Design selection for strong orthogonal arrays

Strong orthogonal arrays (SOAs) were recently introduced and studied as a class of space‐filling designs for computer experiments. An important problem that has not been addressed in the literature is that of design selection for such arrays. In this article, we conduct a systematic investigation into this problem, and we focus on the most useful SOA(n,m,4,2 + )s and SOA(n,m,4,2)s. This article first addresses the problem of design selection for SOAs of strength 2+ by examining their three‐dimensional projections. Both theoretical and computational results are presented. When SOAs of strength 2+ do not exist, we formulate a general framework for the selection of SOAs of strength 2 by looking at their two‐dimensional projections. The approach is fruitful, as it is applicable when SOAs of strength 2+ do not exist and it gives rise to them when they do. The Canadian Journal of Statistics 47: 302–314; 2019 © 2019 Statistical Society of Canada     

The context of employment discrimination: interpreting the findings of a field experiment

Although field experiments have documented the contemporary relevance of discrimination in employment, theories developed to explain the dynamics of differential treatment cannot account for differences across organizational and institutional contexts. In this article, I address this shortcoming by presenting the main empirical findings from a multi‐method research project, in which a field experiment of ethnic discrimination in the Norwegian labour market was complemented with forty‐two in‐depth interviews with employers who were observed in the first stage of the study. While the experimental data support earlier findings in documenting that ethnic discrimination indeed takes place, the qualitative material suggests that theorizing in the field experiment literature have been too concerned with individual and intra‐psychic explanations. Discriminatory outcomes in employment processes seems to be more dependent on contextual factors such as the number of applications received, whether requirements are specified, and the degree to which recruitment procedures are formalized. I argue that different contexts of employment provide different opportunity structures for discrimination, a finding with important theoretical and methodological implications.     

Media Disaster Reporting Effects on Public Risk Perception and Response to Escalating Tornado Warnings: A Natural Experiment

Previous research has evaluated public risk perception and response to a natural hazards in various settings; however, most of these studies were conducted either with a single scenario or after a natural disaster struck. To better understand the dynamic relationships among affect, risk perception, and behavioral intentions related to natural disasters, the current study implements a simulation scenario with escalating weather intensity, and includes a natural experiment allowing comparison of public response before and after a severe tornado event with extensive coverage by the national media. The current study also manipulated the display of warning information, and investigated whether the warning system display format influences public response. Results indicate that (1) affect, risk perception, and behavioral intention escalated as weather conditions deteriorated, (2) responses at previous stages predicted responses at subsequent stages of storm progression, and (3) negative affect predicted risk perception. Moreover, risk perception and behavioral intention were heightened after exposure to the media coverage of an actual tornado disaster. However, the display format manipulation did not influence behavioral responses. The current study provides insight regarding public perception of predisaster warnings and the influence of exposure to media coverage of an actual disaster event.     

构建现代远程开放教育考试体系初探

现代远程开放教育是基于以学习者为中心的开放学习和个别化学习。我们应从素质教育的培养目标出发 ,依据现代考试测量理论 ,利用现代科技手段 ,建立现代远程开放教育考试体系 ,客观、准确地评价学习者的进步状况以及在学识、能力等方面达到的水平 ,使学习者在学习过程中不断自我完善 ,培养他们积极进取的精神     

ALL-BIAS DESIGNS FOR POLYNOMIAL SPLINE REGRESSION MODELS

Polynomial spline regression models of low degree have proved useful in modeling responses from designed experiments in science and engineering when simple polynomial models are inadequate. Where there is uncertainty in the number and location of the knots, or breakpoints, of the spline, then designs that minimize the systematic errors resulting from model misspecification may be appropriate. This paper gives a method for constructing such all‐bias designs for a single variable spline when the distinct knots in the assumed and true models come from some specified set. A class of designs is defined in terms of the inter‐knot intervals and sufficient conditions are obtained for a design within this class to be all‐bias under linear, quadratic and cubic spline models. An example of the construction of all‐bias designs is given.     

中学化学实验研究选题探讨

中学化学实验研究的关键问题是如何选择研究课题。应从中学化学教学的需要、中学化学实验研究的内容、中学化学实验的发展趋势以及中学化学实验教学改革等方面来选择研究课题。     

关于高校实验室建设的几点思考

为把高校实验室建成开放式的创新实践基地 ,更好地发挥其在教学、科研、生产等方面的重要作用 ,应加强对高校实验室的硬件建设 ,并进行科学的统筹规划 ,加速提升实验室整体实力 ;加强实验教学师资队伍建设 ,实现实验室建设的跨越式发展     

开放式数控切割机神经网络误差补偿研究

分析了影响数控火焰切割机加工精度的主要因素,利用开放式数控系统的软件开放性,提出了采用IGCAQBP学习算法的神经网络方法来对包括金属热变形、机械传动误差等非线性因素在内的多种因素造成的加工误差进行误差补偿,设计了嵌入开放式数控系统中的神经网络误差补偿器,给出了实用的补偿器使用方法,并对误差补偿功能进行了扩展,仿真结果和实际应用表明该方法稳定有效。     

Windows2000下数控系统运动控制器的应用研究

通过对自行研制的GD102运动控制器特性的研究,将其驱动程序划分为内核支持层、寄存器读写层、基本命令层和应用层;分析了各层次的功能和实现原理及各层次间的通信机制。在分析Windows2000下内核模式驱动程序的构成和I/O请求处理流程的基础上,以DriverWorks为工具开发了运动控制器的驱动程序,并对驱动程序开发中的一些关键问题进行了论述。该驱动程序已被成功地应用到实际开放式数控系统项目,并取得了良好的效果。     

开设化学设计性实验的探索与实践

阐述开设设计性实验的意义,并在实践的基础上,给出了开设化学设计性实验的方案,总结了开设设计性实验的体会。