Optimal designs for multivariate logistic mixed models with longitudinal data

This paper considers the optimal design problem for multivariate mixed-effects logistic models with longitudinal data. A decomposition method of the binary outcome and the penalized quasi-likelihood are used to obtain the information matrix. The D-optimality criterion based on the approximate information matrix is minimized under different cost constraints. The results show that the autocorrelation coefficient plays a significant role in the design. To overcome the dependence of the D-optimal designs on the unknown fixed-effects parameters, the Bayesian D-optimality criterion is proposed. The relative efficiencies of designs reveal that both the cost ratio and autocorrelation coefficient play an important role in the optimal designs.     

Reliability analysis of load-sharing systems with memory

The load-sharing model has been studied since the early 1940s to account for the stochastic dependence of components in a parallel system. It assumes that, as components fail one by one, the total workload applied to the system is shared by the remaining components and thus affects their performance. Such dependent systems have been studied in many engineering applications which include but are not limited to fiber composites, manufacturing, power plants, workload analysis of computing, software and hardware reliability, etc. Many statistical models have been proposed to analyze the impact of each redistribution of the workload; i.e., the changes on the hazard rate of each remaining component. However, they do not consider how long a surviving component has worked for prior to the redistribution. We name such load-sharing models as memoryless. To remedy this potential limitation, we propose a general framework for load-sharing models that account for the work history. Through simulation studies, we show that an inappropriate use of the memoryless assumption could lead to inaccurate inference on the impact of redistribution. Further, a real-data example of plasma display devices is analyzed to illustrate our methods.

     

施工企业投标优化的问题与对策

通过对某大型施工企业多个铁路、公路施工项目部的调查，总结了企业当前投标优化方面存在的问题。针对企业以铁路、公路项目为主业的特点，提出了优势项目滚动发展、建立有效激励制度、做好投标准备、优化施工组织设计、应用报价技巧等优化对策。对于施工企业改善市场经营效果，提高中标质量，增加项目盈利有重要的借鉴作用。     

Internal consistency of demographic assumptions in the shared socioeconomic pathways

A new set of alternative socioeconomic scenarios for climate change researches—the shared socioeconomic pathways (SSPs)—includes for the first time a more comprehensive set of demographic conditions on population, urbanization, and education as the central scenario elements, along with other aspects of society, in order to facilitate better analyses of challenges to climate change mitigation and adaptation. However, it also raises a new question about the internal consistency of assumptions on different demographic and economic trends under each SSP. This paper examines whether the interactions between the demographic and economic factors implied by the assumptions in the SSP projections are consistent with the research literature, and whether they are consistently represented in the projection results. Our analysis shows that the interactions implied by the demographic assumptions in the SSPs are generally consistent with findings from the literature, and the majority of the assumed relationships are also evident in the projected trends. It also reveals some inconsistency issues, resulting mainly from the use of inconsistent definitions of regions and limitations in our understanding of future changes in the patterns of interactions at different stages of socioeconomic development. Finally, we offer recommendations on how to improve demographic assumptions in the extended SSPs, and how to use the projections of SSP central elements in climate change research.     

非洲国家发展特征的三个维度及其本质——以撒哈拉以南非洲国家为考察中心

在撒哈拉以南非洲国家发展进程中,非洲社会传统特质与外部世界影响的交互作用,导致了按照西式民族国家模式构建的非洲国家在发展进程中受挫。它们大多处于"前民族国家"发展阶段。这些"前民族国家"虽然具备法理主权,但却缺乏经验主权。它们是在构建"民族国家"过程中,将早期非洲的国家机构与非国家组织等融为一体所形成的产物。这些国家具有一种以"新家长制"为特点的前现代性特征,使国家权威及认同下移至家族、氏族、部落、宗教群体、地域性社群等。同时,这些国家还维持着现代民族国家的外壳,以及由非洲地区一体化所促成的"地区国际社会"。不过,现代国家与后现代国际体系都只是法理主权架构下的表象,这使得非洲国家之间的竞争压力在消解的同时,也被其内外的各种非国家行为体所消解。     

汉代统治阶层对民间信仰的限制和引导

汉代民间的鬼神祭祀并非单纯地以祈福禳灾为目的,它还包含有以祝诅等巫术伤害他人,被伤害者甚至有可能是最高统治阶层。祭祀中害人巫术的存在,无疑会对社会治安、统治阶层本身乃至统治秩序的正常运行造成影响。面对这样的挑战,汉代的统治阶层设立严刑峻法、设置祠祝官进行抵御;而统治阶层中的知识分子将先秦以来限制祭祀规模的传统理念用于现实政治,致力于革新鬼神观念、宣扬"淫祀无福",试图在思想上对民众进行引导。     

《清兵卫与葫芦》:对立之中的独立意识——兼论志贺直哉追求独立自我的轨迹

《清兵卫与葫芦》是志贺直哉早期创作的经典代表作品。众多专家学者关注该作品中所体现出来的青年志贺直哉的对立思想,对于青年志贺直哉渴望实现独立自我的人生理想之表达却有所忽略。因此,本文通过文本细读,试对处于人生对立时期的青年志贺直哉其思想中所蕴藏的独立意识进行初步分析,旨在从文学伦理观建构和嬗变的视域下,来阐明志贺直哉追求独立自我的人生思考和行动轨迹。     

Outlier detection in high-dimensional regression model

An outlier is defined as an observation that is significantly different from the others in its dataset. In high-dimensional regression analysis, datasets often contain a portion of outliers. It is important to identify and eliminate the outliers for fitting a model to a dataset. In this paper, a novel outlier detection method is proposed for high-dimensional regression problems. The leave-one-out idea is utilized to construct a novel outlier detection measure based on distance correlation, and then an outlier detection procedure is proposed. The proposed method enjoys several advantages. First, the outlier detection measure can be simply calculated, and the detection procedure works efficiently even for high-dimensional regression data. Moreover, it can deal with a general regression, which does not require specification of a linear regression model. Finally, simulation studies show that the proposed method behaves well for detecting outliers in high-dimensional regression model and performs better than some other competing methods.     

农村医疗减贫效果被低估了吗 ——来自社会空间视角的解释

将社会资本纳入Grossman健康人力资本理论模型,结合灾难性医疗支出概念并构建农村保障社会医疗间接减贫框架,再利用空间Tobit杜宾模型和2014年中国家庭跟踪调查数据(CFPS)对理论假说进行检验.结果表明:(1)农村保障制度对单个家庭医疗减贫作用不显著,但是其通过社区社会空间产生的溢出效应不容忽视.处于同一农村社区社会空间的其他拥有保障的家庭更愿意为病贫家庭给予经济援助,农村保障的医疗减贫溢出效果显著,并且农村社区家庭之间社会空间关系越紧密越有助于医疗减贫溢出效应有效发挥.(2)地缘关系和社会关系对农村医疗减贫的调节作用需要一定的社区收入水平支撑,而且随着大病医疗保险对农村家庭医疗致贫风险分散能力的提高,该调节效应也在不断增强.     

Diagnostics for quasi-likelihood nonlinear models

Quasi-likelihood nonlinear models (QLNMs) are an extension of generalized linear model and include a widen class of models as special cases. This article investigates some diagnostic methods in QLNMs. An equivalency between a case-deletion model and a mean-shift outlier model in QLNM is established. Two simulation study and a real dataset are used to illustrate the proposed diagnostic methods.