• 동력기계공학회지
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• 제9권1호
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• pp.23-29
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• 2005

Numerical analysis of three-dimensional viscous flow-fields in the turbine rotor passages was carried out to investigate flow physics including the interaction between secondary vortices, tip leakage vortex, and the rotor wake. The blade tip geometry was accurately modeled adopting the embedded H grid system. An explicit four-stage Runge-Kutta scheme was used for the time integration of both the mean flow and turbulence equations. The computational results for the entire turbine rotor flows, particularly the tip clearance flow and the secondary flows, were interpreted and compared with the experimental data from the Penn State turbine stage. The predictions for major features of the flow field have been found to be in good agreement with the experimental data.

• Communications for Statistical Applications and Methods
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• 제26권2호
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• pp.103-129
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• 2019

The main goal of a case-control study is to learn the association between various risk factors and a primary outcome (e.g., disease status). Particularly recently, it is also quite common to perform secondary analyses of the case-control data in order to understand certain associations between the risk factors of the primary outcome. It has been repeatedly documented with case-control data, association studies of the risk factors that ignore the case-control sampling scheme can produce highly biased estimates of the population effects. In this article, we review the issues of the naive secondary analyses that do not account for the biased sampling scheme, and also the various methods that have been proposed to account for the case-control ascertainment. We additionally compare the results of many of the discussed methods in an example examining the association of a particular genetic variant with smoking behavior, where the data were obtained from a lung cancer case-control study.

• Nuclear Engineering and Technology
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• 제35권5호
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• pp.378-386
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• 2003

Recently failures of nuclear fuel rods in Korean nuclear power plants were reported and their failure causes have been investigated by using PIE techniques. Destructive and physico-chemical examinations reveal that the clad hydriding phenomena had caused the rod failures primarily and secondarily in each case. In this study, the basic mechanisms of the primary and the secondary hydriding failures are reviewed, PIE data such as cladding inner and outer surface oxide thickness and the restructuring of the fuel pellets are analyzed, and they are compared with the predicted behaviors by a fuel performance code. In addition, post-defected fuel behaviors are reviewed and qualitatively analyzed. The results strongly support that the hydriding processes, primary and secondary, played critical roles in the respective fuel rods failures and the secondary hydriding failure can take place even in the fuel rod with low linear heat generation rate.

• Human Ecology Research
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• 제60권4호
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• pp.625-643
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• 2022

The purpose of this study was to explore the trends and core keywords of the secondary school home economics teacher selection test using content analysis and text network analysis. The sample comprised texts of the secondary school home economics teacher 1st selection test for the 2017-2022 school years. Determination of frequency of occurrence, generation of word clouds, centrality analysis, and topic modeling were performed using NetMiner 4.4. The key results were as follows. First, content analysis revealed that the number of questions and scores for each subject (field) has remained constant since 2020, unlike before 2020. In terms of subjects, most questions focused on 'theory of home economics education', and among the evaluation content elements, the highest percentage of questions asked was for 'home economics teaching·learning methods and practice'. Second, the network of the secondary school home economics teacher selection test covering the 2017-2022 school years has an extremely weak density. For the 2017-2019 school years, 'learning', 'evaluation', 'instruction', and 'method' appeared as important keywords, and 7 topics were extracted. For the 2020-2022 school years, 'evaluation', 'class', 'learning', 'cycle', and 'model' were influential keywords, and five topics were extracted. This study is meaningful in that it attempted a new research method combining content analysis and text network analysis and prepared basic data for the revision of the evaluation area and evaluation content elements of the secondary school home economics teacher selection test.

• 대한가정학회지
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• 제26권3호
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• pp.109-124
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• 1988

The purpose of the present study was to set up the basic outline to define and to develop "housing education" in the field of home economics education. The main focus included in the present study was to suggest the basic data on the current status of housing education in Korea by examining the content of the textbooks and the secondary data o teacher's educational background. The methods used in the study were the contentanalysis of the elementary school curriculum and the secondary data analysis of the data on teachers and their education. The results of this study ere on follows, 1. The elementary school curriculum defined as the related fields of housing education were classified into 4 domains: housing planning, housing maintenance, housing environment, housing decoration. 2. The subject areas related to housing education was found to be moral education, social education, physical education, art, practical education. The total hours studying on housing education were the average of 1.1 hours per week. 3. Among the above 4 domains, the total hours used for housing decoration amounted to the highest rate through all the subject areas. 4. According to the secondary dta analysis, 49.5% of the teacher were the national teacher's college graduates, but there are no courses on housing education as such in the curriculum of the national teacher's college. it was concluded that more consideration should be given to the teacher training courses.

