Exact distribution of Durbin's distribution-free test statistic for Balanced Incomplete Block Designs, and comparison with the Chi-square and F approximation

Durbin's distribution-free rank test can be used to test the null hypothesis that there are no differences among the treatments in a Balanced Incomplete Block Design. Until now only the chi-square and F approximations for the test statistic were known. In this paper the exact distribution has been given for 15 designs and comparison is made with the chi-square and F approximation.     

A strategic predictive distribution for tests of probabilistic calibration

Forecasts of probability distributions are needed to support decision making in many applications. The accuracy of predictive distributions should be evaluated by maximising sharpness subject to calibration. Sharpness relates to the concentration of the predictive distributions, while calibration concerns their statistical consistency with the data. This paper focuses on calibration testing. It is important that a calibration test cannot be gamed by forecasts that have been strategically designed to pass the test. The widely used tests of probabilistic calibration for predictive distributions are based on the probability integral transform. Drawing on previous results for quantile prediction, we show that strategic distributional forecasting is a concern for these tests. To address this, we provide a simple extension of one of the tests. We illustrate ideas using simulated data.     

基于卡方检验的地方建筑类大学生就业模式研究

这几年来关于高校毕业生都存在一个普遍就业难的问题,而地方建筑类大学的就业情况与男女性别关系密切,本文分析了建筑类专业毕业生就业的特点,通过对学生的问卷调查,运用SPSS软件的数据分析法就大学生就业情况进行统计分析,得出学生就业情况与期望工作环境等存在密切的联系,并给出相应的策略及建议,这对当前建筑类专业的毕业生来说,有着一定的理论指导意义。     

Asymptotic non-deficiency of the Bayes sequential estimation in a family of transformed Chi-square distributions

Bayes sequential estimation in a family of transformed Chi-square distributions using a linex loss function and a cost c > 0 for each observation is considered in this paper. It is shown that an asymptotic pointwise optimal rule (A.P.O.) is asymptotically non-deficient, i.e., the difference between the Bayes risk of the A.P.O. rule and the Bayes risk of the optimal procedure is of smaller order of magnitude than c, the cost of single observation, as c → 0.     

Equivalence between Tie-corrected Spearman Test and a Chi-square Test in a Fourfold Contingency Table

Summary In the present paper, for the Spearman Rank Correlation Test, it is shown: Applying the Tie-corrected Spearman Test to the data in a Fourfold Contingency Table, that is to a sample result where the number of ties reaches his extreme possible value, the test turns out to be equivalent to a Chi-square Test for this Fourfold Table. This result seems to be a good justification for applying this rank test also in the case of “many ties”.     

Increasing the credibility of the twin birth instrument

Twin births are an important instrument for the endogenous fertility decision. However, twin births are not exogenous either as dizygotic twinning is correlated with maternal characteristics. Following the medical literature, we assume that monozygotic twins are exogenous, and construct a new instrument, which corrects for the selection although monozygotic twinning is usually unobserved in survey and administrative datasets. Using administrative data from Sweden, we show that the usual twin instrument is related to observed and unobserved determinants of economic outcomes, while our new instrument is not. In our applications we find that the classical twin instrument underestimates the negative effect of fertility on labor income. This finding is in line with the observation that high earners are more likely to delay childbearing and hence have a higher risk to get dizygotic twins.     

自动化仪表工程质量影响因素及其控制分析

同所有化工安装工程相关的专业相同,自动化仪表工程也具有系统化、科学化以及专业化的特点,因此,其安装的质量是非常重要的。     

Robust calibration and arbitrage-free interpolation of SSVI slices

Decisions in Economics and Finance - We describe a robust calibration algorithm of a set of SSVI maturity slices (i.e., a set of 3 SSVI parameters $$theta _t, rho _t, varphi _t$$...     

基于Web的网络化虚拟仪器技术及应用

网络化虚拟仪器是继虚拟仪器之后,仪器仪表领域出现的又一个新的发展方向,它是将Internet技术与虚拟仪器技术相结合,继承并发展了虚拟仪器的概念,延伸和扩大了虚拟仪器的资源。文章利用LabVIEW平台的G Web服务器和DataSocket服务器,将数据发布到以太网或Internet网上。二者结合,可以开发性能优异而体系开放的远程虚拟实验室系统,丰富学校的实验教学。     

基于Web的网络化虚拟仪器技术及应用

网络化虚拟仪器是继虚拟仪器之后,仪器仪表领域出现的又一个新的发展方向,它是将Internet技术与虚拟仪器技术相结合,继承并发展了虚拟仪器的概念,延伸和扩大了虚拟仪器的资源。文章利用LabVIEW平台的G Web服务器和DataSocket服务器,将数据发布到以太网或Internet网上。二者结合,可以开发性能优异而体系开放的远程虚拟实验室系统,丰富学校的实验教学。