关于合成脲醛树脂最佳投料比的实验探讨

就脲醛树脂的投料比,以及分批加入尿素进行了实验探讨,得出最佳投料比。     

基于S.D模型的供应链两阶段联合库存优化分析

运用系统动力学方法构建了基于供应链管理的联合库存S．D模型．首先,在联合库存系统边界优化的基础上,构建了基于供应链管理的两阶段联合库存因果关系图;其次,构造出S．D模型的流图,确切描述出反馈系统的动态性能,界定了流图的主要变量,构造合理的模拟方程和函数,阐述流图中各子模块内部运行机理;最后,结合具体公司的库存管理现状,在模型通过检验的前提下,进行了模型行为预测分析及联合库存模式与传统库存模式之对比分析,从中得出一些较有实际意义的模拟分析结果。     

The effect of prior education on students’ competency in digital logic: the case of ultraorthodox Jewish students

In line with the growing interest in extending the diversity of CS students, we examined the performance of a unique group of students studying an introductory course in Digital logic: ultraorthodox Jewish men, whose previous education was based mostly on studying Talmud and who lacked a conventional high-school education. We used questions from the Digital Logic Concept Inventory . We compared the results to those of religious Jewish men with a conventional high-school education, and to the results reported in the literature. The ultraorthodox group performed better than the other groups in tasks that concerned number representation. No other statistically significant differences were found. Talk-aloud protocols revealed that the ultraorthodox students utilized a viable conceptual understanding in their performance. We can conclude that students’ unique, alternative prior education should not be merely viewed as an obstacle to their academic studies, but also as a potential source for strengths.     

Metacognitive development and moving away

It is now largely accepted that social and cultural factors have a significant impact on cognitive development in children. Piaget acknowledged the impact of social factors and peer interaction on cognitive development. However, there has been relatively little work on the impact of social and cultural factors on the development of metacognition in first‐year university students. Using the Learning and study strategies inventory (LASSI) as a measure of metacognition, this study samples first‐year undergraduates in Hong Kong (N = 1815) and identifies significant differences in metacognitive abilities between students living in their home environment and those who have moved away from their family and, in some cases, culture, to pursue undergraduate education.     

国内航空公司实施收益管理的博弈分析

收益管理是航空公司提高收益水平的重要技术,其思想已经得到民航业广泛认同。许多国内航空公司使用了国外的收益管理系统,但是运行效果并不非常理想。本文在分析国内航空市场特点的基础上,通过构建博弈模型,研究了在竞争环境下的航空公司收益管理的舱位配置问题,分析了影响舱位控制因素。     

备件的联合库存模式研究

备件管理是资产密集型企业管理的重要内容。在分析库存三要素的基础上，阐述了库存模式发展的历程，分析了备件联合库存的不同表现形式及在我国实行备件联合库存的意义，最后提出了实施备件联合库存的策略。     

具有提前期的三级和二级药品库存模型比较

根据总成本最小原则,在考虑需求提前期影响的情况下,建立了基于随机提前期的三级药品库存优化模型和基于常值提前期的二级药品库存优化模型.运用Matlab软件研究了提前期与库存成本的关系,说明了提前期的变化对药品库存系统有着重要的影响.通过数据实例借助Lingo软件对2个模型进行了仿真计算和比较,结果表明,在保证服务水平的前提下,具有提前期的二级药品库存的总成本比三级药品库存的总成本有明显降低.     

与大学生个人发展相关的隐性知识测量工具的研究

隐性知识是影响个人发展(Personal Development，简称PD)的重要因素。为了研究隐性知识与个人发展的关系，我们根据提出的PD隐性知识结构，以大学生为例，编制相应的隐性知识测量工具。然后，通过分层一随机一整体抽样的方法，从北京师范大学的在校生中抽取了609名本科生和研究生进行正式测验。统计结果表明，该测量工具具有良好的鉴别度、信度和效度，可以作为大学生PD隐性知识水平的工具。     

一类易变质产品供应链联合定价和库存管理的平均收益准则模型

本文讨论了一类易变质(Perishable)产品供应链在长期平均收益准则下的最优联合定价和库存策略问题。我们分析了该问题最优促销定价和库存联合策略的性质和存在性,获得了长期平均收益准则下最优促销定价和库存联合策略的最优结构。分析的结果表明该类易变质产品供应链在无限阶段长期平均收益准则下的最优促销定价和库存联合策略是一由基准库存和标价向量刻画的与各阶段变质产品库存水平[EQUATION]相关的基准库存标价策略。