An improved alternative estimation procedure for current population mean in presence of positively and negatively correlated auxiliary variables in two-occasion rotation patterns

Abstract

The present study confirms the influential role of a positively and a negatively correlated auxiliary variables in enhancing the precision of estimates of current population mean in two occasion rotation (successive) sampling. Exponential-type estimators of current population mean have been proposed for three different situations: (i) the information on a positively correlated auxiliary variable is readily available on both occasions (ii) the information on a negatively correlated auxiliary variable is readily available on both occasions and (iii) the information on both positively and negatively correlated auxiliary variables are readily available on both the occasions. The characteristics of the proposed estimators have been explored and their efficacious performances are compared with the natural and recent contemporary estimators. Optimum replacement strategies of the proposed estimation procedures have been formulated. Simulation and empirical studies are carried out to justify the proposition of the proposed estimators and appropriate recommendations have been put forward to the survey practitioners.     

Distribution of the two‐sample t‐test statistic following blinded sample size re‐estimation

We consider the blinded sample size re‐estimation based on the simple one‐sample variance estimator at an interim analysis. We characterize the exact distribution of the standard two‐sample t‐test statistic at the final analysis. We describe a simulation algorithm for the evaluation of the probability of rejecting the null hypothesis at given treatment effect. We compare the blinded sample size re‐estimation method with two unblinded methods with respect to the empirical type I error, the empirical power, and the empirical distribution of the standard deviation estimator and final sample size. We characterize the type I error inflation across the range of standardized non‐inferiority margin for non‐inferiority trials, and derive the adjusted significance level to ensure type I error control for given sample size of the internal pilot study. We show that the adjusted significance level increases as the sample size of the internal pilot study increases. Copyright © 2016 John Wiley & Sons, Ltd.     

Model averaging inconcentration–QT analyses

This article describes how a frequentist model averaging approach can be used for concentration–QT analyses in the context of thorough QTc studies. Based on simulations, we have concluded that starting from three candidate model families (linear, exponential, and Emax) the model averaging approach leads to treatment effect estimates that are quite robust with respect to the control of the type I error in nearly all simulated scenarios; in particular, with the model averaging approach, the type I error appears less sensitive to model misspecification than the widely used linear model. We noticed also few differences in terms of performance between the model averaging approach and the more classical model selection approach, but we believe that, despite both can be recommended in practice, the model averaging approach can be more appealing because of some deficiencies of model selection approach pointed out in the literature. We think that a model averaging or model selection approach should be systematically considered for conducting concentration–QT analyses. Copyright © 2016 John Wiley & Sons, Ltd.     

Exponentiality Test Based on the Progressive Type II Censoring via Cumulative Entropy

In this article, we use cumulative residual Kullback-Leibler information (CRKL) and cumulative Kullback-Leibler information (CKL) to construct two goodness-of-fit test statistics for testing exponentiality with progressively Type-II censored data. The power of the proposed tests are compared with the power of goodness-of-fit test for exponentiality introduced by Balakrishnan et al. (2007 Balakrishnan, N., Habibi Rad, A., Arghami, N.R. (2007). Testing exponentiality based on Kullback-Leibler information with progressively type-II censored data. IEEE Transactions on Reliability 56(2):301–307.[Crossref], [Web of Science ®] , [Google Scholar]). We show that when the hazard function of the alternative is monotone decreasing, the test based on CRKL has higher power and when the hazard function of the alternative is non-monotone, the test based on CKL has higher power. But, when it is monotone increasing the power difference between test based on CKL and their proposed test is not so remarkable. The use of the proposed tests is shown in an illustrative example.     

