• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.181-194
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• 2013

Landslides are known as gravitational mass movements that can carry the flow materials ranging in size from clay to boulders. The various types of landslides are differentiated by rate and depositional features. Indeed, flow characteristics are observed from very slow-moving landslides (e.g., mud slide and mud flow) to very fast-moving landslides (e.g., debris avalanches and debris flows). From a geomechanical point of view, shear-rate-dependent shear strength should be examined in landslides. This paper presents the design of advanced ring-shear apparatus to measure the undrained shear strength of debris flow materials in Korea. As updated from conventional ring-shear apparatus, this apparatus can evaluate the shear strength under different conditions of saturation, drainage and consolidation. We also briefly discussed on the ring shear apparatus for enforcing sealing and rotation control. For the materials with sands and gravels, an undrained ring-shear test was carried out simulating the undrained loading process that takes place in the pre-existing slip surface. We have observed typical evolution of shear strength that found in the literature. This paper presents the research background and expected results from the ring-shear apparatus. At high shear speed, a temporary liquefaction and grain-crushing occurred in the sliding zone may take an important role in the long-runout landslide motion. Strength in rheology can be also determined in post-failure dynamics using ring-shear apparatus and be utilized in debris flow mobility.

• Journal of Gifted/Talented Education
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• v.22 no.4
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• pp.967-983
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• 2012

The purpose of this study was to find the effects of the science camp program on Science Process Skills and Scientific Attitudes for the Scientific Gifted Students. For this purpose, this research developed the science camp program. This program was totally consisted 30 lessens. there was 2 part in this program. It contained Astronomic Space Science(14 class), Aerospace Science(16 class). To find the effects of the science camp program on Science Process Skills and Scientific Attitudes for the Scientific Gifted Students. 20 participants was selected. these students were attended at a scientific gifted class(5th grade) of an elementary school located in Ulsan. First, Science Process Skills was used to find the effect of the science camp program And the results were analyzed by SPSSWIN 18.0. The results of this study were as follows. the science camp program was a positive effects on Science Process Skills of the Scientific Gifted Students(t=8.649, p=.000). Second, the science camp program was a positive effects on Scientific Attitudes of the Scientific Gifted Students(t=3.431, p=.003). According to this research, the science camp program on Science Process Skills and Scientific Attitudes for the Scientific Gifted Students. It will be contribute on the curriculum construction of the gifted school or gifted class.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.44-44
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• 2015

저수지나 하천 사면에서 발생하는 산사태와 토석류는 저수지와 하천 수체에 충격을 가한다. 이로 인해 발생하는 수면 충격파는 전파되어 반대편 제방으로 파의 처오름 또는 댐 제체위로의 물넘이로 큰 피해를 줄 수 있다. 최근 외국에서는 2차원 충격파 생성 및 전파의 기본 과정을 구명하기 위한 실험적 연구가 이뤄지고 있으며, 이들 연구들은 충격파의 발생과 전파, 사면활동 물질과 수체의 상호작용 그리고 자유 수면과 유속분표의 발달에 대한 자세한 관측 자료를 제시하고 있다. 아울러 충격파에 영향을 주는 지배 매개변수를 제시하고 있다. 하지만, 이러한 실험적 연구의 최근 진보에도 불구하고, 이들 지배 매개변수를 고려한 충격파 지배공식들은 대상 지역의 복잡한 바닥 지형이나, 평면적 지형 변화를 단순한 추정치로만 고려하게 된다. 따라서 복잡한 지형조건에서 토석류와 수체의 상호작용과 수면 충격파의 전파를 합리적으로 해석하는 데는 한계가 있다. 이 경우 수치모델링 기법을 대안으로 적용할 수 있으나, 수치모델링은 수면에서 충격파의 전파와 수중에서 토석류의 전파를 동시에 모의해야 하고, 뉴턴 유체와 비뉴턴 유체의 특성을 동시에 고려해야하므로 수치해석 연구자들에게는 하나의 큰 도전사항이다. 이 연구는 경계면 포착기법을 이용한 계산유체동력학 기법을 이용하여 사면활동과 이로 인한 정지 수역에서의 충격파의 발생 및 전파를 재현하기 위한 수치 모델링 기법을 개발하는 것이 목적이다. 사면활동과 수면의 경계면을 포착하고 위치를 정립하기 위해서 VOF (volume of fluid) 경계면 재구축 기법을 이용한다. 지배 방정식은 비압축성(incompressible) 질량 보존방정식과 나비어-스톡스(Navier-Stokes) 방정식이며, 서로 다른 유체의 상(phase)애 대한 체적분할이송방정식을 이용한다. 큰와 모의 계열의 난류 모델링 기법을 적용하여 충격파의 전파와 붕괴에 대한 난류의 영향을 고려하였다. 토석류는 비뉴턴 흐름저항 관계식을 적용하여 그 흐름특성을 재현하였다. 이들 지배방정식은 2차 정확도의 유한체적법(finite volume method)을 이용하여 해석한다. 외국의 연구자들이 관측하여 제시한 길이 11 m 그리고 폭 0.5 m의 수로에서 발생한 충격파를 수치적으로 재현하여 개발된 모형의 실제 문제에 대한 적용성을 보여준다.

