• Journal of Electrical Engineering and Technology
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• 제2권2호
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• pp.267-273
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• 2007

A depletion-mode MOSFET has been analyzed to evaluate its electrical behavior using a novel 3-D numerical simulation package. The characterizing analysis of the BC MOSFET was performed through short-channel narrow-channel and small-geometry effects that are investigated, in detail, in terms of the threshold voltage. The DIBL effect becomes significant for a short-channel device with a channel length of $<\;3({\mu}m)$. For narrow-channel devices the variation of the threshold voltage was sharp for $<4({\mu}m)$ due to the strong narrow-channel effect. In the case of small-geometry devices, the shift of the threshold voltage was less sensitive due to the combination of the DIBL and substrate bias effects, as compared with that observed from the short-channel and narrow-channel devices. The characterizing analysis of the narrow-channel and small-geometry devices, especially with channel width of $<\;4({\mu}m)$ and channel area of $<\;4{\times}4({\mu}m^2)$ respectively, can be accurately performed only from a 3-D numerical simulation due to their sharp variations in threshold voltages.

• 농업과학연구
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• 제2권2호
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• pp.375-380
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• 1975

본 연구는 인공배지(Rice Polish Agar) 위에서 자라는 문고병균(C. sasakii)의 균사생장, 색소형성 및 균핵형성에 미치는 광선의 영향을 구명하기 위하여 배양적 성질이 다른 두균주(D-3, D-15)를 사용하여 실시하였던 바 다음과 같은 결과를 얻었다. 1) 두 균주 모두 연속관선조사구, 광암교호구 및 암처리구에서 균사 생장량에 차이가 없었다 그리고 균주 D-3는 균사 및 배양기가 갈색으로 착색되엇고 암처리구보다 관선조사구에서 더 많이 착색되었으나 균주 D-15에서는 갈색 색소형성이 없었다. 2) 균핵형성에 미치는 광선의 영향은 두 균주간에 차이가 있었다. 즉 균주 D-15는 각 처리간의 총 균핵형성량에는 유의차가 없었으나, 암처리구에서 광암교호구 및 연속 광선조사구 보다 대형균핵이 많이 형성되었다. 반면 균주 D-3는 연속광선조사구에서는 많은 균핵을 광암교호구에서는 중간정도, 암처리구에서는 적은량의 균핵을 형성하였다.

• 한국산학기술학회논문지
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• 제9권3호
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• pp.822-830
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• 2008

본 논문은 기업의 연구개발 관련 지출이 기업가치에 긍정적 영향을 미치는가를 증권거래소(KSE)상장기업과 코스닥(KOSDAQ)기업을 대상으로 하여 실증적으로 확인하는 것을 목표로 한다. 실증적 분석 결과, 두 시장 모두에서 연구개발비 총액은 기업 가치에 대하여 유의하게 긍정적 영향을 미치고 있었으며, 자산으로 계상한 연구개발비를 포함시킨 모형, 비용으로 계상한 연구개발비를 포함하는 모형들도 모두 두 시장에서 기업 가치에 유의한 긍정적 효과를 나타낸다는 결과가 나타났다. 두 시장 모두에서 자산으로 계상된 연구개발 지출보다는 비용으로 계상된 연구개발비가 기업 가치에 유의한 긍정적 효과를 나타낸다는 결과가 도출되었다.

• Journal of information and communication convergence engineering
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• 제12권4호
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• pp.208-214
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• 2014

In this paper, in order to solve the problems of a narrow viewing angle and the flip effect in a three-dimensional (3D) integral imaging display, we propose an improved system by using an eye tracking method based on the Kinect sensor. In the proposed method, we introduce two types of calibration processes. First process is to perform the calibration between two cameras within Kinect sensor to collect specific 3D information. Second process is to use a space calibration for the coordinate conversion between the Kinect sensor and the coordinate system of the display panel. Our calibration processes can provide the improved performance of estimation for 3D position of the observer's eyes and generate elemental images in real-time speed based on the estimated position. To show the usefulness of the proposed method, we implement an integral imaging display system using the eye tracking process based on our calibration processes and carry out the preliminary experiments by measuring the viewing angle and flipping effect for the reconstructed 3D images. The experimental results reveal that the proposed method extended the viewing angles and removed the flipping images compared with the conventional system.

