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41.
Diagnostics measures for detecting outliers in data from block designs of experiments with correlated errors are considered. Influence is often assessed by deleting suspected outlying observations. Autocorrelation of order one is considered to model correlation in each block. Cook-statistic is developed for detecting the effect of a single outlier, where results are illustrated with an example.  相似文献   
42.
For the two-sample location and scale problem we propose an adaptive test which is based on so called Lepage type tests. The well known test of Lepage (1971) is a combination of the Wilcoxon test for location alternatives and the Ansari-Bradley test for scale alternatives and it behaves well for symmetric and medium-tailed distributions. For the cae of short-, medium- and long-tailed distributions we replace the Wilcoxon test and the .Ansari-Bradley test by suitable other two-sample tests for location and scale, respectively, in oder to get higher power than the classical Lepage test for such distribotions. These tests here are called Lepage type tests. in practice, however, we generally have no clear idea about the distribution having generated our data. Thus, an adaptive test should be applied which takes the the given data set inio consideration. The proposed adaptive test is based on the concept of Hogg (1974), i.e., first, to classify the unknown symmetric distribution function with respect to a measure for tailweight and second, to apply an appropriate Lepage type test for this classified type of distribution. We compare the adaptive test with the three Lepage type tests in the adaptive scheme and with the classical Lepage test as well as with other parametric and nonparametric tests. The power comparison is carried out via Monte Carlo simulation. It is shown that the adaptive test is the best one for the broad class of distributions considered.  相似文献   
43.
There are increasing numbers of families in Australia headed by sole parents, but little is known about the experiences of those who also care for a child with a disability. Additional caring responsibilities have previously been shown to impact on the work participation of parents. This study involved qualitative analyses of interview data conducted with sole mothers with school‐aged children with disability (N = 11). Thematic analysis revealed four themes that enabled and supported participation in the workforce: social support; managing appointments; characteristics of the workplace; and the role of the school. Results suggest the importance of practical help from family and friends in facilitating participation in paid employment. Additionally, the importance of flexible appointment scheduling on the part of service providers was highlighted, as well as the importance of workplace flexibility and supportive workplace cultures. Such factors were important in supporting sole mothers to balance work with care, with important implications for personal and family wellbeing.  相似文献   
44.
为解决汽车侧围外板尾翼在拉延成型后出现起皱和开裂的问题,设计了3种造型方案.通过造型设计分析及Autoform模拟,对比3种方案,对原工艺进行整改和优化,得到了抬高造型台阶面的最优造型方案.该方案能改善进料速度、增加材料流动性,有效地消除开裂、起皱的缺陷,对同类和其他类似产品的冲压工艺设计具有参考意义.  相似文献   
45.
We study partial linear single-index models (PLSiMs) when the response and the covariates in the parametric part are measured with additive distortion measurement errors. These distortions are modeled by unknown functions of a commonly observable confounding variable. We use the semiparametric profile least-squares method to estimate the parameters in the PLSiMs based on the residuals obtained from the distorted variables and confounding variable. We also employ the smoothly clipped absolute deviation penalty (SCAD) to select the relevant variables in the PLSiMs. We show that the resulting SCAD estimators are consistent and possess the oracle property. For the non parametric link function, we construct the simultaneous confidence bands and obtain the asymptotic distribution of the maximum absolute deviation between the estimated link function and the true link function. A simulation study is conducted to evaluate the performance of the proposed methods and a real dataset is analyzed for illustration.  相似文献   
46.
Efforts to improve child survival in lower-income countries typically focus on fundamental factors such as economic resources and infrastructure provision, even though research from post-industrial countries confirms that family instability has important health consequences. We tested the association between maternal union instability and children’s mortality risk in Africa, Latin America and the Caribbean, and Asia using children’s actual experience of mortality (discrete-time probit hazard models) as well as their experience of untreated morbidity (probit regression). Children of divorced/separated mothers experience compromised survival chances, but children of mothers who have never been in a union generally do not. Among children of partnered women, those whose mothers have experienced prior union transitions have a higher mortality risk. Targeting children of mothers who have experienced union instability—regardless of current union status—may augment ongoing efforts to reduce childhood mortality, especially in Africa and Latin America where union transitions are common.  相似文献   
47.
The professionalization of evaluation continues to be debated at numerous conferences in the U.S. and abroad. At this time, AEA member views on the potential benefits and negative side effects of professionalization are essential as the discussion evolves. This study provides recent views on major topics in professionalization, including potential benefits, negative side effects, processes, competencies, and procedures. Results from in-depth interviews and an online survey demonstrate that AEA members view potential benefits of professionalization to be stakeholder trust, evaluator reputation and identity, while concerns about a potential negative side effect known as the “narrowing effect” (i.e., some evaluators will be alienated based on their background, competencies, etc.) were expressed by participants. These recent findings can inform the ongoing discussion of professionalization, and suggest new directions for future research on evaluation.  相似文献   
48.
船舶航行风险是由各种风险因素交互作用产生。综合 HHM-RFRM 理论,构建船舶航行多维风险情景危险度测度模型,以风险因素耦合视角探讨船舶航行风险管理问题。在船舶航行多维风险情景危险度测度模型中结合贝叶斯定理,对船舶航行风险情景进行了定性与定量化过滤、评级。最后以大连港某从事商务活动的货船为例,验证了所提出方法的可行性。传统的风险评估方法只能评估单个风险因素对系统的影响,此评估方法克服了这一局限性,为船舶航行风险管理提供新的视角。  相似文献   
49.
Over the last decade the health and environmental research communities have made significant progress in collecting and improving access to genomic, toxicology, exposure, health, and disease data useful to health risk assessment. One of the barriers to applying these growing volumes of information in fields such as risk assessment is the lack of informatics tools to organize, curate, and evaluate thousands of journal publications and hundreds of databases to provide new insights on relationships among exposure, hazard, and disease burden. Many fields are developing ontologies as a way of organizing and analyzing large amounts of complex information from multiple scientific disciplines. Ontologies include a vocabulary of terms and concepts with defined logical relationships to each other. Building from the recently published exposure ontology and other relevant health and environmental ontologies, this article proposes an ontology for health risk assessment (RsO) that provides a structural framework for organizing risk assessment information and methods. The RsO is anchored by eight major concepts that were either identified by exploratory curations of the risk literature or the exposure‐ontology working group as key for describing the risk assessment domain. These concepts are: (1) stressor, (2) receptor, (3) outcome, (4) exposure event, (5) dose‐response approach, (6) dose‐response metric, (7) uncertainty, and (8) measure of risk. We illustrate the utility of these concepts for the RsO with example curations of published risk assessments for ionizing radiation, arsenic in drinking water, and persistent pollutants in salmon.  相似文献   
50.
In this article, we calibrate the Vasicek interest rate model under the risk neutral measure by learning the model parameters using Gaussian processes for machine learning regression. The calibration is done by maximizing the likelihood of zero coupon bond log prices, using mean and covariance functions computed analytically, as well as likelihood derivatives with respect to the parameters. The maximization method used is the conjugate gradients. The only prices needed for calibration are zero coupon bond prices and the parameters are directly obtained in the arbitrage free risk neutral measure.  相似文献   
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