• The Journal of the Korea Contents Association
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• v.18 no.9
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• pp.555-568
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• 2018

This study has expanded the existing studies on the characteristics of consumers using the personal level of cultural dimensions and self-construal. As Korean are becoming more individualistic and independent, we have focused on consumer independence in self-construal. The purpose of this study was to investigate the effects of consumer independence on consumers' attitudes and purchase intention toward consensus claim in ads. We hypothesized that individuals with higher in independence are more likely to show negative attitudes and the purchase intention towards the ads focused on consensus claim. Two experiments revealed that consumers higher in independence, depicting consensus claim in ads reduces consumers' attitudes and purchase intention. Based on the results, we suggest that for individuals higher in independence, consensus claims in product advertisement are less effective advertising strategy which ultimately lower consumers' purchase intentions. Important theoretical and practical implications are discussed.

• Journal of The Korean Association of Information Education
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• v.19 no.1
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• pp.57-68
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• 2015

Since the entering SW-centered society in which people make the best use of SW in order to express their own personal ideas or to solve problems, the significance of SW education has been emphasized. It is generally known that storytelling provides motivational and contextual environments. This study conducted an experimental research to find out how Aesop's fables-applied SW educational program would influence computational thinking. Of these students who had participated in an SW educational camp on every Saturday for a total of 6 weeks, the experimental group learned on basic concepts of Scratch programming as working on Aesop's fables and they were led to diverse SW activities such as stories, games, simulations arts, and others. After that, the study carried out a comparison research in relation to the groups' SW concepts, SW implementation and attitudes toward SW education. The result shows that the experimental group came up with higher levels of SW concepts, implementation and positive attitude toward SW education.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.101.1-101.1
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• 2013

심화 지구과학 교과서는 과학 계열 고등학교 학생들을 대상으로 지구과학 심화 내용에 대한 다양한 탐구 활동을 통하여 개념과 원리, 탐구 기능 창의적 문제 해결력 그리고 과학적 태도를 함양함과 동시에 대학에서 학문을 연구하는데 필요한 기본적인 능력을 기르는데 필요한 지식 및 탐구 방법을 습득할 수 있도록 실험서 형태로 내용을 구성하였다. 총 5개 대단원 중 우주 속의 지구에는 푸코진자, 시간과 역, 태양계, 달을 대상으로 한 직접 실험과 CLEA와 실제 관측 자료를 활용한 별의 일생, 성단과 변광성, 외부 은하, 그리고 허블의 법칙을 실험실에서 실습해볼 수 있도록 안내하고 있다. 2011년 8월 초판 발간으로 지금까지 20개 과학 고등학교에서 채택되어 2614명의 학생이 이용하였고, 현재 활용 실태 조사 결과를 바탕으로 수정작업이 이루어지고 있다.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.453-465
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• 2014

