A Shrinkage Estimation of Central Subspace in Sufficient Dimension Reduction

Sliced regression is an effective dimension reduction method by replacing the original high-dimensional predictors with its appropriate low-dimensional projection. It is free from any probabilistic assumption and can exhaustively estimate the central subspace. In this article, we propose to incorporate shrinkage estimation into sliced regression so that variable selection can be achieved simultaneously with dimension reduction. The new method can improve the estimation accuracy and achieve better interpretability for the reduced variables. The efficacy of proposed method is shown through both simulation and real data analysis.     

Non-parametric estimation of data dimensionality prior to data compression: the case of the human development index

In many applications in applied statistics, researchers reduce the complexity of a data set by combining a group of variables into a single measure using a factor analysis or an index number. We argue that such compression loses information if the data actually have high dimensionality. We advocate the use of a non-parametric estimator, commonly used in physics (the Takens estimator), to estimate the correlation dimension of the data prior to compression. The advantage of this approach over traditional linear data compression approaches is that the data do not have to be linearised. Applying our ideas to the United Nations Human Development Index, we find that the four variables that are used in its construction have dimension 3 and the index loses information.     

L'adoption par l'OIT d'une approche fondée sur la durabilité et ses conséquences sur le droit d'expression collective des travailleurs

L'action de l'OIT pour le développement durable s'est d'abord organisée autour des notions de «transition juste» et d'«emplois verts», en lien avec la protection de l'environnement. Aujourd'hui, les objectifs du développement durable devraient permettre à l'Organisation de se saisir pleinement de la dimension sociale du développement durable, grâce à l'ODD 8, qui mentionne le travail décent, et à la cible 16.7 sur la participation à la prise de décisions. L'auteure examine comment l'OIT pourrait promouvoir l'expression collective des travailleurs dans le contexte du débat sur un «avenir du travail durable» et cherche à déterminer qui doit avoir un droit d'expression et comment celui-ci doit s'exercer.     

Conditional variance estimation via nonparametric generalized additive models

Generalized additive models provide a way of circumventing curse of dimension in a wide range of nonparametric regression problem. In this paper, we present a multiplicative model for conditional variance functions where one can apply a generalized additive regression method. This approach extends Fan and Yao (1998) to multivariate cases with a multiplicative structure. In this approach, we use squared residuals instead of using log-transformed squared residuals. This idea gives a smaller variance than Yu (2017) when the variance of squared error is smaller than the variance of log-transformed squared error. We provide estimators based on quasi-likelihood and an iterative algorithm based on smooth backfitting for generalized additive models. We also provide some asymptotic properties of estimators and the convergence of proposed algorithm. A numerical study shows the empirical evidence of the theory.     

农业机械化服务对粮食生产成本效率的影响——来自中国小麦主产区的经验证据

运用超越对数SFA模型测算1994—2016年中国15个小麦主产地区成本效率，继而构建空间杜宾计量模型考察农业机械化服务对小麦生产成本效率的直接影响与空间溢出效应。结果表明：中国小麦生产成本效率仍存在17.3%的损失；农业机械化服务对小麦成本效率具有正向显著的直接效应和空间溢出效应，即本区域农机化水平对其他区域小麦成本效率有显著的正向影响；从空间维度来看，农业机械化的空间溢出效应主要表现在经度相近地区之间，纬度相近地区之间并不显著；从时间维度看，2004年前后农业机械化的空间溢出效应具有明显差异，2004年之后空间溢出效应更加明显。据此提出农机补贴向农机服务组织倾斜，建设和推广农机信息平台以及作物种植沿经度布局的政策建议。     

Modelling hierarchical clustered censored data with the hierarchical Kendall copula

This article proposes a new model for right‐censored survival data with multi‐level clustering based on the hierarchical Kendall copula model of Brechmann (2014) with Archimedean clusters. This model accommodates clusters of unequal size and multiple clustering levels, without imposing any structural conditions on the parameters or on the copulas used at various levels of the hierarchy. A step‐wise estimation procedure is proposed and shown to yield consistent and asymptotically Gaussian estimates under mild regularity conditions. The model fitting is based on multiple imputation, given that the censoring rate increases with the level of the hierarchy. To check the model assumption of Archimedean dependence, a goodness‐of test is developed. The finite‐sample performance of the proposed estimators and of the goodness‐of‐fit test is investigated through simulations. The new model is applied to data from the study of chronic granulomatous disease. The Canadian Journal of Statistics 47: 182–203; 2019 © 2019 Statistical Society of Canada     

新时代社会组织党建工作的价值维度

习近平新时代中国特色社会主义思想关于党的建设新要求为社会组织党建工作明确了多维的价值诉求：在方向价值方面加强党的领导和政治引领;在政党价值方面扩大执 政基础和增强政治互信;在组织价值方面加强基层组织建设、提升组织力;在文化价值方面树立社会主义核心价值观和倡导先进文化;在社会价值方面汇聚人才力量,提升群众组 织力;在发展价值方面以良性互动促进社会组织健康发展。     

列斐伏尔“空间生产”的批判维度

列斐伏尔社会空间生产批判理论彰显在日常生活批判、政治批判、生态批判三大维度。在日常生活批判上,包括对日常生活空间异化的批判和对自由、多元、开放的日常生活空间的向往,从而呼吁人们进行日常生活的艺术革命。在政治批判上,“空间生产”不仅考察了空间生产与城市化、全球化的紧密关系,而且阐述了空间生产的政治意识形态色彩,从而内蕴着空间正义的追求。在生态批判上,“空间生产”不仅阐述了空间生产的生态意蕴,而且批判了空间生产导致的非生态化现象,从而内蕴着空间生态伦理的追求。列斐伏尔空间生产批判中彰显的理论焦虑和现实关切,可以说,也是对发达工业社会城市空间生产无节制扩张的生态伦理反思。