Bayesian goodness-of-fit test for censored data

We propose a Bayesian computation and inference method for the Pearson-type chi-squared goodness-of-fit test with right-censored survival data. Our test statistic is derived from the classical Pearson chi-squared test using the differences between the observed and expected counts in the partitioned bins. In the Bayesian paradigm, we generate posterior samples of the model parameter using the Markov chain Monte Carlo procedure. By replacing the maximum likelihood estimator in the quadratic form with a random observation from the posterior distribution of the model parameter, we can easily construct a chi-squared test statistic. The degrees of freedom of the test equal the number of bins and thus is independent of the dimensionality of the underlying parameter vector. The test statistic recovers the conventional Pearson-type chi-squared structure. Moreover, the proposed algorithm circumvents the burden of evaluating the Fisher information matrix, its inverse and the rank of the variance–covariance matrix. We examine the proposed model diagnostic method using simulation studies and illustrate it with a real data set from a prostate cancer study.     

Bad Probability,Good Statistics,and Group Testing for Binomial Estimation

This article examines some improperly stated but often used textbook probability problems. Moving from a probabilistic to a statistical setting provides insight into group testing (i.e., observing only whether one or more of a group responds and not the response of each individual). Exact methods are used to construct tables showing (i) that group testing n times to estimate p can be more efficient than n individual tests even for small n and large p, (ii) optimal grouping strategies for various (n, p) combinations, and (iii) the efficiencies and biases achieved.     

Local information and the design of sequential hypothesis tests

Various results on sequential hypotheses testing are reviewed. Optimal stopping rules are related to a local measure of statistical information. In some cases, local information can be approximated by L-numbers discovered by Lorden, and simple rules based on these approximations are asymptotically optimal to better order than the cost for a single observation.     

语言行为模式与语言测试

建立语言行为模式的必要性现已被语言测试领域的一些研究者所承认。文章评价了现有的几种行为模式,并提出了在语言测试中,影响语言行为的因素的模式。     

论科学观察活动的主体性

着重对科学观察活动进行了剖析,揭示了科学观察活动的主体性。科学观察活动是主体积极参与和构建观察对象的过程,难免具有可错性、局限性和不确定性。所以,作为检验科学理论的实践标准不能局限于科学观察和科学实验,科学理论还必须接受生产和生活实践的广泛检验。     

企业职工技能鉴定存在问题分析及对策研究

论述了目前企业职工技能鉴定工作中所存在的问题,阐析了产生这些问题的原因。在此基础上提出企业在发展壮大过程中必须规范企业职工技能鉴定体制,健全职业鉴定制度,充分发挥职业技能考核员作用,同时引进激励约束机制等一系列具体对策。     

预应力锚杆柔性支护技术应用的现场监测与分析

对大连新天地高层建筑群体深基坑支护工程的施工过程进行了现场监测,得到了采用的预应力锚杆柔性支护法中钢筋内力和坑顶位移的监测结果,对内力和位移变化的原因进行了分析,提出了施工中应注意的问题.     

Stories in Decisions: How At-Risk Individuals Decide to Request Predictive Testing for Huntington Disease

Huntington Disease (HD) is a hereditary neurological disease that typically occurs in mid-life. There is no prevention or cure, but persons at risk may request predictive genetic testing to learn whether or not they will develop the disease later in life. Many studies describe why such persons request this knowledge. Few consider how people actually make this novel decision. Drawing on in-depth interviews with sixteen test candidates, this article differentiates three types of stories about—as well as embedded in—the experience of deciding. Each type of story sheds a different light on the meaning and experience of making this decision. Stories of having to know reveal that decision-making may be experienced as a self-evident act while stories of evolving toward it feature an incremental process of weighing up the implications. Stories of taking the decision feature a pivotal point which involves the narrator in seeing anew the opportunity to make a choice. Emphasizing previously neglected temporal, biographical and phenomenological dimensions of decision-making, this typology underscores the relevance of narrative in complex processes of decision-making. It also illustrates the inadequacy of understanding decision-making purely through the lens of rational choice.     

新一轮确权对农户耕地质量保护行为的影响——来自广西的经验证据

耕地质量事关农业可持续发展,基于广西壮族自治区818份调研问卷,探索并验证新一轮确权对农户耕地质量保护行为的影响。研究发现,新一轮确权能够有效激励农户采纳土壤肥力提升和养分平衡行为,激励农户更多采纳保护性耕作行为。具体表现为:确权颁证增加了农户施用有机肥、施测土配方肥和施石灰三类行为的概率,提升了农户采纳秸秆还田、免耕和深松三类技术的可能性。考虑到确权颁证的内生性和不同耕地质量保护行为相互之间可能的关联,分别使用PSM模型和Mvprobit模型进行稳健性检验,依然支持上述发现。进一步分析表明,确权颁证的政策效应有滞后性,相对持有确权证期限较短的农户,持有确权证期限较长的农户更可能采纳上述各类耕地质量保护行为。并且,农地确权对部分类型耕地质量保护行为的影响受到土地调整经历的负向调节,二轮承包期间经历过土地调整会削弱新一轮确权对农户施有机肥、施石灰和采纳免耕技术三类保护性措施的激励作用。     

Testing the Goodness of Fit of Parametric Regression Models with Random Toeplitz Forms

ABSTRACT: We introduce a class of Toeplitz‐band matrices for simple goodness of fit tests for parametric regression models. For a given length r of the band matrix the asymptotic optimal solution is derived. Asymptotic normality of the corresponding test statistic is established under a fixed and random design assumption as well as for linear and non‐linear models, respectively. This allows testing at any parametric assumption as well as the computation of confidence intervals for a quadratic measure of discrepancy between the parametric model and the true signal g;. Furthermore, the connection between testing the parametric goodness of fit and estimating the error variance is highlighted. As a by‐product we obtain a much simpler proof of a result of 34 ) concerning the optimality of an estimator for the variance. Our results unify and generalize recent results by 9 ) and 15 , 16 ) in several directions. Extensions to multivariate predictors and unbounded signals are discussed. A simulation study shows that a simple jacknife correction of the proposed test statistics leads to reasonable finite sample approximations.