How non-normality affects the quadratic discriminant function

The quadratic discriminant function is commonly used for the two group classification problem when the covariance matrices in the two populations are substantially unequal. This procedure is optimal when both populations are multivariate normal with known means and covariance matrices. This study examined the robustness of the QDF to non-normality. Sampling experiments were conducted to estimate expected actual error rates for the QDF when sampling from a variety of non-normal distributions. Results indicated that the QDF was robust to non-normality except when the distributions were highly skewed, in which case relatively large deviations from optimal were observed. In all cases studied the average probabilities of misclassification were relatively stable while the individual population error rates exhibited considerable variability.     

科技英语疑问句的信息功能探析

句子的功能所实现的交际任务是传递信息。根据话语信息传递和语言交际功能理论原则,通过甄选科技英语相关例证作为分析语料,从英语的科技文体视角探析了疑问句在科技英语信息推进中的五大作用,同时指出了解这些相关作用的必要性。     

A semiparametric maximum likelihood ratio test for the change point in copula models

In the present paper, a semiparametric maximum-likelihood-type test statistic is proposed and proved to have the same limit null distribution as the classical parametric likelihood one. Under some mild conditions, the limiting law of the proposed test statistic, suitably normalized and centralized, is shown to be double exponential, under the null hypothesis of no change in the parameter of copula models. We also discuss the Gaussian-type approximations for the semiparametric likelihood ratio. The asymptotic distribution of the proposed statistic under specified alternatives is shown to be normal, and an approximation to the power function is given. Simulation results are provided to illustrate the finite sample performance of the proposed statistical tests based on the double exponential and Gaussian-type approximations.     

辩证地看待信息网络技术在医学领域的作用

信息网络技术正逐步改变着我们的生活和工作方式,作为现代科学重要组成部分的现代医学,信息网络技术必将对它产生积极而深远的影响,我们应该辩证地看待信息技术在医学中的作用,这样才能正确有效地利用它为医学服务.     

On the distribution of the sum of independent uniform random variables

Motivated by an application in change point analysis, we derive a closed form for the density function of the sum of n independent, non-identically distributed, uniform random variables.     

Missing siblings: seeking more adequate social responses

Little is known about the experience of family and friends when a young adult goes missing, less is known about how siblings make sense of the experience. Police assistance to locate the missing person may be sought but there is little recognition of going missing or missingness as a social issue, and there is little or no adequate social response to the needs of those left behind. This paper links knowledge of siblings, loss and grief to an understanding of this phenomenon. It presents the methodology and findings of an exploratory, qualitative study into the experiences of nine adult siblings of long-term missing people in Australia and presents the themes drawn from their accounts. The themes are briefly elaborated using direct quotations from participants in the study and represented in a diagram. The paper seeks to develop greater understanding of the inter-relationship between missingness and other social issues, to give voice to the views of participants and to encourage practitioners to engage more purposefully in work with family and friends affected by this issue. Some implications for social work practice are presented.     

新时期高等师范教育面临问题及对策研究

新时期高师院校的发展面临"学术性"与"师范性"双重滞后、培养目标与时代发展的要求有所脱节、课程与教学存在明显滞后、教育教学与基础教育联系不够、"终结性"与"一体化"冲突等问题。要通过促进"学术性"与"师范性"的和谐统一,强化"学术性"基础之上的"师范性",优化教学内容和课程体系,推进教师职前与职后教育的一体化来推动高师院校教师教育体系的创新和发展。     

论国家助学贷款的制度创新:功能金融理论的分析

作为一项个人金融与高等教育形式的人力资本投资结合的有效方式,国家助学贷款制度实施近7年来,始终未能实现其制度设计的预期目标,在政策与实践之间存在诸多矛盾,主要原因在于制度变迁的路径是基于金融的“机构范式”,而且,沿着既定方向的改革道路已走到尽头。因此,国家助学贷款的制度创新,需要进行范式转换和新的路径选择,即根据功能金融理论,从金融的“机构范式”到“功能范式”,应注重金融生态环境建设,在对现有国家助学贷款的金融功能重新定位的基础上,着力推进社区银行参与国家助学贷款,并在开发二级市场前提下完善国家助学贷款的金融竞争机制。     

ESTIMATING THE ROOT OF A NONPARAMETRIC REGRESSION FUNCTION IN A ROBUST FASHION

For a nonparametric regression model y = m(x)+e with n independent observations, we analyze a robust method of finding the root of m(x) based on an M-estimation first discussed by Härdle & Gasser (1984). It is shown here that the robustness properties (minimaxity and breakdown function) of such an estimate are quite analogous to those of an M -estimator in the simple location model, but the rate of convergence is somewhat limited due to the nonparametric nature of the problem.     

如何有效发挥高校媒体的育人功能

高校媒体对高校育人意义非凡,只有对其有效整合,综合管理,才能充分发挥其新闻价值,培养符合时代需要的建设人才.