• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.4
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• pp.407-417
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• 2018

In this study, the antioxidant, cytoprotective and antimicrobial activities of 50% ethanol extract of Polygoni multiflori Radix (PMR) and its ethyl acetate fraction were evaluated to confirm the applicability as a functional ingredient. The activities of the major constituent of PMR were verified and 2, 3, 5, 4′-tetrahydroxystilbene 2-O-${\beta}$-D-glucoside (THSG) was confirmed to be the main component of extract and fraction using HPLC-DAD, LC-EIS-MS analysis. The phenolic and THSG contents of the ethyl acetate fraction were 11.1- and 3.0-folds higher than those of the ethanol extract, respectively. As a result of the DPPH assay and that of luminol dependent chemiluminescence assay in $Fe^{3+}$-EDTA/H2O2 system. the ethylacetate fraction was superior to the ethanol extract in free radical and ROS scavenging activities. Especially, the ethyl acetate fraction and THSG exhibited the similar scavenging activity like L-ascorbic acid in ROS scavenging activity. The ethyl acetate fraction perceived the most potent cytoprotective effect against oxidative damage of erythrocytes induced by photosensitization reaction, followed by the ethanol fraction, THSG and that of (+)-${\alpha}$-tocopherol, which was used as a positive control. Antimicrobial activities were evaluated by disc diffusion and broth microdilution assay against S. aureus, E. coli, P. aeruginosa and C. albicans. In particular, the antibacterial activity of the extract and fraction against S. aureus was superior to that of methyl paraben. Taken together, our results suggest that PMR could be used as a natural ingredient for antioxidant, cytoprotective and antimicrobial activities.

• Journal of Science Education
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• v.38 no.1
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• pp.168-181
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• 2014

The purpose of this study was to monitor evaluation in science education at primary and secondary school in Korea. In order to do this, the survey was administered. The subject was 518 teachers; 292 elementary school teachers, 110 middle school science teachers and 116 general high school science teachers. It was found that the ratio of paper examination increased while that of performance evaluation decreased according to the grade of school. In the science paper examination, the ratio of selection type item was higher than that of supply type item, and the ratio of item belonging to knowledge area was higher than that of item belonging to the inquiry area regardless of the grade of school, teaching career, and teacher's gender. The teachers recognized the necessity of supply type item, but they suffered from the reliability of the result of that item. And it was hard for them to do performance evaluation because it took much time and effort. This study suggested that the high-quality in-service teacher training be provided and laboratory assistants who help the science experiment and grading test papers be employed in order to fulfil the performance evaluation and increase the ratio of supply type item and items belonging to the inquiry area.

• Journal of Science Education
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• v.39 no.2
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• pp.133-150
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• 2015

The purpose of this study was to investigate the suitability of elective of the 2009 revised high school science curriculum. This study surveyed 911 students in 126 high schools by using proportionate stratified sampling. Each participating students carried out the on-line survey comprising 13 items about personal and academic suitability. The result of analyzing the response of the questionnaire were as follows. First, there were deviation of study-load, depth, difficulty, etc. between science elective I and II. Second, even though 'science' subject was developed as a subject for improving scientific literacy, it was found that it was considered difficult next to Physics I. Besides, it showed 'science' subject could not function properly to improve the ability to communicate. According to the results of analyzing the degree of interest in science elective, it can not be determined 'no interest in subject' is from the reason of difficulty or large amount of contents to memorize. The results of this study will be useful to provide suggestions for the improvement of next high school science curriculum and textbooks.

• Korean Journal of Culture and Social Issue
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• v.30 no.2
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• pp.193-220
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• 2024

This study was conducted by applying Selby and Joiner (2009)'s Emotional Cascade Model to the phenomenon of non-suicidal self-injury of adolescents, focusing on the school counselor's counseling experience. To this end, a focus group interview(FGI) was conducted with 56 counselors who had experience in counseling self-injured adolescents, and this study applied Braun and Clake's thematic analysis(2012). As a result, 8 categories and 16 subtopics were derived: 'negative emotional experience', 'maladaptive cognitive emotional dysregulation strategy', 'experience of emotional cascade', 'temporary relief of psychological pain', 'aggravation of the emotional cascade state', 'emotional pain from nonsuicidal self-injury', 'vicious cycle of nonsuicidal self-injury' and 'difficulty in controlling behavior that co-occurs with nonsuicidal self-injury'. These results are significant in expanding the understanding regarding the non-suicidal self-injury of adolescents through the perspective of school counselors who are in a position to consider the various systems surrounding adolescents in an integrated manner. Based on the research results, implications, limitations and future research were discussed.

