Reexamining the Impact of Nonnormality in Two-Group Comparison Procedures     

Yoonjeong Kang  Ming Li 《Journal of Experimental Education》2015,83(2):147-174

The authors performed a Monte Carlo simulation to empirically investigate the robustness and power of 4 methods in testing mean differences for 2 independent groups under conditions in which 2 populations may not demonstrate the same pattern of nonnormality. The approaches considered were the t test, Wilcoxon rank-sum test, Welch-James test with trimmed means and Winsorized variances, and a nonparametric bootstrap test. Results showed that the Wilcoxon rank-sum test and Welch-James test with trimmed means and Winsorized variances were not robust in terms of type I error control when the 2 populations showed different patterns of nonnormality. The nonparametric bootstrap test provided power advantages over the t test. The authors discuss other results from the simulation study and provide recommendations.  相似文献   

A Classroom Exercise to Examine the Trade‐off between Mission Capacity and Life Cycle Cost          下载免费PDF全文

Keebom Kang  Kenneth H. Doerr 《Decision Sciences Journal of Innovative Education》2015,13(1):3-20

This article presents a classroom exercise, centered on a simulation that has been used for 4 years in an MBA program to help students develop an understanding of the trade‐offs involved in managing capital assets in the public sector. Though often ignored in business schools, mission is a key criterion that must be considered when managing such assets, and acts as a surrogate for profit. The case presents a rich environment in which the impact of cost reductions (or additional investments) on mission can be quantified, and trade‐offs can be assessed and discussed. It gives students a chance to develop creative ideas for process improvement, and provides sufficient data for them to analyze the impact of their suggestions in a rigorous way.  相似文献   

Cheating among elementary school children: A machine learning approach     

Li Zhao  Yi Zheng  Junbang Zhao  Guoqiang Li  Brian J. Compton  Rui Zhang  Fang Fang  Gail D. Heyman  Kang Lee 《Child development》2023,94(4):922-940

Academic cheating is common, but little is known about its early emergence. It was examined among Chinese second to sixth graders (N = 2094; 53% boys, collected between 2018 and 2019) using a machine learning approach. Overall, 25.74% reported having cheated, which was predicted by the best machine learning algorithm (Random Forest) at a mean accuracy of 81.43%. Cheating was most strongly predicted by children's beliefs about the acceptability of cheating and the observed prevalence and frequency of peer cheating at school. These findings provide important insights about the early development of academic cheating, and how to promote academic integrity and limit cheating before it becomes entrenched. The present research demonstrates that machine learning can be effectively used to analyze developmental data.  相似文献   

基于区域产业互动的三螺旋协同创新能力评价研究     

康健  胡祖光 《科研管理》2014,35(5):19-26

三螺旋模型中的企业维度可区分为生产性服务业和制造业两个具有不同特征并互动演化的亚类,依据SCP分析范式,在解析"大学—政府—生产性服务业"和"大学—政府—制造业"两个并行三螺旋协同创新结构和行为的基础上,引入复合系统协调度模型,对基于区域产业互动的三螺旋协同创新能力评价方式进行理论推演和实例分析。结果表明:应用两个并行互动的创新三螺旋对区域协同创新能力进行评价,可以在理论上丰富三螺旋理论体系,同时在实践上为区域协同创新能力的提升提供更为详细的决策参考信息。  相似文献   

学生满意度研究：现状、演进路径及前沿——基于Web of Science数据库     

康国光  沈振锋  徐跃进  陈啸 《现代情报》2014,34(8):29-36

了解学生满意度领域的研究现状、演进路径和研究前沿,有助于国内学者把握国际同行们的研究动态和热点问题。利用HistCite和CiteSpace软件分析,认为以学生满意度为主题的研究大致可分为3个阶段,且已出现了一批著名的研究学者和一系列经典文献,美国在这一领域中处于绝对领先地位,中国台湾地区为后起新秀。在学生满意度领域中,大致形成了4条演进路径,出现了顾客满意度、质量等研究热点,对在线学习满意度的研究或许成为未来的研究趋势和前沿。  相似文献   

