• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.611-619
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• 2017

This paper intends to develop unit water production cost (UWPC) between alternative water resources including desalination, freshwater reservoirs, single-purpose dams, underground dams, and two indirect water in-take technologies - riverbank filtration and aquifer storage and recovery (ASR). The UWPCs of water supply schemes including each alternative are determined based on project cost, and operation and maintenance estimation models, which were developed based on real project cost data. The sensitivity analysis of UWPCs reveals that ASR is the lowest cost option in producing drinkable water among the alternatives, followed by riverbank filtration and underground dam. It is expected that economics related to the finding plays a critical role in supporting water resources planning and budget allocation for central and local water authority in Korea.

• Environmental and Resource Economics Review
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• v.23 no.3
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• pp.453-472
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• 2014

Analyzing the effects of carbon emissions trading, which is scheduled to be introduced in Korea in 2015, requires an accurate assessment of $CO_2$ abatement costs by both industries and firms. Firms faced with regulatory constraints are unlikely to minimize their production costs due to rising production costs caused by allocative inefficiency of inputs. The use of a distance function would results in underestimation of $CO_2$ abatement costs, because it fails to capture the allocative distortion costs. Recognizing the disadvantage of the previous approach, first, this paper tests for allocative efficiency of input for the Korean steel industry over the period 1990-2010, then derives the marginal $CO_2$ abatement costs by applying a cost function approach. The hypothesis of allocative efficiency in inputs is rejected and the steel industry pays an annual average cost of 92,000 won in removing an additional ton of $CO_2$ over the sample period.

• Journal of Korea Port Economic Association
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• v.26 no.4
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• pp.188-206
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• 2010

Data Envelopment Analysis(DEA) is an operations research-based method for measuring the performance efficiency of decision units that are characterized by multiple inputs and outputs. DEA has been applied successfully as a performance evaluation tool in many fields. However, it has not been extensively applied in the shipbuilding industry. This paper applied the input-oriented DEA model, and Malmquist indices to the 7 shipbuilding firms to measure the efficiency and productivity changes during the period of 2004 to 2009. The Malmquist indices will be decomposed into three components such as pure efficiency change, scale efficiency change, and technical change. The empirical results show the following findings. First, the DEA findings indicate that main source of inefficiency is scale rather than pure technical. Second, the Malmquist indices show that an overall decrease in productivity.

• International Area Studies Review
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• v.14 no.2
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• pp.43-60
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• 2010

This paper measures R&D efficiency and productivity changes of 24 nations including Korea, Japan and China by the non-parametric Malmquist productivity index. The principle findings of this study are as follows. First, R&D efficiency scores of Korea and Japan are 0.837 and 0.834 respectively. Meanwhile China shows 0.420, the worst performance among the selected countries. Second, Korea marked annual productivity increase of 25%, highest among the selected countries', for 2000-2005. R&D productivity in Japan and China, however, decreased 1.9% and 0.9% respectively. Third, annual rates of technology change and technical efficiency change in Japan are 0.6% and -2.5%. Therefore decrease of productivity in Japan is mainly due to technical inefficiency. In case of China, improvement of technical efficiency is the main contributor to productivity growth but technical progress has edged downward in the sample period. In Korea, with annual rate of technology change and technical efficiency change being 5.2% and 18.2% respectively, both efficiency improvement and technical progress has pulled the R&D productivity growth.

• Journal of Embryo Transfer
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• v.10 no.2
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• pp.145-151
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• 1995

초기배의 성판정은 대상가축의 성을 선발하는 수단으로써 가축의 육종 및 번식에 있어 가치가 매우 높다. 체세포, 체외수정 또는 처녀발생 초기배의 성을 결정하기 위해 capillary polymerase chain reaction (PCR)을 이용하였으며 성판정에 이용되는 상실배 또는 배반포는 체외수정과 그 후의 난관상피세포와의 공배양에 의해 생산되었다. 초기배의 genomic DNA는 0.2$\mu$g/$\mu$L proteinase K를 함유하고 있는 PCR lysis buffer에 하나의 초기배를 부유하게 50˚C 에서 1시간동안 배양한 후 95˚C에서 10분간 효소를 비활성화시킴으로써 준비되었다. 웅성 초기배에서는 두개의 증폭산물(소특이)만이 생산되었다. 이 기법에 의한 성판정 결과 초기배의 성비는 예상되는 1:1의 성비와 유의적인 차이가 없었다. 잔여 난구세포 또는 투명대에 결합된 정자 등으로 인한 잘못된 성판정이 종종 발생하였는데, 이는 citrate 처리후 투명대를 완전히 제거함으로써 false positive 또는 negative 결과를 극복할 수 있었다. 이상과 같은 결과는 체외생산 소 초기배의 신속하고(2시간 증폭) 정확한 성판정의 가능성과 초기배 이외의 세포로부터의 오염이 확립된 수세방법에 의해 효과적으로 배제될 수 있음을 제시하였다.

