• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.182.1-182.1
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• 2010

현재 전 세계적으로 가장 널리 개발하고 보급되어지고 있는 풍력산업의 시장 규모는 매년 확대되고 있다. 특히 소형 풍력발전 시스템은 낙도 등의 전력 공급이 어려운 지역에 경제성 있는 전력 보급을 가능하게 한다. 국내의 미전화 지역과 일반 가정에서 풍력 에너지 자원을 적극 활용 개발하기 위해서 보다 우수한 성능의 풍력발전기용 블레이드를 설계하고자, 공기역학적인 최적설계에 대해 연구함으로써 추후 보급형 풍력발전 시스템의 개발에 필요한 설계 기술을 확립하고자한다. 본 연구는 설계된 블레이드의 유동해석 및 성능예측을 위하여 경제적으로 많은 지원이 필요한 대규모 풍동실험이 아닌 상용 CFD를 사용하여 보다 효율적으로 우수한 성능을 가지는 풍력 터빈을 설계함에 있다. Reynolds Averaged Navier-Stokes 방정식에 기반을 둔 CFD의 경우 이론적으로 명확한 해석이 가능하고, 실제 터빈의 운전 환경과 동일한 다양한 물리적 변수를 입력 데이터로서 활용할 수 있는 장점이 있기 때문에 풍력 터빈의 설계 과정에서 반영된 미소한 블레이드 형상변화 및 운전 조건의 변화에 따른 유동장의 변화 및 풍력터빈 성능을 정확히 예측할 수 있는 장점을 가지고 있다.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.2
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• pp.40-47
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• 2007

Poor visibility is very important information in aviation meteorology factor, because secure safety, trust and economical efficiency increase for aircraft movements. The Incheon International Airport 4 years recent times was to period aircraft movements delay and cancellation due to meteorology is 52% and 30%. And then fog is 63% and 43% in meteorology factor. Therefore, the analysis against the economic loss size of an airline due to the fog is necessary. This study is indirectly estimated economic disaster scale of flight return and cancellation due to the fog in the Incheon International Airport from 5 to 6 March 2006. This is based on an aviation operational statistics data and meteorology observation data. Result of estimated, total 14 flights return to Gimpo, Jeju and Gimhae in this period are about 208,205,700 won. And estimated total 10 flights cancellation are about 718,657,000 won.

• The Korean Journal of Applied Statistics
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• v.14 no.1
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• pp.1-11
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• 2001

In PPS sampling, measure of size(MOS) is used to determine the probability of selection of sampling unit. However, some large scale surveys conducted in NSO(National Statistical Office) showed that the sampling units have the similar MOS. In such case, simple cluster sampling method instead of PPS sampling is recommended to give the interviewers a similar work load. In this paper, MSE and CV of the above two sampling methods applied to the 1997 Economically Active Population Survey sample design are compared.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.69-71
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• 2007

최근 들어 전력 계통은 점차 복잡해지고 계통의 규모 역시 빠른 속도로 성장하고 있다. 한국전력거래소는 전력계통의 안정적, 경제적 운영을 담당하고 있는 기관으로 '01년 현재의 에너지관리시스템(EMS)를 도입하여 실시간 전력계통에 대한 정확한 판단을 기반으로 전력계통의 안정성과 경제성 확보에 주력하고 있다. EMS의 대표적인 기능은 계통데이터의 수집(SCADA), 자동발전제어(AGC), 계통해석(NA) 등으로 대별되며, 이중 계통해석 기능은 프로그램 규모면에서 가장 큰 부분을 차지하고 있다. 계통해석 기능은 또다시 상태추정(SE), 상정사고분석(CA), 안전도해석(SENH), 고장해석(SCT) 등의 프로그램으로 구성되어 다양한 실시간 계통해석을 수행하게 된다. 전력계통 해석은 먼저 대상계통을 수학적 모델로 정식화하기 전에 계통망의 기하학적 구조를 기술하는 단계가 필요한데 이를 토폴로지 처리라고 하며, 보통 그래프이론인 노트(Node)와 마디(Branch)를 사용하여 전력계통망을 구성하는 요소들의 연결관계를 정의하게 된다. 본고는 이론적 수준을 넘어 EMS의 계통해석 기능에서 실계통을 해석하기 위해 쓰이고 있는 토폴로지 처리의 기본 알고리즘을 분석하여 국내 전력산업 기술 선진화에 기여하고자 한다.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2007.05a
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• pp.101-110
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• 2007

