电阻测量中减小系统误差的措施

伏安法测电阻是实验室测量电阻的常用方法。但是,在测量过程中所选择的测量电路不同,所选择的仪器、仪表不同,测量的结果和误差大小也不尽相同。为此,在这里讨论如何减小实验测量误差,以便提高实验的精确程度,对提高学生实验能力有着极为重要的意义。     

A novel wide-range precision instrument for measuring three-dimensional surface topography

We developed a measuring instrument that had wide range, high precision, small measuring touch force. The instrument for three-dimensional （3D） surface topography measurement was composed of a high precision displacement sensor based on the Michelson interference principle, a 3D platform based on vertical scanning, a measuring and control circuit, and an industrial control computer. It was a closed loop control system, which changed the traditional moving stylus scanning style into a moving platform scanning style. When the workpiece was measured, the lever of the displacement sensor returned to the balanced position in every sample interval according to the zero offset of the displacement sensor. The non-linear error caused by the rotation of the lever was, therefore, very small even if the measuring range was wide. The instrument can measure the roughness and the profile size of a curved surface.     

减少差压式汽包水位测量误差的一种方法

对汽包内置式平衡容器测量汽包水位的原理进行了分析和研究;以贵溪300MW机组应用为例,介绍了采用汽包内置式平衡容器减少差压式水位测量误差的方法,该方法提高了差压式汽包水位测量的精确度,取得良好的改造效果。     

关于误差与有效数字

实验教学中对于数据的处理是培养学生严格科学态度关健的一环。在大学物理实验中怎样具体分析处理实验误差,把握有效数字,是实验教学的起步。     

汉语语音识别中区分性声调模型及最优集成方法

提出了2种解决汉语语音识别中声调问题的方法:利用区分性方法对基于隐马尔可夫模型(HMM)的声调模型进行训练;提出将区分性训练的声调模型加入大词汇量连续语音识别系统的最优方法,该方法根据最小音子错误的训练准则以及利用扩展Baum-Welch算法区分性训练与模型相关的概率权重,对声学模型以及声调模型概率进行加权.实验结果表明区分性训练的声调模型能够显著地提高连续语音声调识别率以及大词汇量语音识别系统的识别率,同时区分性的模型权重训练能够在区分性声调模型加入连续语音识别系统之后进一步提高系统的识别性能.     

大陆法系民法对罗马法错误制度的继受及中国民法中的重大误解

错误制度关涉诸多法益的冲突,立法者在设计有关错误的规则时必须进行利益衡量.大陆法系民法继受并发展了罗马法中的错误规则,但在利益衡量上存在不同的立法模式. 我国民法中的重大误解的相关规则实为大陆法系民法中错误制度的内容,但我国民法中的重大误解制度在利益衡量上却存在着失衡的缺陷.     

Sources of variance in end-of-course student evaluations

Abstract

Evaluation of college instructors often centers on course ratings; however, there is little evidence that these ratings only reflect teaching. The purpose of this study was to assess the relative importance of three facets of course ratings: instructor, course and occasion. We sampled 2,459 fully-crossed dyads from a large university where two instructors taught the same two courses at least twice in a 3-year period. Generalizability theory was used to estimate unconfounded variance components for instructor, course and occasion, as well as their interactions. Meta-analysis was used to summarize those estimates. Results indicated that a three-way interaction between instructor, course and occasion that includes measurement error accounted for the most variance in student ratings (24%), with instructor accounting for the second largest amount (22%). While instructor - and presumably teaching - accounted for substantial variance in student course ratings, factors other than instructor quality had a larger influence on student ratings.     

本科教学质量的分析与研究——以2014年陕西省为例

本文通过对陕西省各高校2014年本科教学质量报告中的数据进行提取、归类和分析,且利用误差分析法和决策模型对其进行研究与讨论,得到客观的决策结论;再根据专家调查报告得出相应的主观决策结果,同时该结果还体现了专家的认知经验和权威性;最后根据主、客观的决策结果运用决策模型得出综合决策结论。该结论不仅能比较好地体现各学校的本科教学质量,也能对未来的持续发展提供了一个可行的方案。     

Evaluating the Selection of Normal-Theory Weight Matrices in the Satorra–Bentler Correction of Chi-Square and Standard Errors

In the application of the Satorra–Bentler scaling correction, the choices of normal-theory weight matrices (i.e., the model-predicted vs. the sample covariance matrix) in the calculation of the correction remains unclear. Different software programs use different matrices by default. This simulation study investigates the discrepancies due to the weight matrices in the robust chi-square statistics, standard errors, and chi-square-based model fit indexes. This study varies the sample sizes at 100, 200, 500, and 1,000; kurtoses at 0, 7, and 21; and degrees of model misspecification, measured by the population root mean square error of approximation (RMSEA), at 0, .03, .05, .08, .10, and .15. The results favor the use of the model-predicted covariance matrix because it results in less false rejection rates under the correctly specified model, as well as more accurate standard errors across all conditions. For the sample-corrected robust RMSEA, comparative fit index (CFI) and Tucker–Lewis index (TLI), 2 matrices result in negligible differences.     

朱子论诚敬

本文主要从四个方面论述朱子“诚敬”思想：朱子对“诚意”的诠释；朱子用理学观念对“诚”的阐发；朱子关于“诚”与“敬”、“信”关系的论述；朱子有关“诚意”和“致知”关系的发挥。朱子的上述思想对21世纪人们深刻的遍。