66,679 research outputs found
Performance Analysis of Best Relaying Protocol Selection with Interferences at Relays
In this paper, we investigate the performance of selecting the best protocol between amplify and forward (AF) and decode and forward (DF) in multiple relay networks with multiple interferences at relays. In the selection scheme, the best protocol between AF and DF is selected depending on the comparisons of signal-to-interference and noise ratio (SINR) for all source-relay links. All relays measure the received SINR to decide forwarding signal or not. When SINR is above a certain threshold then DF is used otherwise AF is used. Particularly, we develop an accurate mathematical model for best relaying protocol by considering the effect of interferences to our scheme. Firstly, we derive the asymptotic closed form expression for the symbol error rate (SER) for the system under study. Also we derive an upper and lower bound of symbol error rate and show how they were tight with exact SER. Furthermore an approximate expression for the outage probability is derived. Numerical results are finally presented to validate the theoretical analysis with a different number of relays
The Leptoquark Implication from the CMS and IceCube Experiments
The recent excess in the CMS measurements of and channels
and the emergence of PeV comsic neutrino events at the IceCube experiment share
an intriguing implication for a leptoquark with a 600-650 GeV mass. We
investigate the CMS constraints on the flavor structure of a scenario with the
minimal leptoquark Yukawa couplings and correlate such a scenario to the
resonant enhancement in the very high energy shower event rates at the IceCube.
We find for a single leptoquark, the CMS signals require large couplings to the
third generation leptons. This leads to an enhancement in the
-nucleon scattering cross-section and subsequently more
events at PeV energies. However, a visible enhancement above the Standard Model
scattering would require a leptoquark Yukawa coupling larger than one that can
be easily tested at the upcoming LHC runs.Comment: PRD version. Meson decay constraints and additional citations are
added. 6 pages, 2 figures, 1 tabl
Eulerian and modified Lagrangian approaches to multi-dimensional condensation and collection
Turbulence is argued to play a crucial role in cloud droplet growth. The
combined problem of turbulence and cloud droplet growth is numerically
challenging. Here, an Eulerian scheme based on the Smoluchowski equation is
compared with two Lagrangian superparticle (or su- perdroplet) schemes in the
presence of condensation and collection. The growth processes are studied
either separately or in combination using either two-dimensional turbulence, a
steady flow, or just gravitational acceleration without gas flow. Good
agreement between the differ- ent schemes for the time evolution of the size
spectra is observed in the presence of gravity or turbulence. Higher moments of
the size spectra are found to be a useful tool to characterize the growth of
the largest drops through collection. Remarkably, the tails of the size spectra
are reasonably well described by a gamma distribution in cases with gravity or
turbulence. The Lagrangian schemes are generally found to be superior over the
Eulerian one in terms of computational performance. However, it is shown that
the use of interpolation schemes such as the cloud-in-cell algorithm is
detrimental in connection with superparticle or superdroplet approaches.
Furthermore, the use of symmetric over asymmetric collection schemes is shown
to reduce the amount of scatter in the results.Comment: 36 pages, 17 figure
Adiabatic and non-adiabatic perturbations for loop quantum cosmology
We generalize the perturbations theory of loop quantum cosmology to a
hydrodynamical form and define an effective curvature perturbation on an
uniform density hypersurfaces . As in the classical cosmology,
should be gauge-invariant and conservation on the large scales. The
evolutions of both the adiabatic and the non-adiabatic perturbations for a
multi-fluids model are investigated in the framework of the effective
hydrodynamical theory of loop quantum cosmology with the inverse triad
correction. We find that, different from the classical cosmology, the evolution
of the large-scales non-adiabatic entropy perturbation can be driven by an
adiabatic curvature perturbation and this adiabatic source for the
non-adiabatic perturbation is a quantum effect. As an application of the
related formalism, we study a decay model and give out the numerical results.Comment: 10 pages, 3 figure
Geometric curvatures of plane symmetry black hole
In this paper, we study the properties and thermodynamic stability of the
plane symmetry black hole from the viewpoint of geometry. Weinhold metric and
Ruppeiner metric are obtained, respectively. The Weinhold curvature gives phase
transition points, which correspond to the first-order phase transition only at
N=1, where is a parameter in the plane symmetry black hole. While the
Ruppeiner one shows first-order phase transition points for arbitrary . Both of which give no any information about the second-order phase
transition. Considering the Legendre invariant proposed by Quevedo et. al., we
obtain a unified geometry metric, which gives a correctly the behavior of the
thermodynamic interactions and phase transitions. The geometry is also found to
be curved and the scalar curvature goes to negative infinity at the Davies'
phase transition points when the logarithmic correction is included.Comment: 16 pages, 6 figure
Examining Stakeholder Perspectives: Process, Performance and Progress of the Age-Friendly Taiwan Program.
Since Taiwans age-friendly city (AFC) program was launched in 2012, the central government has provided various resources to the countrys 22 local authorities, including budgetary support, policy advocacy, and consultation from a team of experts. This study examines stakeholder perspectives on the process, performance, and outcome of the AFC program. A 53-item questionnaire was developed based on the World Health Organization (WHO) guideline, including mechanisms and processes (20 items), outcome evaluations (23 items), and resource integration (10 items). There was a great difference found among scores between facilitators and experts for inter-exchange experience with local and international cities (40%) and monitor and revise indicators (37%) in mechanisms and processes, evaluate performance of indicators and action plans (37%) in outcome evaluations, and interaction between government and community (46%) and interaction between civil organization and senior society (39%) in resource integration. Clearly, facilitators showed overly optimistic assessments in AFC mechanisms and processes, outcome evaluation, and resource integration. The results showed disconnect between experts expectations versus actual practice conducted by facilitators. Implications of these findings are to integrate top down expectations with the realities of bottom up practice to design more realistic evaluations; continue to educate stakeholders about design, implementation and evaluation; and further integrate resources from government, civil organizations, and community
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