4,644 research outputs found
The classification of all single travelling wave solutions to Calogero-Degasperis-Focas equation
Under the travelling wave transformation, Calogero-Degasperis-Focas equation
was reduced to an ordinary differential equation. Using a symmetry group of
one-parameter, this ODE was reduced to a second order linear inhomogeneous ODE.
Furthermore, we applied the change of the variable and complete discrimination
system for polynomial to solve the corresponding integrals and obtained the
classification of all single travelling wave solutions to
Calogero-Degasperis-Focas equation.Comment: 9 page
Nonadiabatic quantum pumping in mesoscopic nanostructures
We consider a nonadiabatic quantum pumping phenomena in a ballistic narrow
constriction. The pumping is induced by a potential that has both spatial and
temporal periodicity characterized by and . In the zero frequency
() limit, the transmission through narrow constriction exhibits
valley structures due to the opening up of energy gaps in the pumping region --
a consequence of the periodicity. These valley structures remain robust in
the regime of finite , while their energies of occurrence are shifted
by about . The direction of these energy shifts depend on the
directions of both the phase-velocity of the pumping potential and the
transmitting electrons. This frequency dependent feature of the valley
structures gives rise to both the asymmetry in the transmission coefficients
and the pumping current. An experimental setup is suggested for a possible
observation of our nonadiabatic quantum pumping findings.Comment: 4 pages, 2 figure
corrections to polarized top decay into a charged Higgs
We calculate the radiative corrections to polarized top quark
decay into a charged Higgs boson and a massive bottom quark in two variants of
the two-Higgs-doublet model. The radiative corrections to the polarization
asymmetry of the decay may become as large as . We provide analytical
formulae for the unpolarized and polarized rates for and for . For our closed-form expressions for the unpolarized and
polarized rates become rather compact.Comment: 24 pages, 5 figures in the text, content modified, comments added,
appendices added, references updated, replaced with published versio
Anomalous oxidation of Fe-Si alloys under a low oxygen pressure at 800 °C
The authors acknowledge financial support by NSFC of China under the research projects (Nos. 50971129 and 51371183).Abstract The oxidation of three Fe-xSi alloys (x = 5, 9, 13 at.%) under 10−20 atm O2 at 800 °C formed in all cases SiO2 layers. For Fe-5Si this layer broke down and healed up periodically forming an anomalous internal oxidation zone with spherical and net-shaped SiO2 particles. The SiO2 layer formed on the other two alloys spalled off due to the growth and thermal stress accumulated. The critical silicon content needed for its external oxidation on Fe-Si alloys calculated according to an extension of Wagner's theory under the present experimental conditions is significantly smaller than the experimental results.PostprintPeer reviewe
PHP61 The Financial Impacts of Pharmacist Intervention in Inpatient Department of a Local Hospital in Taiwan
Morphometric analysis of S. mortenseni. (DOC 44Â kb
Effect of boundaries on the force distributions in granular media
The effect of boundaries on the force distributions in granular media is
illustrated by simulations of 2D packings of frictionless, Hertzian spheres. To
elucidate discrepancies between experimental observations and theoretical
predictions, we distinguish between the weight distribution {\cal P} (w)
measured in experiments and analyzed in the q-model, and the distribution of
interparticle forces P(f). The latter one is robust, while {\cal P}(w) can be
obtained once the local packing geometry and P(f) are known. By manipulating
the (boundary) geometry, we show that {\cal P}(w) can be varied drastically.Comment: 4 pages, 4 figure
Is the first radial excitation of ?
We present a quantitative analysis of the observed by
SELEX mainly focusing on the assumption that is the first
radial excitation of the ground state . By solving the
instantaneous Bethe-Salpeter equation, we obtain the mass MeV for
the first excited state, which is about 26 MeV heavier than the experimental
value MeV. By means of PCAC and low-energy theorem we calculate
the transition matrix elements and obtain the decay widths:
MeV, MeV, and
the ratio as well. This ratio is quite different from the
SELEX data . The summed decay width of those three channels is
approximately 21.7 MeV, already larger than the observed bound for the full
width ( MeV). Furthermore, assuming is state,
we also explore the possibility of wave mixing to explain the SELEX
observation. Based on our analysis, we suspect that it is too early to conclude
that is the first radial excitation of the ground
state . More precise measurements of the relative ratios and
the total decay width are urgently required especially for wave mixing.Comment: 12 pages, 8 figure
A Multiple Commutator Formula for the Sum of Feynman Diagrams
In the presence of a large parameter, such as mass or energy, leading
behavior of individual Feynman diagrams often get cancelled in the sum. This is
known to happen in large- QCD in the presence of a baryon, and also in the
case of high-energy electron-electron as well as quark-quark scatterings. We
present an exact combinatorial formula, involving multiple commutators of the
vertices, which can be used to compute such cancellations. It is a non-abelian
generalization of the eikonal formula, and will be applied in subsequent
publications to study the consistency of large- QCD involving baryons, as
well as high-energy quark-quark scattering in ordinary QCD.Comment: uu-encoded latex file with two postscript figure
Long-term trends in tropical cyclone tracks around Korea and Japan in late summer and early fall
This study investigates long-term trends in tropical cyclones (TCs) over the extratropical western North Pacific (WNP) over a period of 35 years (1982-2016). The area analyzed extended across 30-45 degrees N and 120-150 degrees E, including the regions of Korea and Japan that were seriously affected by TCs. The northward migration of TCs over the WNP to the mid-latitudes showed a sharp increase in early fall. In addition, the duration of TCs over the WNP that migrated northwards showed an increase, specifically in early to mid-September. Therefore, more recently, TC tracks have been observed to significantly extend into the mid-latitudes. The recent northward extension of TC tracks over the WNP in early fall was observed to be associated with changes in environmental conditions that were favorable for TC activities, including an increase in sea surface temperature (SST), decrease in vertical wind shear, expansion of subtropical highs, strong easterly steering winds, and an increase in relative vorticity. In contrast, northward migrations of TCs to Korea and Japan showed a decline in late August, because of the presence of unfavorable environmental conditions for TC activities. These changes in environmental conditions, such as SST and vertical wind shear, can be partially associated with the Pacific decadal oscillation
Leaf segmentation and tracking using probabilistic parametric active contours
Active contours or snakes are widely used for segmentation and tracking. These techniques require the minimization of an energy function, which is generally a linear combination of a data fit term and a regularization term. This energy function can be adjusted to exploit the intrinsic object and image features. This can be done by changing the weighting parameters of the data fit and regularization term. There is, however, no rule to set these parameters optimally for a given application. This results in trial and error parameter estimation. In this paper, we propose a new active contour framework defined using probability theory. With this new technique there is no need for ad hoc parameter setting, since it uses probability distributions, which can be learned from a given training dataset
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