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251.
A new method for estimating the proportion of null effects is proposed for solving large-scale multiple comparison problems. It utilises maximum likelihood estimation of nonparametric mixtures, which also provides a density estimate of the test statistics. It overcomes the problem of the usual nonparametric maximum likelihood estimator that cannot produce a positive probability at the location of null effects in the process of estimating nonparametrically a mixing distribution. The profile likelihood is further used to help produce a range of null proportion values, corresponding to which the density estimates are all consistent. With a proper choice of a threshold function on the profile likelihood ratio, the upper endpoint of this range can be shown to be a consistent estimator of the null proportion. Numerical studies show that the proposed method has an apparently convergent trend in all cases studied and performs favourably when compared with existing methods in the literature.  相似文献   
252.
介绍了作者对雕刻行业CAT/CAD/CAM系统进行研究开发所发取得的部分成果,其中包括浮雕轮廓仿形CAT装置的实现,测量数据的筛选与处理方法Dmax浮雕曲面造型算法及数控加工文件的形成等。  相似文献   
253.
A variable-centered and a person-centered approach were performed to examine the role of early memories of warmth and safeness (EMWS) and current experiences of warmth and safeness (CEWS) on depressive and anxious symptoms among adolescents from community and residential youth care (RYC) settings. Variable-centered results revealed EMWS were only indirectly (through CEWS) associated with depressive and anxious symptoms. Person-centered outcomes allowed to identify four different profiles based on EMWS and CEWS, which differed on depressive and anxious symptoms. EMWS and CEWS seem to play an important role in psychological distress during adolescence. CEWS seem to have a protective role on RYC adolescents' psychological distress, even when EMWS were poor.  相似文献   
254.
We hypothesized that the goodness-of-fit between profiles of observed, caregiver-provided ethnic–racial socialization (ERS), and child self-regulation (i.e., inhibitory control) would differentially associate with child behavioral outcomes. Conversations between 80 caregivers (45% Latinx; 55% Black) and their children (M age  = 11.09; 46% female) were rated for ERS. Measures included an inhibitory control composite (ages 2.5–3.5) and the Child Behavior Checklist (CBCL; age 12). Three profiles were determined: Comprehensive (n  = 34), Reactive (n  = 8), and Pragmatic (n  = 38). Only youth with low inhibitory control in preschool appeared to benefit from Pragmatic ERS, whereas youth with normative or high inhibitory control in early childhood displayed lower internalizing and externalizing behaviors when they had Comprehensive or Reactive rather than Pragmatic caregivers.  相似文献   
255.
该软件系统不仅可以对平面凸轮机构进行准确的运动分析、精确的凸轮设计,还可以对所设计的凸轮机构进行形象的运动模拟显示。  相似文献   
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