Estimating the number of true null hypotheses in multiple hypothesis testing

The overall Type I error computed based on the traditional means may be inflated if many hypotheses are compared simultaneously. The family-wise error rate (FWER) and false discovery rate (FDR) are some of commonly used error rates to measure Type I error under the multiple hypothesis setting. Many controlling FWER and FDR procedures have been proposed and have the ability to control the desired FWER/FDR under certain scenarios. Nevertheless, these controlling procedures become too conservative when only some hypotheses are from the null. Benjamini and Hochberg (J. Educ. Behav. Stat. 25:60–83, 2000) proposed an adaptive FDR-controlling procedure that adapts the information of the number of true null hypotheses (m ₀) to overcome this problem. Since m ₀ is unknown, estimators of m ₀ are needed. Benjamini and Hochberg (J. Educ. Behav. Stat. 25:60–83, 2000) suggested a graphical approach to construct an estimator of m ₀, which is shown to overestimate m ₀ (see Hwang in J. Stat. Comput. Simul. 81:207–220, 2011). Following a similar construction, this paper proposes new estimators of m ₀. Monte Carlo simulations are used to evaluate accuracy and precision of new estimators and the feasibility of these new adaptive procedures is evaluated under various simulation settings.     

中国式现代化系统运行研究论纲

推进中国式现代化是一个系统工程。中国式现代化系统运行蕴含着深刻的内在逻辑,文化根基的深厚滋养是发生前提,战略目标的辩证统一是方向引领,核心要素的稳定运转是现实根基,评估优化的高效实施是可靠保证,系统机制的勾联融通是核心要旨。以内在逻辑为支撑,中国式现代化系统运行具备由文化根基层、目标引领层、核心要素层、评估优化层、系统机制层所构成的立体结构,呈现出开放性、整体性、结构性、稳定性、层次性的鲜明特征,理解中国式现代化系统运行需要把握好顶层设计与实践探索、战略与策略、守正与创新、效率与公平、活力与秩序、自立自强与对外开放等重大关系。中国式现代化系统运行的实践路径包括坚持和加强党的全面领导,构建中国式现代化评估指标体系,提供坚实的学科体系支撑,注重系统运行的风险防范。     

2030年前俄罗斯经济创新发展战略

一、经济创新的重要性在提高俄罗斯经济增长速度,改善居民生活质量和提高俄罗斯产品的国际竞争力等方面实现预期目标的关键是,正确选择和坚决落实过渡时期国家改革发展的长远政策。创新政策的提出是基于以下背景:第一,主要的技术基础已经老化甚至到了严重破损的程度。绝大多数机器、仪器和运输工具尚停留在20世纪70~80年代的技术水平上,近15年来没有进行过任何更新,有形损耗率为60%~70%,已经不适应生产具有竞争力产品的需要,因此,必须在尽可能短的时间内对其进行更新改造。第二,国家加工业产品已经老化并缺少竞争力,正在被排挤出国际和国内…     

基于偏正态随机效应模型的信度保费

信度模型是非寿险经验费率厘定的主要方法。传统的Buhlmann-Straub信度模型可以表示为随机截距模型,而随机截距模型假设随机效应服从正态分布。在实际的保险损失数据中,部分个体风险的损失可能远远高于总体平均水平,从而使得不同个体风险之间的风险差异呈现右偏特征。在这种情况下,Buhlmann-Straub模型有可能低估高风险的信度保费。本文在随机截距模型中假设随机效应服从偏正态分布,求得了偏正态随机效应假设下的信度保费。可以证明,Buhlmann-Straub信度保费是其特例。模拟分析和实证研究的结果都表明,偏正态随机效应假设下的信度模型可以更好地预测高风险的信度保费,从而改进传统信度模型的保费估计结果。     

The limiting spectral distribution for large sample covariance matrices with unbounded m-dependent entries

ABSTRACT

In this note, the limiting spectral distribution for large sample covariance matrices with unbounded m-dependent structure is obtained under the third moment for the entries. This partially extends the results of Hui and Pan (Comm. Statist. Theory and Methods, 2010, 39: 935–941).     

