Collective versus Individual Effects in Survival Analysis of Multiple Failures

In survival analysis, we sometimes encounter data with multiple censored outcomes. Under certain scenarios, partial or even all covariates have ‘similar’ relative risks on the multiple outcomes in the Cox regression analysis. The similarity in covariate effects can be quantified using the proportionality of regression coefficients. Identifying the proportionality structure, or equivalently whether covariates have individual or collective effects, may have important scientific implications. In addition, it can lead to a smaller set of unknown parameters, which in turn results in more accurate estimation. In this article, we develop a novel approach for identifying the proportionality structure. Simulation shows the satisfactory performance of the proposed approach and its advantage over estimation under no assumed structure. We analyse three datasets to demonstrate the practical application of the proposed approach.     

Goodness-of-fit tests of generalized linear mixed models for repeated ordinal responses

Categorical longitudinal data are frequently applied in a variety of fields, and are commonly fitted by generalized linear mixed models (GLMMs) and generalized estimating equations models. The cumulative logit is one of the useful link functions to deal with the problem involving repeated ordinal responses. To check the adequacy of the GLMMs with cumulative logit link function, two goodness-of-fit tests constructed by the unweighted sum of squared model residuals using numerical integration and bootstrap resampling technique are proposed. The empirical type I error rates and powers of the proposed tests are examined by simulation studies. The ordinal longitudinal studies are utilized to illustrate the application of the two proposed tests.     

A Rejection Principle for Sequential Tests of Multiple Hypotheses Controlling Familywise Error Rates

We present a unifying approach to multiple testing procedures for sequential (or streaming) data by giving sufficient conditions for a sequential multiple testing procedure to control the familywise error rate (FWER). Together, we call these conditions a ‘rejection principle for sequential tests’, which we then apply to some existing sequential multiple testing procedures to give simplified understanding of their FWER control. Next, the principle is applied to derive two new sequential multiple testing procedures with provable FWER control, one for testing hypotheses in order and another for closed testing. Examples of these new procedures are given by applying them to a chromosome aberration data set and finding the maximum safe dose of a treatment.     

Combining Inverse Probability Weighting and Multiple Imputation to Improve Robustness of Estimation

Inverse probability weighting (IPW) and multiple imputation are two widely adopted approaches dealing with missing data. The former models the selection probability, and the latter models data distribution. Consistent estimation requires correct specification of corresponding models. Although the augmented IPW method provides an extra layer of protection on consistency, it is usually not sufficient in practice as the true data‐generating process is unknown. This paper proposes a method combining the two approaches in the same spirit of calibration in sampling survey literature. Multiple models for both the selection probability and data distribution can be simultaneously accounted for, and the resulting estimator is consistent if any model is correctly specified. The proposed method is within the framework of estimating equations and is general enough to cover regression analysis with missing outcomes and/or missing covariates. Results on both theoretical and numerical investigation are provided.     

太湖流域的治水传统与水生态文明的承传

通过对太湖地区传统水利生态的一些基本规律的认识,诸如太湖与三江一体化,活水周流等,分析了水生态文明结构的长期稳定性,及其水文生态结构的长期承传性。新时代下基本生态水文结构所形成的水环境问题,仍可以从古代的水利生态结构中寻求解决之路。许多现代水利工程所产生的问题,仍可以从古代的经验中得到解决。水污染的解决,景观水面的增加,古代的活水周流经验可以直接应用。传统文人所重视的水文景观,需要在现代社会承传并推广。     

信任对农民创业机会识别的影响

基于信任视角,构建农民创业者信任对创业机会识别的理论分析框架,运用链式多重中介方法,对浙江、安徽、河南和陕西4省880份农民创业者访谈数据进行实证分析,结果发现:信任能显著提高农民创业机会识别;农民创业者信任能通过外部知识获取与创业警觉性对创业机会识别产生间接影响,其作用路径有三条:外部知识获取的部分中介作用、创业警觉性的部分中介作用及外部知识获取与创业警觉性的链式中介作用。因此,政府应完善农民创业相关规章与制度;推进农村文化建设,提高信任水平;增加农民创业知识与技能的供给,培养农民创业者的机会警觉性。     

