《学生体质健康标准》制定工作实证研究的抽样方案实施与测试数据统计处理实务     

祁国鹰  张敬军  任云兰 《北京体育大学学报》2006,29(9):1217-1218,1228

详细介绍了<学生体质健康标准>制定工作实证研究的抽样方案及其实施和测试数据统计处理实务;同时提出了对测试数据统计分析和利用的思路.  相似文献   

教育研究的抽样问题——有目的抽样   总被引：1，自引：0，他引：1  

孙亚玲  罗黎辉 《云南师范大学学报(哲学社会科学版)》2002,34(3):127-129

教育研究常常遇到抽样的问题，而我们阐述较多的是如何使用随机抽样以保证教育研究的科学性。对使用较多的有目的抽样则阐述较少。本以随机抽样的局限性为引子，集中对教育科研中有目的抽样的含义、变式、以及如何应用做了初步的探讨，以期引起研究的重视。  相似文献   

政策悖论框架下学位论文抽检政策的效能分析     

占茜  赵金敏 《江苏高教》2021,(2):28-37

学位论文抽检政策是基于结果导向的问责制度而产生的质量保障手段,分析其效能可以为政策进一步完善与有效实施提供启示。检视J省2016-2019年学术型硕士学位论文抽检数据和相关政策文本,发现抽检政策实施和强化后,学位论文质量持续提升,然而不同类型院校和不同学科呈现出差异化政策回应,其中教学型大学和教学研究型大学的论文质量提升最快,文学和艺术学的论文质量提升较快,法学、经济学、教育学论文质量改善较慢,且政策强化后,各类院校和学科对政策的再次回应也呈现出差异。差异化效能反映出三组关键政策要素的博弈以及其中产生的相悖结果:公平与效率的政策价值博弈、简约与精细的政策规则博弈、外在激励与内在动力的政策措施博弈。忽视这三组博弈会抑制政策发挥应有的效能。为提高效能,抽检政策需处理好潜在的要素相悖问题,更好地平衡公平与效率的价值目标,适度细化规则,增强政策实施的内在动力。  相似文献   

A dynamic multilevel modeling approach to university students’ anxiety and hope regulation     

《Contemporary educational psychology》2021

Preparing for an exam entails various exam-related emotions. To ensure psychologically healthy behavior and an effective learning process, emotion regulation is highly important. In the present study, we used a dynamic multilevel modeling approach to analyse the interplay of exam-related anxiety and hope, as well as four regulation strategies over time. This study provides valuable insights into students’ emotion regulation in academic settings. Specifically, we measured students’ emotions and regulation strategies (cognitive approach, cognitive avoidance, behavioral approach, behavioral avoidance) across two weeks of measurement. In total, 217 university students answered several questionnaires via an electronic device during two different measurement periods lasting 7 days each. These measurement periods were 5 weeks (day 35–29) and one week (day 7 to 1) prior to an important exam. During their everyday life, they answered these questionnaires six times a day. We applied dynamic multilevel modeling to analyse the data. Results revealed cross-lagged relationships of exam-related emotions on regulation strategies, with the strongest cross-lagged relationship being found for hope and the cognitive approach regulation strategy. Moreover, the temporal distance to the exam affected the strength and direction of these cross-lagged relationships. This study suggests the importance of considering the mechanisms of emotion regulation on the situation level, and that strategies should be tailored to the individual situation rather than employing universal strategies. Further, the extent to which we can interpret the lagged relationships as suggestive of causal mechanisms are discussed.  相似文献   

Optimization of Power Dissipation in Pipelined Analog-to-Digital Converter     

徐江涛  姚素英  赵毅强  张为  李树荣  张生才 《天津大学学报(英文版)》2004,10(4):280-284

Power optimization for pipelined analog-to-digital converter(ADC) was studied. Operational principle of pipelined ADC was discussed and noise voltage caused by two important thermal noise sources, sampling switch and amplifier, was quantitatively analyzed. Method used to minimize power and the values under simple model were presented. Power can be saved by making the sampling and feedback capacitors scale down in the pipeline. And the size of capacitors was limited by thermal noise in high resolution ADC. The equivalent circuits of the two important thermal noise sources were established. Thermal noise was optimally distributed among the pipeline stages, and the relationship between scaling factor and closed loop gain was obtained for minimum power dissipation. Typical closed loop gain was 2 or 4 in pipeline ADC, and the corresponding scaling factor was 1.217 and 1.317. These results can serve as useful guidelines for designers to minimize the ADC‘s power consumption.  相似文献   

