On a system of nonhomogeneous components sharing a common frailty

The components of a reliability system subjected to a common random environment usually have dependent lifetimes. This paper studies the stochastic properties of such a system with lifetimes of the components following multivariate frailty models and multivariate mixed proportional reversed hazard rate (PRHR) models, respectively. Through doing stochastic comparison, we devote to throwing a new light on how the random environment affects the number of working components of a reliability system and on assessing the performance of a k-out-of-n system.     

关于中国现代史分期问题的思考

目前,史学界对于中国现代史的分期看法不一,形成不同的主张：或以重大政治历史事件为标准,或依据《关于建国以来党的若干历史问题的决议》,或以经济社会发展目标模式为分期标准。这些标准都不符合中国通史的学科分期要求。中国现代史作为通史,其分期应当以社会形态的变迁为标准,应根据社会主义的不同发展模式,将其划分为新民主主义时期或社会主义的准备时期、苏联模式社会主义时期或传统社会主义时期、中国特色社会主义时期或现代社会主义时期。     

Re-Defining the Who,When, and Where of Mentoring for Professional Statisticians

Organizations tailor their mentoring strategies to accommodate internal resources and preferences, producing different approaches in academic, government, and corporate environments. Across these settings, three common barriers impede effective mentoring of statisticians: overspecialization, time constraints, and geographic dispersion. The authors share mentoring strategies that have emerged at their organization, Mathematica Policy Research, to overcome these obstacles. Practices include creating a methodology working group to unite researchers with diverse backgrounds, integrating mentoring into existing workflows, and harnessing modern technological infrastructure to facilitate virtual mentoring. Although these strategies emerged within a specific professional context, they suggest opportunities for statisticians to expand the channels through which mentorship can occur.     

时代交替视野下的明代“北虏”问题

无论是在世界史还是在东亚史上,16世纪都是一个重要的时代。正是在这时,明朝深为"北虏南倭"问题所困扰。学界以往对明代"北虏"问题的解释框架,基本上局限于传统的游牧民族与农耕民族冲突史及明蒙关系史。在与其相提并论的"南倭"问题得到新的解释并被置于一个更广阔的海洋贸易史框架后,对"北虏"问题的认识变化依然不大。事实上,在长城沿线发生的、以明朝和蒙古为主角的一系列事件,同样是全球史时代变化的组成部分。这使我们认识到,"内陆史视角"的观察与思考应成为传统的"海洋史视角"的重要补充。     

Quantile regression and variable selection for the single-index model

In this paper, we propose a new full iteration estimation method for quantile regression (QR) of the single-index model (SIM). The asymptotic properties of the proposed estimator are derived. Furthermore, we propose a variable selection procedure for the QR of SIM by combining the estimation method with the adaptive LASSO penalized method to get sparse estimation of the index parameter. The oracle properties of the variable selection method are established. Simulations with various non-normal errors are conducted to demonstrate the finite sample performance of the estimation method and the variable selection procedure. Furthermore, we illustrate the proposed method by analyzing a real data set.     

三不朽思想和历史传承——中国第一座水电站百年石碑的人类学考察

百年石龙坝石碑所承载的内容是厚重的,从中可感悟到当年在中国民族工业与西方列强利益的博弈过程中,中国人自办民族工业的历史心性。石碑正是百年前石龙坝人立德、立功、立言的精神体现。这种石刻记忆不仅具有延续性,而且是一种意义制造,是第一代水电工业的开创者在国家和世界历史的背景中定位集体和个体的历史和文化身份的表现,并会随着世代更迭而传承。     

Robust bootstrap estimates in heteroscedastic semi-varying coefficient models and applications in analyzing Australia CPI data

This article deals with the estimation of the parametric component, which is of primary interest, in the heteroscedastic semi-varying coefficient models. Based on the bootstrap technique, we present a procedure for estimating the parameters, which can provide a reliable approximation to the asymptotic distribution of the profile least-square (PLS) estimator. Furthermore, a bootstrap-type estimator of covariance matrix is developed, which is proved to be a consistent estimator of the covariance matrix. Moreover, some simulation experiments are conducted to evaluate the finite sample performance for the proposed methodology. Finally, the Australia CPI dataset is analyzed to demonstrate the application of the methods.     

深圳城市治理的三种模式研究

城市社区治理体系改革是基层党和政府与社区各类组织之间权力职能关系的一种多方位调整,居民自治、党建引领与企业参与分别代表着目前实践中的三种不同改革思路,其内在逻辑折射出改革者对于解决社区现实问题的区别性研判,以及对社区治理体制改革内容的差异化理解,并将深刻影响城市治理的发展向度.在住房商品化改革深入推进,社区形态经历复杂转型,社区利益主体日渐多元,居民的民主法治观念逐渐觉醒,基层群众自治需求增长的现实背景下,以深圳在居民自治、社区党建、社区服务等方面探索出的"盐田模式""南山模式""桃源居模式"为例,阐释三者之间的关系并分析其中的优缺点,对于研判城市社区治理体系改革的趋向和特征有启迪作用.