A generalized Fleming and Harrington's class of tests for interval‐censored data

The class $G^{\rho,\lambda }$ of weighted log‐rank tests proposed by Fleming & Harrington [Fleming & Harrington (1991) Counting Processes and Survival Analysis, Wiley, New York] has been widely used in survival analysis and is nowadays, unquestionably, the established method to compare, nonparametrically, k different survival functions based on right‐censored survival data. This paper extends the $G^{\rho,\lambda }$ class to interval‐censored data. First we introduce a new general class of rank based tests, then we show the analogy to the above proposal of Fleming & Harrington. The asymptotic behaviour of the proposed tests is derived using an observed Fisher information approach and a permutation approach. Aiming to make this family of tests interpretable and useful for practitioners, we explain how to interpret different choices of weights and we apply it to data from a cohort of intravenous drug users at risk for HIV infection. The Canadian Journal of Statistics 40: 501–516; 2012 © 2012 Statistical Society of Canada     

宋代乡村第五等户在城市经济发展中的作用

宋代乡村第五等户是宋代户口的主要构成部分。在农业人口为主体的封建国家中,他们是社会生产的主要承担者、国家财富的主要创造者、推动经济发展与物质文明进步的重要力量。宋代乡村第五等户在国家户口中比例大,生存条件差,特别是在失去土地无法生存后,“流移转徙”到城市,为城市经济发展提供了人力资源,为资本主义萌芽做了早期准备,推动了城市服务业发展,促进了城市商品经济发展。探讨第五等户在经济发展中的作用,对寻求今天解决农民问题的方式方法,具有现实意义。     

Bootstrap Determination of the Co‐Integration Rank in Vector Autoregressive Models

This paper discusses a consistent bootstrap implementation of the likelihood ratio (LR) co‐integration rank test and associated sequential rank determination procedure of Johansen (1996). The bootstrap samples are constructed using the restricted parameter estimates of the underlying vector autoregressive (VAR) model that obtain under the reduced rank null hypothesis. A full asymptotic theory is provided that shows that, unlike the bootstrap procedure in Swensen (2006) where a combination of unrestricted and restricted estimates from the VAR model is used, the resulting bootstrap data are I(1) and satisfy the null co‐integration rank, regardless of the true rank. This ensures that the bootstrap LR test is asymptotically correctly sized and that the probability that the bootstrap sequential procedure selects a rank smaller than the true rank converges to zero. Monte Carlo evidence suggests that our bootstrap procedures work very well in practice.     

Multivariate functional response low‐rank regression with an application to brain imaging data

We propose a multivariate functional response low‐rank regression model with possible high‐dimensional functional responses and scalar covariates. By expanding the slope functions on a set of sieve bases, we reconstruct the basis coefficients as a matrix. To estimate these coefficients, we propose an efficient procedure using nuclear norm regularization. We also derive error bounds for our estimates and evaluate our method using simulations. We further apply our method to the Human Connectome Project neuroimaging data to predict cortical surface motor task‐evoked functional magnetic resonance imaging signals using various clinical covariates to illustrate the usefulness of our results.     

THE POWER AND SIZE OF NONPARAMETRIC TESTS FOR COMMON DISTRIBUTIONAL CHARACTERISTICS

This paper considers the power and size properties of some well known nonparametric linear rank tests for location and scale as well as the Kolmogorov-Smirnov omnibus test and proposed alternatives to it. Independence between some classes of linear rank tests is established facilitating their joint application. Monte Carlo study confirms the asymptotic power properties of the linear rank tests but raises concerns about their application in more general and practically relevant circumstances. It also indicates that the new omnibus tests constitute viable alternatives with superior properties to the Kolmogorov-Smirnov test in certain circumstances.     

Nonparametric confidence intervals for Tmax in sequence-stratified crossover studies

Tmax is the time associated with the maximum serum or plasma drug concentration achieved following a dose. While Tmax is continuous in theory, it is usually discrete in practice because it is equated to a nominal sampling time in the noncompartmental pharmacokinetics approach. For a 2-treatment crossover design, a Hodges-Lehmann method exists for a confidence interval on treatment differences. For appropriately designed crossover studies with more than two treatments, a new median-scaling method is proposed to obtain estimates and confidence intervals for treatment effects. A simulation study was done comparing this new method with two previously described rank-based nonparametric methods, a stratified ranks method and a signed ranks method due to Ohrvik. The Normal theory, a nonparametric confidence interval approach without adjustment for periods, and a nonparametric bootstrap method were also compared. Results show that less dense sampling and period effects cause increases in confidence interval length. The Normal theory method can be liberal (i.e. less than nominal coverage) if there is a true treatment effect. The nonparametric methods tend to be conservative with regard to coverage probability and among them the median-scaling method is least conservative and has shortest confidence intervals. The stratified ranks method was the most conservative and had very long confidence intervals. The bootstrap method was generally less conservative than the median-scaling method, but it tended to have longer confidence intervals. Overall, the median-scaling method had the best combination of coverage and confidence interval length. All methods performed adequately with respect to bias.     

论汉代的市

汉代的市不仅仅是从事商业活动的场所,同时也是封闭的行政区域.政府规定在市中从事商业活动的人及其家庭必须围绕着市居住,在此基础上形成了市籍制度及与此相关的专职官吏.     

大学排名对高等学校发展的启示

开展大学评价是市场经济的产物,是一种社会需求。在市场经济条件下,社会需求始终是高等学校发展的重要推动力。本文以南京林业大学为例,分析了国内民间的大学评价指标体系,根据大学的排名结果,提出了高等学校发展的思路:准确定位,科学制定发展战略目标;稳定学校规模,本科生与研究生教育协调发展;发挥学科优势,突出办学特色;提高科技投入效率,增强科技竞争力。     

Rawls and Bentham reconciled

The paper deals with the characterization of a class of social welfare orderings. The social evaluation functions which represent these orderings are separable in the components of the ordered utility vector. The characterization is based on the Strong Pareto Property, Co-cardinality, Continuity and a new Independence Property. Since this class encompasses the utilitarian rule and since there are members of this family which almost coincide with the rules of rank dictatorship this family bridges the gap between pure utilitarianism and rank dictatorship.     

论北魏墓志文末补记三代家世履历现象

北魏洛阳时代锐意进取,拓跋王朝迅速迈过门阀士族化的门槛,社会面貌日新月异。反映时代变迁的墓志铭在语言风格和书写范式方面随之改变,尤以志文末尾附记三代家世履历最为显著,此举刻意迎合厘定姓族门第之规章典制,额外强调身份等级和资源分配之决定要素家世门第。其中,既有父系的官资履历,亦包括母系的族姓出身,体现北朝士族社会高度重视婚宦的特点。结合中古门阀制度的背景知识,对其内容进行梳理分析,有助于了解当时的仕进程式和婚姻状况,亦不难发现中古贵族社会阶级固化、对流停滞局面的形成机理。通过与明清联系比较,足可揭示古代中国由世袭格局向对流形态演进的总体趋势。跳脱文本窠臼,在尊重“史考”的前提下充分发挥“史义”之阐释功能,把石刻文献研究由“史料”推向“史学”的层次,此乃当代学术发展的必由之路。