Regression M-estimators with One Modified Form of Doubly Censored Data

In this article, we consider the M-estimators for the linear regression model when both response and covariate variables are subject to double censoring. The proposed estimators are constructed as some functional of three types of estimators for a bivariate survival distribution. The first two estimators are the generalizations of the Campbell and Földes (1982 Campbell, G. and Földes, A. 1982. “Large sample properties of nonparametric statistical inference”. In Nonparametric Statistical Inference., Edited by: Gnredenko, B. V., Puri, M. L. and Vineze, I. 103–122. Amsterdam: North-Holland.  [Google Scholar]) and Dabrowska (1988 Dabrowska, D. M. 1988. Kaplan-Meier estimate on the plane. Annals of Statistics, 18: 1475–1489. [Crossref], [Web of Science ®] , [Google Scholar]) estimators proposed by Shen (2009 Shen, P. S. 2009. Nonparametric estimation of the bivariate survival function one modified form of doubly censored data. Computational Statistics, 25: 203–313. [Crossref], [Web of Science ®] , [Google Scholar]). The third estimator is the generalization of the Prentice and Cai (1992 Prentice, R. L. and Cai, J. 1992. Covariance and survivor function estimation using censored multivariate failure time data. Biometrika, 79: 495–512. [Crossref], [Web of Science ®] , [Google Scholar]) estimator. The consistency of the proposed M-estimators is established. A simulation study is conducted to investigate the performance of the proposed estimators. Furthermore, the simple bootstrap methods are used to estimate standard deviations and construct interval estimators.     

On capacity evaluation for multi-state weighted k-out-of-n system

ABSTRACT

Weighted k-out-of-n system has been widely used in various engineering areas. Performance of such system is characterized by the total capacity of the components. Therefore, capacity evaluation is of great importance for research on the behavior of the system over time. Capacity evaluation for binary weighted k-out-of-n system has been reported in the literature. In this paper, to shorten computational time, we first develop a multiplication method for capacity evaluation of binary weighted k-out-of-n system. We then generalize capacity evaluation to multi-state weighted k-out-of-n system. Recursive algorithm and multiplication algorithm are developed for capacity evaluation for such system. Comparison is made of the two methods in different aspects. An illustrative example of an oil transmission system is presented to demonstrate the implementation of the proposed methods.     

Nonparametric Estimation of the Bivariate Distribution Function with Doubly Truncated Data

Doubly truncated data play an important role in the statistical analysis of astronomical observations as well as in survival analysis. In this article, using inverse-probability-weighted (IPW) approaches, we derive the nonparametric maximum likelihood estimator (NPMLE) of joint distribution function with bivariate doubly truncated data. The asymptotic properties of the NPMLE are established. A simulation study is conducted to investigate the performance of the NPMLE.     

Race and Place: Exploring the Intersection of Inequity and Volunteerism Among Older Black and White Adults

Although the historical impact of racial segregation and ongoing health and economic inequities between older Black and White adults is well documented, little is known about the relationships among race, individual- and neighborhood-resources, and formal volunteering in later life. This study explores this intersection. Individual-level data from 268 respondents aged 55+ were collected in the St. Louis metropolitan area through paper-based mail surveys. Objective neighborhood data were obtained at the zip code level from secondary sources and matched with respondents. Using exploratory factor analysis, we constructed a 14-item environmental scale with 3 neighborhood dimensions (economic, social, and built environment). Older Black adults had lower levels of education; had fewer financial assets; lived in neighborhoods with less economic resources and lower built environment scores; and fewer formally volunteered when compared to older White adults. Individual resources (financial assets, health) and neighborhood resources (social and built environment) were positively associated with formal volunteering among older Black adults. Only individual resources (age, marital status, financial assets, health) were associated with formal volunteering among older White adults. A coherent set of policies that bolsters individual and environmental capacities may increase the rate of volunteerism among older black adults.     

署名為王洛賓創作的歌曲《老鄉,上戰場》曲調探源

多年來日本電影《蒲田進行曲》的主題曲《蒲田進行曲》(以下簡稱《蒲田》)多被疑為借用了王洛賓的《老鄉,上戰場》的曲調;《老鄉上戰場》(以下簡稱為《老鄉》一直被看作是王洛賓的重要作品之一。經筆者查證,此曲調並非王洛賓原創,原曲應為美國音樂劇The Vagabond King(筆者譯《乞丐國王》)中的"Song of the Vagabonds"(流浪者之歌,以下簡稱《流浪》)一曲中的副歌部分。《老鄉》及《蒲田》的曲調均引自同一母體《流浪》,它們自身之間並無直接聯繫。     

小说《三国志》之精髓与主题——2006年7月在日本《三国志》研讨会上的报告

小说《三国志》描写汉末三国变幻莫测的政治、军事、外交斗争,总结了各集团成败兴衰的历史经验,突出强调了争取人心、延揽人才、重视谋略的重要性。其思想内容丰厚,反映了向往国家统一的政治理想,歌颂“忠义”英雄,并以此为经纬,把历史评价与道德评判有机地融合在一起,使作品达到了难能可贵的高度和深度。     

Some multivariate goodness-of-fit tests based on data depth

Based on data depth, three types of nonparametric goodness-of-fit tests for multivariate distribution are proposed in this paper. They are Pearson’s chi-square test, tests based on EDF and tests based on spacings, respectively. The Anderson–Darling (AD) test and the Greenwood test for bivariate normal distribution and uniform distribution are simulated. The results of simulation show that these two tests have low type I error rates and become more efficient with the increase in sample size. The AD-type test performs more powerfully than the Greenwood type test.     

Imputation for semiparametric transformation models with biased-sampling data

Widely recognized in many fields including economics, engineering, epidemiology, health sciences, technology and wildlife management, length-biased sampling generates biased and right-censored data but often provide the best information available for statistical inference. Different from traditional right-censored data, length-biased data have unique aspects resulting from their sampling procedures. We exploit these unique aspects and propose a general imputation-based estimation method for analyzing length-biased data under a class of flexible semiparametric transformation models. We present new computational algorithms that can jointly estimate the regression coefficients and the baseline function semiparametrically. The imputation-based method under the transformation model provides an unbiased estimator regardless whether the censoring is independent or not on the covariates. We establish large-sample properties using the empirical processes method. Simulation studies show that under small to moderate sample sizes, the proposed procedure has smaller mean square errors than two existing estimation procedures. Finally, we demonstrate the estimation procedure by a real data example.     

清代清水江流域侗、苗族杉木造林方法初探

清代黔东南清水江流域侗、苗族人民在长期大规模人工杉木林的生产和生活实践中,借鉴汉民族杉木造林方法,并结合本民族固有的农耕传统,创造性地形成了一整套从播种、育苗、栽种到管理的颇具特色、行之有效的杉木造林方法。侗、苗族的这种传统造林方法保证了山林资源的永久可持续利用,并与以林契为代表的契约制度共同揭示了清水江流域林业生生不息、长久不衰的奥秘。     

咏物诗的情节链与李商隐的《锦瑟》诗

本文归纳前人对李商隐《锦瑟》诗旨意理解的六种主要观点,提出“咏物诗的情节链”的新概念,试图为诸家分歧的解说找到一条内在贯通的脉络,从而为阐释此诗找到一个新的突破点。