• Proceedings of the Korea Water Resources Association Conference
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• pp.264-268
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• 2008

미래 발생 가능한 수문 및 기상현상의 예측과정은 지식의 부족과 자연현상의 다양성으로 인해 불확실성을 포함하게 된다. 하지만 많은 예측들은 아직까지 확정적으로 제공되고 있으며, 결과적으로 예측결과의 불확실성 정도를 제공하지 못하고 있다. 앙상블 유량예측(ESP, Ensemble Streamflow Prediction)은 이러한 불확실성을 고려하여 수자원시스템의 의사결정에 있어 중요한 요소 중 하나인 유량예측을 수행할 수 있는 방법이다. 하지만 ESP의 결과는 기상자료, 유역 초기조건, 수문모형의 매개변수, 단순화된 수문모형에 의해 비교적 큰 불확실성을 포함하게 되며, 따라서 실제적인 현업에서의 사용을 위해서는 불확실성 정도를 줄이기 위한 사전 및 사후처리 과정이 요구된다. 본 연구에서는 국내에서 활용 가능한 기후 예보자료를 사용하여 앙상블 유량예측에 적용할 수 있는 사전처리 방안들을 검토하고, 국내에서 사후처리를 위해 적용되었던 최적선형 보정기법에 더해 다양한 기법들을 강우유출모형인 TANK모형의 모의결과 보정에 적용하였다. 사전 및 사후처리를 적용한 결과 기상자료와 유량예측과정에 존재하는 불확실성을 저감시키는 것이 가능하였다. 특히 사전 및 사후 처리가 동시에 적용되었을 경우 그 향상 정도가 단순히 각각의 방법에 의한 향상 정도를 합한 것보다 높게 나타날 수 있음이 확인되었다. 사전 및 사후처리를 동시에 적용한 경우 이수기에는 RPS(Ranked Probability Score) 평가방법 내에서 54%를, 홍수기에는 8%를 향상시키는 것이 가능하였다.

• Journal of Korean Society of Transportation
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• v.22 no.3
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• pp.215-226
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• 2004

본 연구는 한국 미국 유럽의 ITS 사업평가방법론을 비교분석(Comparative Analysis)하여 과학적인 국내 ITS사업평가지침 도입방안을 제언하는 것이다. 이를 위해 우리나라의 ITS사업평가의 문제점 및 국외 선진평가방법론을 분석하고 시사점을 도출하여 국내 ITS평가지침을 제도화하기 위한 정책방향을 제언하였다. 국내 외 사례(미국 유럽 한국) 비교분석결과, 국내에서도 중 장기적인 ITS 투자재원의 효율적 배분과 단기적인 시스템운영의 효율화를 위해서 과학적인 ITS평가지침(ITS Evaluation Guideline)의 도입이 제도화되어야 한다. 또한 세부추진방안으로 ITS사업을 지속적이고 반복적으로 모니터링 할 수 있는 ITS사업평가체계의 도입, ITS 서비스의 효과척도(MOE)를 과학적으로 분석할 수 있는 평가기법(운영성능평가, 경제성평가, 사전 사후비교분석, 시뮬레이션분석)정립, ITS특성을 고려한 새로운 평가기법 도입(위험도분석, 행태분석, 시뮬레이션분석) 및 기타 정책적 활용을 위한 지원(평가자료의 데이터베이스화, 한국형 ITS평가용 시뮬레이터개발, ITS사업효과 계량화 등)방안이 필요한 것으로 나타났다.

• Proceedings of the Korean Society of Disaster Information Conference
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• pp.317-318
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• 2017

본 연구는 사전재해영향성 평가제도의 개선 방안을 제안하기 위해 환경영향성평가의 연혁 변화 및 DB 구축 시스템에 대해 살펴보았다. 또한 재해 사전 분석의 이론적 개념을 분석하여 사전재해영향성 평가제도의 이론적 개념을 살펴보았다. 이러한 결과를 바탕으로 사전재해영향성 평가의 문제점을 도출하고 개선방안을 제안하였다. 이러한 결과를 바탕으로 사전재해영향성 평가의 문제점을 도출하고 개선방안을 제안하였고, 또한 사전재해영향성평가 문제점을 환경영향성평가 비교 분석을 통해서 사전재해 영향성평가 개선방안을 제안하였다. 개선방안으로 첫째 정책적 개선안으로 행정계획 지침 분리, 소규모 개발 사업 간소화 등을 제안하였다. 둘째 기술적 개선안으로 통합관리시스템 개발, 사후재해영향성검토제 도입을 제안하였다.

• Journal of Korean Home Economics Education Association
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• v.21 no.1
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• pp.71-88
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• 2009

This study was a quasi-experimental study to test a research question: Is the school library-assisted instruction effective in enhancing students' academic achievement? To solve the research question, 14 hours of school library-assisted instruction and traditional lecture were carried out to 164 9th grade middle school female students(82 of experimental group, 82 of control group). SPSS 12.0 was used for statistical analysis of frequency analysis, $x^2$-test, and t-test. The results showed that there was a statistically significant difference between the pre-test and the post-test in the total academic achievement scores of both experiment group and comparison group. There was a statistically significant difference between the pre-test and the post-test in paper and pencil test scores for comparison group. There were statistically significant differences between the pre-test and the post-test both in paper and pencil test scores and performance assessment for two groups. But there were no statistically significant differences between the experiment group and the comparison group in post-test pre-test gap of total academic achievement, paper and pencil test, and performance assessment scores.

