564 research outputs found
Stochastic Process Associated with Traveling Wave Solutions of the Sine-Gordon Equation
Stochastic processes associated with traveling wave solutions of the
sine-Gordon equation are presented. The structure of the forward Kolmogorov
equation as a conservation law is essential in the construction and so is the
traveling wave structure. The derived stochastic processes are analyzed
numerically. An interpretation of the behaviors of the stochastic processes is
given in terms of the equation of motion.Comment: 12 pages, 9 figures; corrected typo
Disability Prevention Programs for Older People: Factors Associated with Medical and Nursing Care Costs
This study aimed to clarify factors associated with medical and nursing care costs for older people living in community and to suggest an effective disability prevention programs. Total of participants in this study was 83 individuals (29 men and 54 women; mean age 81.2 ± 6.3 years old) on November 1st – December 28th, 2014. This study compared the average medical and nursing care costs per month with national average for those aged ≥ 65 years old. Logistic regression test was conducted to examine its association with medical and nursing care costs. Those who had outing activities ≥ 3 times a week were approximately three times less likely to reduce medical and nursing care costs than those who had outing activities < 3 times a week despite three controlled covariates (OR = 3.23 and 95% CI = 1.03 – 10.42). Disability prevention programs that improve frequency of outing at least three times in a week may become a valid economic approach to older people who do not live in nursing home
Exact results on the dynamics of multi-component Bose-Einstein condensate
We study the time-evolution of the two dimensional multi-component
Bose-Einstein condensate in an external harmonic trap with arbitrary
time-dependent frequency. We show analytically that the time-evolution of the
total mean-square radius of the wave-packet is determined in terms of the same
solvable equation as in the case of a single-component condensate. The dynamics
of the total mean-square radius is also the same for the rotating as well as
the non-rotating multi-component condensate. We determine the criteria for the
collapse of the condensate at a finite time. Generalizing our previous work on
a single-component condensate, we show explosion-implosion duality in the
multi-component condensate.Comment: Two-column 6 pages, RevTeX, no figures(v1); Added an important
reference, version to appear in Physical Review A (v2
Ambient Conditions of Winter Thunderstorms in Japan to Reproduce Observed Gamma‐Ray Glow Energy Spectra
Electric field of thunderclouds modifies components and energy spectra of the cosmic-ray air shower. In particular, thunderstorms accelerate charged particles, resulting in an enhancement of gamma-ray fluxes on the ground, known as a gamma-ray glow. This phenomenon has been observed in recent years by the Gamma-Ray Observation of Winter THunderclouds collaboration from winter thunderstorms in the Hokuriku area of Japan. The present work examines the ambient conditions required to produce spectral features of the previously detected gamma-ray glows, by using Monte Carlo simulations of particle interactions in the atmosphere. We focus on three parameters, the strength and length of the electric field, and the length of a null-field attenuation region below the electrified region. The average spectrum of observed gamma-ray glows in winter thunderstorms of Japan requires an electric field intensity close to 0.31 MV/m, slightly exceeding the Relativistic Runaway Electron Avalanche threshold of 0.284 MV/m. The vertical size of the electric field region should be comparable to 1 km. The estimated attenuation region size is 300–500 m, necessary to reduce the low-energy photon flux of the average gamma-ray glows. There is still a wide range of acceptable parameter sets with degeneracy to make a similar spectrum
Stability analysis of the D-dimensional nonlinear Schroedinger equation with trap and two- and three-body interactions
Considering the static solutions of the D-dimensional nonlinear Schroedinger
equation with trap and attractive two-body interactions, the existence of
stable solutions is limited to a maximum critical number of particles, when D
is greater or equal 2. In case D=2, we compare the variational approach with
the exact numerical calculations. We show that, the addition of a positive
three-body interaction allows stable solutions beyond the critical number. In
this case, we also introduce a dynamical analysis of the conditions for the
collapse.Comment: 6 pages, 7 figure
Measurement of CMRg1 Using 18FDG by Quantitative Positron Autoradiography - Establishment of Simplified Standarization Procedure and Evaluation of Rate Constants
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18F-Fluoro-2\u27-Deoxyuridine and Experimental Brain Tumor
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The Dissociation Between Glucose and Amino Acid Metabolism in Brain Tumor - Clinical and Experimental Study -
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Solutions of Gross-Pitaevskii equations beyond the hydrodynamic approximation: Application to the vortex problem
We develop the multiscale technique to describe excitations of a
Bose-Einstein condensate (BEC) whose characteristic scales are comparable with
the healing length, thus going beyond the conventional hydrodynamical
approximation. As an application of the theory we derive approximate explicit
vortex and other solutions. The dynamical stability of the vortex is discussed
on the basis of the mathematical framework developed here, the result being
that its stability is granted at least up to times of the order of seconds,
which is the condensate lifetime. Our analytical results are confirmed by the
numerical simulations.Comment: To appear in Phys. Rev.
Cerebral Circulation and Metabolism of Malignant Brain Tumor - Clinical Investigation by Positron Emission Computed Tomography -
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