Current strategic trends in service distribution and software development in response to Web as a platform represent a paradoxical concurrent pursuit of 'economy of scale' and 'service'. From the software perspective, the major novel elements of the Web 2.0 era are Web as a platform and the emergence of long-tail service enabling web sites to function as an independent distribution channel. The current study analyzed the platform strategy for establishing a community of interactive developer and customers taking the issue of economy of scale into consideration. Software industry should face the new reality and utilize the open source community for cost minimization and securing customer base. Furthermore, Lego-style software development should be adopted for maintaining cost-competitiveness in customized software development.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.5
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• pp.97-108
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• 2010

Recent patterns of diversification of a disaster, depending on the size of the larger trend, quick and efficient response to disaster prevention, to increase the importance and role of advanced equipment and technology of fire protection industry is becoming more, over market size 11 trillion won and 10 million workers in industries of national importance, but to exceed, As most SMEs compared to other industries are backwardness. Therefore, in this study closely the characteristics of the fire protection industry analysis, the systematization of theoretical models of the finance cooperative system considering the characteristics of fire protection industry and provider the fosterage, they will contribute to independent economic activity and industrial development for operators to use the finance cooperative system of fire protection industry.

• Journal of Labour Economics
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• v.34 no.1
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• pp.103-138
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• 2011

This paper examines the changes in relative wage of top 10 college graduates to the other college graduates among the age group of 26-28 years using Korean Labor and Income Panel Study (KLIPS). From 1999 to 2008, the wage differential between top 10 college graduates and the other college graduates increased in South Korea. This wage differential seems to persist along with their age. Within industry wage differential among college graduates also rose but in the late 2000s it became smaller than the wage differential within firm size and industry. Increase in elite college wage premium has led to recent changes in college wage premium.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.1067-1075
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• 2009

The Bimodal Tram being developed in Korea is a new transit system that provides both benefits of rail and bus systems in terms of accessibility and fixed time schedule. This study accomplished a feasibility study for introducing the Bimodal Tram system by considering the travel demand and existing transit system at a city level based on its population. The feasibility of Bimodal Tram system varies depending on cities with respect to demographic scale, mode shares, and operational distances. The strategies introduced here will help any cities where transport agencies are trying to introduce the Bimodal Tram as a new transit system.

• Journal of Hydrogen and New Energy
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• v.19 no.6
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• pp.552-560
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• 2008

In 1997, Korean government established the National Energy and Resources Plan, which targeted from 1997 to 2005 with strategic energy technology development. At the end of 2005, Korean government built a New National Energy and Resources Plan preparing for upcoming 10 years from 2006 until 2015 based on energy technology trees comparing with the previous plan, which based on the energy R&D projects. In this research, we prioritize the relative preferences and efficiency by an AHP/DEA CCR-I and BCC-I integrated model approach considering scale efficiency for well focused R&D and efficiency of developing Greenhouse Gas technologies as an extended research from a view point of econometrics as an extended research.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.4
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• pp.527-548
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• 2008

It is said that there exist trouble factors of female-owned businesses and they disturb the growth of female-owned businesses. This paper, focusing on the balancing of work and family roles and discontinuance of career, examines whether trouble factors of female-owned businesses can explain the characteristics of female-owned businesses in Kwangju-Cheonnam region. The results show that these disturbing factors effect the accumulation of capitals for start-ups of femaleowned businesses and careers of female business owners, so that female-owned businesses enter disproportionately on service industry and their sizes are small. These support existing study results.