How repeated studying and testing affects multimedia learning: Evidence for adaptation to task demands

Two biases can occur in multimedia learning: overconfidence and over-reliance on text processing. The present research sought to identify these biases and to investigate whether they can be reduced, and hence learning fostered, when studying and testing are repeated. In 2 experiments (Exp.1: N = 79, Exp.2: N = 52), students learned either with text only or with text and pictures (multimedia) about how the toilet flush works, gave judgments-of-learning (JOLs), were tested on the learning contents; afterwards this study-test cycle was repeated. Results from both experiments revealed stronger overconfidence due to multimedia in both study-test cycles (JOLs higher than learning outcomes). Eye movement data showed a relative increase in attention on the picture versus text from cycle 1 to cycle 2; this relative increase in attention was related to better learning outcomes. Repeated studying and testing thus helped to reduce over-reliance on text processing in multimedia learning, fostering performance.     

Within and between person associations of calibration and achievement

Self-regulated learning (SRL), the ability to set goals and monitor and control progress toward these goals, is an important part of a positive mathematical disposition. Within SRL, accurate metacognitive monitoring is necessary to drive control processes. Students who display this accuracy are said to be calibrated, and although calibration is a growing area of research within Educational Psychology, unanswered questions remain about calibration's role as an aspect of metacognition, including the unique association between calibration and academic performance. In this study, calibration is characterized as part of a dynamic system that varies across tasks within the same person; variance in calibration is associated with variance in performance gain for the same student across tasks (quizzes within a year-long mathematics curriculum, ST Math). Both accurate determinations of certainty (Sensitivity) and uncertainty (Specificity) have unique small, yet statistically significant, associations with performance gains from pre to posttest in ST Math. For Specificity, there also remains a contextual association with performance at the Person level. Results are discussed in light of prior research on calibration and of theories of SRL; the data and analyses present a novel approach to studying calibration within a dynamic system and offer insights for future work.     

Optimum calibration of a parallel kinematic manipulator using digital indicators

This paper presents a calibration method for parallel manipulators using a measurement system specially installed on an external fixed frame. The external fixed frame is important as an error reference for calibration in certain operations, such as in the configuration of a parallel manip- ulator functioning as a machine tool where the workpiece is fixed to a worktable. The pose of the end-effector is mea- sured using three digital indicators installed on the external fixed frame. To enable measurement, the end-effector is assumed to be a plane large enough that all digital indicators could touch. The error is defined as the difference between the theoretical and actual readings of the digital indicators. The geometric parameters of the parallel manipulator are optimized to minimize this error. This calibration method is low cost and feasible for compensating geometric parameter errors for a parallel manipulator. Optimal pose selection for the calibration is achieved using a swarm intelligence search algorithm. The method is implemented on a prototype of a six degrees-of-freedom （DOFs） Gough-Stewart platform constructed to function as a machine tool.     

热电偶检定用扫描开关的研制

本文介绍一种扫描开关,在保证低热电势的前提下,方便增加通道数量,同时可以通过扫描开关的硬件和软件实现热电偶双极法和同名极法检定的转换,无需用户重新连接,方便灵活。     

用MSA方法校准激光测距仪

用MSA方法校准激光测距仪是一种有效的校准方法,它可以评价激光测距仪可用性,使测试准确度更可信.详细介绍了用MSA方法校准激光测距仪理论依据、校准测试方案及测试结果,还就结果进行了讨论.     

摄像机标定算法研究

文章在Heikkila方法的基础上,研究了另外一种确定模板参考点圆心在像平面上对应像点的方法,然后根据这些点对来标定摄像系统。     

一种透反射比测试系统的非线性校准

文章详细介绍了一种透反射比测试仪的测试原理及校准方法.实验表明,该方法简单有效,经校准后仪器的精度有大幅度的提高.     

基于ATMEGA64和MCP3202的数据检测卡设计

介绍了一种基于ATMEGA64和MCP3202的多通道数据检测卡的设计过程,详细说明了系统功能和软、硬件设计方法,并着重指出系统软件校正、标定的方法。该系统具有准确性高、稳定性好、成本低廉等特点,已经成功应用于某大型医疗设备中,取得了理想效果。     

The measurement of calibration in real contexts

Accurate judgment of performance, or calibration, is an important element of self-regulated learning (SRL) and itself has been an area of growing study. The current study contributes to work on calibration by presenting practical and predictive results of varying calibration measures from authentic educational data: elementary-aged students' interactions with a year-long digital mathematics curriculum. Comparison of predictive validity of measures show only small differences in explained variance in models predicting posttest performance while controlling for pretest. A combined model including Sensitivity and Specificity outperforms other single measures, confirming results in Schraw, Kuch, & Gutierrez (2013); however, results show that student patterns of calibration within these data differ from those assumed in simulation studies and these differences have implications for the calculability of popular calibration measures.     

关于非晶硅面阵探测器无损检测成像系统噪声的校正

详细论述了基于非晶硅面阵探测器的无损检测成像系统．介绍了PaxScan非晶硅面阵探测器性能和成像过程,给出了所设计的系统各主要组成部分及其主要功能．分析了引起图像退化的原因,针对面阵探测器导致图像退化的因素,分别做了校正．实验表明,系统成像质量能达到工业检测最高级B级．