• 한국수학교육학회지시리즈A:수학교육
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• 제56권3호
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• pp.235-255
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• 2017

This study compared and contrasted the topics related to congruence and symmetry in the elementary mathematics textbooks series of Korea, Japan, Hong Kong, Finland, and Singapore in three aspects: (a) when to teach, (b) what to teach, and (c) how to teach. Firstly, the results of when to teach showed differences across the countries with a variation of teaching the topics among grades from 3 to 6. Secondly, the results of what to teach revealed subtle but significant differences. Regarding congruence, Korea and Japan deal with congruence in a systematic manner, while Finland tends to address the brief definition of congruence, and Hong Kong and Singapore focus on teaching tessellation which implies congruence. Regarding symmetry, Korea and Japan deal only with a symmetric figure for a line and that for a point, while Hong Kong includes a rotational symmetry and Finland extends further to cover the figures positioned in a symmetry both for a line and for a point. Lastly, the results of how to teach demonstrated that Korea tends to focus on the procedure of drawing both triangles to be congruent and symmetric figures. This implies that we need to consider alternative methods such as using various instructional materials and making an explicit connection among mathematical concepts in teaching congruence and symmetry.

• 대한수학회논문집
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• 제34권1호
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• pp.333-349
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• 2019

The paper study the curvature theory of a line-trajectory of constant Disteli-axis, according to the invariants of the axodes of moving body in spatial motion. A necessary and sufficient condition for a line-trajectory to be a constant Disteli-axis is derived. From which new proofs of the Disteli's formulae and concise explicit expressions of the inflection line congruence are directly obtained. The obtained explicit equations degenerate into a quadratic form, which can easily give a clear insight into the geometric properties of a line-trajectory of constant Disteli-axis with the theory of line congruence. The degenerated cases of the Burmester lines are discussed according to dual points having specific trajectories.

• 복식문화연구
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• 제19권3호
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• pp.622-636
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• 2011

The purpose of this study was to assess the effects of self-image congruence on attitudes toward purchase intentions of children's clothing via the Behavioral Intention Model. The empirical study was conducted via on-line survey and data were collected from mothers with children aged 6 to 10 years. A total of 593 respondents answered the questionnaire and 574 usable data were statistically analyzed. SPSS 18.0 was used to conduct descriptive statistical analysis, factor analysis, reliability analysis, cluster analysis, Chi-square test, ANOVA, and multiple regressions. A K-means cluster analysis was conducted based on three dimensions brand images of children's wear. Respondents were divided into four groups: elegant image group, multiple image group, ordinary image group, and childlike image group. Characteristics of consumers and clothing evaluative criteria that mothers considered important differed significantly across groups. Moreover, based on these groups, each dimension of self-congruence had different effects on brand attitude. Brand attitude and subjective norms had different effects on purchase intentions. In conclusion, levels of self-congruence and factors influencing purchase intention varied according to brand images of children's wear.

• 한국수학교육학회지시리즈A:수학교육
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• 제46권3호
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• pp.273-292
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• 2007

The purpose of this study was to find out how second, fourth and sixth graders understood the main contents related to spatial sense in the Seventh National Mathematics Curriculum. For this purpose, this study examined students' understanding of the main contents of congruence transformation (slide, flip, turn), mirror symmetry, cubes, congruence and symmetry. An investigation was conducted and the subjects included 483 students. The main results are as follows. First, with regards to congruence transformation, whereas students had high percentages of correct answers on questions concerning slide, they had lower percentages on questions concerning turn. Percentages of correct answers on flip questions had significant differences among the three grades. In addition, most students experienced difficulties in describing the changes of shapes. Second, students understood the fact that the right and the left of an image in a mirror are exchanged, but they had poor overall understanding of mirror symmetry. The more complicated the cubes, the lower percentages of correct answers. Third, students had a good understanding of congruences, but they had difficulties in finding out congruent figures. Lastly, they had a poor understanding of symmetry and, in particular, didn't distinguish a symmetric figure of a line from a symmetric figure of a point.

• Structural Engineering and Mechanics
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• 제17권6호
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• pp.829-862
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• 2004

This paper presents a method for the nonlinear analysis of beam elements subjected to the cyclical combined actions of torsion, biaxial flexure and axial forces based on an extension of the disturbed compression field (DSFM). The theoretical model is based on a hybrid formulation between the full rotation of the cracks model and the fixed direction of the cracking model. The described formulation, which treats cracked concrete as an orthotropic material, includes a new approach for the evaluation of the re-orientation of both the compression field and the deformation field by removing the restriction of their coincidence. A new equation of congruence permits evaluating the deformation of the middle line. The problem consists in the solution of coupled nonlinear simultaneous equations expressing equilibrium, congruence and the constitutive laws. The proposed method makes it possible to determine the deformations of the beam element according to the external stresses applied.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제38권2호
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• pp.215-230
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• 2024

합동과 대칭은 일상생활에서 접할 수 있는 친숙한 개념으로, 이러한 개념을 효과적으로 이해하고 습득하기 위하여 적절한 시각적 예시의 역할이 중요하다. 본 연구에서는 초등 수학 교과서에서 합동과 대칭 개념을 학습하는 과정에서 제시되는 시각적 예시를 살펴보았으며 오목다각형의 활용에 초점을 맞추어 분석하였다. 분석 결과, 교과서에서 다양한 형태의 다각형이 합동과 대칭의 교수학습을 위한 시각적 예시로 활용되고 있었고 합동, 선대칭도형, 점대칭도형의 순서로 오목다각형의 활용 빈도가 높게 나타났다. 또한, 개념의 도입보다 성질 탐구에서 오목다각형이 더 자주 활용되는 것을 확인하였다. 이러한 분석 결과를 바탕으로 합동과 대칭의 교수학적 시사점을 모색하였다.

