We present Monte Carlo simulations and scaling theories for the size and temperature dependence of the diffusion coefficients of clusters of atoms and vacancies on surfaces. The mechanisms and rate-determining steps a...
We present Monte Carlo simulations and scaling theories for the size and temperature dependence of the diffusion coefficients of clusters of atoms and vacancies on surfaces. The mechanisms and rate-determining steps are found for a realistic model of the Xe/Pt(111) system. The coarsening of ensembles of clusters is also considered. By explicitly deriving the coarsening exponents, we show that the coarsening rate for systems dominated by coalescence due to cluster diffusion differs from the rates seen for Ostwald ripening.
Experimental results are presented for the relaxation of a two dimensional soap foam in which wall breakage is initiated through gentle warming of the foam cell. Significantly different phenomenology from the relaxati...
Experimental results are presented for the relaxation of a two dimensional soap foam in which wall breakage is initiated through gentle warming of the foam cell. Significantly different phenomenology from the relaxation of nonbreaking foams is observed. At a critical ‘‘break time,’’ which depends on the temperature ramping rate and initial conditions, a large scale mechanical cascade of wall rupture sets in, leading to a rapid disintegration of the foam. In the cascade regime, whose behavior is essentially independent of the ramping rate, a dynamical scaling behavior, associated with the distribution of cell edge lengths, is proposed.
Static-vortex solutions for a type-II superconductor, obtained from a systematic procedure using Fourier transformation, are presented. The superconductor may be stratified with different values of the London penetrat...
Static-vortex solutions for a type-II superconductor, obtained from a systematic procedure using Fourier transformation, are presented. The superconductor may be stratified with different values of the London penetration depth and/or nonlocal. Nonlocal screening of electromagnetic fields is accounted for by using Pippard theory, giving results which may be useful for low Ginzburg-Landau parameter superconductors. Dirty and clean limits are examined. Boundary-value problems are formulated and both three-dimensional (3D) and 2D (pancake) vortex solutions are obtained. The calculation of derived quantities such as magnetic flux is illustrated.
The problem of determining the front speed for one-dimensional real reaction-diffusion equations is considered. A new solution to the problem, valid for a large class of functions, is proposed. In contrast with other ...
The problem of determining the front speed for one-dimensional real reaction-diffusion equations is considered. A new solution to the problem, valid for a large class of functions, is proposed. In contrast with other methods, this new approach does not rely on the explicit computation of the front solutions and provides an explicit formula relating the nonlinear speed to the parameters of the equation.
作者：
Yamada, HYamamoto, KYamaguchi, YSengoku, MFaculty of Engineering
Niigata University Niigata Japan 950-21 Received his B.S.
M.S. and Ph.D. degrees from Hokkaido University Sapporo Japan in 1988 1990 and 1993 respectively all in Electronic Engineering. Since 1993 he has been with Niigata University where he is currently a Lecturer. His current research involves superresolution techniques electromagnetic wave measurements and radar signal processings. Dr. Yamada is a member of the IEEE. Received his B.S. degree from Niigata University
Niigata Japan in 1994 in Information Engineering. He is currently in the Master's program in Information Engineering. His current research involves superresolution technique and antenna measurements. Received his B.E. degree in Electronics Engineering from Niigata University in 1976 and his M.E. and Dr. of Eng. degrees from Tokyo Institute of Technology
Tokyo Japan in 1978 and 1983 respectively. In 1978 he joined the Faculty of Engineering Niigata University where at present he is a Professor. From 1988 to 1989 he was a Research Associate at the University of Illinois at Chicago. His interests are in the field of propagation characteristics of electromagnetic wave in lossy medium radar polarimetry microwave remote sensing and imaging. Dr. Yamaguchi is a senior member of IEEE and a member of the Japan Society for Snow Engineering. Received his B.E. degree in Electrical Engineering from Niigata University
Japan in 1967 and his M.E. and Ph.D. degrees from Hokkaido University in 1969 and 1972 respectively. In 1972 he joined the staff at Hokkaido University as a Research Associate. In 1978 he was an Associate Professor at Niigata University where he is presently a Professor. During 1986–1987 he was a Visiting Scholar at the University of California Berkeley and at the University of Illinois Chicago. His research interests include transmission of information network theory and graph theory. He is a recipient of the Best Paper Award of I.E.I.C.E. in 1992. Dr. Sengoku is a senior member of IEE
An application of the superresolution method for the analysis of the electromagnetic scattering data is expected to be effective for experimental verification of the geometrical optics approximation theory and the ana...
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An application of the superresolution method for the analysis of the electromagnetic scattering data is expected to be effective for experimental verification of the geometrical optics approximation theory and the analysis of multiple paths. There exist many techniques for the superresolution method. It is desirable to select an appropriate technique based upon the characteristics of the individual algorithms. Among these techniques, the Root-MUSIC method has been proposed;this method enables treatment of the signal attenuating exponentially with respect to frequency. In the modified Root-MUSIC method, arbitrary frequency characteristics can be treated. This paper investigates the estimation accuracy of the scattering center and the attenuation coefficient when the Root-MUSIC method and the modified Root-MUSIC method are applied to the estimation of scattering. With the backscattering data of a conducting sphere, the estimation accuracy of the scattering parameters versus the signal-to-noise ratio (SNR) and the number of snapshots is investigated by computer simulation. As a result, it is found that the estimation accuracy of the modified Root-MUSIC method is much better than that of the conventional Root-MUSIC method in the case of a low SNR and a small number of snapshots. Experimental results are also reported.
The dynamics of velocity fluctuations, governed by the one-dimensional Burgers equation, driven by a white-in-time random force f with the spatial spectrum ‖f(k)‖2∝k−1, is considered. High-resolution numerical expe...
The dynamics of velocity fluctuations, governed by the one-dimensional Burgers equation, driven by a white-in-time random force f with the spatial spectrum ‖f(k)‖2∝k−1, is considered. High-resolution numerical experiments conducted in this work give the energy spectrum E(k)∝k−β with β=5/3±0.02. The observed two-point correlation function C(k,ω) reveals ω∝kz with the ‘‘dynamic exponent’’ z≊2/3. High-order moments of velocity differences show strong intermittency and are dominated by powerful large-scale shocks. The results are compared with predictions of the one-loop renormalized perturbation expansion.
High-resolution numerical experiments, described in this work, show that velocity fluctuations governed by the one-dimensional Burgers equation driven by a white-in-time random noise with the spectrum ‖f(k)‖2¯...
High-resolution numerical experiments, described in this work, show that velocity fluctuations governed by the one-dimensional Burgers equation driven by a white-in-time random noise with the spectrum ‖f(k)‖2¯∝k−1 exhibit a biscaling behavior: All moments of velocity differences Sn≤3(r)=‖u(x+r)-u(x)‖n¯≡‖Δu‖n¯ ∝rn/3, while Sn>3(r)∝rnξ with ξn≊1 for real n>0 [Chekhlov and Yakhot, Phys. Rev. E 51, R2739 (1995)]. The probability density function, which is dominated by coherent shocks in the interval Δu<0, is scrP(Δu,r)∝(Δu)−q with q≊4. A phenomenological theory describing the experimental findings is presented.
We show that the two uni-directional n-cubes, namely UHC1n and UHC2n proposed by Chou and Du (1990) as interconnection schemes are Hamiltonian. In addition, we show that (1) if n is even, both architectures are vertex...
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