钢管拱施工安全风险管控

崔家营汉江特大桥是汉十高铁的关键控制性工程,跨汉江航道通航孔采用(135+2×300+135)m连续刚构拱桥,是世界上首座时速350公里、跨度300米连续钢构拱桥,全桥钢管拱6800吨,共计112个吊装节段,主拱钢管拱距汉江水面高度最高达105m,最大吊重达110吨,因工期紧,钢管拱4跨同时施工,用于拼装、提升拱肋大型...     

不完全合同理论视角下渐进性创新的逆向研发外包组织模式、技术溢出与创新能力研究

既有研发外包组织理论主要基于技术优势企业视角,关注如何治理技术溢出等交易成本,忽视了缺少专利和隐性知识的企业进行渐进性创新时最优研发外包组织选择。基于不完全合同视角,从企业对研发中激励代理方努力与降低渐进性创新的不完全替代性成本之间的权衡出发,分析委托方如何合作、并购、委托以及新建研发等组织最优选择。结果表明,当委托方技术水平较低时,最优组织将需要给代理方更多控制权以激励其努力,相反,委托方则保留更多控制权以降低不完全替代性成本。委托方市场规模通过影响代理方的私人收益降低不完全替代性成本,使得委托方愿意放弃控制权以激励代理方努力。新建研发可以看作是委托方通过承担更多时间和风险成本,从而降低不完全替代性成本。在不同组织形式中,委托方对研发投入的积极性是不同的,这决定了委托方通过研发外包获得的技术溢出效应和企业创新能力。     

依赖性与嵌入性：产学研合作创新持续性研究

作为合作创新的重要形式,产学研合作创新为资源整合、产业优化与经济发展作出了重要贡献。基于国家重点产业专利信息服务平台,以我国电子元器件产业产学研合作发明专利为数据来源,采用Logistic回归模型实证检验依赖性与嵌入性对产学研合作创新持续性的影响。结果表明：在依赖性的3个要素中,地理邻近性对产学研合作创新持续性不具有显著影响,知识相似性和身份相似性均对产学研合作创新持续性具有显著正向影响;在嵌入性的3个要素中,结构嵌入性对产学研合作创新持续性不具有显著影响,关系嵌入性和位置嵌入性均对产学研合作创新持续性具有显著正向影响。但是,当所有因素同时进入回归模型时,只有知识相似性和关系嵌入性对产学研合作创新持续性具有显著正向影响,身份相似性和位置嵌入性的影响不再显著。     

基于线性规划和灰色关联投影法的资本结构优化模型

本文阐述了资本结构的优化目标,结合线性规划与灰色关联投影法构建了一个资本结构优化模型。     

“Panelizing” Repeated Cross Sections

This paper considers the implementation of a non-stationary, heterogeneous Markov model for the analysis of binary dependent variables in a time series of repeated cross-sectional (RCS) surveys. The model offers the opportunity to estimate entry and exit transition probabilities and to examine the effects of time-constant and time-varying covariates on the hazards. We show how maximum likelihood estimates of the parameters can be obtained by Fishers method-of-scoring and how to estimate both fixed and time-varying covariate effects. The model is exemplified with an analysis of the labor force participation decision of Dutch and West German women using ISSP (and other) data from 10 annual Dutch surveys conducted between 1987 and 1996 and 7 annual West German surveys conducted between 1988 and 1994. Some open problems concerning the application of the model are discussed.     

Casinos,casino size,and crime: A panel data analysis of Michigan counties

Growth in legal gaming in the United States over the past quarter century or so is well-documented. One important factor fueling this growth was the passage of the Indian Gaming Regulatory Act of 1988, which permitted Native American tribes to establish, under agreements or “compacts” with the states in which they are located, casinos offering what is known as Class III gaming: slot machines, blackjack, roulette, and other games. Since the passage of the Act, there have been 21 Native American casinos established in Michigan. Also, three non-Native American casinos opened in Detroit in 1999 and 2000. This growth in the number of casinos has sparked a wide-ranging debate over the social and economic impacts of casino development.The purpose of this research is to focus on the crime issue in the broader casino debate. We investigate the impact of these Michigan casinos on the rates of burglary, robbery, larceny and motor vehicle theft (property crimes) in casino host counties as well as in nearby counties. We employ a panel data set with annual observations on all 83 Michigan counties for the period 1994–2010. The dataset includes crime rates taken from the FBI crime data series, variables for the presence of a casino in a county or in a nearby county, the scale of a casino's operations as measured by revenues, and a variety of control variables suggested by the broader literature investigating the factors that determine crime rates generally.Our results suggest that in most cases the property crime rates studied are not affected by the presence or size of a casino in a county or in a nearby county. The largest such impact, which is negative, is for motor vehicle theft. The size of a casino does have a small positive effect on the motor vehicle theft rate.     

新零售下社区生鲜配送模式的综合评价

新零售模式下社区生鲜“最后500m”的冲刺已成为生鲜农产品快速配送的关键问题。基于目前已有的配送模式:“社区+便利店”模式、第三方配送以及众包模式,通过层次分析法从服务水平、配送成本、客户体验三个方面对三种配送模式进行量化分析,得出每种配送模式在各层次的权重。研究结果表明配送中降低配送成本是关键,减少货物赔损率、提高客户满意度才能实现有效率的配送。     

外埠市场营销策略研究

“得外埠终端者得天下”和“营销重心下移”是近年来在营销界最为响亮的战略口号之一。如何进行外埠市场营销，是企业普遍需要研究的重要课题，本文试图从市场营销组合[4P]的角度，即从产品策略、定价策略、渠道策略和促销策略出发，分析如何成功地开拓城市外围的广阔市场。