A Compact-FDTD Algorithm for Dispersion Analysis

针对传统的时域有限差分（FDTD）方法具有精度较低,色散误差较大等缺陷。本文采用紧致格式和高阶FDTD相结合的方法进行数值模拟,并且对紧致格式高阶FDTD和传统FDTD方法的数值稳定性及其色散误差进行对比,得出本文中方法具有更低的色散误差和更好的稳定性等优点。     

A Note on the Use of Flanders Interaction Analysis

Abstract

The experiment compared group-Individual (GI) and group (G) counseling groups with a control (C) group. The groups were equal In ability and Initial grade point averages. Results Indicate that those S's In the G groups had an observably larger GPA ten weeks following the completion of the experiment than the S's In the C group. It was suggested that a period of Incubation is necessary before the Insights gained during group counseling are translated Into action.     

A Note on Cluster Effects in Latent Class Analysis

This article examines the effects of clustering in latent class analysis. A comprehensive simulation study is conducted, which begins by specifying a true multilevel latent class model with varying within- and between-cluster sample sizes, varying latent class proportions, and varying intraclass correlations. These models are then estimated under the assumption of a single-level latent class model. The outcomes of interest are measures of bias in the Bayesian Information Criterion (BIC) and the entropy R ² statistic relative to accounting for the multilevel structure of the data. The results indicate that the size of the intraclass correlation as well as between- and within-cluster sizes are the most prominent factors in determining the amount of bias in these outcome measures, with increasing intraclass correlations combined with small between-cluster sizes resulting in increased bias. Bias is particularly noticeable in the BIC. In addition, there is evidence that class separation interacts with the size of the intraclass correlations and cluster sizes in producing bias in these measures.     

基于局部离散度的监督型线性判别分析及其应用

鉴于线性判别分析(Linear Discriminant Analysis,LDA)算法存在的弊端,本文提出了一种基于局部离散度的监督型线性判别分析(Supervised Linear Discriminant Analysis based on Local Dispersion,SLDALD)算法.新方法的改进主要有:1)从像元邻域的角度出发,对类内散布矩阵、类间散布矩阵进行重新定义,得到类内邻域散布矩阵和类间邻域散布矩阵.新定义充分考虑了不同区域之间像元光谱特征离散度的差异性; 2)在计算类间邻域散布矩阵时,赋予类边界像元较大的权重,让特征降维更针对此类像元; 3)在计算类内邻域散布矩阵时,加大类边界像元的权重,让后续的特征降维针对此类像元.同时,降低噪声点的权重,以抑制噪声点对特征降维的干扰.实验结果表明:相比依据LDA算法所获得的低维特征的分类结果,以SLDALD算法所获得的低维特征为依据,影像分类精度得到明显地提高.     

包含高阶色散的交叉相位调制不稳定性分析

从包含高阶色散项的广义非线性薛定谔方程出发,得到了描述交叉相位调制(XPM)不稳定色散方程的一般表达式,研究了四种不同情况下调制不稳定的增益频谱特性.结果表明:由于四阶色散的影响,单光束传输时,在光纤的反常色散区出现一个新的调制不稳定频谱区;双光束传输时,在普通光纤和色散缓变光纤(DDF)的正常和反常色散区,XPM不稳定均发生在两个频谱区.     

现金流量表附注信息化处理要点分析

现金流量表附注的信息化处理是指运用计算机及财务报袁软件获取、加工账务数据,以输出现金流量信息的过程。当前现金流量表附注的信息化处理存在着手工随意调节数据、设置项目来源困难、现金流量表附注模板欠缺等问题．要利用财务报表软件准确编制出现金流量表附注中的九个调整项目,关键在于运用帐务取数功能设置项目来源和取数公式。     

用梯度折射率微球制作表面漫射材料的研究

本文提出一种用梯度折射率微球构成的表面散射材料.用四阶Runge-Kutta方法进行的光线追迹计算,确定了这种结构的工作条件.对其漫射性能的分析表明,在合适的工艺参数下该结构材料可以具有较好的视频(可见光)隐形作用.     

The Application of Dispersion Analysis to a Political Problem

Three methods (mail survey, telephone survey, and keeping time) for measuring teaching time were compared. Sixth-grade teachers from 74 schools assessed time spent on teaching native language in an average school week. They used each of the three methods with a time lag of a few weeks. Total teaching time and the teaching time spent on language categories were measured; the main language categories were communication, reading, grammar, spelling, and writing. The analysis of the data showed that the means of the total score and of the main category scores for spelling and writing were about equal for each of the methods. Moreover, the rank order of the mean main category scores was identical for each of the methods. The correlations of the scores showed that the individual scores of the three methods did not sufficiently converge.     

关于次中紧空间的一个注记

本文深入地讨论了次中紧空间的性质并得到了其上的一个映射定理，这改进了[1]中的结果．     

Note on Narrating Disability

We outline a theoretical view of narrative inquiry as both phenomenon and method, and we explore the growth and development of narrative inquiry in the field of education. Drawing on research with participants labeled as developmentally disabled, we show how narrative inquiry can illuminate how disability is understood and lived out in social, cultural, and institutional narratives that shaped the lived and told stories of individuals.     

关于悬链线的一点注记

悬链线是微积分、微分方程、微分几何、变分计算及数值分析中的一个重要课题.本文通过一些诸如方轮自行车、旋转的最小面积等有趣的例子,计算悬链线和相应半圆下面的面积,证明悬链线到处都有,但并不是无处不在.     

Miwa问题的注记

本文给一反例说明Ｍｉｗａ问题的解答中的两个条件是相互独立的．     

匈牙利算法的注记

分析在指派问题的教学中所遇到的问题,在剖析匈牙利算法的基础上,提出了改进的算法,并通过2个例子进行介绍。     

关于两尺度序列的一点注记

通常两尺度序列{hk},{gh}有几种不同形式,这样与之相关的一些结论也有所不同．为了澄清一些著作相关的混乱和方便初学者以及工程应用,本文对照给出两尺度序列的几种形式及其相应的结论与相关应用．     

关于广义Minkowsky不等式的注记

纠正了文[2]的关于广义 Minkowsky不等式的错误,推广了相应的结论。