Distance Testing for Selecting the Best Population

Consider testing the null hypothesis that a given population has location parameter greater than or equal to the largest location parameter of k competing populations. This paper generalizes tests proposed by Gupta and Bartholomew by considering tests based on p -distances from the parameter estimate to the null parameter space. It is shown that all tests are equivalent when k →∞ for a class of distributions that includes the normal and the uniform. The paper proposes the use of adaptive quantiles. Under suitable assumptions the resulting tests are asymptotically equivalent to the uniformly most powerful test for the case that the location parameters of all but one of the populations are known. The increase in power obtained by using adaptive tests is confirmed by a simulation study.     

Asymptotic properties of Bayes risk for one-sided tests

Consider a given sequence {T_n} of estimators for a real-valued parameter θ. This paper studies asymptotic properties of restricted Bayes tests of the following form: reject H₀:θ ≤ θ₀ in favour of the alternative θ > θ₀ if T_n ≤ C_n, where the critical point C_n is determined to minimize among all tests of this form the expected probability of error with respect to the prior distribution. Such tests may or may not be fully Bayes tests, and so are called T_n-Bayes. Under fairly broad conditions it is shown that and the T_n-Bayes risk where a_n is the order of the standard error of T_n, - is the prior density, and μ is the median of F, the limit distribution of (T_n – θ)/a_nb(θ). Several examples are given.     

Optimal bounds for the mean of the total time on test for distributions with decreasing generalized failure rate

During any life test experiment it is of interest to study potential costs (or profits) of performing the test to the very end. Assuming that these costs are proportional to lifetimes of analysed items the experimenter needs to know the remaining total time on test, having just observed successive failure in the test. We derive sharp upper bounds on the expectation of the remaining total time on test statistic when the underlying distributions have decreasing generalized failure rate with respect to generalized Pareto distributions. In particular we obtain the bounds valid for distributions with decreasing density or failure rate. The results are illustrated with numerical examples.     

车用电动燃油泵性能检测及评价系统开发研究

针对当前电动燃油泵性能检测方法的弊端,开发了一种基于单片机的新型燃油泵性能检测与评价系统,实现了燃油泵参数的自动采样、存储、动态显示功能,并能够依据检测结果自动评价燃油泵的性能.实际测试结果表明,该系统可有效提高电动燃油泵的检测精度和检测效率.     

需求要素对我国经济增长影响的边限协整分析

为了更好地预测需求各构成要素对我国经济增长的影响程度,在建立了无约束误差修正模型的基础上,运用边限检验方法进行了实证研究。结果表明,中国经济增长与需求因素之间存在着长期的稳定关系,需求的不同组成部分对中国经济增长有不同的影响。在长期,只有资本形成总额的影响显著;在短期内,需求各要素对中国经济增长有显著影响。     

大学英语的翻译教学及其测试

大学英语翻译是测试学生英语应用能力的一种重要方式,随着社会发展的需求,在历次教学大纲修改中,对学生翻译能力的要求也越来越高。为适应这一变化,对翻译的测试方式、题目类型以及评分标准页进行了不断的改革,其中有成绩也有不足。因此,在翻译教学过程中必须采取针对性的措施,才能真正提高学生的翻译能力,达到教学目的。     

锡崖沟瀑布景观工程水力模型试验研究

根据锡崖沟景区规划设计,沿锡崖沟水库溢洪道下部开凿底洞引水,在水库下游红岩大峡谷常年形成20m宽大瀑布．以满足瀑布流的重力和紊动阻力相似的原则进行了其正态模型设计．通过模型放水试验表明：流量变化对瀑布水流流态影响很大,溢流槽空间狭小,加之上游进口扇形扩散段扩散角偏大,水流扩散不充分,堰顶溢流不均匀,瀑布景观效果差．将模型的溢流堰顶修改为T型复式断面后,顺应了水流的流动特性,在各级流量下均能获得比较好的瀑布景观效果．     

On Efficient Estimators of the Proportion of True Null Hypotheses in a Multiple Testing Setup

We consider the problem of estimating the proportion θ of true null hypotheses in a multiple testing context. The setup is classically modelled through a semiparametric mixture with two components: a uniform distribution on interval [0,1] with prior probability θ and a non‐parametric density f . We discuss asymptotic efficiency results and establish that two different cases occur whether f vanishes on a non‐empty interval or not. In the first case, we exhibit estimators converging at a parametric rate, compute the optimal asymptotic variance and conjecture that no estimator is asymptotically efficient (i.e. attains the optimal asymptotic variance). In the second case, we prove that the quadratic risk of any estimator does not converge at a parametric rate. We illustrate those results on simulated data.     

汉语双音词判定的语法意义标准

目前学术界区分汉语双音词和双音节非词成分的标准主要有意义标准、结构标准、修辞标准等五种,文章在分析以上标准不足之处的基础上,提出了新的判定标准——语法意义标准,并进行了事实和理论验证。     

Welfare state dissatisfaction and support for major welfare reform: Towards means-tested welfare or a universal basic income?

This research note investigates how people combine their views on two radically opposing welfare reforms: a universal basic income and a fully means-tested welfare state. Using data from the 2016–2017 European Social Survey, we found that support for transformative welfare reform is rooted in perceptions of the performance of the current system. The preferred direction of reform, however, strongly depends on the specific aspects of the welfare state people are happy or unhappy with. At the country-level, we show that underperforming welfare states—in terms of higher poverty rates and lower social spending—increase popular demand for transformative welfare reform, in either direction. These findings are of crucial importance for ongoing debates about the future of the welfare state.