排序方式： 共有121条查询结果，搜索用时 328 毫秒
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Young‐Hoo Kwon Jeffrey B. Casebolt 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):315-340
One of the most serious obstacles to accurate quantification of the underwater motion of a swimmer's body is image deformation caused by refraction. Refraction occurs at the water‐air interface plane (glass) owing to the density difference. Camera calibration‐reconstruction algorithms commonly used in aquatic research do not have the capability to correct this refraction‐induced nonlinear image deformation and produce large reconstruction errors. The aim of this paper is to provide a thorough review of: the nature of the refraction‐induced image deformation and its behaviour in underwater object‐space plane reconstruction; the intrinsic shortcomings of the Direct Linear Transformation (DLT) method in underwater motion analysis; experimental conditions that interact with refraction; and alternative algorithms and strategies that can be used to improve the calibration‐reconstruction accuracy. Although it is impossible to remove the refraction error completely in conventional camera calibration‐reconstruction methods, it is possible to improve the accuracy to some extent by manipulating experimental conditions or calibration frame characteristics. Alternative algorithms, such as the localized DLT and the double‐plane method are also available for error reduction. The ultimate solution for the refraction problem is to develop underwater camera calibration and reconstruction algorithms that have the capability to correct refraction. 相似文献
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Communication patterns in computer mediated versus face-to-face group problem solving 总被引：3，自引：0，他引：3
David H. Jonassen Hyug Kwon II 《Educational technology research and development : ETR & D》2001,49(1):35-51
Research has shown that when group problem solving is computer mediated, communications become more task oriented with clearer
role expectations, while face-to-face communications are more cohesive and personal. None of this research has examined those
patterns of interactions in terms of the problem solving activities engaged. In this study, we compared the perceptions of
participants, the nature of the comments made, and the patterns of communication in face-to-face and computer-mediated groups
in terms of problem-solving activities while solving well-structured and ill-structured problems. The quantity of messages
in the computer conference was smaller but more task related than in the face-to-face conversations because participants reflected
more on ideas and perspectives in reaching their decisions. A cluster analysis of communication patterns showed that computer-mediated
group decisions more closely resembled the general problem-solving process of problem definition, orientation, and solution
development as group interaction progressed, while the face-to-face group interactions tended to follow a linear sequence
of interactions. Participants who solved problems through computer conferencing were more satisfied with the process and believed
that there was a greater quality in the problem-solving process. 相似文献
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Malek-Lasater Adrien D. Kwon Kyong-Ah Horm Diane M. Sisson Susan B. Dev Dipti A. Castle Sherri L. 《Early Childhood Education Journal》2022,50(2):207-219
Early Childhood Education Journal - The purpose of this study was to examine the frequency of and relationship between responsive feeding practices used during early childhood education (ECE)... 相似文献
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Lim Chaehyun Kwon Kyong-Ah Bingham Gary Eldon 《Early Childhood Education Journal》2022,50(7):1157-1167
Early Childhood Education Journal - Preschool children’s relationships with their teachers play an important role in their learning and development. Despite this importance, extant research... 相似文献
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Infants' visual short‐term memory (VSTM) for simple objects undergoes dramatic development: Six‐month‐old infants can store in VSTM information about only a simple object presented in isolation, whereas 8‐month‐old infants can store information about simple objects presented in multiple‐item arrays. This study extended this work to examine the development of infants' VSTM for complex objects during this same period (N = 105). Using the simultaneous streams change detection paradigm, Experiment 1 confirmed the previous developmental trajectory between 6 and 8 months. Experiment 2 showed that doubling the exposure time did not enhance 6‐month‐old infants' change detection, demonstrating that the developmental change is not due to encoding speed. Thus, VSTM for simple and complex objects appears to follow the same developmental trajectory. 相似文献
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Kyungbin Kwon Suhkyung Shin Su Jin Park 《Educational technology research and development : ETR & D》2018,66(6):1479-1503
The current experimental study examined the effects of graphic organizers in a collaborative learning context where students constructed knowledge during online discussions. As the results could vary depending on how students interacted with the graphic organizers, this study compared two different approaches: instructor-provided versus student-generated graphic organizers. Thus, the purpose of this study was to investigate the effects of receiving or generating graphic organizers on students’ engagement in online discussions. Thirty-six graduate students enrolled in an online graduate course participated in the study. While analyzing an instructional design case, students were asked to discuss design issues in a randomly assigned group. There were three conditions: control condition without graphic organizers, instructor-provided, and student-generated graphic organizers. Major findings revealed that both generating and receiving graphic organizers facilitated students’ higher levels of cognitive engagement, and encouraged students to consider alternative views during the discussions. Without the graphic organizer, students tended to simply summarize previous messages or raise new issues rather than elaborating on previous topics. There was a significant finding regarding the ways of interacting graphic organizers. Students discussed more topics when they were given instructor’s graphic organizers rather than when they were asked to generate them. 相似文献
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