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101.
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
102.
A Classroom Exercise to Examine the Trade‐off between Mission Capacity and Life Cycle Cost 下载免费PDF全文
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
103.
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
104.
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
105.
106.
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
107.
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
108.
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
109.
110.
分析企业科技期刊与企业科技发展的关系,论述企业科技期刊在推动企业科技进步、促进企业经济发展中的作用.针对企业科技文化的现状,提出了办好企业科技期刊的建议. 相似文献