• Journal of the Korean Data Analysis Society
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• v.20 no.5
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• pp.2437-2447
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• 2018

Public investment is necessary for the facilities inducing social benefits. We may over-or underestimate the social benefit without considering major factors deciding benefits. This study attempts to analyze and to compare the ex ante and ex post estimation of social benefit on the Nak-dong River Biological Resource Center based on CVM. According to the ex ante estimation results, the WTP per household for the center is around 6176.6 won a year. Total annual WTP in Korea is estimated at 98,118 millions of won. Ex post visitors for the center is more than two times of ex ante estimation, mainly due to central and regional governments' efforts and change in preference for the environmental goods. It is, however, possible that the ex ante estimation would overestimate visitors because of the model. In benefit estimate, we need to consider changes in income per household, changes in demographic and households structure, preferences for the environmental amenity, and specification of regional range. In addition, we need to establish extended time-series data enough to analyze influential factors and to implement periodical evaluation of ex ante and ex post estimation for the public facilities.

• Journal of Korean Society of Transportation
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• v.31 no.6
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• pp.67-89
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• 2013

This study is to perform empirical analysis on observational before-after studies in Naive Method, Comparison Group(CG) Method and Empirical Bayes(EB) Method, and to compare with their results and to propose ways to apply to evaluation researches. For this purpose, the evaluation of road safety audit executed on Y$\breve{o}$ng-dong freeway in 2005 and 2006 was performed. As a result, all three methods have showed improved effects due to safety treatments. The safety effectiveness of Naive method is the largest, CG Method is the second and EB method is the last. The results of Naive method are overestimated due to the trend of reducing traffic accidents and those of CG method are affected by the external casual effects of comparison group. In the EB method, as "regression to the mean" phenomenon are controlled by reference group's accident model, it's result is relatively more accurate than that of other methods. In the conduct of evaluation studies, the analysts have to understand the pros and cons of each evaluation method. And after leading the survey on accident trends of related all sites, evaluation analysis is performed to be able to minimize bias.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.521-534
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• 2019

From the day of luxurious inland river cruise ship started in Chongqing, China, the controversy is continuous; some people think those luxurious cruise ships on inland river might reduce the experience to enjoy the scenery of the Three Gorges, while some people think, which could improve the experience. In the study, the service facilities provided by luxurious inland river cruise ship will be evaluated by Pre-Post comparison based on IPA methods. After a review of the service facilities provided by luxurious inland river cruise ship running on Three Gorges areas. The tourists who would take the trip were asked to fill an questionnaire to examine the desired service facilities performance, which represents the highest level of the service facilities of the cruise ship that is expected by customers. After the trip, they were asked again to fill another questionnaire to examine the importance of service facilities and the performance of service. Pre-Post comparison would be examined to tell whether there is any change between pre and post experience. IPA would be used to evaluate the service facilities provided by inland river cruise ship. At last, some strategic suggestions to the development of inland river cruise ship are made.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• pp.76-79
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• 2003

주요 우주 발사체 보유 국가에서 1957년부터 1999년 사이에 발사된 우주 발사체의 성공 및 실패 이력에 대해 베이즈 분석기법을 적용하여 각국의 발사체에 대한 신뢰도를 분석하였다. 베이즈 분석기법에서 사전분포함수로는 베타함수를 사용하였으며, 미래의 발사체 성공률을 표현하는 사후분포함수는 년도별 누적된 발사 이력을 반영한 베타 사전함수를 이용하여 년도마다 발사체 신뢰도를 평가하는 경우와 첫 발사부터 1999년까지의 발사 성공률에 대한 평균과 분산을 반영할 베타 사전함수를 이용하여 년도별 발사체 신뢰도를 구하는 경우로 나누어 구하였다. 발사 이력이 많은 국가의 경우에는 베이즈 분석기법으로 구한 성공률과 산술적으로 구한 성공률은 거의 동일하였으나, 발사 이력이 적은 국가에서는 비교적 큰 차이를 나타내었다 따라서 발사 이력이 적은 경우에는 산술적 평균에 의한 성공률보다는 베이즈 기법을 이용한 향후 발사체의 발사 성공률 분석이 우주 발사체의 신뢰도를 평가하는데 적합하다는 것을 알 수 있었다.

• Journal of The Korean Association For Science Education
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• v.28 no.6
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• pp.664-674
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• 2008

The purpose of this study was to analyze the effects of the teaching and learning programs for science teachers' scientific hypothesis testing-method invention. Subjects were 30 secondary school science teachers. The potato juice task was administered to the subjects before and after instructional treatments. The four-step strategy including the steps of identifying factors, identifying variables, selecting variables and inventing methods, was applied to the development of the teaching and learning programs for the science teachers. The programs were developed by 6 experts through the R&D method. The results of this study revealed that the number and elaborateness of science teachers' scientific hypothesis testing-methods increased after the instructional treatments. The testing ability of testing-methods invented by science teachers in the posttest was stronger than the one of the methods invented in the pretest. This study also discussed the implications of these findings for teaching and learning in science education.

• Journal of Korean Society of Transportation
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• v.32 no.2
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• pp.119-129
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• 2014

This study aims to evaluate the accident reduction effects of 'Section Speed Enforcement System' (SSES) operation in freeways. In pursuing the above, this study collects the accident data for 5 years (2 years before operation and 3 years after operation) at all 9 sections where SSESs are operated, and evaluates annually the effects before and after operation using the comparison group method (C.G. Method). The measures of effectiveness are total accidents (TAs), fatal and serious accidents (FSAs), total injuries (TIs) and fatal and serious injuries (FSIs). The main results are as follows. First, TAs and TIs are reduced to 41.7 and 17.1%, respectively. Second, FSAs and FSIs are reduced to 41.7 and 32.2%, respectively. Therefore, SSES has more effectiveness at fatal and serious accident. Third, the accident reduction effect has been increasing, and particularly the effect of 'after three years' is evaluated to be notable.