Bayesian credible intervals for response surface optima

In response surface methodology, one is usually interested in estimating the optimal conditions based on a small number of experimental runs which are designed to optimally sample the experimental space. Typically, regression models are constructed from the experimental data and interrogated in order to provide a point estimate of the independent variable settings predicted to optimize the response. Unfortunately, these point estimates are rarely accompanied with uncertainty intervals. Though classical frequentist confidence intervals can be constructed for unconstrained quadratic models, higher order, constrained or nonlinear models are often encountered in practice. Existing techniques for constructing uncertainty estimates in such situations have not been implemented widely, due in part to the need to set adjustable parameters or because of limited or difficult applicability to constrained or nonlinear problems. To address these limitations a Bayesian method of determining credible intervals for response surface optima was developed. The approach shows good coverage probabilities on two test problems, is straightforward to implement and is readily applicable to the kind of constrained and/or nonlinear problems that frequently appear in practice.     

How Sunday, price, and social norms influence donation behaviour

We describe a natural field experiment investigating donation behaviour. The setting was an art gallery where donations could be deposited into a transparent box in the foyer. Two aspects of the donation environment were manipulated: signs on the donation box and the initial contents of the box. We used three sign treatments: a control with no sign, a sign that thanked donors, and a sign that indicated donations would be matched. We used two initial contents treatments: one with relatively little money ($50) and one with four times as much. The average donation per donor was significantly larger in the $200 treatments but this was offset by a decrease in the propensity to donate. In the matching treatments donations were significantly larger both at the per donor and per visitor level. A control variable turned out to have the largest influence on donation behaviour: the day of the week. The average donation per visitor was 51% higher on Sundays, when compared to every other day of the week.     

特低渗透油藏 CO2 驱室内实验研究

针对大庆外围油田特低渗透油藏剩余油潜力大、井网加密效益差、水驱采收率低等问题，提出了特低渗透油藏 CO2驱技术。通过细管实验和天然岩芯 CO2 驱油实验，确定了 CO2 与高台子油田原油的最小混相压力，评价了特低渗透砂岩油藏 CO2 驱油效果。实验结果表明，CO2 驱可以应用于高台子油田，并取得较好的驱油效果。当天然岩芯空气渗透率为0.58 mD 时，在水驱基础上，气驱可以进一步提高采收率 8% 以上，特低渗透油藏实施 CO2 驱油技术是可行的。     

虚拟世界经济收益模式研究

虚拟世界经济收益模式分为直接收益模式和间接收益模式,前者主要包括时间销售和虚拟物品销售等,后者主要包括现实货币交易和微型服务外包.其中间接收益模式对服务贸易发展、产业结构升级、增加低水平劳动力就业都具有特殊意义,更适合中国目前的形势.通过对虚拟世界收益模式新形式的初步分析.为政策制定提供参考.     

协同商务环境下虚拟企业组织结构研究

从虚拟企业的特性出发,分析了协同商务环境下虚拟企业组织结构设计中应注意的问题,探讨了协同商务环境下虚拟企业组织结构的组成要素,提出了协同商务环境下虚拟企业组织结构设计框架.     

固守·承继·创新——汤池试验留给我们的启示

伴随着时代的不断发展,中国正大踏步地迈进世界的大舞台。面对多元文化的冲击,中国传统文化的继承与弘扬正面临着诸多的考验,人们为此做出过许多的探索与努力。汤池的庐江中华文化教育中心也正是其中之一。汤池的试验,对于承继传统文化提供的启示是：坚定弘扬传统文化的信念,注重传统文化对人由外而内的塑造以及实现传统与现代的对接。     

普通化学课程多媒体网络教学模式的探索

在现代教育理论的指导下,探讨运用多媒体网络教学优势。多媒体网络辅助教学作为一种先进的教学手段在教学各方面都起着非常重要的作用,丰富课堂内容,激发学生学习兴趣,培养学生创新思维和解决问题的能力,提高普通化学教学质量。     

Determining the effects of intraclass correlation on factorial experiments

This paper considers the effects of the presence of eqmi-correlation between observations in a k-way factorial experiment, A technique to provide unbiased F-tests is also constructed.     

Marginally oversaturated designs

A special class of supersaturated design, called marginally over saturated design (MOSD), in which the number of variables under investigation (k) is only slightly larger than the number of experimental runs (n), is presented. Several optimality criteria for supersaturated designs are discussed. It is shown that the resolution rank criterion is most appropriate for screening situations. The construction method builds on two major theorems which provide an efficient way to evaluate resolution rank. Examples are given for the cases n=8, 12, 16, and 20. Potential extensions for future work are discussed.     

Comments on the special issue of communications in statistics (vol.a8, no. 10) concerned with weather modification experiments

As stated by the Editors of the Special Issue. It was complied with reference to two of my statements; that much of the current weather modification literature is slanted and unreliable. and(2) that progress in the building of a reliable weather modification technology requires an interdisciplinary study of as many completed cloud seeding experiments as possible. The material published in the Special Issue relates to two completed experiments, the Tasmania and the Israeli experiments. It is shown that a realistic appraisal of a completed experiment requires a prolonged effort, including an examination of quite a few relevant publications and, on occasion, Some numerical work on published raw data. It appears that an interdisciplinary reanalysis of the Tasmania experiment can contribute to the development of a reliable cloud seeding technology.