组合投资规模与风险关系研究中抽样设计问题的解决

本文研究了传统组合投资规模与风险关系实证研究中抽样设计的缺陷，包括不同规模单一组合的无放回逐一组合随机抽样相对放回组合随机抽样的缺陷，不同规模多次组合的组合标准差放回简单随机抽样相对无放回简单随机抽样的缺陷。在此基础上，给出了组合标准差放回和无放回简单随机抽样样本容量的确定公式。最后，文章通过实证研究验证了上述结论     

对中学生自发的抽样知识的调查研究

对抽样知识的理解是统计素养的基础，而抽样方法是抽样知识的重要组成部分．中学生在没有学抽样知识前就表现出了统计学上常用的几种抽样方法萌芽．总体上，他们在抽样过程中对随机性缺乏认识，认识不到随机样本的统计公平性，而更相信分层抽样，而且不同年级、不同层次水平的学生对抽样知识的认识也存在差异。     

B-splines smoothed rejection sampling method and its applications in quasi-Monte Carlo integration

The rejection sampling method is one of the most popular methods used in Monte Carlo methods. It turns out that the standard rejection method is closely related to the problem of quasi-Monte Carlo integration of characteristic functions, whose accuracy may be lost due to the discontinuity of the characteristic functions. We proposed a B-splines smoothed rejection sampling method, which smoothed the characteristic function by B-splines smoothing technique without changing the integral quantity. Numerical experiments showed that the convergence rate of nearly O(N-1) is regained by using the B-splines smoothed rejection method in importance sampling.     

“中级财务会计”教学改革初探

会计学作为一门应用型学科，与会计实践密切相关。近年来，财政部对会计核算法规作了较大的调整，这些调整直接影响到中级财务会计课程的教学，需要对其教学的诸方面进行相应的改革。     

逻辑分析仪的数据获取

逻辑分析仪是数据测试中最典型的先进仪器．该个绍了其测试数据中的一个重要环节：数据的获取．     

夫琅禾费衍射的计算机模拟

根据夫琅禾费衍射理论 ,利用数学软件及计算机蒙特卡罗随机抽样方法 ,准确地再现了夫琅禾费衍射实验现象及规律 ,可应用于辅助教学     

4～7岁儿童空间认知和推理能力的测试研究

4~7岁儿童对空间图形的正确认识总体上处于较好水平.对图形和空间认知成绩的快速提高期出现在5岁半~5岁11个月(学龄前),对点数、推理能力的认知成绩的快速提高期出现在7岁~7岁5个月(初入学).与自然因素、基因遗传相比,人与环境间的互动作用,是儿童发展的主要的和根本的原因.我们既不能忽视自然成熟的因素,又须重视教育的重要影响.     

安徽电大开放教育毕业生追踪调查抽样方案的确定及实施

抽样方案的确定及实施是安徽广播电视大学开放教育试点毕业生追踪调查课题的一个重要环节。本文在结合中央电大对开放教育试点毕业生追踪调查抽样要求的基础上，根据安徽电大的实际情况，提出了采用二重抽样（double sampling）的抽样方案和实施步骤，实际运用时，方法科学、操作简便，取得了较理想的结果。     

Student engagement as a function of environmental complexity in high school classrooms

The purpose of this study was to investigate the linkage between the quality of the learning environment and the quality of students' experience in seven high school classrooms in six different subject areas. The quality of the learning environment was conceptualized in terms of environmental complexity, or the simultaneous presence of environmental challenge and environmental support. The students (N = 108) in each class participated in the Experience Sampling Method (ESM) measuring their engagement and related experiential variables. Concurrently, environmental complexity and its subdimensions were observed and rated from video with a new observational instrument, The Optimal Learning Environments – Observational Log and Assessment (OLE-OLA). Using two-level HLM regression models, ratings from the OLE-OLA were utilized to predict student engagement and experiential variables as measured by the ESM. Results showed that environmental complexity predicted student engagement and sense of classroom self-esteem. Implications for research, theory and practice are discussed.