14,545 research outputs found
Evolution equations of curvature tensors along the hyperbolic geometric flow
We consider the hyperbolic geometric flow introduced by Kong and Liu [KL]. When the Riemannian
metric evolve, then so does its curvature. Using the techniques and ideas of
S.Brendle [Br,BS], we derive evolution equations for the Levi-Civita connection
and the curvature tensors along the hyperbolic geometric flow. The method and
results are computed and written in global tensor form, different from the
local normal coordinate method in [DKL1]. In addition, we further show that any
solution to the hyperbolic geometric flow that develops a singularity in finite
time has unbounded Ricci curvature.Comment: 15 page
Relativistic corrections to the Pionium Lifetime
Next to leading order contributions to the pionium lifetime are considered
within non-relativistic effective field theory. A more precise determination of
the coupling constants is then needed in order to be consistent with the
relativistic pion-pion scattering amplitude which can be obtained from chiral
perturbation theory. The relativistic correction is found to be 4.1% and
corresponds simply to a more accurate value for the non-relativistic decay
momentum.Comment: 5 pages, Latex. Includes corrections based on a more precise matching
to the pion-pion scattering amplitude from chiral perturbation theor
A rapid staining-assisted wood sampling method for PCR-based detection of pine wood nematode Bursaphelenchus xylophilus in Pinus massoniana wood tissue
For reasons of unequal distribution of more than one nematode species in wood, and limited
availability of wood samples required for the PCR-based method for detecting pinewood nematodes in
wood tissue of Pinus massoniana, a rapid staining-assisted wood sampling method aiding PCR-based
detection of the pine wood nematode Bursaphelenchus xylophilus (Bx) in small wood samples of P.
massoniana was developed in this study. This comprised a series of new techniques: sampling, mass
estimations of nematodes using staining techniques, and lowest limit Bx nematode mass determination
for PCR detection. The procedure was undertaken on three adjoining 5-mg wood cross-sections, of
0.5 · 0.5 · 0.015 cm dimension, that were cut from a wood sample of 0.5 · 0.5 · 0.5 cm initially, then
the larger wood sample was stained by acid fuchsin, from which two 5-mg wood cross-sections (that
adjoined the three 5-mg wood cross-sections, mentioned above) were cut. Nematode-staining-spots
(NSSs) in each of the two stained sections were counted under a microscope at 100· magnification. If
there were eight or more NSSs present, the adjoining three sections were used for PCR assays. The
B. xylophilus – specific amplicon of 403 bp (DQ855275) was generated by PCR assay from 100.00% of
5-mg wood cross-sections that contained more than eight Bx NSSs by the PCR assay. The entire
sampling procedure took only 10 min indicating that it is suitable for the fast estimation of nematode
numbers in the wood of P. massonina as the prelimary sample selections for other more expensive
Bx-detection methods such as PCR assay
Time-Periodic Solutions of the Einstein's Field Equations II
In this paper, we construct several kinds of new time-periodic solutions of
the vacuum Einstein's field equations whose Riemann curvature tensors vanish,
keep finite or take the infinity at some points in these space-times,
respectively. The singularities of these new time-periodic solutions are
investigated and some new physical phenomena are found. The applications of
these solutions in modern cosmology and general relativity can be expected.Comment: 10 pages, 1 figur
Exploring universality in nuclear clusters with Halo EFT
I present results and highlight aspects of halo EFT to loosely bound systems
composed of nucleons and alpha particles, with emphasis on Coulomb
interactions.Comment: 3 pages, 2 figures, talk given at the 21th European Conference on
Few-Body Problems in Physics, Salamanca, Aug. 29th - Sep. 3rd, 201
Radiative corrections to the Casimir force and effective field theories
Radiative corrections to the Casimir force between two parallel plates are
considered in both scalar field theory of one massless and one massive field
and in QED. Full calculations are contrasted with calculations based on
employing ``boundary-free'' effective field theories. The difference between
two previous results on QED radiative corrections to the Casimir force between
two parallel plates is clarified and the low-energy effective field theory for
the Casimir effect in QED is constructed.Comment: 17 pages, revte
Performance comparison of packet scheduling algorithms in LTE-A HetNets
© 2016 IEEE. Performance comparison of various Packet Scheduling (PS) algorithms such as Proportional Fair (PF), Maximum Largest Weighted Delay First (MLWDF) and Exponential/Proportional Fair (EXP/PF) has been studied in HetNets environment. The performance indicators such as throughput, Packet Loss Ratio (PLR), delay and fairness are considered to judge the performance of the scheduling algorithms. Various strategies such as increasing the number of pico cells in the cell edge were used in the simulation for the performance evaluation study. The results achieved by various simulations show that adding the pico cells to the existing macros enhances the overall system performance in addition to various scheduling algorithms implemented in macros. Simulation results show that the overall system gain has increased by adding picos, provide better coverage in the cell edge and increase the capacity of the network to provide better Quality of Service (QoS). Furthermore, simulations show that MLWDF performs better for video traffic than compared to other with PS algorithms
Benchmarking of real-time LTE network in dynamic environment
© 2016 IEEE. LTE/LTE-A is high speed wireless communication technology which got evolved from 2G/3G. LTE provides very high throughput in uplink and downlink and hence it is attracting more and more subscribers every day. This paper analyzes the performance of real time LTE network of two different LTE service providers through drive test. Test cases were performed under dynamic environment where the test user is dynamic or the environment around the test user is dynamic (travelling in train or car). The performance comparison of different Key Performance Indicators (KPI) such as Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Reference Signal Strength Indicator (RSSI) and throughput (uplink - UL and downlink - DL) are made between the two LTE service providers. The performance tests were performed using Nemo tool in a real-time LTE network. Average values were obtained for different KPIs to study the performance of the LTE network
New Results for Diffusion in Lorentz Lattice Gas Cellular Automata
New calculations to over ten million time steps have revealed a more complex
diffusive behavior than previously reported, of a point particle on a square
and triangular lattice randomly occupied by mirror or rotator scatterers. For
the square lattice fully occupied by mirrors where extended closed particle
orbits occur, anomalous diffusion was still found. However, for a not fully
occupied lattice the super diffusion, first noticed by Owczarek and Prellberg
for a particular concentration, obtains for all concentrations. For the square
lattice occupied by rotators and the triangular lattice occupied by mirrors or
rotators, an absence of diffusion (trapping) was found for all concentrations,
except on critical lines, where anomalous diffusion (extended closed orbits)
occurs and hyperscaling holds for all closed orbits with {\em universal}
exponents and . Only one point on these critical lines can be related to a
corresponding percolation problem. The questions arise therefore whether the
other critical points can be mapped onto a new percolation-like problem, and of
the dynamical significance of hyperscaling.Comment: 52 pages, including 18 figures on the last 22 pages, email:
[email protected]
Coulomb interactions within Halo Effective Field Theory
I present preliminary results of effective field theory applied to nuclear
cluster systems, where Coulomb interactions play a significant role.Comment: Talk given at the 20th European Conference on Few-Body Problems in
Physics, Pisa, Italy, September 10-14, 200
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