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31.
Tahani Coolen-Maturi 《统计学通讯:理论与方法》2017,46(19):9476-9493
Measuring the accuracy of diagnostic tests is crucial in many application areas including medicine, machine learning, and credit scoring. The receiver operating characteristic (ROC) surface is a useful tool to assess the ability of a diagnostic test to discriminate among three-ordered classes or groups. In this article, nonparametric predictive inference (NPI) for three-group ROC analysis for ordinal outcomes is presented. NPI is a frequentist statistical method that is explicitly aimed at using few modeling assumptions, enabled through the use of lower and upper probabilities to quantify uncertainty. This article also includes results on the volumes under the ROC surfaces and consideration of the choice of decision thresholds for the diagnosis. Two examples are provided to illustrate our method. 相似文献
32.
通过梳理资本核算理论框架,结合中国实际情况测量了1981-2014年资本服务流量。资本分类、组合役龄效率-退役剖面计算、资本回报率确定和初始单位效率生产性资本存量估计等方面与既有研究有所不同。测量结果表明:按照1990年不变价格,各类资本服务流量呈增加趋势,其中无形资产服务流量前期较为波动;设备类服务流量增速最高;总资本服务增长率前期呈V型后期呈倒U型,与GDP增速变动不一致,整体来看前者高于后者;比较发现测量结果高于其它研究,差距先收敛后扩大。 相似文献
33.
通过对广告受众心理进行分析,总结出新形势下广告受众心理的主要特点。具体受众心理分析是:一、感性心理:情趣情调;自我比拟;理想向往;流行时尚;交流互动;品牌偏好。二、理性——感性心理:实用价值观念变异;自我价值中的理性与感性;体现个性。 相似文献
34.
Bethany L. Carr Beverley Copnell Meredith McIntyre 《Women and birth : journal of the Australian College of Midwives》2019,32(2):e259-e263
Background
Meconium stained amniotic fluid commonly occurs postdates (?>40 weeks gestation) indicating fetal maturity. Previous literature indicates that different ethnicities mature at different rates.Aim
To compare the rate of meconium stained amniotic fluid of Australian-born and non-Australian born women.Methods
A retrospective correlation study design was implemented, using data collected in the birth outcomes system at one tertiary hospital. Data was collected from all women who gave birth to a term (>/=37 weeks gestation), singleton, liveborn baby between January 1st to December 31st, 2014. Maternal country of birth was used for comparison. Categorical data was analyzed using Chi-Square test for Independence. Continuous variables were assessed for normality, and differences were compared using an Independent t-test or a Mann–Whitney U test. All tests were two-tailed and p < 0.05 was considered statistically significant.Results
3,041 women were included; 1131 Australian-born and 1910 non-Australian born. Meconium stained amniotic fluid occurred more frequently in non-Australian born women compared to Australian-born women (23.5% vs. 19.8 p = 0.02). Their babies were significantly smaller (Mean = 3265 g, Standard Deviation 463.8 vs Mean = 3442 g, Standard Deviation 499.2, p < 0.001), with no difference in gestational length (Mean = 39.4, Standard Deviation 1.28 vs Mean = 39.5, Standard Deviation 1.18, p = 0.06). Increasing gestational age had the strongest association with meconium stained amniotic fluid;?>/=42 weeks gestation occurring 3.52 (95% Confidence Interval: 2.00, 6.22, p = <0.001) more than <40 weeks gestation.Conclusion
Maternity health services should record ethnicity and region of birth to provide individualised care as women born overseas often have poorer perinatal outcomes when compared to Australian-born women. 相似文献35.
《Journal of Policy Modeling》2019,41(4):586-606
Raising employment, in particular employment among older individuals and low educated individuals, stands high on the agenda of policy makers in many OECD countries. Increased sensitivity in recent years to rising inequality has made the challenge only larger. In this paper we evaluate alternative fiscal policy scenarios to face this challenge. We construct and use an overlapping generations model for an open economy where individuals differ not only by age, but also by innate ability and human capital. The model allows us to study effects on aggregate employment, per capita income and welfare, as well as effects for specific age and ability groups. We show that well-considered fiscal policy changes can significantly improve macroeconomic productive efficiency, without increasing intergenerational or intragenerational welfare inequality. Our results strongly prefer a reduction in the labor tax rate on older workers and on all low-wage earners, financed by an overall reduction in non-employment benefits. An alternative financing option is to raise the consumption tax rate. These results are to be seen as long-run effects for economies at potential output. 相似文献
36.
何星亮 《广西民族大学学报(哲学社会科学版)》2020,(1):117-123
探讨史前拔牙个体的年龄和次数,对了解史前社会生活和社会意识、宗教信仰具有重要意义。认为中国和日本新石器时代的原生拔牙应该是青春期或成年期拔牙。中国新石器时代只存在一次拔牙现象,而日本新石器时代存在多次拔牙现象。这说明虽然同处新石器时代,但社会结构和社会意识有所不同。 相似文献
37.
Nil Kamal Hazra 《统计学通讯:理论与方法》2017,46(19):9842-9858
Stochastic orders are very useful tools to compare the lifetimes of two systems. Optimum lifetime of a series (resp. parallel) system with general standby component(s) depends on the allocation strategy of standby component(s) into the system. Here, we discuss three different models of one or more standby components. In each model, we compare different series (resp. parallel) systems (which are formed through different allocation strategies of standby component(s)) with respect to the usual stochastic order and the stochastic precedence order. The results related to the cold as well as the hot standby models are obtained as particular cases of the results discussed in this article because the model considered here is a general one. 相似文献
38.
The older the bolder: Does relative age among peers influence children’s preference for competition?
Having been relatively old at school tends to have a long lasting positive effect on professional achievement, in particular in competitive environments (sports, politics). We investigate the roots of this pattern and study whether the relative age position of children at school plays a role in shaping their preference for competition. We run a controlled experiment in high schools across two states in Australia. Our participants are students who are the very oldest or very youngest in their classroom. We elicit their preference for competition using the Niederle and Vesterlund (2007) task and find evidence of an effect of relative age. This effect is concentrated on male students. We find no differences in self-confidence, and risk attitudes between relatively old and young students. These results suggest that the observed pattern may come from pure preference for competition. 相似文献
39.
The receiver operating characteristic (ROC) curve is one of the most commonly used methods to compare the diagnostic performance of two or more laboratory or diagnostic tests. In this paper, we propose semi-empirical likelihood based confidence intervals for ROC curves of two populations, where one population is parametric and the other one is non-parametric and both have missing data. After imputing missing values, we derive the semi-empirical likelihood ratio statistic and the corresponding likelihood equations. It is shown that the log-semi-empirical likelihood ratio statistic is asymptotically scaled chi-squared. The estimating equations are solved simultaneously to obtain the estimated lower and upper bounds of semi-empirical likelihood confidence intervals. We conduct extensive simulation studies to evaluate the finite sample performance of the proposed empirical likelihood confidence intervals with various sample sizes and different missing probabilities. 相似文献
40.
This study investigated the relationships between types of activity and quality of life (QOL) for older men and women at different ages. Based on cross-sectional data that included 220 community-dwelling elderly persons aged 65 and older in southern Taiwan, the results showed that the participation rates in many activities declined with age for both genders. Social activity and solitary leisure activity were significantly associated with QOL for old-old men, but not for young-old men. Only social activity was significantly associated with QOL for young-old women, but there was no significant association between any activity and QOL for old-old women. 相似文献