• 한국의학물리학회지:의학물리
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• 제9권2호
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• pp.105-113
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• 1998

고에너지 광자선을 발생시키는 의료용선형가속기의 선질은 경우에 따라 변이를 가져오게 된다. 이러한 변이를 정확하게 판정하여 줄 수 있는 방사선측정법의 활용은 매우 중요하다. 보편적으로 광자선의 측정에 있어서 전리함의 사용이 아주 빈번하였으나 전자포탈영상장치(EPID)의 등장은 새로운 방사선측정법에 대한 가능성의 시작을 예견해준다. 실험은 6MV 광자선의 대칭성, Light/Radiation congruence, 그리고 Wedge filter를 통한 간편한 에너지의 변화에측과 위치의 정확도에 대하여 측정을 시행하였다. 사실 방사선측정의 대표적인 방법은 물팬톰-전리함응 이용한 모델인데 본 실험에서는 영상의 화소가 지니는 디지탈 값을 적절한 소프트웨어로 읽어내어서 데이터를 환산하여 결과를 얻었다. 선행실험에서 얻은 상대선량률을 적용하여 대칭성에서는 조사야영역이 l0$\times$10$cm^2$ 일 때 횡축과 종축에서 1.2%, 1.2%로 비교적 오차가 적었다. 그리고 Light/Radiation field congruence 여부는 횡축이 0.3%, 그리고 종축이 0.2%로서 예상한 기대값에 접근하였다. 다음으로 wedge filter를 활용한 에너지의 변이와 위치의 정확도에 대한 움직임을 알 수 있었다.

• 의정연구
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• 제23권2호
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• pp.67-108
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• 2017

대의 민주주의에 있어 대표자가 얼마나 시민의 이념적 선호를 대변하는지는 매우 중요한 문제이다. 의회 혹은 정부와 시민 간의 이념적 일치는 주로 정당정치가 오래된 서구 민주주의 국가를 중심으로 연구되어 왔으나, 민주주의의 역사가 비교적 짧은 우리나라에서는 아직 많은 연구가 이루어지지 못했다. 본 논문은 2002년부터 2016년까지의 설문자료를 바탕으로 한국 정치공간의 시민과 대표 간 이념적 일치를 다양한 방식으로 개념화하고 측정하였다. 먼저 좌-우의 단차원적 공간으로 분석한 결과, 시민과 국회 간의 이념적 거리와 달리 시민과 정부 간의 거리는 2000년대 이후 꾸준히 증가하고 있는 것으로 나타났다. 이러한 여야 간 양극화와 정부의 대표성 악화는 민주주의의 규범적 측면에서 부정적이라 할 수 있다. 하지만 다차원적 공간에서 정부와 시민 간의 이념적 거리는 쟁점에 따라 다르게 나타났는데, 대북지원에서는 2008년 보수정권이 들어선 이후 점차 증가한 반면, 복지정책의 경우는 이전의 진보 정권에 비해 악화된 것으로 조사되었다. 이렇게 쟁점별로 이념적 일치가 다르게 나타난다는 점은 시민과 정당 모두에게 많은 점을 시사한다. 시민들에게는 단차원적 이념을 넘어 자신에게 가장 중요한 쟁점을 대변하는 대표자를 구별하는 능력이, 정당에게는 기존의 지지층과 함께 늘어나는 무당층을 대변하기 위해 효과적인 당 조직의 정비와 프로그램 마련이 요구되고 있는 것이다.

• 호남수학학술지
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• 제36권4호
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• pp.739-753
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• 2014

In this study, it is aimed to analyze how relationship among Blaschke vectors that the obtained formulae in [2, 3] change if parameter ruled surfaces of the spacelike line congruence are not choosed as principle ruled surfaces. Moreover, using the relation among Blaschke vectors, we obtain Manheim's and Liouville's formulae. This new method can be applied to congruences. Thus, we can obtain new formulae in lines space.

• Human Ecology Research
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• 제56권1호
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• pp.15-32
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• 2018

This study analyzes difference in consumers' and front-line workers' perceptions on 'consumer complaint behavior with hateful intentions' though the Co-orientation Model in three dimensions. In addition, we seek to contribute to reducing the conflict between consumers and front-line workers in the service contact point by finding factors that affect the difference in perception between two parties. This study findings and implications are as follows. First, Taking a look at the mutual orientation between consumers and front-line workers, mutual perceptions have been found to match in agreement but with a significant difference in perceived agreement (congruence), which indicates that the internal perceptions of both consumers and front-line workers do not match. The findings confirm that consumers and front-line workers have different perspectives on consumer complaint behavior with hateful intentions and therefore raise a need for efforts and institutional devices for improvement. Second, the study has found that consumers' economic responsibility as part of their social responsibilities and front-line workers' perceptions on consumers' civic responsibility affect the perception difference between these two groups and suggest a need for educating consumers about economic responsibility. Meanwhile, unlike consumers, front-line workers view consumers' complaint behavior with hateful intentions from an ethical point of view, raising a need for a transition of perspectives on complaint behavior with hateful intentions.