知识缺失还是知识自负？知识水平对公众食品安全信心的影响研究

通过对中国10个城市成年受访者的调查,发现公众对当前食品安全问题的感知风险水平较高,反映其对食品安全形势较担忧,且对政府食品安全管理部门存在信任危机。不过公众的感知控制力较高,普遍认为自己有保障自身食品安全的能力,因此在日常的食品消费中仍然有较高的信心。研究证实中国公众在食品安全的知识层面存在着知识自负现象,公众自我评估的主观知识水平显著高于实际拥有的客观知识水平,且真正对公众食品安全信心产生影响的是公众的主观知识水平。这说明传统缺失模型所倡导的以科普、辟谣为主要形式的致力于教育公众、提升公众客观知识水平的行动能够取得的效果可能非常有限;而公众的主观知识水平和感知控制力的提升能有效提振公众的食品安全信心。     

利用数控增益放大器提高A/D转换器的分辨率

文章介绍利用数控增益放大器LH0086大幅度提高A／D转换器分辨率的方法,可将8位A／D转换器的分辨率提高到接近16位A／D的水平,适用于高速数据系采集系统,给出了相应的硬件原理图和软件框图。     

卫星光通信中平台抖动补偿技术研究

以卫星光通信系统为例,对空间光通信系统中光学平台的抖动进行了分析。研究了一种自调节前馈补偿技术,通过自适应信号处理或对前馈控制器进行直接优化,可对光学平台的抖动进行有效抑制。     

Factors associated with expectation of household's future financial condition

Path analysis is used to examine the causal relationships among selected objective and subjective factors associated with a household's expectation of future financial condition. Results indicate that respondents who perceive the effect of changes in the external environment on their own household's financial condition as positive are younger, have higher net worth, perceive more internal control over their situation, and report that most of the changes in the external environment are positive. Respondents who are younger, have higher income, perceive more internal control over their situation, and believe the effect of changes in the external environment on their household's financial condition are positive are more likely to be optimistic about their financial future. It is important that educators and financial advisors recognize the significant role perception of being in control plays in determining expectations of future financial condition.Journal Paper No. J-15256 of the Iowa Agriculture and Home Economics Experiment Station, Project No. 2809. Data were collected in conjunction with the cooperative regional research project NC-182, Family Resource Utilization as a Factor in Determining Economic Well-Being of Rural Families. Cooperating states are Arizona, California, Illinois, Indiana, Iowa, Kansas, Michigan, and Minnesota.Her current research interests include family financial management and consumer bankruptcy; she received her Ph.D. from the University of Missouri.She received her Ph.D. from the University of Illinois; her current research interests include gender roles, family financial management, and economic well-being.She received her Ph.D. from the University of Illinois. Her research interests are economic well-being and quality of life.Her current research interests include the economic well-being of various family forms. She received her Ph.D. from the University of Illinois.     

多分销中心供应链模型及其牛鞭效应的H∞控制

本文在文^[1]具有一个分销中心供应链模型的基础上,建立了具有多个分销中心的供应链结构模型,采用供应链上游库存与订货偏差波动之和与下游顾客需求偏差波动之比描述牛鞭效应。提出顾客末端需求波动最差条件下H_∞控制方法,以抑制牛鞭效应。这一方法本质就是供应链末端需求波动最差情况下,制定供应链管理的最优决策。并且以一个石油分销系统为对象进行了供应链牛鞭效应的H_∞控制仿真实验。     

Cybernetic Risk Analysis

The Pearl Harbor case study reveals that risk analysis failure may be caused by any of a number of factors. However, the most important variables are system load, gain, lead time, and lag time. The dynamics of such cybernetic systems analysis constitute an important aspect in this regard. Four different risk management strategies, or organization designs, have been proposed in this paper. Each has a unique combination of the imputed variables and each has a unique cause of surprise, risk analysis failure, and crisis.     

Determination of recovery effort for a probabilistic recovery system under various inventory control policies

In this study we investigate the desired level of recovery under various inventory control policies when the success of recovery is probabilistic. All the used and returned items go into a recovery process that is modelled as a single stage operation. The recovery effort is represented by the expected time spent for it. The effect of increasing recovery effort on the success probability together with unit cost of the operation is included by assuming general forms of dependencies. Alternative to recovered items, demand is satisfied by brand-new items. Four inventory control policies that differ in timing of and information used in purchasing decision are proposed. The objective is to find the recovery level together with inventory control parameter that minimize the long-run average total cost. A numerical study covering a wide range of system parameters is carried out. Finally computational results are presented with their managerial implications.     

两阶段供应链中三种定价方式研究

本文考虑渠道一体化对品牌建设的作用,在一个制造商和两个零售商的两阶段供应链系统中,其中确定性的市场需求与产品的市场零售价格有关,通过分析以下三种定价方式下的最优定价和库存策略下供应链成员和系统的收益,1)商品市场零售价格由零售商各自决定,两零售商和制造商之间存在着竞争活动;2)商品市场零售价格由制造商统一制定;3)市场零售价格、转让价格和系统库存水平按渠道协调的最优原则确定,确定了同一产品品牌内部的市场竞争、定价控制权及转让价格对渠道性能及品牌自身造成的影响,并由此提出了分散决策系统中的一种激励机制.     

异质产品供应链定价控制权与零售商横向兼并效应分析

针对一部线性合约与供应商是否具有绝对定价控制权,比较分析零售商横向兼并集中度提高对消费者福利的影响.结果表明,(1)当供应商具有绝对定价控制权时,零售商横向兼并对消费者产生的影响取决于产品替代性程度大小:若替代性程度较高,则将产生有利影响,反之,将产生不利影响;(2)当供应商没有绝对定价控制权时,零售商横向兼并对消费者产生的影响取决于零售商兼并前的相对定价控制权强弱与兼并后的相对定价控制权增幅大小:若零售商在供应链中处于相对弱势地位,且零售商横向兼并使零售商的定价控制权增幅较大,则兼并将对消费者产生有利影响,否则,将对消费者产生不利影响.     

基于σ/ Q 的库存控制中安全库存的优选策略

研究了单项目库存控制问题中的安全库存选择策略,评论了安全库存的决定要素,讨论 了基于以上要素的成本构成。进一步讨论了安全库存策略在理论和实践应用中的矛盾,提出 了一种实践中容易操作的安全库存的直观求解方法,以利于管理者实际运用,有效克服运作环 境的不确定性