer Behavior
This paper investigates the manufacture’s production and pricing strategies with carbon tax policy and strategic customer behavior, and analyze the impact of carbon tax policy and its parameter on the manufacturer’s optimal strategies and maximum expected profit. We derive the optimal production, pricing strategies and maximum expected profit under the rational expectations equilibrium. The results show that the manufacturer’s optimal production quantity and maximum expected profit are decreasing in carbon tax rate, and the manufacturer’s optimal price is increasing in the carbon tax rate. Compared with the no carbon emission policy scenario, we prove that the manufacturer’s optimal production quantity decreases, the manufacturer’s optimal price increases, the manufacturer’s maximum expected profit decreases, and the carbon tax policy effectively reduces the manufacturer’s carbon emissions
Consistency check of charged hadron multiplicities and fragmentation functions in SIDIS
We derived the conditions on certain combinations of integrals of the
fragmentation functions of pion using HERMES data of the sum for the charged
pion multiplicities from semi-inclusive deep-inelastic scattering (SIDIS) off
the deuteron target. In our derivation the nucleon parton distribution
functions (PDFs) are assumed to be isospin SU(2) symmetric. Similar conditions
have also been obtained for the fragmentation functions (FFs) of kaon by the
sum of charged kaon multiplicities as well. We have chosen several FFs to study
the impact of those conditions we have derived. Among those FFs, only that
produced in the nonlocal chiral-quark model (NLQM) constantly satisfy the
conditions. Furthermore, the ratios of the strange PDFs and the
nonstrange PDFs extracted from the charged pion and kaon
multiplicities differ from each other significantly. Finally, we demonstrate
that the HERMES pion multiplicity data is unlikely to be compatible with the
two widely-used PDFs, namely CTEQ6M and NNPDF3.0.Comment: 11 pages, 5 fig
Combined explanations of -physics anomalies, and neutrino masses by scalar leptoquarks
We extend the contents of the standard model (SM) by introducing TeV-scale
scalar leptoquarks to generate neutrino masses and explain some current
observed deviations from the SM predictions, including the anomalous magnetic
moments of charged leptons (electron and muon) and -physics anomalies
( and ). The model consists of
singlet leptoquark , doublet leptoquark
and triplet leptoquark . We combine the constraints arising from the low-energy lepton flavor
violation, meson decay and mixing observables. We perform a detailed
phenomenological analysis and identify the minimized texture of leptoquark
Yukawa matrices to accommodate a unified explanation of the anomalies and
neutrino oscillation data.Comment: 30 pages, 5 figures, matches published versio
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