• Bulletin of the Korean Chemical Society
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• 제16권7호
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• pp.640-643
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• 1995

The internal standard method, which is widely used in chromatographic techniques, is applied to the size exclusion chromatography for the on-line determination of dn/dc value of the sample. This method is found to provide the dn/dc value with suitable accuracy in determining the absolute molecular weight and the molecular weight distribution of the polymers when a light scattering detector is used.

• 한국항공운항학회지
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• 제22권2호
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• pp.27-33
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• 2014

There are several methods to improve the flight efficiency of HALE(High Altitude Long Endurance) UAV(Unmaned Aerial Vehicle). Airframe structural point of view, weight reduction of the airframe structure is the most important method to improve the flight efficiency. In order to reduce the weight of airframe structures, new concepts which are different from traditional airframe structure design such as the mylar wing skin should be introduced. The spar is the most important component in a mylar skin wing structure, so the spar weight reduction is the key point for reduction of the wing structural weight. In this study, design trade-off study for the front spar of the HALE UAV wing is conducted in order to reduce the weight. Design and analysis procedure of high aspect ratio wing spar are introduced. Several front spar structures are designed and trade-off study regarding the weight and strength for the each spar are performed. Spar design configurations are verified by the static strength test. Finally, optimal front spar design is decided and applied to the HALE UAV wing design.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.99-100
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• 2012

Aggregate thermal properties and cooling methods are most important to evaluate the residual mechanical properties of concrete. In this study, we evaluate the residual mechanical properties of concrete according to the aggregate type and cooling method. We use the normal weight aggregate and light weight aggregate which have different thermal properties. After heating to the target temperature, we evaluate the mechanical properties according to the slow and fast cooling condition. As a result, normal weight aggregate concrete has higher effectiveness of cooling conditions than light weight aggregate concrete.

• 한국산업안전학회:학술대회논문집
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• 한국안전학회 1997년도 추계 학술논문발표회 논문집
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• pp.135-142
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• 1997

For lighting of dark and hazardous workplaces such as compartments of ships under construction, workers should use hand lamps of explosion-proof type. However, the heavy weight of such lamps has prevented most impatient workers from using such types of lamps extensively. In this paper, ire developed a light weight hand lamp of intrinsic safety type which reduced the weight a lot while maintaining or improving the lighting and explosion-proof function. We made a Prototype which consisted of lamp fixture and low/high frequency power supply. Testing results show that the hand lamp meets well all the explosion-proof testing requirements of the Korea Industrial Safety Corporation.

• 펄프종이기술
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• 제30권3호
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• pp.57-62
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• 1998

This study is intended to analyze how formations affect the tensile and tear strengths of paper at the same basis weight. Light transmitance method using a scanner was employed to measure the degree of formation in terms of gray scale. Scanning method showed close relationship between gray scale value and basis weight. At the same basis weight a sheet of paper with good formation had higher tensile strength in terms of breaking length than that of a paper with poor formation. There was little difference in tear strength depending on formations.

• 한국기계기술학회지
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• 제20권6호
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• pp.751-756
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• 2018

A study on the weight reduction of a motor shaft in electric vehicle by using optimum design technique was carried out. The structural analysis of a motor shaft was performed by using ANSYS to investigate the structural safety. We also used HEEDS to find the optimal hollow shaft thickness. When the material of the hollow shaft is changed to SCM822H by using ANSYS 14.5 and HEEDS MDO, the weight could be reduced by about 53 % compared to the conventional solid one. From this study, the optimized dimensions of a hollow shaft were determined for light weight design.

• 한국산림과학회지
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• 제73권1호
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• pp.43-54
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• 1986

파종상(播種床)에서 피음처리(被陰處理)를 행(行)한 잣나무 유묘(幼苗)의 상대광도별(相對光度別) 생장관계(生長關係)를 분석(分析)하였던 바 기(其) 결과(結果)를 요약(要約)하면 다음과 같다; 1) 신장생장(伸長生長)에 있어서 지상부(地上部)는 상대광도(相對光度) 37% 구(區)에서, 그리고 기외(其外)의 기관(器官)은 100% 구(區)에서 가장 크게 나타났다. 광도(光度)가 지상부(地上部) 및 지하부(地下部), 묘장(苗長), 직경생장(直徑生長)에 미치는 영향(影響)은 기여율(寄與率) 93%, 26.2%, 21.4%. 48.7%였다. 2) 엽령(葉令)에 따라 엽속(葉束) 및 엽장(葉長)의 변화(變化)는 크게 나타났다. 엽속(葉束)은 1년생(年生)의 경우 광도(光度)가 높을수록, 그리고 2년생(年生)은 상대광도(相對光度) 37% 구(區)에서 가장 많았다. 그리고 엽장(葉長)은 각(各) 처리간(處理間)에 큰 차(差)가 없었다. 이때 광도(光度)가 미치는 엽속(葉束) 및 엽령(葉令)에 대(對)한 기여율(寄與率)은 각각(各各) 39%, 27.8% 였고 엽장(葉長)은 2.5%였다. 3) 중량생장(重量生長)은 상대광도(相對光度) 100% 구(區)에서 가장 컸으나 점차 광도(光度)가 낮아짐에 따라 감소(減少)하는 경향(傾向)이었다. 광도(光度)가 미치는 기여율(寄與率)은 생중량(生重量) 및 건중량(乾重量)의 경우 38%와 7.6%였고, 엽건중량(葉乾重量)은 13.18%로 나타났다. 4) T/R 율(率)은 상대광도(相對光度)가 점차 낮아 질수록 증가(增加)하는 경향(傾向)이었다. 이때 광도(光度)가 T/R율(率)에 미치는 기여율(寄與率)은 7.0%였다. 5) 엽건중량(葉乾重量)과 타기관(他器官)의 생장량간(生長量間)에는 정(正)의 상관(相關)을 인정(認定)할 수 있었고 이들간에는 직선회귀(直線回歸) 관계(關係)에 있음도 알 수 있었다.

