• 아동학회지
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• 제30권2호
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• pp.43-55
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• 2009

This study investigated trajectories of change in the career maturity of elementary school students and of attachment to parents and academic achievement as predictors of change. The 2844 participants were 1524 boys and 1320 girls in the Korea Youth Panel Survey. They were fourth graders in 2004 and became seventh graders in 2007. Latent growth curve modeling indicated that : (1) Trajectories of change in career maturity from fourth grade to seventh grade modeled quadratic growth. (2) Variance of career maturity in initial levels, linear slope and quadratic slope indicated individual differences intrajectories of change in career maturity. (3) Attachment to parents influenced initial levels of career maturity academic achievement influenced both initial levels and linear slope of career maturity.

• 한국과학교육학회지
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• 제24권1호
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• pp.1-16
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• 2004

The purpose of this study was to examine the role of cognitive conflict in the conceptual change process. Ninety-seven high school students in Korea participated in this study. Before instruction, we conducted pretests to measure learning motivation and learning strategies. During instruction, we tested the students' preconceptions about Newton's 3rd Law and presented demonstrations. After this, we tested the students' cognitive conflict levels and provided students learning sessions in which we explained the results of the demonstrations. After these learning sessions, we tested the students' state learning motivation and state learning strategy. Posttests and delayed posttests were conducted with individual interviews. The result shows that cognitive conflict has direct/indirect effects on the conceptual change process. However, the effects of cognitive conflict are mediated by other variables in class, such as state learning motivation and state learning strategy. In addition, we found that there was an optimal level of cognitive conflict in the conceptual change process. We discuss the complex role of cognitive conflict in conceptual change, and the educational implications of these findings.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2000년도 추계정기학술대회:지능형기술과 CRM
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• pp.417-426
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• 2000

This study suggests integrated neural network models for Interest rate forecasting using change-point detection, classifiers, and classification functions based on structural change. The proposed model is composed of three phases with tee-staged learning. The first phase is to detect successive and appropriate structural changes in interest rare dataset. The second phase is to forecast change-point group with classifiers (discriminant analysis, logistic regression, and backpropagation neural networks) and their. combined classification functions. The fecal phase is to forecast the interest rate with backpropagation neural networks. We propose some classification functions to overcome the problems of two-staged learning that cannot measure the performance of the first learning. Subsequently, we compare the structured models with a neural network model alone and, in addition, determine which of classifiers and classification functions can perform better. This article then examines the predictability of the proposed classification functions for interest rate forecasting using structural change.

• 대한화학회지
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• 제65권2호
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• pp.145-150
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• 2021

The present study describes a hands-on experiment to help students understand the concept of phase change or phase transition and its application in a phase change material (PCM). PCMs are substances that have the capability of storing and releasing large amounts of thermal energy. They act as energy storage materials that provide an effective way to save energy by reducing the electricity required for heating and cooling. Lauric acid (LA) was selected as an example of the PCM. Students investigated the temperature change of LA and the temperature (of air) inside the test tube. The differences in the temperatures of the systems helped students understand how PCMs work. A one-group pretest and posttest design was implemented with 34 grade-11 students in science and mathematics. Students' understanding was assessed using a multiple-choice test and a questionnaire. The findings revealed that the designed activity helped students understand the concept of phase change and its application to materials for thermal energy storage.

• Journal of Information Processing Systems
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• 제18권4호
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• pp.587-598
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• 2022

To increase building change recognition accuracy, we present a deep learning-based building change detection using remote sensing images. In the proposed approach, by merging pixel-level and object-level information of multitemporal remote sensing images, we create the difference image (DI), and the frequency-domain significance technique is used to generate the DI saliency map. The fuzzy C-means clustering technique pre-classifies the coarse change detection map by defining the DI saliency map threshold. We then extract the neighborhood features of the unchanged pixels and the changed (buildings) from pixel-level and object-level feature images, which are then used as valid deep neural network (DNN) training samples. The trained DNNs are then utilized to identify changes in DI. The suggested strategy was evaluated and compared to current detection methods using two datasets. The results suggest that our proposed technique can detect more building change information and improve change detection accuracy.

• 대한기계학회논문집A
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• 제26권3호
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• pp.528-536
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• 2002

As one step for the safety performance of LNG storage tank, the change in fracture toughness within the X-grooved weld heat-affected zone (HAZ) of newly developed 9% Ni steel, which was submerged arc (SA)-welded, was investigated. Both crack initiation fracture toughness and crack arrest fracture toughness were evaluated by the crack tip opening displacement (CTOD) tests and compact crack arrest (CCA) tests. As the evaluated region approached the fusion line, each test result shorted different tendency, that is, crack initiation toughness decreased while crack arrest toughness increased. The results were discussed through the observation of the microstructural change.

