8,665 research outputs found
Latency Optimal Broadcasting in Noisy Wireless Mesh Networks
In this paper, we adopt a new noisy wireless network model introduced very
recently by Censor-Hillel et al. in [ACM PODC 2017, CHHZ17]. More specifically,
for a given noise parameter any sender has a probability of
of transmitting noise or any receiver of a single transmission in its
neighborhood has a probability of receiving noise.
In this paper, we first propose a new asymptotically latency-optimal
approximation algorithm (under faultless model) that can complete
single-message broadcasting task in time units/rounds in any
WMN of size and diameter . We then show this diameter-linear
broadcasting algorithm remains robust under the noisy wireless network model
and also improves the currently best known result in CHHZ17 by a
factor.
In this paper, we also further extend our robust single-message broadcasting
algorithm to multi-message broadcasting scenario and show it can broadcast
messages in time rounds. This new robust
multi-message broadcasting scheme is not only asymptotically optimal but also
answers affirmatively the problem left open in CHHZ17 on the existence of an
algorithm that is robust to sender and receiver faults and can broadcast
messages in time rounds.Comment: arXiv admin note: text overlap with arXiv:1705.07369 by other author
Revisiting B\to\pi K, \pi K^{\ast} and \rho K decays: CP violations and implication for New Physics
Combining the up-to-date experimental information on and decays, we revisit the decay rates and CP asymmetries of
these decays within the framework of QCD factorization. Using an infrared
finite gluon propagator of Cornwall prescription, we find that the time-like
annihilation amplitude could contribute a large strong phase, while the
space-like hard spectator scattering amplitude is real. Numerically, we find
that all the branching ratios and most of the direct CP violations, except
, agree with the current experimental data
with an effective gluon mass . Taking the unmatched
difference in direct CP violations between and
decays as a hint of new physics, we perform a
model-independent analysis of new physics contributions with a set of
(q=u,d) operators. Detail
analyses of the relative impacts of the operators are presented in five cases.
Fitting the twelve decay modes, parameter spaces are found generally with
nontrivial weak phases. Our results may indicate that both strong phase from
annihilation amplitude and new weak phase from new physics are needed to
resolve the puzzle. To further test the new physics hypothesis, the
mixing-induced CP violations in and are
discussed and good agreements with the recent experimental data are found.Comment: Version published in JHE
mixing within minimal flavor-violating two-Higgs-doublet models
In the "Higgs basis" for a generic 2HDM, only one scalar doublet gets a
nonzero vacuum expectation value and, under the criterion of minimal flavor
violation, the other one is fixed to be either color-singlet or color-octet,
which are named as the type-III and type-C models, respectively. In this paper,
the charged-Higgs effects of these two models on mixing are
studied. Firstly, we perform a complete one-loop computation of the
electro-weak corrections to the amplitudes of mixing.
Together with the up-to-date experimental measurements, a detailed
phenomenological analysis is then performed in the cases of both real and
complex Yukawa couplings of charged scalars to quarks. The spaces of model
parameters allowed by the current experimental data on
mixing are obtained and the differences between type-III and type-C models are
investigated, which is helpful to distinguish between these two models.Comment: 19 pages, 3 figures, 2 tables; More references and discussions added,
final version published in the journa
Chicken Feather Fibre Mat/PLA Composites for Thermal Insulation
In order to add more economic value to chicken feather, a waste material of the poultry industry, it has been researched to incorporate chicken feather fibre (CFF) into resin to produce value-added composites. In the present research, chicken feather fibre was separated from the rachises and used to produce fibre mats. Then fibre mats were incorporated into polylactic acid (PLA) to make composites with low thermal conductivity. The procedure for making chicken feather fibre mat using an automatic dynamic sheet former was explored. Two different composite fabrication methods were investigated. One involved fabricate composite samples by hot pressing chicken feather fibre mats with PLA sheet. The other involved making composite specimens by hot pressing PLA powder and chicken feather fibre mats. A decrease in tensile strength compared to PLA had been expected before composite specimen fabricating according to previous research and so alkali treated fibre mats were used to improve tensile strength of composites.
It was concluded that chicken feather fibre mats with uniform quality could be made by controlling the jet-to-spin ratio and water wall thickness of the dynamic sheet former cylinder. Stable mat/PLA composites could be fabricated by hot pressing chicken feather fibre mats with PLA powder. Results from tensile testing indicated that alkali treatment could improve tensile strength to a small degree. SEM image analysis revealed that poor interfacial bonding between fibre barbs and PLA matrix had occurred. Thermal conductivity testing demonstrated improved thermal insulation with addition of CFF to PLA
Perturbative QCD study of decays to a pseudoscalar meson and a tensor meson
We study two-body hadronic decays, with being a light
pseudoscalar (tensor) meson, in the perturbative QCD approach. The CP-averaged
branching ratios and the direct CP asymmetries of the modes are
predicted, where is the difference between the strange numbers of
final and initial states. We also define and calculate experimental observables
for the modes under the mixing, including CP
averaged branching ratios, time-integrated CP asymmetries, and the CP
observables , and . Results are compared to the ones in the literature, and to the ones, which indicate
considerable U-spin symmetry breaking. Our work provides theoretical
predictions for the decays for the first time, some of which will
be potentially measurable at future experiments.Comment: 6 pages, 1 figur
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