• KSBB Journal
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• v.25 no.3
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• pp.244-250
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• 2010

This study characterized the anti-Helicobactor pylori activity of Xanthium strumarium L. extract obtained by lactic acid fermentation. The growth of the Lactobacillus strains was typically robust upon lactic acid production in monocultures containing Xanthium strumarium L. extract. Lactic acid fermentation in mixed cultures of Lactobacillus brevis KCTC 3498 and Lactobacillus casei KCTC 3109 produced higher of anti- H. pylori activity than monocultures. Concerning antioxidant activity of fermented extracts, total polyphenol contents were the highest in co-cultures of Lactobacillus brevis KCTC 3498 and Lactobacillus helveticus KCTC 3545. Electron donating ability using diphenyl picryl hydrazyl (DPPH) showed 70% scavenging in Lactobacillus casei KCTC 3109.

• Journal of Labour Economics
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• v.30 no.2
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• pp.33-60
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• 2007

This study analyzes the trend of the gender wage gap and its sources in the Korean labor market for the years 1985-2004. Following Oaxaca and Ransom (1994), the gender wage gap is composed of the productivity-related gap and non-productivity-related gap (unobserved productivity gap and discrimination). Empirical findings indicate that both the productivity-related gap and non-productivity-related gap have dwindled, while the decline of the former far excelled that of the latter. The non-productivity-related gender wage gap is much larger for married women than for single women, possibly implying a lower unobserved productivity of married women because of their childcare responsibilities. The non-productivity-related gap is also very substantial in the male-dominated occupations as compared to the female=dominated occupations, supporting the existence of network externalities in employment.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.04a
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• pp.97.2-97
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• 1978

숙성한 퇴비에서 16종의 사상균을 분리하고 이들의 xylanase 및 cellulase의 활성을 측정하였다. 이 결과 효소활성이 강한 6 균주를 선별하고 이들의 형태학적 특성을 속까지 동정하고 선별된 균주가 생산하는 xylanase와 cellulase의 성질을 비교 검토하였다. 선별된 균주의 배양기질에 따른 효소생산량 산량을 비교하기 위해 cellulose와 xylan으로 배양한 후 이들을 분해하는 효소활성의 비 즉 xylanase/cellulase 비를 계산하고 이들 효소의 일반 성질을 검토하였다. 차후 연구에서 이들 효소를 분리, 정제하기 위해 acetone에 의한 침전성을 아울러 실험하였다.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.79-79
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• 2002

가축의 개량에 있어서 수정란이식은 인공수정보다 획기적으로 향상시킬 수 있었으며, 첨단기술 이용 가축 생산에 필수도구이다. 그러나 수정란의 상태에 따른 수태율에서 큰 차이를 보이고 있어, 수태율 향상 개발이 시급한 실정이다. 임신중기의 IGF-Ⅰ의 농도는 비임신기보다 증가하고, 산욕기에 급격히 감소하여 비임신기의 농도이하로 떨어지는 특징이 있어 임신관련 기전을 이해하는데 도움이 될 수 있다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.306-307
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• 2000

넙치양식의 급속한 발달과 더불어 넙치용 배합사료가 개발되어 이미 상품으로 생산·판매되고 있으나, 현장에서는 초기사료를 제외하고 여전히 생사료 위주의 사료공급이 주를 이루고 있다. 또한, 생사료의 사용으로 사료비가 양식전체 경영비의 50∼70%를 차지하고 있으며(Bai, 1996), 성장 위주의 과잉 공급에 의한 수질오염과 양식어류의 생리적 불균형으로 각종 질병의 발생 및 어체의 질적 저하 등으로 양식생산성이 저하되는 결과를 초래하고 있다. (중략)