Detection of interactions in experiments on large numbers of factors

One of the main advantages of factorial experiments is the information that they can offer on interactions. When there are many factors to be studied, some or all of this information is often sacrificed to keep the size of an experiment economically feasible. Two strategies for group screening are presented for a large number of factors, over two stages of experimentation, with particular emphasis on the detection of interactions. One approach estimates only main effects at the first stage (classical group screening), whereas the other new method (interaction group screening) estimates both main effects and key two-factor interactions at the first stage. Three criteria are used to guide the choice of screening technique, and also the size of the groups of factors for study in the first-stage experiment. The criteria seek to minimize the expected total number of observations in the experiment, the probability that the size of the experiment exceeds a prespecified target and the proportion of active individual factorial effects which are not detected. To implement these criteria, results are derived on the relationship between the grouped and individual factorial effects, and the probability distributions of the numbers of grouped factors whose main effects or interactions are declared active at the first stage. Examples are used to illustrate the methodology, and some issues and open questions for the practical implementation of the results are discussed.     

Smallholder Preferences for Agri‐environmental Change at the Bhoj Wetland,India

Incentive‐based approaches have gained policy interest in linking change in agricultural land management with environmental conservation. This article investigates how scheme design influences smallholder farmers' decisions to switch to organic farming to reduce water pollution, drawing on a study at a Ramsar wetland site providing water for the city of Bhopal. Results from a choice experiment suggest that transitional payments are necessary to overcome farmer constraints to adopt organic farming, and that effective land certification has the potential to act as a self‐enforcing mechanism linking farmer incomes with wetland conservation benefits.     

英语RC挂靠偏向的眼动实验研究

RC挂靠现象研究对揭示歧义句加工内部心理过程具有重要意义,现有的修饰语挂靠若干假说是否适用中国英语学习者值得深入探索。本研究通过Tobii T-120型眼动仪,随机抽取49名英语专业本科生进行歧义句加工眼动实验。研究显示,RC关系从句呈现NP1挂靠偏向,支持语言调整假说。     

电子信息工程专业综合实验初探

提出了一个建设电子信息综合实验室 ,并开设电子信息综合实验的设想。该设想的实现 ,不仅可以充分利用实验室的现有设备 ,而且能将多门专业基础课和专业实验课有机的结合起来 ,进一步改善电子信息工程专业实验的效果     

局域网技术在计算机硬件实验室建设中的应用

本文介绍了把NOVELL网络应用于微机原理与接口技术等硬件实验中的方法与优势 ,以求能充分利用现有资源 ,改进计算机硬件实验教学的手段 ,提高硬件实验的教学效果 .     

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.     

空调用换热器性能综合实验台的开发研究

根据热力学和传热学中换热器性能的基本测试原理,研究开发了空调用套片式换热器综合实验台.该实验台可以在不同工况条件下对不同结构形式的R22和R410A蒸发器及冷凝器的换热性能和阻力性能进行实验.通过对R22冷凝器的实验研究结果表明,实验台自控程度高,实验数据精确可靠.     

世纪之交的高师物理实验教学初探

本文从大、中学物理实验教学的现状出发，对大学物理实验教学在培养适应多样化需要的跨世纪人才中，应怎样优化和改革各教学环节作了初步探索。     

改革化学实验教学加强科学素质教育

化学是一门以实验为基础的自然科学.在化学教学过程中，对化学实验进行改革，加强学生的科学素质教育，可以使学生的科学观察、实验操作以及综合科学研究素质得到培养和发展．     

转基因食品人体实验的伦理辩护

转基因食品还处在发展的初期,有许多不确定性因素,它可能对人体健康有潜在危害,有必要在转基因食品进入市场前进行人体试验。那么,转基因食品人体实验能够得到伦理辩护吗?本文通过正反观点的论证与分析认为,转基因食品的人体实验是对公众的身体健康负责的必然要求,可以得到伦理辩护。