• Journal of Energy Engineering
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• v.17 no.4
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• pp.233-240
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• 2008

Conventionally, the second-order self-adjoint neutron transport equations have been studied using the even parity and the odd parity equations. Recently, however, the SAAF(self-adjoint angular flux) form of neutron transport equation has been introduced as a new option for the second-order self-adjoint equations. In this paper we validated the SAAF equation mathematically and clarified how it relates with the existing even and odd parity equations. We also developed a second-order SAAF differencing formula including DSA(diffusion synthetic acceleration) from the first-order difference equations. Numerical result is attached to show that the proposed methods increases accuracy with effective computational effort.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.65-65
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• 2000

반도체 소자의 고집적화는 배선에서 많은 문제점을 야기 시킨다. 이러한 문제점들 중에서 대표적인 것이 과도한 전류밀도에 의한 electro-migration(EM)이다. 이는 앞으로 배선의 선폭이 0.25$mu extrm{m}$미만일 경우 더욱 심화될 전망이다. 이에 대안으로 Al-합금에서 Cu로 대체하여 이러한 문제를 해결하려 하고 있다. 그런데, Cu는 Si 및 SiO2와 높은 반응성과 빠른 확산속도를 가지기 때문에 확산방지막이 필요로 되어진다. 현재에는 TiN, TaN 등의 확산방지막이 사용되어지고 있으나, TiN 박막의 경우 표면에 Ti와 oxide와의 결합에 의해 Ti-O 성분이 존재하는데, 이럴 경우 Cu 증착을 하는데 있어 부정적인 요인이 된다. 또한, 이러한 화합물은 Cu와 TiN 계면사이에 밀착성을 나쁘게 하여 고전류 인가시 EM에 있어 높은 저항성을 가질 수가 없다. 따라서, 본 연구는 MOCVD방식으로 Cu 박막을 증착하기에 앞서 수소플라즈마를 이용하여 TiN 표면에 형성된 산소 화합물을 제거한 후 Cu를 증착하여 동일한 조건에서 EM 가속화 실험을 하였다. 그림 1은 Cu/TiN 구조에 있어 수소 전처리를 한 배선의 구조의 MTF(mean time to failure)가 65분이고 전처리를 하지 않은 배선구조는 40분으로 약 50% 긴 MTF를 가지는 것으로 나왔다. 결론적으로 Cu와 TiN 계면에 좋은 밀착성은 EM에 있어 우수한 저항성을 가지는 것으로 나왔다.

• Journal of Gifted/Talented Education
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• v.15 no.2
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• pp.59-76
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• 2005

We examined the relations between the score of the divergent thinking in mathematical (Mathematical Creative Problem Solving Ability Test; MCPSAT: Lee etc. 2003) and non-mathematical situations (Torrance Test of Creative Thinking Figural A; TTCT: adapted for Korea by Kim, 1999). Subjects in this study were 213 eighth grade students(129 males and 84 females). In the analysis of data, frequencies, percentiles, t-test and correlation analysis were used. The results of the study are summarized as follows; First, mathematically gifted students showed statistically significantly higher scores on the score of the divergent thinking in mathematical and non-mathematical situations than regular students. Second, female showed statistically significantly higher scores on the score of the divergent thinking in mathematical and non-mathematical situations than males. Third, there was statistically significant relationship between the score of the divergent thinking in mathematical and non-mathematical situations for middle students was r=.41 (p<.05) and regular students was r=.27 (p<.05). A test of statistical significance was conducted to test hypothesis. Fourth, the correlation between the score of the divergent thinking in mathematical and non-mathematical situations for mathematically gifted students was r=.11. There was no statistically significant relationship between the score of the divergent thinking in mathematical and non-mathematical situations for mathematically gifted students. These results reveal little correlation between the scores of the divergent thinking in mathematical and non-mathematical situations in both mathematically gifted students. Also but for the group of students of relatively mathematically gifted students it was found that the correlations between divergent thinking in mathematical and non-mathematical situations was near zero. This suggests that divergent thinking ability in mathematical situations may be a specific ability and not just a combination of divergent thinking ability in non-mathematical situations. But the limitations of this study as following: The sample size in this study was too few to generalize that there was a relation between the divergent thinking of mathematically gifted students in mathematical situation and non-mathematical situation.

