• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.178-178
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• 2021

최근 들어 기후변화로 인한 극심한 가뭄 피해가 한반도에 발생하고 있다. 가뭄 상황에 대비하여 댐을 안정적으로 운영하기 위해서는 갈수빈도 유입량에 대한 분석이 필수적이다. 갈수빈도해석의 경우, 홍수빈도해석과 유사하게 확률밀도함수의 극값에 대한 확률값을 산정하며, 확률 분포형의 역함수에 비초과확률을 대입하여 산정한다. 그러나 홍수와 달리 가뭄은 지속기간이 긴 특성 탓에 자기상관을 고려해야하며, 댐 및 저수지 등 대규모 시설물의 경우 일반적인 하천과 달리 저류효과로 인해 누적 유량에 대한 고려가 필요하다. 이에 K-water는 자체 제작한 누가차분법 및 Disaggregation 두 가지 방법을 채택하여 실무에서 사용해왔다. 그러나 누가차분법을 사용할 경우, 빈도유입량이 지나치게 크게 산정되는 문제가 있으며, Disaggregation 방법을 사용하는 경우, 특정 빈도 이상의 극한가뭄에서 유입량의 차이가 유의미하지 않아 산정된 빈도유입량과 최근 발생한 극심한 가뭄의 실측유입량간 큰 차이가 발생하고 있다. 따라서 본 연구에서는 자기상관을 고려한 선형회귀모형에 근거하여 빈도유입량을 배분하는 방법을 제안한다. 또한, 앞서 서술한 네 가지 빈도유입량 방법(월빈도분석, 누가차분법, K-water Disaggregation, 자기상관 선형회귀모형)에 대한 수식적 비교를 수행하며, 국내 댐 유역에 적용 및 평가를 통해 자료 특성에 따른 적절한 빈도유입량 산정방식에 대한 기준을 제안한다. 본 연구를 통해 가뭄특성을 고려한 합리적인 댐 유입량을 산정함으로써 보다 유연한 수자원시설물의 가뭄대응이 이루어질 것으로 기대된다.

• Journal of the Korea Society of Computer and Information
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• v.17 no.3
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• pp.135-141
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• 2012

Development of the Internet has brought many changes in methods of education and assesment. When enforcing the on-line distance education, the tests to check the outcomes of the learning are taken on the Internet. The current trends of education evaluation are focused on the types of questions and the detachments of exam proctor but verifying the authentication of answer sheet. There are several forms to make answers; selection type, short-answer type, write-out answer type, practical exercise type, etc. All the forms can be done on the Internet except the practical exercise type because the source of the examinee's answer sheet is unreliable. In this paper, we made the verification system to solve the doubt by setting the proved information on the answer sheet. Putting the information down to confirm the authenticity during the exam on the server is distinct character of this system. After the test finished, the system will operate when examinee turn in the answer sheet.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.1
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• pp.87-103
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• 2013

This study was investigated to examine the effects of writing activities based on Polya's Problem Solving Stages on Learning Accomplishment and Attitudes. A total of 54 students were selected from two Grade 6 classes of P Elementary School in G City to form an experimental group(n=27) and a control group (n=27). The experimental group was applied to a class which was creating writing activities according to Polya's Problem Solving Stages to problem solving and inquiry activities. The control group was taught by the traditional method to the same activities. The five questions for each area were selected as a descriptive assessment of the second semester of Grade 5 in the area of the Academic Achievement pre-test, developed by the G Education and Science Research. The post-test was selected by a descriptive assessment of the content of the first semester in Grade 6. The same questions were posed for both the pre-test and the post-test of the Mathematical Attitudes assessment. We examined the pre-test at the beginning of the school term, then the students were re-examined after one semester, using the same questions as the pre-test. This research showed that there was a meaningful difference in Learning Accomplishment as a result of T-test in the 5% level of significance. Secondly, there was a meaningful difference in the Mathematical Attitudes as a result of T-tests. It shows that writing activities based on Polya's Problem Solving Stages have an influence on improving Learning Accomplishment and Attitudes.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.529-538
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• 2018

The purposes of this study were to examine the stress, quality of sleep, Social support according to Myes-Briggs Type Indicator(MBTI) personality type in nursing students. Structured questionnaires were used for survey with a convenience sample of 290 nursing students. Data were analyzed using descriptive statistics, t-test, Pearson's correlation coefficient, and multiple regression with SPSS/WIN 18.0. Extroversion preference(${\beta}=.23$, p=.047) in quality of sleep, thinking prefernce((${\beta}=.06$, p=.025) in tangible support, judgement preference(${\beta}=.24$, p=.014) in appraisal support and perception preference(${\beta}=-.21$, p=.011) in Self-esteem maintenance were significantly associated factors with stress. Therefore, intervention programs for managements of stress should include systematic and indivisual intervention through the convergence of departments, university and specialists in nursing students.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.4
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• pp.61-66
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• 2004

The objective of the present study is to develop methodology for the assessment of combustion stability of liquid rocket injectors. To simulate actual combustion occurring inside of a thrust chamber, a fullscale injector has been employed in the study, which bums gaseous oxygen and mixture of methane and propane. The main idea of the experiment is that the mixing mechanism is considered as a dominant factor significantly affecting combustion instability in a fullscale thrust chamber. A single split triplet injector has been used with an open-end cylindrical combustion chamber. The characteristics revealed by excited dynamic pressures in gaseous combustion show degrees of relative acoustic damping depending on operating conditions. Upon test results, the direct comparison between various types of injectors can be realized for the selection of the best design among prospective injectors.