Changes in velocity profile according to blood viscosity in a microchannel     

Eunseop Yeom  Yang Jun Kang  Sang-Joon Lee 《Biomicrofluidics》2014,8(3)

Red blood cells (RBCs) are important to dictate hemorheological properties of blood. The shear-thinning effect of blood is mainly attributed to the characteristics of the RBCs. Variations in hemorheological properties alter flow resistance and wall shear stress in blood vessels. Therefore, detailed understanding of the relationship between the hemorheological and hemodynamic properties is of great importance. In this study, blood viscosity and blood flow were simultaneously measured in the same microfluidic device by monitoring the flow-switching phenomenon. To investigate blood flows according to hemorheological variations, the flow rate of blood samples (RBCs suspended in autologous plasma, dextran-treated plasma, and in phosphate buffered saline solution) was precisely controlled with a syringe pump. Velocity profiles of blood flows were measured by using a micro-particle image velocimetry technique. The shape of velocity profiles was quantified by using a curve-fitting equation. It is found that the shape of the velocity profiles is highly correlated with blood viscosity. To demonstrate the relationship under ex vivo conditions, biophysical properties and velocity profiles were measured in an extracorporeal rat bypass loop. Experimental results show that increased blood viscosity seems to induce blunt velocity profile with high velocity component at the wall of the microchannel. Simultaneous measurement of blood viscosity and velocity profile would be useful for understanding the effects of hemorheological features on the hemodynamic characteristics in capillary blood vessels.  相似文献   

“双一流”目标下一流大学科研效率评价     

李康  范跃进 《科研管理》2022,43(9):41-47

    “双一流”建设是我国高等教育强国建设的战略安排,是我国高等教育发展的必由之路。“双一流”建设之一流大学建设高校,是高等教育强国建设的“领头雁”,研究一流大学建设高校科研创新效率,加快提升科学研究水平具有重大现实意义。本文以一流大学高校为研究对象,构建了突出科研产出质量和服务的综合效率评价指标体系,在传统DEA模型基础上运用随机前沿分析理论,通过三阶段DEA模型方法测度一流大学建设高校的科研效率,并进一步分析环境因素对科研效率的影响差异。研究结果表明：（1）环境变量和随机误差是影响一流大学科研效率的重要因素,我国一流大学整体科研效率存在虚高现象,剔除环境因素后样本高校综合效率和纯技术效率均值都明显下降。（2）地区经济水平、居民受教育程度和政府扶持力度对各个高校科研效率存在差异性影响,并据此将高校分为稳定型、发展型和改进型三类。（3）一流大学建设高校科研效率存在分化倾向,规模收益递减现象突出,其科研效率提升的关键是缩减规模、完善内部治理结构、优化资源配置,持续深化科研体系改革。  相似文献   

“90后”大学生价值观存在的问题分析     

马金莲  康小丽 《科教文汇》2014,(25):16-17

本文通过问卷调查的方式对兰州高校“90后”大学生价值观进行了全面详细的了解分析,得出“90后”大学生价值观存在的问题主要表现为价值追求功利化、价值取向本位化及价值选择矛盾化等。  相似文献   

语义网本体在离散数学课程教学中的应用     

康达周 《科教文汇》2014,(7):58-60

语义网本体广泛应用于知识工程、人工智能以及计算机科学领域,在教育、科研等方面也有重要作用。针对当前离散数学课程教学中存在的内容广、概念多、高度抽象和理论化等困难,利用本体作为辅助离散数学课程教学的重要工具,辅助学生理解、应用和实践离散数学知识,提出本体在教学过程中不同方面所起的作用以及教学思路与方法,得到了很好的教学效果和学生反馈。  相似文献   

制冷空调专业“专业软件应用”课程建设探讨     

康彦青  尚雪梅  郑爱平 《科教文汇》2014,(30):79-80

分析了制冷空调专业计算机工程辅助设计方面目前存在的问题,提出了解决方案,探讨了该专业＂专业软件应用＂课程建设的目的、课程建设的方法及其效果。  相似文献