Performance of traditional f tests in repeated measures designs under covariance heterogeneity

This study investigates the performance of two traditional F tests, one for main effects and the other for interaction in repeated measures designs under several conditions of covariance heterogeneity. Overall, the test for interaction is more vulnerable than the one for main effects. Distortion in the level of significance is less serious for the case of equal group size.     

利率下降对我国居民跨期消费选择的影响分析

利率下降对居民跨期消费选择影响存在收入效应和替代效应.由于这两种效应对居民当期消费的作用方向完全相反,因而总效应要取决于这两种效应的强弱.对于我国中低收入居民来说,利率下降对其跨期消费选择的收入效应特别明显,替代效应则趋于零,因而降患反而会减少其当期消费数量.对于我国中高收入居民来说,利率下降对其跨期消费选择的替代效应在很大程度上被收入效应所抵消了,因而降息拉动其当期消费也不明显.为了刺激居民消费,除了实施降息政策以外,还必须采取其他政策与之配合.     

岩体变形参数的应力状态效应研究

岩体力学参数存在随应力状态不同而变化的特性，称为应力状态效应。岩体力学特性的实测值具有空间场分布特征，分析表明地应力（或围压）的有规律变化是造成岩体力学参数空间变化的主要原因。考虑到实测地应力多具有较大的离散型，尝试利用反演方法获取地应力场信息，通过多元回归分析得到实测岩体变形参数与地应力的经验关系，以研究岩体变形参数的应力状态效应。通过一工程实例研究：得到地下厂房区域的岩体变形模量为16 GPa左右，与反演分析结果也比较符合；通过应力状态效应研究得到的岩体变形参数物理场，是一个渐变的物理场模型，是更为符     

Fractional replication in simulation studies

It is shown how to use fractional replication in simulation studies. Examples are given. Considerable savings in number of runs required can be achieved through the use of fractional replication ideas.     

Bayesian inference of asymmetric stochastic conditional duration models

This paper extends stochastic conditional duration (SCD) models for financial transaction data to allow for correlation between error processes and innovations of observed duration process and latent log duration process. Suitable algorithms of Markov Chain Monte Carlo (MCMC) are developed to fit the resulting SCD models under various distributional assumptions about the innovation of the measurement equation. Unlike the estimation methods commonly used to estimate the SCD models in the literature, we work with the original specification of the model, without subjecting the observation equation to a logarithmic transformation. Results of simulation studies suggest that our proposed models and corresponding estimation methodology perform quite well. We also apply an auxiliary particle filter technique to construct one-step-ahead in-sample and out-of-sample duration forecasts of the fitted models. Applications to the IBM transaction data allow comparison of our models and methods to those existing in the literature.     

The typification of Hispanics as criminals and support for punitive crime control policies

The Hispanic population is now the largest and fastest growing minority in the United States, so it is not surprising that ethnic threat linked to Hispanics has been associated with harsher crime control. While minority threat research has found that individuals who associate blacks with crime are more likely to support harsh criminal policies, the possibility that this relationship exists for those who typify Hispanics as criminal has yet to be examined. Using a national random sample, this study is the first to use HLM to find that perceptions of Hispanics as criminals do increase support for punitive crime control measures, controlling for various individual and state influences. Moderated and contextual analyses indicate this relationship is most applicable for individuals who are less apt to typify criminals as black, less prejudiced, less fearful of victimization, politically liberal or moderate, not parents, and living in states with relatively fewer Latin American immigrants.     

风险社会与媒介表征

风险社会的形成与大众媒介表征密不可分:大众媒介通过拟态环境的构建,形成了公众的风险感知,促成了风险传播的蝴蝶效应.在此基础上,探讨媒介形成社会风险的三方面成因:价值层面上,媒介的社会整合功能不足,价值培养欠缺;制度层面上,公益节目欠缺,政府信息制度贯彻不力;内容层面上:网络媒介的风险长尾效应日渐突出.     

随钻电阻率测井介电效应校正图版分析及方法

以斯伦贝谢公司随钻电阻率测井仪ARC675系列为例，重点分析了介电效应对相位移和幅度衰减电阻率的影响规律。给出了ARC675随钻电阻率测井仪在2MHz和400kHz工作频率下的校正图版和校正方法，编制了自动介电效应校正计算机程序并对油田实际随钻电阻率测井数据进行了介电效应校正，校正的结果验证了对介电效应影响规律的分析，得到了更为正确的地层电阻率值。实例证明拟合公式是正确的。     

On the use of partial confounding for the construction of alternative regular two-level blocked fractional factorial designs

In this paper, we consider experimental situations in which a regular fractional factorial design is to be used to study the effects of m two-level factors using n=2^m−k experimental units arranged in 2^p blocks of size 2^m−k−p. In such situations, two-factor interactions are often confounded with blocks and complete information is lost on these two-factor interactions. Here we consider the use of the foldover technique in conjunction with combining designs having different blocking schemes to produce alternative partially confounded blocked fractional factorial designs that have more estimable two-factor interactions or a higher estimation capacity or both than their traditional counterparts.     

提高教师素质培养大学生应用写作能力

学生应用写作水平不高的主要原因在于授课教师的专业知识不足，缺乏实践经验，教学积极性不高。因此，学校应合理配置师资，鼓励教师将理论知识与实践结合起来，提高教学效果。