• 약학회지
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• 제40권3호
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• pp.357-368
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• 1996

The in vitro antibacterial activity of a novel fluoroquinolone, DWP20373(1-Cyclopropyl-6-fluoro-8-methoxy-7-(2,7-diazabicyclo[3,3,0]oct-4-ene-7-yl)-1,4-dihydro-4 oxoquino line-3carboxylic acid) was compared with those of ciprofloxacin (CPFX), sparfloxacin (SPFX) and ofloxacin (OFLX). DWP20373 was more active than SPFX and OFLX but was less potent than CPFX against gram-negative bacteria. DWP20373 showed an excellent activity against L-MRSA and H-MRSA ($MlC_{90}=0.781{\sim}1.563{\mu}g/ml$).The activity of DWP20373 decreased moderately in the presence of 5mM $Mg^{2+}$. However, pH and serum had no effect on the activity of DWP20373. DWP20373 possessed a rapid bactericidal activity against gram-positive and gram-negative strains.

• Biomolecules & Therapeutics
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• 제24권3호
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• pp.298-304
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• 2016

Dianthus superbus (D. superbus) is a traditional crude drug used for the treatment of urethritis, carbuncles and carcinomas. The objective of this study was to confirm the cognitive enhancing effect of D. superbus in memory impairment induced mice and to elucidate the possible potential mechanism. Effect of D. superbus on scopolamine induced memory impairment on mice was evaluated using the Morris water maze and passive avoidance tests. We also investigated acetylcholinesterase (AChE) activity and brain-derived neurotropic factor (BDNF) expression in scopolamine-induced mice. HPLC-DAD analysis was performed to identify active compounds in D. superbus. The results revealed that D. superbus attenuated the learning and memory impairment induced by scopolamine. D. superbus also inhibited AChE levels in the hippocampi of the scopolamine-injected mice. Moreover, D. superbus increased BDNF expression in the hippocampus. Eight compounds were identified using HPLC-DAD analysis. The content of 4-hydroxyphenyl acetic acid was higher than contents of other compounds. These results indicated that D. superbus improved memory functioning accompanied by inhibition of AChE and upregulation of BDNF, suggesting that D. superbus may be a useful therapeutic agent for the prevention or treatment of Alzheimer's disease.

• 대한화장품학회지
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• 제24권3호
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• pp.24-30
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• 1998

Inhibitory effects of the new material obtained from Areca catechu seed (CC-516) according to a special process, and its applicability to the skin as a cosmetic raw material in terms of its efficacy were presented. Areca catechu extract out of 150 medicinal plants, exhibited high inhibitory effect on the porcine pancreatic elastase ($IC_{50}$ : $40.8{\mu}$g/ml). It also had an inhibitory effect on the human leukocyte elastase ($IC_{50}$ : 48.1$\mu$g/ml), hyaluronidase ($IC_{50}$ : $416{\mu}$g/ml), antioxidative activity ($IC_{50}$ : $45.4\mu$g/ml) and free radical scavenging activity ($SC_{50}$ : $10.2{\mu}$g/ml). The cream contained 3％ of CC-516 improved skin hydration above 16.5％. Especially, the skin elasticity increases more than 35% and skin wrinkles decreased more than 23％. The CC-516 was designed to be utilized in cosmetology. The cream containing 3％ of this product has not only protecting effect on the skin mechanical properties provided by the collagen and the elastin in the derm but also restructuring effect of scarring or aging tissue.

• 유통과학연구
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• 제14권3호
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• pp.39-44
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• 2016

Purpose - The purpose of this research is to investigate whether Korea's economic growth can be explained by the endogenous growth theory. Specifically, we test whether R&D expenditure has a positive and significant effect on the economic growth. Research design, data, and methodology - We hypothesize that R&D expenditure has a positive effect on the economic growth after adding control variables in the growth equation. Korean annual data from 1963 to 2011 from Science and Technology Annual of the Ministry of Education, Science and Technology, the Bank of Korea, etc. are used. We estimate the growth equation by GMM in addition to OLS. Results - We found that R&D expenditure has a positive and significant effect on the economic growth after adding the ratio of investment to GDP, the ratio of FDI to GDP, the ratio of government expenditure to GDP, inflation and the ratio of trade openness to GDP as control variables in the growth equation. Conclusions - Our results show that Korea's rapid economic growth for the past five decades can be explained by the R&D-based endogenous economic growth theory. Our results suggest that the policy attention of the Korean government be paid to R&D promotion.

