Linearity,symmetry, and equidistance in semantic differential scales for measuring images of self and images of others

ABSTRACT

Violations of linearity, symmetry, and equidistance of scale points in semantic differential scales may be due to respondents failing to figure out antonyms, to a positivity bias, or to respondents curtailing their reading the options. Multiple correspondence analysis on data provided by a randomized between-subjects experiment (split-ballot), using a web survey of 537 German residents, shows that bipolar semantic differential scales allow for linear measurement and conceal no positivity bias, and that using not suitable adjective pairs in semantic differential scales destroys symmetry.     

Distributions generated by perturbation of symmetry with emphasis on a multivariate skew t-distribution

Summary . A fairly general procedure is studied to perturb a multivariate density satisfying a weak form of multivariate symmetry, and to generate a whole set of non-symmetric densities. The approach is sufficiently general to encompass some recent proposals in the literature, variously related to the skew normal distribution. The special case of skew elliptical densities is examined in detail, establishing connections with existing similar work. The final part of the paper specializes further to a form of multivariate skew t -density. Likelihood inference for this distribution is examined, and it is illustrated with numerical examples.     

一类非线性波动方程的新精确解

利用李群对称方法,通过构造变换不变量,将一类1 1维非线性波动方程化为常微分方程,得到了这一类非线性波动方程的一些新的显式精确解,包括孤子解、三角函数解和椭圆函数周期解。     

Testing symmetry under a skew Laplace model

We develop tests of hypothesis about symmetry based on samples from possibly asymmetric Laplace distributions and present exact and limiting distribution of the test statistics. We postulate that the test statistic derived under the Laplace model is a rational choice as a measure of skewness and can be used in testing symmetry for other, quite general classes of skew distributions. Our results are applied to foreign exchange rates for 15 currencies.     

基于EGARCH模型的我国股市信息对称性研究

利用过去17年我国上证综合指数的历史数据,根据股票市场大的波动周期分五阶段经过EGARCH(1,1)模型估计,以验证市场对信息冲出的反映情况.研究结果表明:中国股市存在很大的波动性,尚未达到弱有效性;存在正负杠杆效应交替出现的现象,表现出信息不对称性,但是这种不对称性在明显减小.     

物质结构课程教学改革的思考与实践

本文针对师专化学系物质结构课程的教学目的和现状,提出改革教学的思路,并从优化教材的知识结构,突出讲授内容的实用性和注重化学史和方法论的介绍以培养学生的能力入手,阐述了作者几年来从事物质结构教学改革的实践和体会．     

《孔雀东南飞》人物的对称性分析

《孔雀东南飞》中焦刘两个家庭的人物存在着对称性分布特点。焦刘两家在父权社会家庭绝对权威缺席的情况下,权力的中心却大相径庭。在封建社会,特别是在"独尊儒术"的汉代,焦家的行为是与封建礼教相悖的,而刘家则堪称是封建礼教下的模范家庭。同时,两个家庭人物的对称性背后,是诗作维护封建礼教的主旨。     

关于对贞卜辞同字异形判定的三个问题

对贞卜辞是甲骨文中有特色的文例形式，我们从对贞卜辞的判定、同字异形现象的判定以及两条卜辞刻写先后顺序的判定三个方面来细致研究对贞卜辞，进而为下一步的研究打下基础。     

On Hotelling’s T2 test in a special paired sample case

In a special paired sample case, Hotelling’s T² test based on the differences of the paired random vectors is the likelihood ratio test for testing the hypothesis that the paired random vectors have the same mean; with respect to a special group of affine linear transformations it is the uniformly most powerful invariant test for the general alternative of a difference in mean. We present an elementary straightforward proof of this result. The likelihood ratio test for testing the hypothesis that the covariance structure is of the assumed special form is derived and discussed. Applications to real data are given.