• Journal of Science Education
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• v.34 no.2
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• pp.268-278
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• 2010

The purpose of this study was to develop the paper model of protein synthesis process in order for students to learn more effectively the protein synthesis, and to examine learning effects of instruction using it in high school biology. For this study, 117 students of 12th grade were sampled from a high school in Daejeon metropolitan city. The students were divided into two groups; the control group(n=58) were taught the protein synthesis by explanation-based traditional teaching method, and the experimental group(=59) were taught them by using protein synthesis model. Instruction using the model of protein synthesis process was more effective in improving the students' academic achievements and motivating interests in their learning than the traditional intruction. The class using the models can be another effective teaching method to teach students abstract and complicated concepts like protein synthesis process.

• Journal of Science Education
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• v.34 no.2
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• pp.260-267
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• 2010

The purpose of this study was to investigate the correlation between high school students' observation ability quotient and changes in their stress hormones while observing fruits. This experimental study was performed with 29 first-year female high school students in a metropolitan city. In order to measure the observation ability quotient, an appropriate scientific observation program was developed. In observation program, the subjects carried out observations in an open and autonomous environment and recorded their observations. Their saliva samples were extracted before and after the task so as to analyze the amount of the secreted hormone. Also, their observation ability was measured using the quotient equation of observation ability. And then, in order to investigate the relationship between the observation ability and the cortisol hormone, a correlation analysis was performed. The main results are as follows: First, the amount of learner's hormone secreted during the experiment decreased in overall after the free observation. And the observation ability quotient turned out to be significantly correlated to the cortisol hormone.

• Korean Educational Research Journal
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• v.40 no.3
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• pp.85-108
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• 2019

This study examined the relationship between homeroom teachers' transformational leadership, high school students' satisfaction in school life, and learning motivation. The researchers selected boys and girls' general high school as the target population and gathered survey data. The number of participants was 606; these were students from first and second grades. Questionnaires on teachers' transformational leadership, students' learning motivation, and satisfaction in school life were measured. T-tests showed the following: As a result of the analysis of the difference of transformational leadership, the average of the teachers with careers spanning over 15 years was statistically significantly higher than those whose career spanned over less than 5 years. The group which perceived the transformational leadership of the homeroom teacher as high showed higher motivation scores than the group with lower perception. The means were statistically significant in all the sub-variables. In school - life satisfaction, the average of the former group which perceived the transformative leadership of the homeroom teacher as high was significantly higher than that of the other group.

• Communications of Mathematical Education
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• v.10
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• pp.325-342
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• 2000

본 연구는 1997년도 한국학술진흥재단 대학부설연구소과제 연구비 지원에 의해 2년간 이루어진 ‘창의성 신장을 위한 수학 영재교육 개선 방안에 관한 연구’의 최종 연구 결과이다. 본 연구에서는 창의성에 관한 이론적 고찰, 창의성 신장을 위한 초 ${\cdot}$ 중 ${\cdot}$ 고등학교 영재학생들을 위한 학습 프로그램, 개발된 학습 프로그램의 현장 적용 결과 등을 포함하고 있으며, 이러한 내용들에 대한 상세한 기술이 제시될 것이다.

• 전기의세계
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• v.39 no.1
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• pp.30-35
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• 1990

우리나라 경우 전원지와 부하지간 거리, 윤송용량, 지형, 지상고등을 고려할 때 2000년에는 현재의 345KV 계통을 격상하여 운전하여야 한다고 생각되며 여기에 대한 결론은 1990년도 상반기 안으로 내리라고 보고 있다. 계통전압이 확정되더라ㄷ도 설계, 건설하는데 상당한 시간이 걸린다. 여기에 현재의 기술로는 어떠한 전압, 어떤 환경이라도 여기에 맞는 설계, 건설이 가능하다. 다만 얼마만큼 경제적이면서 신뢰성있고 국산화하는 것이 문제이므로 여기에 국내 연구소, 학계, 제작사회가 협동으로 연구를 하여야한다. 다행이도 1990년부터 실규모 시험선로 건설에 의한 연구계획이 있으므로 산.학.연이 공동으로 연구할 수 있는 좋은 기회가 되리라고 믿는다.

• 기계와재료
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• v.22 no.1
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• pp.14-21
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• 2010

초미세 레이저 가공기술은 미세화, 대면적화, 고속화의 방향으로 발전되고 있다. 이에 따라 이를 대응한 레이저의 사양도 파장의 단파장화 또는 펄스폭의 극초단화, 펄스 반복률의 고반복률화, 출력의 고출력화가 요구되고 있다. 극초단 펄스레이저는 사용자 편의성, 안정성 측면에서 산업체의 요구에 미흡하다. 이에 따라 산업용 초미세 레이저 가공을 위한 광원으로 고품질, 고출력의 단파장 자외선 레이저 활용에 집중하고 있다. 현재 고품질 자외선 레이지는 DPSSL 형태로 구성되어 출시되고 있고, 거의 대부분 수입에 의존하고 있다. 국내외 자외선 UV 현황을 간단히 기술하고, 광주과기원 고등광기술연구소에서 산업원천기술개발사업의 일환으로 개발중인 복합형 자외선 DPSSL에 대한 개발 계획 레이저 특성과 현재의 개발 진행 상황을 소개한다.