Time-discrete beta-process model for interval-censored survival data

Grouped survival data with possible interval censoring arise in a variety of settings. This paper presents nonparametric Bayes methods for the analysis of such data. The random cumulative hazard, common to every subject, is assumed to be a realization of a Lévy process. A time-discrete beta process, introduced by Hjort, is considered for modeling the prior process. A sampling-based Monte Carlo algorithm is used to find posterior estimates of several quantities of interest. The methodology presented here is used to check further modeling assumptions. Also, the methodology developed in this paper is illustrated with data for the times to cosmetic deterioration of breast-cancer patients. An extension of the methodology is presented to deal with two interval-censored times in tandem data (as with some AIDS incubation data).     

On an improved Erdő-Rényi-type law for increments of partial sums

Let X₁, X₂,… be an independently and identically distributed sequence with ξX₁ = 0, ξ exp (tX₁ < ∞ (t ≧ 0) and partial sums S_n = X₁ + … + X_n. Consider the maximum increment D₁ (N, K) = max_{0≤n ≤ N - K} (S_{n + K} - S_n)of the sequence (S_n) in (0, N) over a time K = K_N, 1 ≦ K ≦ N. Under appropriate conditions on (K_N) it is shown that in the case K_N/log N → 0, but K_N/(log N)^1/2 → ∞, there exists a sequence (α_N) such that K_-1/2 D₁ (N, K) - α_N converges to 0 w. p. 1. This result provides a small increment analogue to the improved Erd?s-Rényi-type laws stated by Csörg? and Steinebach (1981).     

Robust weighted Cramér-von Mises Estimators of location,with minimax variance in ϵ-contamination neighbourhoods

We construct weighted Cramér-von Mises location estimators which are asymptotically normally distributed throughout an ?e-contamination neighbourhood of a given, strongly unimodal distribution function, and which minimize the maximum asymptotic variance in such neighbourhoods. Applications to the estimation of a normal or logistic mean are given.     

努力开拓团结进取为实现我院"十五"发展计划而奋斗

回顾和总结了华北工学院"九五"期间所取得的丰硕成果,分析了可持续发展的环境条件,阐述了立足实际,面向未来,制定和实现学院"十五"发展计划的宏伟目标.     

抓好学科建设促进学校发展--"九五"学科建设工作回顾与"十五"发展设想

回顾了华北工学院"九五"期间,学科建设工作并探讨、归纳出学科建设以及促进学校发展的成功经验,决心在"十五"期间继续勇于探索,不断创新,促使学院发展再上新台阶.     

论“三个代表”对高校党建工作的战略指导

“三个代表”是新时期高校党建工作的重要指针,它丰富了新时期高校党建工作的内涵,更加明确党建在高校素质教育中的作用,应当积极贯彻“三个代表”使高校党建工作获得新的发展。     

A remedial strategy for data analysis

Professional evaluators are often called upon to analyze data produced by a catastrophically inadequate evaluation design. This problem is occurring more frequently as accountability pressures force program experts into evaluation activities for which they are not trained. A remedial strategy involving diagnosis of error, application of a corrective procedure and sensitization of program personnel of the need for a more sophisticated stance, is proposed as a solution. A case study is described and the contribution of a remedial strategy to improved evaluation is outlined.     

Cramér-von Mises tests of fit for the Poisson distribution

Goodness-of-fit tests based on the Cramér-von Mises statistics are given for the Poisson distribution. Power comparisons show that these statistics, particularly A², give good overall tests of fit. The statistic A² will be particularly useful for detecting distributions where the variance is close to the mean, but which are not Poisson.     

On a cramér-von mises type statistic for testing bivariate independence

A Cramér-von Mises type statistic for testing bivariate independence, proposed by Hoeffding (1948) and by Blum, Kiefer, and Rosenblatt (1961), is examined in greater detail. The statistic is decomposed into components in the manner of Durbin and Knott (1972), and the components are shown to be related to linear rank statistics. Asymptotic power properties of the Hoeffding statistic and its components in testing for independence with bivariate normal random observations are described; a Monte Carlo study comparing these statistics with other nonparametric statistics for bivariate independence is also reported.     

Infinitesimal sensitivity of posterior distributions

We measure the local sensitivity of a posterior expectation with respect to the prior by computing the norm of the Fréchet derivative of the posterior with respect to the prior over several different classes of measures. We compute the derivative of the posterior upper expectation when the prior varies in a restricted ?-contamination class. A bound on the global sensitivity of a class of priors is obtained. As an application, we show that of all sets with posterior probability 1 — α, the likelihood region minimizes the norm of the Fréchet derivative over the ?-contamination class and so is, in some sense, the most robust region with this posterior probability. But there exist counterexamples to this result for other classes of priors.