“镇改市”过程中的制约因素与改革进路

“镇改市”是我国基层行政体制改革的试验,也是在新型城镇化过程中对基层行政区划改革做出的有益尝试。以构建大中小城市和小城镇协调发展的城镇化空间格局为目标指向,通过激活中小城市的发展“命脉”,改变单纯依靠经济推动乡镇发展的路径依赖,实现“农民城”向新型城镇的跨越,是中国经济发展的新探索。然而,随着改革的推进,缺位的行政规划设计、有限的乡镇管理能力、被异化的政绩观念、社会组织发育不成熟以及市民文化普及不到位等,对“镇改市”的推进造成一定程度的制约,成为“镇改市”过程中难以回避的现实问题。问题的化解离不开政策的引导、技术的支持和法治的保障,这三个维度相互联系、缺一不可,共同为“镇改市”改革的顺利实施“保驾护航”。     

合作社带动农村产业融合的政策、动力与实现机制

推进农村产业融合是发展现代农业的必由之路,而探讨以合作社为载体的农村内生性产业融合模式,对于提升农业产出效率、繁荣农村经济和促进乡村振兴具有重要意义和价值。通过对改革开放以来合作社带动产业融合相关政策的梳理发现,合作社依次经历了初期起步及产业破壁阶段、快速发展与农业产业化阶段、发展壮大与带动农村一二三产业融合阶段。在具体实践中,农业多功能开发、小农户与现代农业衔接、经济良性循环、跨界经营等需求都对合作社带动农村产业融合提供了现实动力,合作社也展现出了资源整合、社会服务和公信力增强等优势,并探索形成了农业内部技术融合、纵向一体化经营融合、现代农业与旅游业融合、农业生态旅游和文化创意产业融合模式。针对目前合作社所面临的规模小、资金少、创意不足等问题,建议从鼓励合作社向综合和联合方向发展、改善合作社融资渠道、挖掘当地特色文化等方面着手构建合作社带动农村产业融合的实现机制。     

粤港澳大湾区背景下珠三角城市群经济一体化与城市关联分析

为研究粤港澳大湾区背景下珠三角经济区各城市区经济之间的联系程度及变化情况,探究广州和深圳两大中心城市在整个珠三角城市群发展过程扮演的角色,选取珠三角九大城市2000～2016年相关经济数据,一方面从GDP、劳动和资本3个方面运用KLD散度对珠三角城市群的经济一体化程度进行测算;另一方面结合引力模型和ADF单位根检验、Johansen协整检验以及Granger因果关系等分析方法对珠三角城市群内经济体之间的经济关联性进行实证分析。研究认为,珠三角城市群经济一体化程度呈现两阶段发展特征,在2013年之前呈逐渐加强趋势,但随后不断减弱;劳动和资本一体化程度整体上远高于GDP一体化程度,经济发展不平衡对珠三角城市群经济一体化程度影响较大;广州经济发展的虹吸效应明显,深圳经济发展的独立性较强,两大中心城市对城市群内部其他经济体经济发展的拉动作用有待加强。广州要继续发挥服务和教育产业优势,积极寻求与其经济合作潜力较大的城市探索互利共赢的交流模式;深圳应积极探寻与其他地区供求互补产业之间的合作可能性;调动具有较高经济合作潜力但不存在双向因果关系或任何经济发展联系的城市组合,探索适合彼此经济发展的合作途径;积极推进粤港澳大湾区建设,加强珠三角资源配置范围,积极探索与香港、澳门合作机会,实现湾区内产业互动发展。     

信息技术课程多元智力教学模式探究

多元智力理论超越了传统以语言——数理逻辑能力为中心的智力观念,它的发展对传统学科教育产生了深刻的影响,本文就信息技术课程学科特点,从多元智力角度对教学方法改革进行探讨和研究。