• Journal of Labour Economics
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• v.29 no.2
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• pp.29-66
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• 2006

This study investigates the structural change of wage determination within internal labor market that have occurred around the financial crisis in 1997 by using the personnel data(1996~2000) of a Korean large firm. We take the effect of performance-based pay system to apply on wage determination of workers using Mincerian earnings function estimation. After introducing the annual salary system in the firm, we did not find the fact that the wage effect of seniority decreases, but we found the wage effect of relative evaluation ratings increases. Then, this study identifies the importance of the reward strategy of firm in Korean internal labor market. Finally, we have concluded that although the firm acknowledged the positive effects of performance-based HRM practices, we have not obtained enough evidence on the transformation into such practices because the seniority-based HRM has been traditionally prevalent in the Korean internal labor market.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.719-723
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• 2014

Research acitivities of university scholars greatly contribute to the development of research literature in their own areas, thereby playing an essential role of accomplishing national values. In Korea, university researchers conduct studies focusing on basic and fundamental research with their great performance disseminated for industry competence of the country. In this study, we examine research fund and performance for drawing implications for future directions.

• Journal of Digital Convergence
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• v.17 no.5
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• pp.333-346
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• 2019

The purpose of this study is to find out the direction of overseas expansion strategy that should be established as a public broadcaster and a media company in order to overseas expand Korea EBS's. This study used a literature research method to analyze the related literature and data for analyzing strategies of major global media companies and overseas public service broadcasters (PSBs). As a result of the research, it suggests that the direction of EBS overseas expansion should approach both commercial business diversification and fulfillment of public responsibility. In particular, it suggests that transferring project of Korea's educational broadcasting system to developing country should be developed as a core business for spreading overseas expansion. In a follow-up study, it is necessary to carry out a research that suggests a comprehensive strategy of overseas expansion of EBS based on the result of this study.

• Communications of Mathematical Education
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• v.19 no.2 s.22
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• pp.327-344
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• 2005

솔리테르(solitaire) 중 간단한 게임인 자리바꾸기 문제에 대해 학습자로 하여금 다양한 해결방법을 산출 하도록 한 후, 그 과정에서 학생들의 수학적 창의성의 발현 과정을 추적해 본다. 제시한 문제 해결 과제에 대한 학습자들의 반응과 해답을 분석함으로써 수학적 창의성에서의 인지적 구성요소인 확산성, 유창성, 논리성, 유연성, 독창성과 정의적 구성요소에 해당하는 적극성, 독자성, 집중성, 정밀성 등이 어떻게 나타나고 있는가를 살펴본다. 또한 그렇게 함으로써 각 구성요소의 의미와 특성을 규명하고자 하며, 나아가 이들 구성요소를 판별할 수 있는 방안에 대한 기초 자료를 제공하고자 한다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1995.10a
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• pp.152-156
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• 1995

서해 연안에 위치한 임해발전소는 지형의 특성상 천해역으로 냉각수를 방출하는데 현재까지는 시공성과 유지관리측면에서 심층방류보다 유리한 표층방류를 대부분 택하고 있다. 본 연구에서는 점차 그 중요도가 증대되는 연안환경 보호측면에서 표층방류된 냉각수의 확산거동을 심도있는 실측을 통하여 살펴보고, 이러한 표층 부력？의 거동을 전문가 해석 기법을 응용한 특성길이 혼합모형인 CORMIX3를 이용한 결과와 비교한다. (중략)

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.814-819
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• 1998

원자력 발전소의 운영개선에 2차 방사성폐기물을 줄여야 하는 것은 중요한 과제이다. 기존 세탁 법은 2차 방사성폐기물을 상당히 많이 배출는데, 개선방안으로 초임계 유체($CO_2$)를 이용한 제염가능성을 알아보았다. 본 연구에서 순광유, 그리고 산업용으로 쓰이는 기어유와 그리스의 초임계 $CO_2$ 내에서의 용해도와, 제거율을 구하였다. 용해도 측정 실험에서는 초임계 상태에서 압력에 따라 용해도가 급격히 증가하였으며 반응시간 또한 매우 빨라 확산성이 매우 우수하였다. 실제 적용을 위해 소량의 첨가용매를 사용한다면 더욱 큰 성과가 기대된다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.519-522
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• 2004

웹의 급격한 확산과 더불어 고객에게 맞춤화된 정보 제공의 필요성이 높아지고 있다. 또한 전자상거래 기업은 맞춤화와 개인화 서비스를 실현하기 위해서 웹 기반의 추천시스템에 많은 관심을 가지고 있다. 협업필터링(Collaborative filtering)은 개인화된 정보필터링 기법으로 추천시스템에서 가장 많이 사용되고 있다. 본 연구에서는 MovieLens 데이터 셋의 아이템속성을 고려하여 클러스터링 기반의 사례기반추론을 통한 협업필터링 추천시스템을 개발하고 기존의 방법과 제안된 모델의 성과를 비교 분석하였다.