• 기술혁신학회지
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• 제20권3호
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• pp.546-575
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• 2017

이 연구는 정부의 연구개발(R&D) 지원이 중견기업의 연구개발 투자에 미치는 영향을 살펴보았다. 이를 위해 중견기업 표본과 이에 대응되는 중소기업 표본을 대상으로 하여 패널 데이터를 수집하여 DID(difference-in-differences) 회귀분석 방법을 이용하여 정부 지원의 효과를 분석하였다. 본 연구의 결과에 따르면, 정부의 연구개발 지원은 중견 중소기업의 연구개발 순투자를 전반적으로 증가시켰다. 중견기업과 중소기업을 비교해 보면, 정부의 연구개발 지원이 기업 연구개발 투자를 촉진하는 효과는 중소기업에 비해 중견기업에서 더 크게 나타났으며, 중소기업에서는 유의한 영향을 미치지 못하였다. 또한 규모에 따라서 중견기업을 구분해 보면, 상대적으로 규모가 작은 초기 중견기업 표본에서 정부지원이 기업 연구개발 투자를 촉진하는 효과가 더 크고 유의하였다. 기술역량에 따라서 중견기업을 구분해 보면, 상대적으로 기술역량이 우수한 기업 표본에서 정부연구개발사업 참여에 따른 보조금이 기업 연구개발 투자를 촉진하는 효과가 더 강하게 나타난 반면 기술역량이 낮은 기업 표본에서 조세 지원이 기업 연구개발 투자를 촉진하는 효과가 더 강하게 나타났다. 연구의 결과는 중견기업의 혁신을 지속적으로 촉진하기 위한 정부의 연구개발 정책 및 관련 지원 사업이 필요하며, 중견기업의 기업규모, 기술역량, 성장잠재력을 감안하여 정책을 신중하게 수립하고 실행해야 함을 시사한다.

• The Korean Journal of Physiology and Pharmacology
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• 제23권2호
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• pp.113-120
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• 2019

Mannosylerythritol lipids (MELs) are glycolipids and have several pharmacological efficacies. MELs also show skin-moisturizing efficacy through a yet-unknown underlying mechanism. Aquaporin-3 (AQP3) is a membrane protein that contributes to the water homeostasis of the epidermis, and decreased AQP3 expression following ultraviolet (UV)-irradiation of the skin is associated with reduced skin moisture. No previous study has examined whether the skin-moisturizing effect of MELs might act through the modulation of AQP3 expression. Here, we report for the first time that MELs ameliorate the UVA-induced downregulation of AQP3 in cultured human epidermal keratinocytes (HaCaT keratinocytes). Our results revealed that UVA irradiation decreases AQP3 expression at the protein and messenger RNA (mRNA) levels, but that MEL treatment significantly ameliorated these effects. Our mitogen-activated protein kinase inhibitor analysis revealed that phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase or p38, mediates UVA-induced AQP3 downregulation, and that MEL treatment significantly suppressed the UVA-induced phosphorylation of JNK. To explore a possible mechanism, we tested whether MELs could regulate the expression of peroxidase proliferator-activated receptor gamma ($PPAR-{\gamma}$), which acts as a potent transcription factor for AQP3 expression. Interestingly, UVA irradiation significantly inhibited the mRNA expression of $PPAR-{\gamma}$ in HaCaT keratinocytes, whereas a JNK inhibitor and MELs significantly rescued this effect. Taken together, these findings suggest that MELs ameliorate UVA-induced AQP3 downregulation in HaCaT keratinocytes by suppressing JNK activation to block the decrease of $PPAR-{\gamma}$. Collectively, our findings suggest that MELs can be used as a potential ingredient that modulates AQP3 expression to improve skin moisturization following UVA irradiation-induced damage.