‘Once upon a time’: examining ability grouping and differentiation practices in cultures of evidence-based decision-making

In an era when evidence-informed decision-making is mooted as a means of achieving equity, data are now being used to revive the in-school stratification of students, despite sustained concerns around the long-term negative consequences of these practices. This institutional ethnography explores how teachers use data in their everyday work, and how evidence-informed decision-making supports the logic of grouping students by ability. Research data are drawn from two Australian schools where achievement data were used to group students, in response to requirements to use evidence-informed practices. This had implications for enacted curriculum and pedagogies, as teachers used grouping to differentiate instruction. Although there were no formal directives to group by ability, a cascade of performance management policies was implicated in the rise of these practices. This use of data was normalised, and ability grouping practices were evident from the early years of schooling onwards.     

Exploring eye movements of experienced and novice readers of medical texts concerning the cardiovascular system in making a diagnosis

This study used the eye‐tracking method to explore how the level of expertise influences reading, and solving, two written patient cases on cardiac failure and pulmonary embolus. Eye‐tracking is a fairly commonly used method in medical education research, but it has been primarily applied to studies analyzing the processing of visualizations, such as medical images or patient video cases. Third‐year medical students (n = 39) and residents (n = 13) read two patient case texts in an eye‐tracking laboratory. The analysis focused on the diagnosis made, the total visit duration per text slide, and eye‐movement indicators regarding task‐relevant and task‐redundant areas of the patient case text. The results showed that almost all participants (48/52) made the correct diagnosis of the first patient case, whereas all the residents, but only 17 students, correctly diagnosed the second case. The residents were efficient patient‐case‐solvers: they reached the correct diagnoses, and processed the cases faster and with a lower number of fixations than did the students. Further, the students and residents demonstrated different reading patterns with regard to which slides they proportionally paid most attention. The observed differences could be utilized in medical education to model expert reasoning and to teach the manner in which a good medical text is constructed. Eye‐tracking methodology appears to have a great deal of potential in evaluating performance and growing diagnostic expertise in reading medical texts. However, further research using medical texts as stimuli is required. Anat Sci Educ 10: 23–33. © 2016 American Association of Anatomists.     

可见和红外波段跟踪测量控制系统

研制了一种光电经纬仪的跟踪测量系统 .该系统可以在可见和红外波段对飞行目标进行跟踪测量 ,还可对测量结果实时输出 .利用误差跟踪控制和共轴跟踪控制技术的多模控制方式 ,可以提高系统自动跟踪的稳定性、跟踪精度和各工作方式间的平滑切换 ,使整个系统的综合性能得到完善 .仪器的速度、加速度分别超过 6 0deg/s、90deg/s2 .该跟踪控制测量系统目前已成功应用于光电经纬仪中     

Visual Representations of DNA Replication: Middle Grades Students’ Perceptions and Interpretations

Visual representations play a critical role in the communication of science concepts for scientists and students alike. However, recent research suggests that novice students experience difficulty extracting relevant information from representations. This study examined students’ interpretations of visual representations of DNA replication. Each of the four steps of DNA replication included in the instructional presentation was represented as a text slide, a simple 2D graphic, and a rich 3D graphic. Participants were middle grade girls (n = 21) attending a summer math and science program. Students’ eye movements were measured as they viewed the representations. Participants were interviewed following instruction to assess their perceived salient features. Eye tracking fixation counts indicated that the same features (look zones) in the corresponding 2D and 3D graphics had different salience. The interviews revealed that students used different characteristics such as color, shape, and complexity to make sense of the graphics. The results of this study have implications for the design of instructional representations. Since many students have difficulty distinguishing between relevant and irrelevant information, cueing and directing student attention through the instructional representation could allow cognitive resources to be directed to the most relevant material.     

On the relations of sociocognitive childhood characteristics,education, and socioeconomic success in adulthood

Sociocognitive characteristics—ranging from self-concepts and interests to goals and self-esteem—have been discussed as key drivers predicting adult socioeconomic success. This study analyzes how childhood sociocognitive characteristics relate to adult socioeconomic success (education, occupational status, and income). Drawing on Eccles et al.’s expectancy value theory, we operationalized sociocognitive characteristics comprehensively via academic self-concept, academic interest, professional goal aspirations and professional goal certainty, and self-esteem. Based on a German sample, we explored the extent to which potential relations were independent of other central childhood factors—namely intelligence and parental socioeconomic background—as well as of adult educational attainment, which simultaneously served as a mediator and outcome. Additionally, we used school track as a moderator variable for these relations. We thus tested the idea that the effects of childhood factors are strongly mediated and moderated by education in highly structured education systems like Germany. Our sample of N = 3906 randomly sampled participants came from a German prospective longitudinal study in which respondents were first assessed at age 12 in 1991 and last surveyed in 2009/10. All characteristics were related to socioeconomic success indicators. However, education played a central role in mediating almost all of the effects of childhood characteristics, as education was the strongest predictor for socioeconomic success, and sociocognitive characteristics—especially self-esteem, professional aspirations, and academic self-concept—predicted education. School tracks moderated these relationships, with sociocognitive characteristics being particularly predictive in the academic track. Furthermore, the effects of sociocognitive characteristics shared substantial variance with intelligence and socioeconomic background. Nevertheless, professional aspirations, academic self-concept, and—in the academic track—academic interests exhibited unique effects, predicting not only education but also further adult socioeconomic success.     

基于在线多实例学习的跟踪研究

介绍一种基于在线多实例学习的目标跟踪方法,在线多实例学习在目标跟踪中的应用是采用基于多实例学习的自适应表观模型,解决了训练样本中存在的模糊歧义问题,探讨了处理训练正包中正样本和负样本的问题,指出了今后多实例学习目标跟踪的研究方向．     

视频中人脸的实时跟踪

介绍了一种简单、快速的实时视频人脸对象跟踪算法．在使用肤色检测算法进行人脸区域定位的基础上,采用差分运动估计,确定最大的搜索区域,在此区域使用两个正交的边缘梯度跟踪模型和内部肤色像素统计直方图跟踪模型跟踪人脸．本算法较好地解决了跟踪的连续性、实时性和精确度间的矛盾．实验结果表明本算法能够对人脸进行实时跟踪,具有一定实际应用价值．     

触发器技术在教学管理系统中的应用

触发器是基于事件驱动的特殊存储过程．在教学管理系统中应用触发器可以解决数据追踪和数据库完整性约束．     

Force ripple suppression in iron-core permanent magnet linear motors using an adaptive dither

This paper presents the design and realization of an adaptive dither to reduce the force ripple in an iron-core permanent magnet linear motor (PMLM). A composite control structure is used, consisting of three components: a simple feedforward component, a PID feedback component and an adaptive feedforward compensator (AFC). The first two components are designed based on a dominant linear model of the motor. The AFC generates a dither signal with the motivation to eliminate or suppress the inherent force ripple, thus facilitating smooth precise motion while uncompromising on the maximum force achievable. An analysis is given in the paper to show the parameter convergence. Computer simulations and real-time experimental results verify the effectiveness of the proposed scheme for high precision motion trajectory tracking using the PMLM.