STATISTICAL METHODS FOR A MIXTURE OF SUBPOPULATIONS

这项研究将考察评估的内在困难。 当观测值的同一性为 还不完全清楚。硬聚类和模糊聚类技术是 调查过了。这项研究将制定评估方法，以 亚群体特征。新的方法论将缓解一些 一种不同种类的混合物的内在困难 亚群。将提出申请，研究有关的问题 出生体重的生物异质性和测量误差， 胎龄和围产儿死亡率。这项研究也将应用于 对胎儿宫内发育和妊娠结局的调查。这 工作仍在进行中。

This study will examine the intrinsic difficulty of estimating subpopulation characteristics when the identities of the observations are not completely known. Hard clustering and fuzzy clustering techniques are investigated. This study will develop estimation of methodologies for the subpopulation characteristics. The new methodologies will alleviate some of the intrinsic difficulties for a heterogeneous mixture of subpopulations. Applications will be made to study the issues concerning biological heterogeneity and measurement error in the birth weight, gestational age and perinatal mortality. This study will also be applied to the investigation of intrauterine growth and pregnancy outcome. This work is still in progress.