Topics in Statistics with Applications

提案ID：0203798 PI：Zhiliang Ying职称：主题统计与applicationsAbstractThis项目解决有关的问题，半参数回归模型与删失数据以及测试和估计项目的差异功能所产生的IRT为基础的标准化测试。研究人员和他的合作者开发新的算法来获得加速失效时间回归的参数估计。这些算法都是基于线性规划，易于实现。估计量是渐近正态的，通过一个简单的reservation方法估计的极限方差。该方法被扩展到删失分位数回归模型，这是常见的计量经济学文献。他们通过估计方程研究了半参数变换模型类，得到了参数估计和推断的一般方法，并通过大样本理论证明了这一点。他们开发了一种新的自适应标准化测试方法，通过具有测量误差的广义逻辑回归模型来检测可能的项目差异功能。这里处理的统计问题的动机是在生物医学科学，社会学，经济学，市场营销，心理学和教育的应用。该项目开发适当的统计模型，计算机算法和数学理论。研究结果可用于促进临床试验和流行病学研究的设计，特别是在癌症、心血管疾病和艾滋病的研究中，分析失业持续时间数据，量化消费者对营销策略的反应，并筛选出用于大规模标准化测试的项目，这些项目对某些群体有偏见，以确保公平

Proposal ID: 0203798PI: Zhiliang YingTitle: Topics in statistics with applicationsAbstractThis project addresses issues related to semiparametric regression models with censored data as well as testing and estimation of item differential functioning arising from IRT-based standardized tests. The investigator and his collaborators develop new algorithms for obtaining parameter estimators for the accelerated failure time regression. These algorithms are based on linear programming which is easy to implement. The estimators are shown to be asymptotically normal, with the limiting variance estimated via a simple resampling method. The approach is extended to censored quantile regression models, which are common in econometrics literature. They study the class of semiparametric transformation models via estimating equations, resulting in a general method for parameter estimation and inference, justified by a large sample theory. They develop a new approach for adaptive standardized tests to detect possible item differential functioning via a generalized logistic regression model with measurement errors. The statistical problems dealt with here are motivated by applications in biomedical sciences, sociology, economics, marketing, psychology and education. The project develops appropriate statistical models, computer algorithms and mathematical theory. The results can be used to facilitate design of clinical trials and epidemiological studies, particularly in studies of cancer, cardiovascular diseases and AIDS, to analyze unemployment duration data, to quantify consumer responses to marketing strategies and to screen out items for use in large-scale standardized tests that are tilted against certain group or groups to ensure fairness