• Journal of the Korean Data and Information Science Society
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• 제28권6호
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• pp.1539-1545
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• 2017

본 연구는 확률과 통계의 내용을 올바르게 지도할 수 있는 역량을 갖춘 수학 교사를 선발하기 위한 중등학교 수학교과 임용고사문제 중에서 확률과 통계 영역의 출세 경향을 분석하고, 앞으로의 출제 방향과 수준에 대하여 논의하고자 한다. 동시에 학교 수학 교사들에게 확률과 통계 단원을 지도하기 위해서 갖추어야 할 내용에 대한 일반적인 가이드를 제시하고자 한다. 첫째, 2015년 개정 고시된 교육과정의 수학 교과 중에서 확률과 통계 단원의 편제와 내용체계, 주요 변화 내용을 조사한다. 둘째, 중등교원임용시험에 15년간 출제 된 확률과 통계 단원의 문제들을 분석한다. 셋째, 기존의 출세 문제들이 중등학교의 확률과 통계를 올바르게 교육할 수 있는 자질을 갖춘 교사를 선발할 수 있는지에 대하여 검토한다. 마지막으로, 앞으로의 출제 내용, 범위, 수준, 그리고 방향에 대해서 논의한다. 결론적으로 4차 산업혁명시대를 맞이하여 빅 데이터의 중요성을 감안한다면 자료와 확률에 대한 통계적사고, 탐색적자료분석, 표본조사, 통계적 추론 그리고 공학적 도구의 활용 등의 출제가 더욱 필요하다고 본다.

• 간호행정학회지
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• 제9권1호
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• pp.63-73
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• 2003

Purpose : The purpose of this study is to analyze the comparison of organizational climate and job satisfaction of nurses between a secondary hospital and a tertiary hospital. Method : The subjects of this study were 50 nurses who were working in a secondary hospital and 50 working in a tertiary hospital. The data was collected by self-reporting questionnaires. The data were analysed using frequency, percentage, mean, standard deviation, t-test, ANOVA, Pearson's correlation coefficient, regression analysis. Result : 1) There was no statistical significance of the difference of organizational climate between a secondary hospital and a tertiary hospital. However, there was a statistical significance of the difference of job satisfaction. 2) In the organizational climate, there was a significant difference by income in a secondary hospital, and by position in a tertiary center. 3) In the job satisfaction, there was significant differences by age, marriage, position, and duration of working in a secondary hospital, otherwise. there was no significant difference in a tertiary hospital. 4) There was significant positive correlation between organizational climate and job satisfaction. Organizational climate significantly affected job satisfaction. Conclusion : It is suggested that the nursing organizational effectiveness program should be developed with reflecting on organizational characteristics that the nurses perceived.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.919-924
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• 2005

Fretting-wear caused by turbulence excitation for KSNP(Korea standard nuclear power plant) steam generator is investigated numerically. Secondary sides density and normal velocity are obtained by the thermal-hydraulic data of the steam generator. Because nonlinear finite element analysis is complex and time consuming, work rate is estimated by using linear analysis for simple straight 2-span tube. Wear volume and depth by using work rate calculation are estimated. Span length, secondary side fluid density and normal velocity are adopted to study the effects on the fretting-wear by turbulence excitation. When secondary sides density and normal velocity is increased, It turns out that secondary side density and normal gap velocity are very important paramater for fretting-wear phenomena of the steam generator.

• Current Optics and Photonics
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• 제6권1호
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• pp.69-78
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• 2022

A high-resolution camera is a precise optical system. Its vibrations during transportation and launch, together with changes in temperature and gravity field in orbit, lead to different degrees of defocus of the camera. Thermal refocusing is one of the solutions to the problems related to in-orbit defocusing, but there are few relevant thermal refocusing mathematical models for systematic analysis and research. Therefore, to further research thermal refocusing systems by using the development of a high-resolution micro-nano satellite (CX6-02) super-resolution camera as an example, we established a thermal refocusing mathematical model based on the thermal elasticity theory on the basis of the secondary mirror position. The detailed design of the thermal refocusing system was carried out under the guidance of the mathematical model. Through optical-mechanical-thermal integration analysis and Zernike polynomial calculation, we found that the data error obtained was about 1%, and deformation in the secondary mirror surface conformed to the optical index, indicating the accuracy and reliability of the thermal refocusing mathematical model. In the final ground test, the thermal vacuum experimental verification data and in-orbit imaging results showed that the thermal refocusing system is consistent with the experimental data, and the performance is stable, which provides theoretical and technical support for the future development of a thermal refocusing space camera.

• 한국사회복지학
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• 제68권1호
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• pp.117-140
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• 2016

이 연구의 목적은 성폭력 피해 아동 청소년이 인지하는 2차 피해의 경험을 보다 깊이 있게 탐색하는 것이다. 연구 목적을 달성하기 위해 2차 피해 경험이 있다고 스스로 인지하고 있는 성폭력 피해 아동 청소년 6명을 연구참여자로 섭외하였고, 2~4회에 걸친 심층면접을 통해 자료를 수집하였다. 수집된 자료는 Colaizzi가 제시한 분석 방법에 따라 분석하였다. 분석 결과 '상처 위에 소금 뿌리는 가해자', '비빌 언덕조차 되어주지 않는 가족', '울타리가 무너진 학교', '상처를 덧내는 사법기관', '믿었던 도끼로 발등 찍는 상담원', '강 건너 불구경하는 이웃'이라는 6개 하위범주를 도출할 수 있었다. 아동 청소년이 경험하는 2차 피해는 성폭력이라는 1차 피해 후에 '이중삼중으로 밀려오는 후폭풍'과 같은 경험으로 드러났다. 연구 결과를 토대로 아동 청소년 성폭력 2차 피해 예방을 위한 사회복지적 함의에 대해 논의하였다.