• 한국기후변화학회지
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• 제2권4호
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• pp.221-235
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• 2011

이 논문에서는 우리나라의 기후변화를 연구한 기존 논문 결과를 정리했다. 필요한 경우, 주변 국가 및 전지구 기후변화를 연구한 논문도 참고했다. 현재까지 축적된 우리나라 기상관측 자료를 분석한 연구를 종합해 보면, 지난 100년간 한반도에 나타난 기온상승은 자연적 변화 범위를 넘어선 것으로 판단된다. 특히, 전구 평균 해수면 온도상승보다 큰 한반도 주변 해역의 온도상승과 연관되어 우리나라 강수량이 많아졌고, 접근하는 태풍 활동도 강해졌다. 이들 기상 요소뿐 아니라 대규모 대기순환장의 변화가 한반도와 주변지역의 기후에 영향을 끼쳐서 여름 몬순인 장마와 겨울 몬순인 한파의 시공간적 특성에 변화를 가져왔다. 이 연구에서는 짧은 준비기간과 지면의 한계, 그리고 저자들의 한정된 지식으로 인하여 관련된 모든 연구를 정리하지 못했지만, 향후 연구자들이 우리나라와 주변지역 기후변화 연구를 하는 데 있어서 도움을 줄 것으로 기대한다.

• 한국보육지원학회지
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• 제12권5호
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• pp.137-155
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• 2016

The purpose of the present study was to investigate the longitudinal relationship between main caregivers' life satisfaction and depression and self-esteem of school-aged children, and to provide plans for improving the lives of the school-aged children. For this purpose, we analyzed the three years'longitudinal panel data (2011-2013) of the Korean Children and Youth Panel Survey (KCYPS) including 2,342 first grade elementary school children employing the latent growth model using SPSS 18.0 and AMOS 22.0. Analysis results were as follows. First, main caregivers'life satisfaction and school-aged children's depression increased as time passes and linear change model was selected. Second, the initial status of main caregivers'life satisfaction had effects on the initial status of their children's depression, but initial status and rates of change of life satisfaction did not have an influence on the rates of change of the depression. However, it was found that the main caregivers' life satisfaction had effects on the school-aged children's self-esteem and it worked as a mediator on the longitudinal relationship between the main caregivers'life satisfaction and the children's depression. School-aged children's self-esteem was a partial mediator on the initial status of their depression and full mediator on these rates of change. These findings suggests that programs improving school-aged children's self-esteem should be developed.

• 한국학교수학회논문집
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• 제22권3호
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• pp.221-240
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• 2019

연구의 목적은 수학 학습부진학생의 수업 결손을 보충하고 학생에게 성공 경험을 제공하기 위한 하나의 방안으로 상호 또래교수 전략을 제안하는 것이다. 이를 위하여 수학 학습부진학생을 수학 성취도가 중학교 단계까지 학교에서 중 수준 이상이고 고등학교에 진학하여 상대적으로 낮아진 학생으로 정의하고, 수학 학습부진학생 4명을 대상으로 상호 또래교수 활동 과정에서 나타나는 정의적 영역의 변화에 초점을 맞추어 상호 또래교수 활동의 장점 및 역할을 살펴보았다. 상호 또래교수 활동은 사전 검사와 사후 검사 및 사전 훈련을 포함하여 약 3개월에 걸쳐 진행되었다. 연구 결과, 상호 또래교수 활동은 전반적으로 수학 학습부진학생의 정의적 영역에 긍정적인 변화를 가져왔다. 연구에 참여한 4명의 학생이 모두 동일한 양상의 변화를 보이지 않고 학생별로 긍정적인 변화의 하위 요소가 다르게 나타났지만, 상호 또래교수 활동은 모든 학생에게 긍정적인 변화를 경험하는 기회를 제공하였다.

• 한국식생활문화학회지
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• 제24권2호
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• pp.146-154
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• 2009

This study was conducted to investigate the vegetable eating behaviors and preferences of elementary school students by stage of change for vegetable intake. The subjects consisted of 191 fourth and fifth grade elementary school students from Gyeonggi province. The stage of change for vegetable intake was categorized into three groups: precontemplation (PC, 18.4%), preparation (P, 43.5%), and action/maintenance (A&M, 48.2%). The trend to eat a variety of foods was more distinctive as the students went from the PC to the A&M stage. The stage of change for vegetable intake was closely related with the kimchi-eating pattern of the students. The A&M group ate more vegetables than the PC group because they liked vegetables and/or wanted to prevent disease. The PC group had a lower tendency to follow recommendations for vegetable eating than the P and A&M groups. The PC group also had an incorrect notion that low vegetable consumption over an extended time would not have a big impact on their health. The vegetables of high preference for the elementary school students were potato, sweet potato, lettuce, radish, perilla leaf, cucumber, and cabbage. The vegetables of low preference were spinach, onion, balloon flower, and green pepper. The PC group had lower preferences for most vegetables than the P and A&M groups. Therefore, careful nutrition education is necessary especially for students in the PC group in order to explain the positive effects of vegetable intake and negative effects of an unbalanced diet. It is also necessary to survey students' tastes consistently and to develop recipes that encourage them to consume more vegetables agreeably.