Alternative Monte Carlo Approach for General Global Illumination     

徐庆  李朋  徐源  孙济洲 《天津大学学报(英文版)》2004,10(4)

Ithasbeenwellknownthatglobalilluminationsimu latesthelighttransportamongallthesurfacesandthelightsourcesinavirtualsceneconsideringdiffusereflection/refrac tionandspecularreflection/refraction .Duetosimplicity,generalityanddimensionalindependence,MonteCarlomethodorrandomwalkmethodisoneofthemostimportantmethodsforsolvingthedifficultglobalillumination .Inpartic ular,MonteCarloisthelastresortwhenallotheranalyticalornumericalmethodsfail[1 ] .　　Lighttransportormultiplelightinteractionsamongthesu…  相似文献   

频带有限信号的局部重构     

强晓凤 《广东技术师范学院学报》2006,(4):28-30,150

本文讨论了从非均匀采样重建频带有限信号.选取不同的非均匀采样序列,利用有效算法进行重建,从得到的结果,分析采样的非均匀性对重建的影响.  相似文献   

Morningness and state academic self-concept in students: Do early birds experience themselves as more competent in daily school life?     

《Contemporary educational psychology》2023

The purpose of the present study was to investigate the role of circadian preference for students’ state academic self-concept (ASC). We focused on students’ tendency to be morning-oriented (i.e., morningness) and examined the association between morningness as a trait and mean levels of state (momentary) general-school ASC in everyday school life using intensive longitudinal data collected among N = 285 (N_obs = 6,140; M_lessons = 21.54) German ninth and tenth graders. Furthermore, we tested whether the strength of this relation between morningness and state general-school ASC was modulated by the time of day (i.e., synchrony effect). Results of multilevel analyses showed that morningness was positively related to students’ mean levels of state general-school ASC. However, our results refuted a synchrony effect on state ASC, as higher morningness related to equally high mean levels of state general-school ASC both early and late in the school day with respect to a typical school schedule with lessons occurring in the morning to early afternoon. The present findings contribute to our understanding of ASC and provide relevant information about how morningness should be positioned with regard to ASC in everyday school life.  相似文献   

Assessment of different genetic distances in constructing cotton core subset by genotypic values     

Wang JC  Hu J  Huang XX  Xu SC 《Journal of Zhejiang University. Science. B》2008,9(5):356-362

One hundred and sixty-eight genotypes of cotton from the same growing region were used as a germplasm group to study the validity of different genetic distances in constructing cotton core subset.Mixed linear model approach was employed to unbiasedly predict genotypic values of 20 traits for eliminating the environmental effect.Six commonly used genetic distances (Euclidean,standardized Euclidean,Mahalanobis,city block,cosine and correlation distances) combining four commonly used hierarchical cluster methods (single distance,complete distance,unweighted pair-group average and Ward's methods) were used in the least distance stepwise sampling (LDSS) method for constructing different core subsets.The analyses of variance (ANOVA) of different evaluating parameters showed that the validities of cosine and correlation distances were inferior to those of Euclidean,standardized Euclidean,Mahalanobis and city block distances.Standardized Euclidean distance was slightly more effective than Euclidean,Mahalanobis and city block distances.The principal analysis validated standardized Euclidean distance in the course of constructing practical core subsets.The covariance matrix of accessions might be ill-conditioned when Mahalanobis distance was used to calculate genetic distance at low sampling percentages,which led to bias in small-sized core subset construction.The standardized Euclidean distance is recommended in core subset construction with LDSS method.  相似文献   

中高级留学生识字量抽样测试报告   总被引：4，自引：0，他引：4  

李大遂 《暨南大学华文学院学报》2003,(2):12-18,45

本报告对某大学部分中高级留学生识字量抽样测试的目的、内容、方法、结果及其对教学的启示。章认为，识字量是反映一个人汉语水平的重要参考数据，应该成为教材编写、班级划分、教材选择和课堂教学的重要依据之一。测试结果显示：中高级留学生综合识字量偏低；对汉字字音掌握较好，对字形掌握最差；对甲、乙两级汉字掌握不扎实；汉字化圈学生在识字量方面有明显优势，但高级阶段优势大幅度下降；华裔学生识字量远低于非华裔学生。作根据测试结果，对如何提高学生识字量提出了相应的建议。  相似文献