Double and group acceptance sampling plan for truncated life test based on inverse log-logistic distribution

This paper introduces a double and group acceptance sampling plans based on time truncated lifetimes when the lifetime of an item follows the inverse log-logistic (ILL) distribution with known shape parameter. The operating characteristic function and average sample number (ASN) values of the double acceptance sampling inspection plan are provided. The values of the minimum number of groups and operating characteristic function for various quality levels are obtained for a group acceptance sampling inspection plan. A comparative study between single acceptance sampling inspection plan and double acceptance sampling inspection plan is carried out in terms of sample size. One simulated example and four real-life examples are discussed to show the applicability of the proposed double and group acceptance sampling inspection plans for ILL distributed quality parameters.     

Modelling period fertility: Schooling and intervals following a birth in Eastern Africa

We describe a regression-based approach to the modelling of age-, order-, and duration-specific period fertility, using retrospective survey data. The approach produces results that are free of selection biases and can be used to study differential fertility. It is applied to Demographic and Health Survey data for Ethiopia, Kenya, Tanzania, and Zimbabwe to investigate differential trends in fertility by education. Parity progression fell and the intervals following each birth lengthened between the 1970s and 2000s in all four countries. Fertility fell most among women with secondary education. In contrast to other world regions, postponement of successive births for extended periods accounted for much of the initial drop in fertility in these African countries. However, family size limitation by women with secondary education in Ethiopia and Kenya and longer birth spacing in Zimbabwe also played significant roles. Thus, birth control is being adopted in Eastern Africa in response to diverse changes in fertility preferences.     

陕西省出生人口性别比定量分析与对策探讨

文章根据陕西省历次人口普查、部分人口抽样调查资料及公安、教育、计生统计报表数据,时全省出生人口性别失衡程度、女婴缺失数量和分因素贡献率等几个问题进行定量分析,并对出生人口性别比综合治理和科学决策提出建议。     

An approximate dual-self model and paradoxes of choice under risk

We derive a simplified version of the model of Fudenberg and Levine, 2006, Fudenberg and Levine, 2011 and show how this approximate model is useful in explaining choice under risk. We show that in the simple case of three outcomes, the model can generate indifference curves that “fan out” in the Marschak–Machina triangle, and thus can explain the well-known Allais and common ratio paradoxes that models such as prospect theory and regret theory are designed to capture. At the same time, our model is consistent with modern macroeconomic theory and evidence and generates predictions across a much wider set of domains than these models.     

血栓弹力图在PCI术后患者抗血小板治疗中的应用研究

目的:研究血栓弹力图在经皮冠状动脉介入治疗(PCI)患者中,使用血栓弹力图所测定的血小板抑制率的波动及临床疗效作用。方法:选取我院2012年1月份至2013年12月份收治的200例冠心病PCI治疗患者,应用血栓弹力图分析仪测定其二磷酸腺苷(ADP)途径诱导的血小板抑制率数据,根据抑制率差异分为3组,抑制率70%的为合格组,抑制率30%的为不合格组,入选不合格组再次分为2组,1组保持常规剂量治疗不变,另一组为大剂量治疗组。结果:随访半年的记录,记录一般情况及严重心脏不良事件发生情况。结果:随访的6个月中,共发生不良事件28例,其中合格组10例(9.6%),常规治疗组11例(22.4%),大剂量治疗组7例(14.9%),3组中不良事件发生率比常规治疗组大于大剂量治疗组,大剂量治疗组大于合格组,统计学上有明显差异(P0.05)。结论:血栓弹力图在PCI患者抗血小板治疗中应用具有一定的指导意义。     

自然资源经济学的难解之题——水资源价格与节约的冲突

日益短缺的水资源面临的价格与节约的冲突,成为自然资源经济学的一个难解之题：水资源严重短缺的趋势,需要通过价格调整其分配与消费,而作为公用事业产品的生活用水,价格的长期粘性不利于水资源节约。提出这个问题,意在提示人们共同探讨破解这一难题的方法。     

Mate Availability and Women's Sexual Experiences in China

Data from the 1999-2000 Chinese Health and Family Life Survey were merged with community-level data from the 1982, 1990, and 2000 Chinese censuses to examine the relationship between the local sex ratio (number of men per 100 women) and sexual outcomes among women (N = 1,369). Consistent with hypotheses derived from demographic-opportunity theory, multilevel logistic regression analyses showed that women are more likely to be sexually active, to have had premarital sexual intercourse, to have been forced to have sex, and to test positive for a sexually transmitted infection when there is a relative abundance of age-matched men in their local community. Education, birth cohort, and geographic location also emerged as significant predictors of women's sexual experiences.     

中国地方政府债务问题探讨

中国地方政府债务问题形成的主要原因,一是政府过多地、直接地参与经济活动,二是城市化加速导致地方政府举债。对于中国地方政府债务问题,总体判断仍为风险可控。一是地方政府加上中央政府的债务占GDP的比例在40%以内,远低于60%的债务率标准。二是中央政府有非常强的控制能力,在各级政府间平衡债权债务,使得中国加总的净债务率较低。三是中国整体的资产负债表仍然健康,尤其是中央政府保持相当健康的资产负债表。对地方政府债务问题,体制性的解决办法是治本之道。要从根本上解决中国地方政府不规范借债问题,须建立规范化的地方政府举债融资机制。     

Robust inference for group sequential trials

For ethical reasons, group sequential trials were introduced to allow trials to stop early in the event of extreme results. Endpoints in such trials are usually mortality or irreversible morbidity. For a given endpoint, the norm is to use a single test statistic and to use that same statistic for each analysis. This approach is risky because the test statistic has to be specified before the study is unblinded, and there is loss in power if the assumptions that ensure optimality for each analysis are not met. To minimize the risk of moderate to substantial loss in power due to a suboptimal choice of a statistic, a robust method was developed for nonsequential trials. The concept is analogous to diversification of financial investments to minimize risk. The method is based on combining P values from multiple test statistics for formal inference while controlling the type I error rate at its designated value.This article evaluates the performance of 2 P value combining methods for group sequential trials. The emphasis is on time to event trials although results from less complex trials are also included. The gain or loss in power with the combination method relative to a single statistic is asymmetric in its favor. Depending on the power of each individual test, the combination method can give more power than any single test or give power that is closer to the test with the most power. The versatility of the method is that it can combine P values from different test statistics for analysis at different times. The robustness of results suggests that inference from group sequential trials can be strengthened with the use of combined tests.     

Testing independence based on Bernstein empirical copula and copula density

In this paper we provide three nonparametric tests of independence between continuous random variables based on the Bernstein copula distribution function and the Bernstein copula density function. The first test is constructed based on a Cramér-von Mises divergence-type functional based on the empirical Bernstein copula process. The two other tests are based on the Bernstein copula density and use Cramér-von Mises and Kullback–Leibler divergence-type functionals, respectively. Furthermore, we study the asymptotic null distribution of each of these test statistics. Finally, we consider a Monte Carlo experiment to investigate the performance of our tests. In particular we examine their size and power which we compare with those of the classical nonparametric tests that are based on the empirical distribution function.