• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.539-544
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• 2013

The effects of culture depth (2-10 cm) and cell density on the growth rate and biomass productivity of Chlorella sp. XQ-200419 were investigated through the use of a self-designed open circular pond photobioreactor-imitation system. With increases in culture depths from 2 to 10 cm, the growth rate decreased significantly from 1.08 /d to 0.39 /d. However, the biomass productivity only increased slightly from 8.41 to 11.22 $g/m^2/d$. The biomass productivity (11.08 $g/m^2/d$) achieved in 4 cm culture with an initial $OD_{540}$ of 0.95 was similar to that achieved in 10 cm culture with an initial $OD_{540}$ of 0.5. In addition, the duration of maximal areal productivity at a 4 cm depth was prolonged from 1 to 4 days, a finding that was also similar to that of the culture at a 10 cm depth. In both cases, the initial areal biomass densities were identical. Based on these results and previous studies, it can be concluded that the influence of culture depth and cell density on areal biomass productivity is actually due to different areal biomass densities. Under suitable conditions, there are a range of optimal biomass densities, and areal biomass productivity reaches its maximum when the biomass density is within these optimal ranges. Otherwise, biomass productivity will decrease. Therefore, a key factor for high biomass productivity is to maintain an optimal biomass density.

• Plant Resources
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• 제8권1호
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• pp.9-12
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• 2005

TO select the most suitable crop and variety of forage for productivity at the southern part of Korea, The crops of wheat, barley and rye were grown from Oct. 1999 to June 2000. Paldanghomil variety of rye crop was shown to have the highest productivity in comparison to other varieties of crops used in this experiment. It showed relatively high plant height, number of tiller, forage yield and dry matter yield. There fore, it was concluded that Paldanghomil of rye crop was the most suitable crop with high yield in the southern part of Korea. The heritabilities of all characters were estimated to be high.

• Journal of Species Research
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• 제1권2호
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• pp.257-261
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• 2012

In Irkutsk region the plants of spring wheat (Tr. aestivum) grow in three agro-ecological zones: steppe, forest-steppe and subtaiga. Due to this reason, the paper determines the coefficients of correlation between the indicators field germination of seeds, plant safety, productivity, temperature and moisture content of the plant habitat for each zone. The zonal moisture saving features of soil treatment for growing wheat plants (Tr. aestivum) are discussed on the basis of these data.

• 한국건설관리학회논문집
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• 제18권1호
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• pp.17-26
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• 2017

국내 해외 플랜트 수주액은 2015년 기준 전년도 대비 약 51% 감소하였고 플랜트산업 중 약 63%로서 가장 높은 비중을 차지하는 화공플랜트의 수주액은 약 43% 감소하였다. 현재 해외국가들의 플랜트 건설업체는 고도의 기술력과 경험 및 축적된 노하우를 바탕으로 엔지니어링 분야에서 우위를 선점하고 있다. 이에 세계 플랜트 산업에서 국내 기업의 경쟁력 확보를 위한 대책이 필요하며, 건설기술력 발전을 통한 국가경쟁력 향상을 위해 생산성 관리는 매우 중요한 현안이다. 또한 생산성은 장기적인 성장에 영향을 미치는 중요한 요소임에 따라 경쟁력 확보를 위해 수정 IPA를 이용하고 화공플랜트로 범위를 한정하여 생산성 저해요인을 분석하고자 한다. 이를 통해 해외 화공플랜트와 관련된 생산성 저해요인의 개선방안 및 대책을 제시한다. 그리고 생산성을 향상시킬 수 있는 요인이 무엇인가를 파악하고 생산성 향상을 위한 시사점을 제시함으로서 중 장기적인 대책을 마련할 수 있을 것으로 기대된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.42-43
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• 2014

Few studies on crew productivity has been conducted, although the data is significant for time and cost estimation. Crew productivity data was collected for over 9 months from a nuclear power plant and analysed in order to identify factors driving the productivity. It was revealed that the crew productivity of form work, rebar work and concrete pouring work was 45.64(㎡/crew·day), 2.93(t/crew·day), 110.25(㎡/crew·day) on average respectively. Moreover, 'nightwork', 'No. of workers per crew' and 'total work amount' were identified as drivers.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.90-91
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• 2013

In the field of nuclear power construction, management and the systematic construction is very necessary. For more efficiently managing, analysis of influence factors and productivity is indispensable now. On this research, we collected the data from the nuclear power plant which is located in Korea. We analyzed the productivity and influence factors. As a result, productivity was 0.75(㎡/man·hour).On one hand, the productivity should be personnel, weather and whether there is a night duty or not. On the other hand, work crew depends upon operators, formwork amount, the presence or absence of night duty.

• KDI Journal of Economic Policy
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• 제38권4호
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• pp.77-94
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• 2016

This paper examines the empirical magnitude of local human capital spillovers in Korea during the 1980s and mid-1990s. Local human capital spillovers exists if plants in regions with a higher level of human capital can produce more given their own amount of input (Moretti 2004c). In particular, this paper explores an educational reform in South Korea which exogenously induced a large amount of variation in regional human capital levels. Using annually collected plant level data, I explore the effect of changes in the regional human capital levels induced by this reform on plant productivity in Korea. My results suggest that this effect is limited. I find a positive correlation between a regional level of human capital and plant productivity. However, after further addressing endogeneity using an instrumental variable, the effect of the overall regional human capital level on productivity decreases and becomes statistically insignificant.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.600-601
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• 2015

Both the importance and process of estimating Nuclear-power plant construction time and cost have increased in significance as energy user costs themselves have become more significant. In estimating construction time, few parameters are more significant than work item production rates and factors significantly affecting the rates. A standardized data collection tool was used to acquire a total of 401 data points from a S Nuclear-power plant project, for selected critical works: form-work, rebar-work, and concrete-pouring. With the data, several hypothesized drivers of the man-hour production rates and crew-day production rates were also analyzed. Findings from this study will enable industry professionals to enhance accuracy of time and cost estimation for nuclear power plant construction.

• 대한안전경영과학회지
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• 제14권1호
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• pp.117-122
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• 2012

This paper deals with the productivity increment through construction of lean production system for automobile factory in China. This lean production system has been progressed according to 5 steps. Step 1 is the work preparation. Step 2 is the process design. Step 3 is the establishment of method to count production quantity. Step 4 is the establishment of measuring method for input and output. Finally, step 5 is the construction of flexible production system able to adapt for environment change. This lean production system is expected to obtain the productivity increment by 50% for plastic plant and reduction by 50% in inventory quantity.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2008년도 춘계학술대회
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• pp.339-344
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• 2008

This study's purpose centers plant management activities that is management system for total plant efficiency's maximization, plant evaluation system that production and safety management activities factor that is enforcing in manufacturing industry can develop evaluation model that can evaluate quantitative activities in process that maximize productivity and safety efficiency wishes to do design.