Joint modeling of longitudinal and survival data with the Cox model and two-phase sampling

A common objective of cohort studies and clinical trials is to assess time-varying longitudinal continuous biomarkers as correlates of the instantaneous hazard of a study endpoint. We consider the setting where the biomarkers are measured in a designed sub-sample (i.e., case-cohort or two-phase sampling design), as is normative for prevention trials. We address this problem via joint models, with underlying biomarker trajectories characterized by a random effects model and their relationship with instantaneous risk characterized by a Cox model. For estimation and inference we extend the conditional score method of Tsiatis and Davidian (Biometrika 88(2):447–458, 2001) to accommodate the two-phase biomarker sampling design using augmented inverse probability weighting with nonparametric kernel regression. We present theoretical properties of the proposed estimators and finite-sample properties derived through simulations, and illustrate the methods with application to the AIDS Clinical Trials Group 175 antiretroviral therapy trial. We discuss how the methods are useful for evaluating a Prentice surrogate endpoint, mediation, and for generating hypotheses about biological mechanisms of treatment efficacy.     

Schematic saturated orthogonal arrays obtained by using the contractive replacement method

This paper presents a general method of constructing schematic saturated orthogonal arrays of strength two. We consider a class of mixed saturated orthogonal arrays produced from saturated symmetric orthogonal arrays by using the contractive replacement method, study the Hamming distances of the rows, construct their association schemes, and prove that they are schematic. Some examples are given to illustrate this construction method.     

边疆、边界与国家:韦伯的“农业-政治”研究的理论启发

本文以19世纪90年代中期德国的工业化和城市化过程为背景,以韦伯对"农业-政治"问题的讨论为核心,提出了国家的边疆、边界等问题,讨论人口、物资、资本等流动下的国家经济建设与政治结构。文中涉及的实质性问题包括：全球化、工业化背景之下的农村发展问题,国家建设与国家治理思路,以及国家边界的多重（政治、经济与文化）含义。本文认为,在法律、政治、经济等角度的国家观之外,可以建立一种社会取向的、以国民为核心的"国民-国家"观,即包容多元,建立共识,赋予国民以平等的基本权利,并建立国民共享权责和符合国民基本特质的政体制度。     

实施系统工程，实现高校思想政治工作的创新

新时期的高校思想政治工作更加复杂化,任务更加艰巨,这就要求我们因事而化、因时而进、因势而新,不断研究新情况,探索新办法,不断开创高校思想政治工作新局面。总结了信电学院的做法,实施系统工程,打组合拳,为高校思想政治工作提供了新的思路。     

民族地区基础教育均衡发展研究的进展与前瞻——教育社会学的视角

基础教育均衡发展是民族地区精准扶贫脱贫的前提和基础.以往相关研究厘清了民族地区基础教育均衡发展的内涵、意义和现状,阐述了问题及其影响因素,对困局的破解有所助益,但依然存在不足之处,难以满足现实需求.鉴于此,本文在评述研究进展的基础上,依据教育社会学相关理论,提出了研究深化的三个进路:研究重心应该从强调硬件环境转向受教育主体理念和行动的研究;研究导向应转变为实践导向,注重学术研究解决现实问题的实效性;研究视角从宏观分析转向微观机制研究,微观着手,放眼长远.最后,本文从社会治理的高度重新审视了民族教育的社会价值,提出了三个研究课题:基础教育何以引领少数民族社会文化成功转型;基础教育如何培育少数民族国家认同和中华民族认同;基础教育何以促进民族交往、交流和交融.     

Coordination in a Single‐Supplier,Multi‐Retailer Distribution System: Supplier‐Facilitated Transshipments

We consider supplier‐facilitated transshipments for achieving supply chain coordination in a single supplier, multi‐retailer distribution system with non‐cooperative retailers. The previous transshipment literature has focused on coordination through retailer‐negotiated transshipments and thus does not consider the supplier's decision‐making. In contrast, in this study, we assume the supplier is an active participant in the system and we seek to understand how the supplier can facilitate the implementation of coordinating transshipments. We study a two‐period model with wholesale orders at the start of the first period and preventive transshipments performed at the start of the second period. Inspired by a supplier‐facilitated transshipment scheme observed in practice, we assume the supplier implements transshipments through a bi‐directional adjustment contract. Under this contract, each retailer can either buy additional inventory from, or sell back excess inventory to, the supplier. We show that coordination can be achieved through carefully designed contracts with state‐dependent adjustment prices and a wholesale price menu. We demonstrate that the supplier's role in facilitating coordinating transshipments is critical. In addition, we use our understanding of the coordinating contract form to derive some simpler and easier‐to‐implement heuristic contracts. We use a numerical study to demonstrate the value, to the supplier, of using the coordinating adjustment and wholesale prices, and to evaluate the heuristics’ performance.     