• Journal of the Korean earth science society
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• v.25 no.8
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• pp.647-655
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• 2004

PISA (Program for International Student Assessment) 2003, the second cycle of PISA, collected data with respect to students' cross-disciplinary problem solving capabilities. Problem solving is defined as the ability to use cognitive processes to solve real cross-disciplinary problems. For the purpose of PISA 2003 assessment, three problem types were chosen: Decision Making, System Analysis and Design, and Trouble Shooting. For this paper a preliminary analysis on Korean students' responses to the PISA 2003 problem-solving items was conducted. The quantitative analysis mainly focused on the difficulties of the PISA 2003 items, while the quantitative analysis dealt with students' responses to open-ended items, which helped understand Korean students' cognitive style and reasoning processes. According to the item analysis result, Korean students had difficulty in representing their answers with pictures or graphs, and interpreting long and complex text. They also showed low achievement with relatively unfamiliar topics or tasks. The paper concluded with several suggestions on improve the quality of science education.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.22 no.2
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• pp.181-200
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• 2011

This study purposed to evaluate a youth reading promotion program that is designed and operated by the National Library for Children & Young Adults. The study specifically assessed the '1318 Bookworm Program' by conducting an in-depth survey and a focus group interview for school librarians who had participated in the program between 2007 and 2010. According to the study findings, the program participants were highly satisfied with the program outcomes. The librarians believed that the program brought positive effects on the cognitive, emotional, and social developments of the participated teens. Among the 1318 program operation process, namely designing, planning, and implementation, both planning and implementation processes were the determining factors for the outcome satisfaction. Finally, study participants expressed the needs for increasing the number of the certified professional school librarians active in the field, expanded organization structure, and further research on youth reading promotion programs in order to facilitate the program support and to enhance its efficiency. They also suggested diversified program contents development and the dissemination of manuals for youth reading promotion programs.

• Journal of The Korean Association For Science Education
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• v.42 no.6
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• pp.597-610
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• 2022

In this study, we investigated actual cases of assessment science teachers conducted and the cases they preferred in a typical situation based on the curriculum in the context of 'Scientific Inquiries in the History' of Scientific Inquiry Experiment. A questionnaire composed of descriptive questions was developed and a survey was conducted with 70 science teachers with experience in teaching 'Scientific Inquiries in History'. Interviews were conducted with eight of them. The assessment cases were analyzed in terms of the assessment areas and assessment methods, and the results were compared. The analyses of the results revealed that 'scientific inquiry ability' accounted for the highest ratio of the assessment areas in the actual cases of assessment. There were few cases that assessed the core concepts presented in the curriculum, 'the nature of science' and 'scientists' inquiry methods'. The assessment methods were greatly biased toward the report method and various assessment methods were not used. In preferred cases of assessment, the ratio of cases that assessed the core concept increased slightly, however the frequencies remained at a low. As for the assessment methods in preferred cases of assessment, the measurement methods decreased, the performance methods increased, and the informal methods which were not shown in the actual cases appeared. However various assessment methods were still not used. The causes of the survey results were analyzed based on the opinions of the teachers who participated in the interviews. Based on above results, plans to actively conduct NOS assessments in Scientific Inquiry Experiment are discussed.

• Journal of the Korean Geotechnical Society
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• v.21 no.2
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• pp.137-144
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• 2005

A direct shear test is classified roughly by one side simple shear test of confining horizontal displacement type and torsional shear test of non-confining one. Direct shear test that has been widely used so far has some problems with test apparatus, testing and the analysis, and in particular that its strength value is everestimated in sandy soils. Also, progressive failure of shearing process happens from shear apparatus restriction and because the shear strain and shear stress are erratic in specimen, we can not define the shear strain value. In the meantime, a simple shear test having advantage of direct shear test is an ideal test method that can get stress-strain relation on shear because it can deliver constant shearing deformation to specimen. However, simple shear test cannot be used practically, because its structure makes tester manufacturing difficult. This paper described a on outline of test apparatus, improvement of test method, and constant pressure test results based on the obtained from improved direct shear apparatus and the standardization of JGS soil testing method.

• Journal of Broadcast Engineering
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• v.19 no.5
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• pp.665-676
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• 2014

As the Learning Model (offered major course) of the connected program between high school and college, we conducted a customized education model for second grade high school students with regard to IT. Being based on the latest major trend and practical training within a given period this model has derived the high level of interest and participation from the students. First of all, the first program has focused on the theory and practice. In case of the theory lecture, the new knowledge and practical experiences attracted students' interests. Secondly, the second program mainly consisted of practical training. The basic knowledge through first learning program enabled the students to follow the second course for advanced experiences as well as the variety of new technology. Finally, the survey and evaluation were carried out on the students who finished programs. Most of the students gave answers that both the theory classes and customized practical training were helpful in finding their major and career exploration. The Learning Model of the connected program between high school and college showed that it can be useful not only to extract students' potential ability and good talent but also for university selection and career choices.