Flow shop scheduling with deteriorating jobs under dominating machines

This paper addresses no-wait or no-idle flow shop scheduling problems with deteriorating jobs, i.e., jobs whose processing times are an increasing function of their starting time. A simple linear deterioration function is assumed and some dominating relationships between machines can be satisfied. It is shown that for the problems to minimize makespan or weighted sum of completion time, polynomial algorithms still exist, although these problems are more complicated than the classical ones. When the objective is to minimize maximum lateness or maximum tardiness, the solutions of a classical version may not hold.     

国有股和法人股对公司业绩的影响--公用事业型上市公司的实证研究

公司的股份集中于少数几个大股东手中是中国公司股权结构的一个普遍特征,研究这些大股东如何凭借其持股地位影响公司业绩是中国公司股权结构研究的一个非常重要的问题.本文选取了在上交所上市的公用事业型公司1998年至2002年的平行数据进行实证研究,结果表明,法人股对公司业绩有积极影响,国有股对公司业绩的影响视具体情况而定.     

不同规模农地抵押贷款可得性研究

以南阳市427户农户调查数据为样本,运用二元Logit回归模型对三类不同土地规模农户的农地抵押贷款可得性及其影响因素进行分析。结果发现,户主年龄、文化程度、家庭收入、房屋价值、社会资本、对贷款政策了解度及土地规模差异均对农户农地抵押贷款可得性具有显著影响。其中,家庭收入与房屋价值是影响不同土地规模农户农地抵押贷款可得性的共同因素,土地规模是影响农地抵押贷款可得性最为直接的关键性因素,随着土地规模增加,金融机构贷款审批更注重农户个人信用程度、社会资本和风险保障措施。     

改革开放40年我国高中阶段教育政策的价值变迁

高中阶段教育是世界各国制定教育规划时共同的关注焦点,也是我国义务教育向高等教育过渡的关键节点。改革开放以来,我国高中阶段教育政策从注重单方面质、量的平行发展到兼顾质与量的统筹发展,再到回归个体本身的个性发展,从关注学生的外部属性再深化到内部属性,价值取向处在逐步演进中,由最初的社会本位取向转变为大众主义取向,紧接着体现出以人为本取向,深刻反映了时代变化与发展的诉求。     

社会自主性的三种提升路径

社会自主性是现代化进程中的重要一维,社会自主性对市场侵蚀的抵抗和对国家权力的制约有利于形成均衡性的治理结构。现代化进程的历史维度、关系范畴的相对维度和治理现代化的功能维度构成理解社会自主性的3种视角。中国经由长期历史沉淀形成的是国家本位主义传统,改革开放打破了国家-社会的同构状态并塑造了一个相对自主的社会。中国社会缺乏自治机制的文化土壤和理念基础,社会自主性的提升需要国家以主动塑造方式,通过输入路径、合作路径和培育路径进行治理推动。     

全球替代性食物体系综述

在世界各地,农业食品领域的工业化造成了日益严重的环境、经济和社会问题,如环境污染、 大量碳排放、食品安全危机、小农边缘化和小农生计的难以维系。 为了应对这些问题,多个国家的不同 群体建立了多种多样的替代性食物体系,如社区支持农业、农夫市集、共同购买、社区菜园等。 替代性食 物体系自 2009 年进入中国至今已有十年,获得了较大发展。 然而,国内研究较少关注国际替代性食物 体系产生的背景及理念。 文章从替代食物体系的产生和发展、主要特征、国内外差异以及学术界的批判 等几个方面进行概述,全面介绍相关的关键问题和概念,为推动国内替代性食物体系研究的发展助力。     

如何建立社区支持农业中的消费者信任——惠州四季分享有机农场的个案研究

信任对 CSA 经济的可持续至关重要。 文章基于信任建立过程和信任发展的阶段性理论,通过单案例的研究方法探讨如何构建社区支持农业中的消费者信任。 研究结果表明:消费者信任的建立分为初始信任与持续信任两个阶段。 在潜在消费者的初始信任阶段,直接或间接关系、公开的信息、农 场主特征和消费体验会引发消费者的计算过程、转移过程、预测过程、意图过程和能力过程而建立消费 者初始信任。 在会员的持续信任阶段,用户体验和社会联系会引发消费者的预测过程和意图过程而维 持会员对农场的信任。     

Bayesian adjustment for unidirectional misclassification in ordinal covariates

In this paper, we study the identification of Bayesian regression models, when an ordinal covariate is subject to unidirectional misclassification. Xia and Gustafson [Bayesian regression models adjusting for unidirectional covariate misclassification. Can J Stat. 2016;44(2):198–218] obtained model identifiability for non-binary regression models, when there is a binary covariate subject to unidirectional misclassification. In the current paper, we establish the moment identifiability of regression models for misclassified ordinal covariates with more than two categories, based on forms of observable moments. Computational studies are conducted that confirm the theoretical results. We apply the method to two datasets, one from the Medical Expenditure Panel Survey (MEPS), and the other from Translational Research Investigating Underlying Disparities in Acute Myocardial infarction Patients Health Status (TRIUMPH).     

A Bayesian Model and Stochastic Exposure (Dose) Estimation for Relative Exposure Risk Comparison Involving Asbestos‐Containing Dropped Ceiling Panel Installation and Maintenance Tasks

Assessing exposures to hazards in order to characterize risk is at the core of occupational hygiene. Our study examined dropped ceiling systems commonly used in schools and commercial buildings and lay‐in ceiling panels that may have contained asbestos prior to the mid to late 1970s. However, most ceiling panels and tiles do not contain asbestos. Since asbestos risk relates to dose, we estimated the distribution of eight‐hour TWA concentrations and one‐year exposures (a one‐year dose equivalent) to asbestos fibers (asbestos f/cc‐years) for five groups of workers who may encounter dropped ceilings: specialists, generalists, maintenance workers, nonprofessional do‐it‐yourself (DIY) persons, and other tradespersons who are bystanders to ceiling work. Concentration data (asbestos f/cc) were obtained through two exposure assessment studies in the field and one chamber study. Bayesian and stochastic models were applied to estimate distributions of eight‐hour TWAs and annual exposures (dose). The eight‐hour TWAs for all work categories were below current and historic occupational exposure limits (OELs). Exposures to asbestos fibers from dropped ceiling work would be categorized as “highly controlled” for maintenance workers and “well controlled” for remaining work categories, according to the American Industrial Hygiene Association exposure control rating system. Annual exposures (dose) were found to be greatest for specialists, followed by maintenance workers, generalists, bystanders, and DIY. On a comparative basis, modeled dose and thus risk from dropped ceilings for all work categories were orders of magnitude lower than published exposures for other sources of banned friable asbestos‐containing building material commonly encountered in construction trades.     

城市新移民文化研究

作为一个文化群体的存在,"新移民"在文化上具有"山寨性"、"快餐性"、"开放性"等特征。这些特征既是他们"扎根城市生活"的生活写照,也显示了他们"永不言弃奋斗精神"之下潜伏着的集体张力。"新移民文化"在很大程度上再次点燃了城市的文化活力。"新移民文化"所拥有的现象特征与内生动力,显现出其所蕴含的城市革新力量与未来发展潜能。他们是推动中国城市化进程至关重要的一环,乃至成为整个中国未来现代化事业中值得信赖的有生力量。