A Comparison of Topography-based and Selection-based Verbal Behavior in Typically Developed Children and Developmentally Disabled Persons with Autism

This study is a replication of Sundberg and Sundberg (1990) that compared topography-based verbal behavior with selection-based verbal behavior in terms of acquisition, accuracy, and testing for the emergence of a new verbal relation. Participants were three typical children and three developmentally disabled persons with autism. The study sought to determine which paradigm (topography-based or selection-based) resulted in more rapid acquisition of tacts and intraverbals, which was associated with the fewest errors, and which paradigm resulted in the emergence of the highest number of new verbal relations. The results of the study showed that the six participants performed quite differently from one another. Most importantly, the results from the person with autism contradicted previous findings favoring selection-based verbal behavior over topography-based approaches for teaching verbal behavior to low-functioning individuals.     

Strengths-Based Approach and Coping Strategies used by Parents Whose Young Children Exhibit Violent Behaviour: Collaboration Between Schools and Parents

This research study explores the strategies adopted by 60 parents of children between 3 and 9 years of age considered to have engaged in violent behaviour, within the meaning of the Safe Schools Act (Ontario Ministry of Education, Canada, 2000). This legal framework requires parents to be involved in the decisions concerning their children. Parents’ perceptions of their involvement lead them to develop coping strategies enabling them to play a more active role in such decision making. This article analyzes their perceptions according to a strengths-based approach and seeks to provide a mediation perspective to social work practice with families.

学术道路自述

回顾几十年来学术研究的道路,开始把鲁迅研究以专著形式系列化。这里的系列,只能说是“小系”,而不是“大系”。在这基础上,扩大研究领域,撰写关于中国现代小说研究,现代文学史研究的论著,同时进行散文创作,出版几本散文集。学术界的前辈、同辈、后辈的学者,在著作和文章中对我的论著、作品,进行热情的评论、分析,至感。     

我国公司发行可转换债券的市场反应

使用事件研究法,分析了我国公司发行可转换债券的市场反应。研究表明,我国公司发行可转换债券后市场没有出现显著负的反应,与股权再融资的市场反应明显不同,与国外可转换债券发行的市场反应有差异。政府的奖优政策是可转换债券市场反应特殊性的重要原因。     

Delaying factors for maternal health service utilization in eastern Ethiopia: A qualitative exploratory study

BackgroundIn Ethiopia, maternal health service utilization is still unacceptably low. The societal and cultural factors that constrain women from attending these services have not yet been sufficiently explored. Using qualitative methods, we aimed to explore the factors that delay maternal health service utilization in eastern Ethiopia.MethodA total of 13 audio-recorded focus group discussions were conducted comprising 88 participants. We conducted separate group discussions with reproductive aged women, mothers-in-law, traditional birth attendants, husbands, and Health Extension Workers to capture their knowledge, practices, feelings, thoughts and attitudes towards maternal health service utilization. The recorded sessions were transcribed into the local language and then translated into English for analysis.ResultThe study identified a number of factors that may delay maternal health service utilization. Factors were grouped using the Three Delays model as a framework. Low level of awareness regarding need, poor involvement of husband, perceived absence of health problems, social power, community misperceptions and cultural restrictions, negative attitudes towards male midwives, acceptance of traditional birth attendants and poor social networking were Delay One factors. Lack of physical accessibility and high transportation costs were categorised as Delay Two factors for skilled birth care attendance. Perceived or experienced poor quality of care were categorised as Delay Three factors for both skilled birth and postnatal care utilization.ConclusionDespite the ongoing government measures to improve maternal health service utilization in Ethiopia, numerous factors continue to contribute to delays in service use, which in turn contribute to high maternal mortality.     

习近平外交思想指向下中日关系发展的新定位

近年来中日关系逐步转寒回暖,无论政治交流氛围,还是经济合作环境都得到了较大改善,这离不开中国政府根据国际形势及中日关系的变化及时调整对日政策,也充分体现了习近平新时代中国特色社会主义外交思想对中日关系缓和发展的引领作用。在安倍首相访华及习近平主席出席大阪G20峰会之后,两国政府在努力建设契合新时代要求的中日关系上达成多点共识。中日双方将依托“一带一路”倡议和第三方市场合作的平台,进一步致力于深化经济合作,维护多边主义和自由贸易体制,共同培育新动能和新的增长点,加速东北亚区域命运共同体的构建。