• 한국환경농학회지
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• 제33권4호
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• pp.358-363
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• 2014

본 연구는 적색광(660 nm)을 이용한 딸기(Fragaria ${\times}$ ananassa Duch. cvs. "Seolhyang")의 일장연장 처리효과를 구명하고자 수행하였다. 포트실험에서 관행의 백열등 40 Lux와 적색광 0.70, 0.87, $1.05{\mu}mol/m^2/s$ (PAR)에 의한 일장연장 처리는 백열등 처리 보다 적색광 강도가 증가할수록 딸기의 초장, 엽수, 과실무게가 증가하는 경향이었다. 재배포장실험에서 적색 LED $0.7{\mu}mol/m^2/s$ 강도의 일장연장처리는 관행의 백열등 40 Lux 처리 보다 딸기의 엽 생체중, 엽병 생체중, 크라운 생체중과 총 생체중을 유의하게 증가시켰다. 적색 LED 처리가 백열등 처리 보다 딸기의 과실수는 5%, 과실무게는 2.9%, 딸기 수확량은 8.5% 증가시키는 경향이었으나 통계적으로 유의한 차이는 나타내지 않았다. 적색 LED 처리는 백열등 처리보다 상품성 있는 15 g 이상의 딸기과실 수를 증가시키는 경향을 보였다. 따라서 딸기의 일장연장을 위한 광원으로 적색 LED도 이용될 수 있을 것으로 기대되며 향후 관련 연구가 계속 수행되어야 할 것으로 판단된다.

• 한국약용작물학회지
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• 제24권4호
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• pp.277-283
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• 2016

Background: The photosynthetic efficiency cool-season, semi-shade ginseng is normal at low morning temperatures, but drops at high afternoon temperatures. Therefore, optimal plant performance would be ensured if it were possible to control daily light transmission rates (LTR). Methods and Results: Plants were grown in a controlled light environment that replicated 11 AM conditions and comparatively analyzed against plant grown under normal conditions. Growth in the controlled light environment resulted in a 2.81 fold increase in photosynthetic efficiency with no change in chlorophyll content, although LTR were high due to low morning temperatures. Increased aerial plant growth was observed in the ginseng plants adapted to the controlled light environment, which in turn influenced root weight. An 81% increase in fresh root weight (33.3 g per plant on average) was observed in 4-year-old ginseng plants grown in controlled light environment compared to the plants grown following conventional practices (18.4 g per plant on average). With regard to the inorganic composition of leaves of 4-year-old ginseng plants grown in controlled light environment, an increased in Fe content was observed, while Mn and Zn content decreased, and total ginsenoside content of roots increased 2.37 fold. Conclusions: Growth of ginseng under a favorable light environment, such as the condition which exist naturally at 11 AM and are suitable for the plant's photosynthetic activity creates the possibility of large scale production, excellent-quality ginseng.

• KSBB Journal
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• 제16권6호
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• pp.568-572
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• 2001

빛은 식물에서 성장과 발달을 비롯한 다양한 생리화학적인 역할은 지닌다. 본 연구는 hGM-CSF 유전자가 도입된 형질전한 담배의 callus를 현탁배양하여 hGM-CSF를 생산할 때에 빛을 조사하는 시간에 따른 hGM-CSF의 생산에 미치는 영향을 확인하고자 실시하였다. 24시간 명배양, 18시간 명배양과 암배양을 실시하여 세포성장과 분비된 총단백질, hGM-CSF 생산량을 비교 관찰하였다. 세포의 성장은 24시간 명배양일 때 건조중량이 14.4 g/L로 가장 높았다. 분비된 총단백질의 양은 세가지 경우에서 큰 차이를 관찰할 수가 없었지만, 단위 세포당 분비된 총단백질의 양은 암배양이 다른 것에 비해 1.5배 가량 높았다. hGM-CSF의 생산은 18시간 명배양 조건이 가장 좋았으며 최대생산량이 495.5ug/L에 이르렀다. 또한 분비된 총단백질에서 hGM-CSF가 차지하는 비율은 18시간 명배양이 24시간 명배양에 비해 최대 1.8배 높았다.