• 한국과학교육학회지
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• 제25권6호
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• pp.671-677
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• 2005

Line graphs are powerful tools in conveying complicated relationships and ideas because line graphs show the relationship that exists between two continuous variables. Also, line graphs can show readers the variations in variables and correlate two variables in a two dimensional space. For these reasons, line graphs have a significant role in physics, especially kinematics. To what extent are Korean college and secondary students able to understand kinematics graphs? Is there a difference between American students and Korean students in interpreting kinematics graphs? The TUG-K instrument (Test of Understanding Graphs in Kinematics) was administered to students in both countries. The results show the difference between American students and Korean students by TUG-K objective. Also, the results are discussed in terms of a graph comprehension theory.

• 한국과학교육학회지
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• 제26권1호
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• pp.49-57
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• 2006

그래프는 물리학자들이나 물리교육자들에게는 좋은 의사소통 도구가 되며, 실험세계를 그래프로 보여줄수 있는 정보전달의 기능을 수행하는 것으로 여겨졌다. 따라서 그래프를 작성하고 해석할 줄 아는 능력은 매우 중요하다. 본 연구에서는 운동학 그래프 해석 능력 검사 도구를 이용하여 우리나라 광역시 180명 대학생들의 운동학 그래프 이해 능력을 조사하였다. 우리나라 대학생들은 위치-시간 그래프에서 속도를 결정하거나, 속도-시간 그래프에서 가속도나 변위를 결정하는 기능에서 높은 정답률을 보였으며, 위치-시간 그래프를 속도-시간 그래프로 변환하거나 가속도-시간 그래프로 변환하는 기능에서 가장 낮은 정답률을 보였다. 또한 그래프와 관련된 지문을 연결하는 기능도 다른 기능들에 비하여 비교적 낮은 정답률을 보였다.

• 한국과학교육학회지
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• 제17권4호
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• pp.383-393
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• 1997

In order to study the effect of student's conceptions about force and motion into the graph construction in kinematics in college physics course, the tasks of constructing the qualitative graph in the similar problem context used in force conception was asked to the first 74 and third 97 student teacher in teachers' university. The frequencies analysis showed that student teachers had the naive conceptions that the throwing force was still acted to a upwarding ball. They also had the popular Aristotelian views about motion. These naive conceptions coexisted with the scientific conception about gravitational force. In a simple pendulum problem no one had the correct acceleration concepts which varies the direction in swing. This result suggest that student teacher had more difficulties in a acceleration problem than in a velocity problem In v-t and a-t graph construction tasks, the number of categories of a-t graphs were more than that of v-t graphs. There were many graph errors in a sign of velocity and acceleration. The acceleration conceptions without the relations of changes in velocity made the kinematics graphs more various shapes. The force and motion conceptions influenced the ability to construct the kinematics graphs.

• Steel and Composite Structures
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• 제26권4호
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• pp.473-484
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• 2018

Free vibration of cross-ply laminated plates using a higher-order shear deformation theory is studied. The arbitrary number of layers is oriented in symmetric and anti-symmetric manners. The plate kinematics are based on higher-order shear deformation theory (HSDT) and the vibrational behaviour of multi-layered plates are analysed under simply supported boundary conditions. The differential equations are obtained in terms of displacement and rotational functions by substituting the stress-strain relations and strain-displacement relations in the governing equations and separable method is adopted for these functions to get a set of ordinary differential equations in term of single variable, which are coupled. These displacement and rotational functions are approximated using cubic and quantic splines which results in to the system of algebraic equations with unknown spline coefficients. Incurring the boundary conditions with the algebraic equations, a generalized eigen value problem is obtained. This eigen value problem is solved numerically to find the eigen frequency parameter and associated eigenvectors which are the spline coefficients.The material properties of Kevlar-49/epoxy, Graphite/Epoxy and E-glass epoxy are used to show the parametric effects of the plates aspect ratio, side-to-thickness ratio, stacking sequence, number of lamina and ply orientations on the frequency parameter of the plate. The current results are verified with those results obtained in the previous work and the new results are presented in tables and graphs.