The purpose of this study was to find out the change in psychological well-being of middle school students by participating in after school physical training activities. To achieve this object, 100 male students of M middle school in K city. "Teenagers' psychological well-being measurement tool" developed by Chung-hee Park(2007). Twice a week, for twelve weeks, the experimental group took part in an after school physical training activity, and the control group, in non-physical classes. The conclusion reached based on the result of this study are as follows. First, there was a statistically significant difference in the change of the family relations factor. Second, there was no statistically significant difference in the change of the student-teacher relations factor between the group Third, there was a statistically significant difference in the change of the self-awareness factor between the group. Fourth, there was no statistically significant difference in the change of the self assertiveness factor between the group. Fifth, there was a statistically significant difference in the change of the friendship factor between the group. Sixth, there was no statistically significant difference in the change of the self-initiative studying factor between the group. In conclusion, taking part in an after school physical training activity on a regular basis can increase the feeling of care and love from family relations, give positive self awareness and attitude towards life, and help building mutual trust between friends by having close relationship.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.264-275
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• 2017

Objective: This study examines the effects of children's art activities through forest experience in relation with Nuri curriculum on environmental sensitivity. Method: A survey was administered to an experimental group of 20 children as well as a control group of 20 children for statistical analysis. after 16-class art activities through forest experience were performed to children aged 4 at a daycare center for 50 days. Result: Children's art activities through forest experience in relation with Nuri curriculum had a positive effect on their environmental sensitivity. In particular, their art activities had a positive effect on their self-awareness, self-regulation, empathy and motivation in the experimental group, supporting the educational effects and benefits of developmental children's art activities through forest experience in relation with Nuri curriculum. In other words, art activities through forest experience are useful in terms of providing children with creative expression activities in art by leading to observation and exploration, as well as educational experiences that have positive attitudes toward the environment. Conclusion: As children's art activities through forest experience have a positive effect on their environmental sensitivity, more useful information on teaching-learning methods will be able to be provided to early childhood teachers in the field. Consequently, children's art activities through forest experience need to be actively introduced in the field of early childhood education as an alternative for learning nature and improving environment-friendly emotional intelligence.

• Communications of Mathematical Education
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• v.23 no.1
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• pp.85-108
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• 2009

The purposes of the study were to develop instructional materials based on Freudenthal's guided reinvention principle for teaching proofs and to investigate how the teaching method based on guided reinvention principle affects on 8th grade students' ability to write proofs and learning attitude toward proofs. Teaching based on guided reinvention principle placed emphasis on providing students opportunities to make a mathematical statement and prove the statement by themselves throughout various activities such as exploring, conjecturing, and testing the conjectures. The study found that students who studied proving with instructional materials developed by guided reinvention principle showed statistically higher mean scores on the posttest than students who studied by a traditional teaching method depending onteacher's explanation. Especially, on the posttest item which requested to prove a whole statement without presenting a picture corresponding to the statement, a big difference among students' responses was found. Many more students in the traditional group did not provide any response on the item. According to the results of the questionnaire regarding students' learning attitudes, the group who studied proving by guided reinvention principle indicated relatively more positive attitudes toward learning proofs than the counterparts.

• Journal of The Korean Association of Information Education
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• v.13 no.4
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• pp.509-516
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• 2009

As the necessity of cyber education is being raised up recently, Cyber Home Learning System(CHLS) is increasingly adopted at all school levels ranging from elementary to high schools. The purposes of this study are to find out that how elementary social studies of CHLS influence on the academic performance and learning attitude of students and their satisfaction. Based on these suggestions on social studies of CHLS are proposed. To accomplish the purposes, comparisons were made between experimental group utilizing social studies of CHLS and control group of traditional class of 54 students(27 students each in experimental and control group) in 5th grade. The results are as follows. Utilizations in social studies of CHLS showed positive effects on academic performance and learning attitude, and students' satisfaction on social studies of CHLS were rather increased. Based on these findings, several suggestions are made. First, strategy to improve motivation and confidence for students to participate on social studies of CHLS are necessary. Second, thinking and problem-solving activities needs to be integrated to social studies of CHLS. Third, for meaningful social studies, environment that can improve communication and thinking ability through interaction needs to be facilitated. Fourth, supporting plan is advised for teachers carrying on the role of manager and facilitator.