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1.
A. A. Abramov S. V. Kurochkin 《Computational Mathematics and Mathematical Physics》2006,46(6):949-954
A new method for calculating the radial spheroidal functions of the first kind is proposed for the arguments that are greater than unity in modulus. A well-known representation of these functions is refined and used for this purpose. The constructs and the software implementation proposed in the paper provide an efficient tool for the calculation of the functions with a desired accuracy in a wide range of parameters. 相似文献
2.
Roland Opfer 《Advances in Computational Mathematics》2006,25(4):357-380
This paper reconstructs multivariate functions from scattered data by a new multiscale technique. The reconstruction uses
standard methods of interpolation by positive definite reproducing kernels in Hilbert spaces. But it adopts techniques from
wavelet theory and shift-invariant spaces to construct a new class of kernels as multiscale superpositions of shifts and scales
of a single compactly supported function φ. This means that the advantages of scaled regular grids are used to construct the
kernels, while the advantages of unrestricted scattered data interpolation are maintained after the kernels are constructed.
Using such a multiscale kernel, the reconstruction method interpolates at given scattered data. No manipulations of the data
(e.g., thinning or separation into subsets of certain scales) are needed. Then, the multiscale structure of the kernel allows
to represent the interpolant on regular grids on all scales involved, with cheap evaluation due to the compact support of
the function φ, and with a recursive evaluation technique if φ is chosen to be refinable. There also is a wavelet-like data
reduction effect, if a suitable thresholding strategy is applied to the coefficients of the interpolant when represented over
a scaled grid. Various numerical examples are presented, illustrating the multiresolution and data compression effects. 相似文献
3.
本工作用x射线衍射技术分析计算了二种天然树脂的局部结构参数,由测得的衍射强度数据求出了它们的结构因子I(r)和径向分布函数RDF(r),并由此得到了分子链内临近原子和次临近原子平均间距、配位数和短程有序畴。 相似文献
4.
Mira Bozzini Licia Lenarduzzi Robert Schaback 《Advances in Computational Mathematics》2002,16(4):375-387
We present an adaptive method to extract shape-preserving information from a univariate data sample. The behavior of the signal is obtained by interpolating at adaptively selected few data points by a linear combination of multiquadrics with variable scaling parameters. On the theoretical side, we give a sufficient condition for existence of the scaled multiquadric interpolant. On the practical side, we give various examples to show the applicability of the method. 相似文献
5.
提出了一种非刚性点匹配的算法并把其运用于医学图像配准.该算法采用信号滤波的方法来获得点集间的匹配信息,并运用松弛标记法将各点邻域关系对模糊的匹配信息进行迭代获得明确的匹配关系.在此基础上,利用高斯径向基函数来描述点模式间的弹性形变,在基本的迭代框架下实现问题的求解.实验结果显示在形变程度为5%、出格点比率50%和噪声标准差为5%的情况下该算法的匹配误差能控制在0.13以下,表明了该算法的鲁棒性和有效性,较好地解决了医学非刚性形变的点匹配问题. 相似文献
6.
7.
The surface wave produced plasma belongs to a class of RF and microwave induced plasmas. It results from the propagation of an electromagnetic wave which uses the plasma column it sustains and the plasma tube as its sole propagating media. This type of plasma offers several advantages compared to the positive column plasma of dc discharges or to other RF and microwave produced plasmas. Surface wave plasmas require no internal electrodes, and they can be applied over an extremely broad range of wave frequencies (27 MHz to 10 GHz demonstrated) and gas pressures (about 10–4 Torr to a few times the atmospheric pressures). Using the surface wave plasma technique, a large variety of plasma column diameters have been created (0.5–150 mm demonstrated) and no limitation on plasma column length (column up to 6 m long demonstrated) has been found. The surface wave produced plasma is used in elemental analysis and to sustain emission in lasing media. This article is intended as a guide for potential users of surface wave plasmas in the field of plasma processing and plasma chemistry. 相似文献
8.
A. D. Smirnov 《Journal of Structural Chemistry》2003,44(5):757-762
The vibrational, rotational, and centrifugal constants have been calculated for the ground electronic states of KRb and RbCs molecules. The calculation is performed using the semiempirical potential curves constructed in a wide range of internuclear distances. The estimated spectroscopic constants are compared with experimental data. 相似文献
9.
叙述了用θ-2θ型X射线衍射仪精确测定电解质溶液结构的新实验技术。设计制作了具有恒温功能的超厚液体样品池,并建立了样品池窗口强度的校正方法。优化了液体X射线衍射数据和结构参数精细化的计算机程序,获得了非常令人满意的实验结果。由θ-2θ型X射线衍射仪精确测定的径向分布函数与θ-θ型衍射仪自由散射比较,表明DRF分辨率有所提高。 相似文献
10.