• KOREAN POULTRY JOURNAL
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• v.50 no.2
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• pp.220-221
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• 2018

• The Science & Technology
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• v.17 no.8 s.183
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• pp.58-64
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• 1984

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.137.1-137
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• 2003

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.10a
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• pp.124-129
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• 2003

현대의 산업계에서 많은 기기들은 민감한 전자부품들을 사용하고 있다. 이들 기기들은 전압의 변동에 민감하게 반응하여 오동작을 일으킬 수 있으며, 이로 인해 산업현장의 안전에 영향을 미치는 주요 요인이 되기도 한다. 특히 순시적인 전압 강하를 허용하지 않는 중요한 부하기기의 사용이 급증하고 있다. 따라서 순시전압저하(instantaneous voltage sag)는 전기의 신뢰성과 안전성에 위협을 주는 요인이다.(중략)

• The Korean Journal of Financial Management
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• v.15 no.1
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• pp.329-350
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• 1998

이 논문에서는 자산의 수익률과 공통요인이 시간가변적 변동성을 갖는 경우의 APT를 검증하고자 시도하였다. 이를 위하여 1980년 1월부터 1995년 12월까지의 17개업종별 포트폴리오 수익률로부터 주성분분석에 의하여 4개의 공통요인을 추출하였다. (이중 첫 번째 요인은 동일가중 시장수익률과 거의 1에 가까운 상관성을 갖고 있으므로, 추출된 첫 번째 요인 대신에 시장수익률을 사용하였다.) 17개 업종별 포트폴리오에 대한 ARCH모형을 추정한 결과, 12개 포트폴리오의 수익률이 조건부 이분산성을 보이고 있다. 또 네 개의 공통요인 중 시장수익률을 포함한 3개의 요인은 뚜렷한 조건부 이분산성을 보이고 있다. 따라서 요인위험--즉, 공통요인에 대한 개별자산의 민감도$({\beta}_{ij})$--은, 개별자산과 공통요인의 상관계수가 일정하다고 가정하여, ARCH모형에 의해 측정된 자산 및 공통요인의 시간가변 표준편차로부터 계산되었다. 이와 같이 계산된 요인위험에 대하여 어느 정도의 위험프리미엄이 주어지고 있는가는 일반화 적률법(GMM)에 의하여 추정하였다. 그 결과, APT의 추정에 사용된 4개의 공통요인 중 시장수익률을 포함한 3개의 요인에 대하여 유의한 위험프리미엄이 추정되었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.821-830
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• 2023

Various studies has tried to unveil causes of cost overrun and schedule delay in the road construction project. However, these causes need standardization due to difference by guidelines, relevant research, and facilities. Therefore, this study identifies and elaborate standard road construction cost and schedule variation factors that can be used in the planning and execution of the project. variation factors have been derived and grouped through literature review and modified and supplemented through expert interview. In addition, the connection with the relevant guidance factors is confirmed and the usability is reviewed by applying actual road construction cases. The factors suggested in this study comprehensively include factors of related guidelines and previous research, more clearly distinguish, support decision making.

• Management & Information Systems Review
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• v.36 no.4
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• pp.53-80
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• 2017

The purpose of this study is to examine the determinants of the number of bank relationships in Korea. Firm-specific determinants considered here include leverage, size, age, return on asset, investment grade, tangibility, liquidity, R&D expenditure. We estimate the effects of these variables, and compare the results with those from previous studies performed for other economies. Concerning the effects of business cycle, we find that the business cycle is an important factor in determining the number of bank relationships. The number of bank relationships varies over the business cycle, and we notice a counter-cyclical behavior, which means the number decreases during economic expansions and increases during contractions. This result can be interpreted as a result of firms' diversification of borrowings into multiple banks in order to reduce the liquidity risk during the recession. In the subsets, however, the number of bank relationships for large firms is stable regardless of the business cycle. Unlisted firms, non-chaebol, and low credit quality firms which have relatively limited access to alternative sources of financing show counter-cyclical behavior. Finally, such phenomena is not observed in the non-competitive credit market, while they show a counter-cyclical behavior in the competitive credit market.

• Environmental and Resource Economics Review
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• v.16 no.3
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• pp.723-738
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• 2007

This paper draws some implications from Logarithmic Mean Weight Divisia Method (LMWDM) on the sources of $CO_2$ emission changes in the manufacturing sectors of Korea, UK, and USA. The sources of change in industrial $CO_2$ emission of a country, as manifested by production scale factor, structural factor, and technical factor, summarizes the forces behind the change in $CO_2$ emissions in each country's manufacturing sector. There are three observations. First one is that Korea's emission is increasing while USA and UK are experiencing reduction or stabilization of $CO_2$ emission in the manufacturing sector. Second implication is that the technical factor affecting $CO_2$ emission in Korea does not help much, or even hinder, the reduction of $CO_2$ emissions, comparing to USA and UK. Third one, which is the combined result of the first and the second one, is that Korea's increasing trend in aggregate $CO_2$ emission throughout the periods in consideration is mainly due to the failure in technical progress, or the deterioration in the structure of within subcategories, or both. The policy implications is clear. The obvious prescription is to launch a nation-wide policy drive which can revert these adverse trends.

• Journal of the Korea Institute of Building Construction
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• v.4 no.4
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• pp.117-126
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• 2004

Construction industry is faced with the problems such as the quickly changeable circumstance and increasing construction companies due to regulation mollification of company registration. In order to overcome these problems, new estimation system based on historical estimation cost is ready to introduce by government step by step. But the time of transition for estimation system causes another problems such as chaos addition to simultaneity of a standard of estimation system and new estimation system, lack of related regulation, accumulation of historical extensive cost data, and adjustment methodology when historical estimation data is applied to next projects. The purpose of this study is to suggest the change factors by activities for estimating historical cost for apartment housing projects. New estimation system is based on historical construction data. For application of this system, the standard adjustment methodology system is necessary. and extensive cost data should be accumulated under an unified construction work classification system. Therefore in this study, according to the construction work classification system, every apartment housing project was classified to 16 work classifications, and 7 major composed items which occupy more than 85% of construction costs are analyzed by detailed activities and by average ratio and maximum ratio each of them. In the result of the study, furniture work, foundation work and masonry work are the works which have big gap of costs between average ration and maximum ratio. In addition to suggestion of change factor by work species, 5 qualified construction specialists are interviewed and change factors in 7 major works are analyzed.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.319-328
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• 2006

The relationships among long-term climate variation at the southern part of the Korean peninsula, oceanic conditions in the South Sea, Korea, and variation in the winter catch of yellowtail (Seriola quinqueradiata) were analyzed using 32 years of time-series data from 1971~2002. In the early 1990s, winter climatic conditions at the southern part of Korean peninsula shifted from a cool to a warm regime with higher air temperature, relative weak wind speed, and lower relative humidity. Also, the winter water temperature at 50 m depth became consistently higher in the South Sea. The annual winter catch of yellowtail in the South Sea increased dramatically in the early 1990s, as did that of anchovy, which is the major food organism for yellowtail. From the results of correlation analysis, we found that the winter catch of yellowtail was more closely related to the increasing of air temperature, water temperature and anchovy catch.