在线品牌社区顾客间互动对顾客愉悦体验的影响

随着互联网和社交媒体的日益普及,企业构建在线品牌社区、鼓励顾客参与品牌社区活动已经成为企业创造价值的一种新的营销策略。实践表明,顾客的愉悦体验是顾客参与在线品牌社区活动的直接结果之一,它有助于提升企业绩效。已有研究虽然关注在线品牌社区顾客的认知因素对顾客愉悦体验的影响,但却忽视了顾客间互动这种在线品牌社区内的主体活动,因而对在线品牌社区顾客间互动是否带来顾客愉悦体验以及如何带来顾客愉悦体验的讨论并不多见。 梳理品牌社区、顾客互动和顾客体验等相关研究,基于价值共创理论和自我决定理论,构建在线品牌社区顾客间互动对顾客愉悦体验的影响机制,提出在线品牌社区顾客间互动对顾客愉悦体验具有正向影响、控制感和融聚感对在线品牌社区顾客间互动与顾客愉悦体验之间具有中介作用、主题匹配对这种中介机制具有调节作用等假设。采用问卷调查在魅族社区获取283个顾客样本数据,测量量表的信度和效度,并利用回归分析检验相应的假设。 研究结果表明,①在线品牌社区顾客间互动正向影响顾客的愉悦体验。②控制感和融聚感对顾客间互动与愉悦体验之间的正向关系起并列中介作用。③顾客间互动的主题匹配调节控制感的中介效应,即当主题匹配程度较高时,在线品牌社区顾客间互动通过控制感正向影响愉悦体验;当主题匹配程度较低时,控制感的中介作用不显著。④主题匹配也调节融聚感的中介效应,即与主题匹配程度较低时相比,当主题匹配程度较高时,融聚感对顾客间互动与愉悦体验之间正向关系的中介效应更大。 研究结果厘清了在线品牌社区顾客间互动对顾客愉悦体验的作用机制,加深了对顾客间互动的理解,丰富了顾客体验和品牌社区方面的研究,并对企业通过在线品牌社区提升顾客关系管理、顾客体验管理和顾客互动管理具有一定的指导意义。     

Neighbor sum distinguishing index of 2-degenerate graphs

We consider proper edge colorings of a graph G using colors in \(\{1,\ldots ,k\}\). Such a coloring is called neighbor sum distinguishing if for each pair of adjacent vertices u and v, the sum of the colors of the edges incident with u is different from the sum of the colors of the edges incident with v. The smallest value of k in such a coloring of G is denoted by \({\mathrm ndi}_{\Sigma }(G)\). In this paper we show that if G is a 2-degenerate graph without isolated edges, then \({\mathrm ndi}_{\Sigma }(G)\le \max \{\Delta (G)+2,7\}\).     

神仙文化遗产在乡村旅游规划中的运用——以自贡市仙市镇的旅游规划为个案

神仙文化是我国特有的传统文化,神仙思想的产生于现代旅游活动有着必然的联系,神仙思想是最具特色的休闲文化。自贡市仙市镇是仙与盐的完美结合。从神仙文化与旅游活动的关系入手,分析了神仙文化与现代休闲文化的契合关系,并具体探讨了神仙文化在自贡市仙市镇乡村旅游规划中的运用问题:强调在景点打造、景观设计以及旅游活动项目的设计上应融入神仙文化元素。     

台港澳地区青年组织开展民众工作比较研究

青年组织是青年群体活动、成长和发展的集体,也是培育社会资本的重要平台与形式。当代政党和非政党组织的一个共性特征和普遍做法是通过青年组织开展民众工作,广泛吸纳青年社会精英,务实政党民意基础,完成政治社会化过程。通过对台港澳地区相关青年组织的考察,梳理其开展民众工作的具体理念和路径,有益于探寻青年组织深入社会、服务社会的内在规律,对我国其他地区同类型青年组织的发展起到一定的借鉴作用。