交强险保费的公平性与保险公司的市场竞争

基于2009-2011年保险公司在各个地区经营交强险业务的实际数据,本文分析了当前的交强险保费水平在不同业务类型和不同地区之间存在的不公平性问题。通过赔付率和费用率的相关性分析,揭示了交强险费用率的异常变化和可能受到的人为干预。定义和计算了交强险的业务结构因子、地区分布因子、固定业务结构的风险选择因子和固定地区分布的风险选择因子,对保险公司在交强险市场上的竞争能力和风险选择能力进行了比较分析。最后通过建立赔付率和费用率的广义线性模型,发现保险公司降低交强险赔付率最为有效的途径是提高它在各个地区的风险选择能力,其次是增加在低风险地区的经营网点。     

基于知识图谱的中小企业创新研究热点和前沿分析

采用Citespace软件,对中文社会科学引文索引数据库收录的1998—2017年中小企业创新文献进行可视化图谱分析,重点考查该领域的研究总体现状,对研究热点和研究前沿进行系统梳理和分析.研究发现:研究机构分布广泛,少数机构因地理临近存在零散的研究合作,研究合作网络有待成长.高影响力的研究团队数量较少,仅高频发文作者之间有较多研究合作.研究热点具有鲜明的时代特征,集中在科技型中小企业、技术创新、制度创新、自主创新、协同创新、创新绩效六个方面.对关键词突变检测发现技术创新、制度创新、自主创新、协同创新及创新能力是研究的前沿.     

Edge selection for undirected graphs

This article explores an ‘Edge Selection’ procedure to fit an undirected graph to a given data set. Undirected graphs are routinely used to represent, model and analyse associative relationships among the entities on a social, biological or genetic network. Our proposed method combines the computational efficiency of least angle regression and at the same time ensures symmetry of the selected adjacency matrix. Various local and global properties of the edge selection path are explored analytically. In particular, a suitable parameter that controls the amount of shrinkage is identified and we consider several cross-validation techniques to choose an accurate predictive model on the path. The proposed method is illustrated with a detailed simulation study involving models with various levels of sparsity and variability in the nodal degree distributions. Finally, our method is used to select undirected graphs from various real data sets. We employ it for identifying the regulatory network of isoprenoid pathways from a gene-expression data and also to identify genetic network from a high-dimensional breast cancer study data.     

Complete convergence and complete moment convergence for arrays of rowwise negatively superadditive dependent random variables

In this paper, some complete convergence and complete moment convergence results for arrays of rowwise negatively superadditive dependent (NSD, in short) random variables are studied. The obtained theorems not only extend the result of Gan and Chen (2007 Gan, S. X., and P. Y. Chen. 2007. On the limiting behavior of the maximum partial sums for arrays of rowwise NA random variables. Acta Mathematica Scientia. Series B 27 (2):283–90.[Crossref], [Web of Science ®] , [Google Scholar]) to the case of NSD random variables, but also improve them.     

民族走廊上乡村集市的民俗谱系及其生成逻辑——以庆阳坝集市为中心的考察

民族走廊上的乡村集市既是物资交换和人群流动之地,也是多民族文化互动及地方性知识形成的特定场域,彰显出作为通道的民族走廊连接不同民族和文化板块的功能特性。位于武陵民族走廊上的众多乡村集市作为历史上中原出入西南地区的驿站,在各民族交往交流交融中构建了互嵌式经济文化网络。其中的民俗谱系是各民族成员基于生产生活需求对物资的功能性转化、文化的选择性采借和社会结构的能动性发展,呈现出流动性与稳定性、多元性与共融性、民族性与地域性、中心性与边缘性、象征性与功能性并存等多元特征。民族走廊上乡村集市的民俗谱系不仅是各民族文化上兼容并蓄、经济上相互依存、情感上相互亲近的记录,也是社区认同、民族认同和国家认同的载体。