The Surface Energy of MgO: Multiscale Reconstruction from Thermal Groove Geometry

The surface energy of MgO is determined using experimental data collected from equilibrated thermal grooves circumscribing island grains. Local equilibrium assumptions at each groove require that the Herring equations be satisfied at each data site, thereby yielding a large and overdetermined system of equations involving the surface energy . This inverse problem is then solved using a new technique that is statistical in nature and multiscale in implementation. The resulting discrete solution represents a statistically significant representation of the surface energy of MgO as a function of surface orientation. Comparisons to results derived from a more traditional approach, along with suggested further applications, are discussed.     

Spectral analysis and numerical simulation for second order elliptic operator with highly oscillating coefficients in perforated domains with a periodic structure

This paper discusses the spectral properties and numerical simulation for the second order elliptic operators with rapidly oscillating coefficients in the domains which may contain small cavities distributed periodically with period ε. A multiscale asymptotic analysis formula for this problem is obtained by constructing properly the boundary layer. Finally, numerical results are given, which provide a strong support for the analytical estimates     

Segmentation of synthetic aperture radar image using multiscale information measure-based spectral clustering

A multiscale information measure （MIM）, calculable from per-pixel wavelet coefficients, but relying on global statistics of synthetic aperture radar （SAR） image, is proposed. It fully exploits the variations in speckle pattern when the image resolution varies from course to fine, thus it can capture the intrinsic texture of the scene backscatter and the texture due to speckle simultaneously. Graph spectral segmen- tation methods based on MIM and the usual similarity measure are carried out on two real SAR images. Experimental results show that MIM can characterize texture information of SAR image more effectively than the commonly used similarity measure.     

On a multiscale continuous percolation model with unbounded defects

We study the multiscale (fractal) percolation in dimension greater than or equal to 2, where the model at each level is the Poisson Boolean model [[, ]]. Also, the random radius is supposed to be unbounded. We prove that if the rate of Poisson field is less than some critical value, then by choosing the scaling parameter large enough one can assure that there is no multiscale percolation. Another result of this paper is that if the expectation of ^2d is finite, then the expectation of the size of the cluster raised to the power is also finite for small , which is a generalization of one of the results of [8].1 Partially supported by FAPESP (97/12826–6, 02/02984–3) and CNPq (300676/00–0)2 Partially supported by FAPESP (00/11462–5, 02/03012–5)     

Dynamical Localization II with an Application to the Almost Mathieu Operator

Several recent works have established dynamical localization for Schrödinger operators, starting from control on the localization length of their eigenfunctions, in terms of their centers of localization. We provide an alternative way to obtain dynamical localization, without resorting to such a strong condition on the exponential decay of the eigenfunctions. Furthermore, we illustrate our purpose with the almost Mathieu operator, H _{, ,} =–+ cos(2(+x)), 15 and with good Diophantine properties. More precisely, for almost all , for all q>0, and for all functions ²( ) of compact support, we show that The proof applies equally well to discrete and continuous random Hamiltonians. In all cases, it uses as input a repulsion principle of singular boxes, supplied in the random case by the multi-scale analysis.     

Lattice and continuum wavelets and the block renormalization group

We obtain a resolution of the identity operator, for functions on a latticeZ ^d, which is derived from the block renormalization group. We use eigenfunctions of the terms of the decomposition to form a basis forl ₂(Z^d) and show how the basis is generated from lattice wavelets. The lattice spacing is taken to zero and continuum wavelets are obtained.     

Comments on “power-law falloff in the Kosterlitz-Thouless phase of a two-dimensional lattice Coulomb gas”

A simple argument is presented by which one can show that the critical inverse temperature _c of a two-dimensional Coulomb gas (standard or hard-core) with activityz satisfies , where in the low-activity limit. Previous results yield .     

多尺度Retinex截断区间对图像质量影响的分析

研究了多尺度Retinex算法对曝光量不足的彩色图像增强处理的结果。改进型多尺度Retinex算法是使用多尺度Retinex增强后在亮度平均值附近以k倍标准差进行截取、拉伸。采用亮度与对比度乘积、图像信息熵等2个判据,实验结果表明在亮度平均值附近k=1倍标准差进行截取后再拉伸得到的图像其2个判据的值都较大,图像最佳。     

Tight-binding molecular dynamics simulation of ZnSe liquid within the local environment dependence

We investigate the structural, electronic and dynamical properties of ZnSe liquid using tight-binding molecular dynamics (TBMD) simulations. We report the TBMD calculations for the solid and liquid forms of the ZnSe compound. To produce more realistic results the TB model includes the local environment dependence in the Hamiltonian matrix at finite temperature for ZnSe. To further demonstrate the efficiency of the TBMD approach, we present results for finite temperature physical properties of ZnSe liquid. We are able to show good agreement with experiment for the atomic mean-squared displacement and melting point.