• 한국농림기상학회지
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• 제23권4호
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• pp.283-294
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• 2021

경사면일사량은 수평면일사량과 해당위치 지형경사도 간의 기하학적 관계인 일사수광비율을 통해 추정할 수 있다. 그러나 이렇게 추정한 일사량은 주변에 햇빛을 차단하는 장애물이 없다는 것을 가정하기 때문에 만약 실제 농사를 짓고 있는 농장 등에 이를 적용할 경우에 지형으로 인한 차광 등의 영향을 충분히 반영하지 못한다. 음영기복도는 태양의 위치와 지형의 기복으로 인한 직달일사의 변이를 밝기(휘도)로 수치화한 격자 형태의 자료로서, 하나의 격자는 가장 어두운 값 0에서 가장 밝은 값 255까지의 값을 갖는다. 본 연구에서는 지형으로 인한 차광효과를 모의하기 위해 30m 해상도의 DEM을 이용하여 연구지역의 음영기복도를 제작하고 휘도 분석을 수행하였다. 연구지역에 설치된 AWS 22개 지점의 기상자료를 수집하여 일조율 80% 이상인 날을 선별하고, 관측일사량과 각 지점의 휘도를 비교하여 휘도가 지형으로 인한 차광효과를 설명할 수 있는지 확인하였다. 분석결과 휘도와 일사량 간에 상관관계가 있는 것을 확인하였으며, 지형의 영향이 큰 지점에서의 직달일사가 시작되는 시점과 끝나는 시점은 태양고도 보다는 휘도와 잘 부합하는 것으로 나타났다. 추가적인 연구를 통해 주변 지형의 영향을 반영한 휘도를 이용한 상세한 일사량 추정이 가능할 것으로 기대된다.

• 대한화장품학회지
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• 제48권2호
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• pp.169-180
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• 2022

Streptococcus sp.는 일반적으로 히알루론산을 생산하는 균주로 알려져 있다. 본 연구에서는 Streptococcus 균주가 배양하면서 만들어내는 여러 대사산물 중 히알루론산 이외의 영양성분에 주목하였다. 히알루론산이 생성되지 않은 조건에서의 Streptococcus sp. 배양 여과물로 모발 실험용 샘플(HAIRCLE^TM)을 제조하고 모발에 미치는 효과를 확인하였다. 모발의 인장강도는 만능시험기(universal testing machine, UTM)로 측정하였으며, 모발표면의 미세구조는 atomic force microscope (AFM)으로 분석하였다. 이 연구를 통해 Streptococcus sp. 배양 여과물은 손상된 모표피개선, 마찰력증가 및 모발강도의 증가 등의 모발개선 효과가 있는 것으로 확인되었다. 또한 in vitro 모발관련 실험을 통해 Streptococcus sp. 배양 여과물이 모발성장인자인 혈관내피세포 성장인자(vascular endothelial growth factor, VEGF), 간세포성장인자(hepatocyte growth factor, HGF), Wnt10b의 발현 촉진 효과가 있음을 확인 하였으며, 안드로젠 수용체(androgen receptor, AR)와 TGF-β2 발현을 저해시켜 남성형 탈모완화 효과도 있음을 확인 하였다. 또한 산화스트레스에 대해 장벽 관련 인자(INV, CLDN-1)의 발현을 증가시키고, 염증성 인자인 COX-2 발현을 억제시킴으로써 손상된 두피 장벽을 개선하고 유도된 염증을 완화시키는 효능이 있음을 확인하였다.

• 한국전기전자재료학회논문지
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• 제24권12호
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• pp.962-968
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• 2011

In this study, we investigated the effects of Mn dopant (0.1~3.0 at% $Mn_3O_4$ sintered at 1000$^{\circ}C$ for 1 h in air) on the bulk trap (i.e. defect) and grain boundary properties of ZnO, ZM(0.1~3.0) using admittance spectroscopy (AS), and impedance-modulus spectroscopy (IS & MS). As a result, three kinds of defect were found below the conduction band edge of ZnO as 0.09~0.14 eV (attractive coulombic center), 0.22~25 eV ($Zn^{{\cdot}{\cdot}}_i$), and 0.32~0.33 eV ($V^{\cdot}_o$). The oxygen vacancy increased with Mn doping. In ZM, an electrically single grain boundary as double Schottky barrier was formed with 0.82~1.0 eV of activation energies by IS & MS. We also find out that the barriers of grain boundary of Mn-doped ZnO (${\alpha}$-factor=0.13) were more stabilized and homogenized with temperature compared to pure ZnO.

• Transactions on Electrical and Electronic Materials
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• 제13권2호
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• pp.60-63
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• 2012

Enhancement of efficiency and luminance of organic light-emitting diodes was investigated by the introduction of a lithium carbonate ($Li_2CO_3$) electron-injection layer. Electron-injection layer is used in organic light-emitting diodes to inject electrons efficiently between a cathode and an organic layer. A device structure of ITO/TPD (40 nm)/$Alq_3$ (60 nm)/$Li_2CO_3$ (x nm)/Al (100 nm) was manufactured by thermal evaporation, where the thickness of $Li_2CO_3$ layer was varied from 0 to 3.3 nm. Current density-luminance-voltage characteristics of the device were measured and analyzed. When the thickness of $Li_2CO_3$ layer is 0.7 nm, the current efficiency and luminance of the device at 8.0 V are improved by a factor of about 18 and 3,000 compared to the ones without the $Li_2CO_3$ layer, respectively. The enhancement of efficiency and luminance of the device with an insertion of $Li_2CO_3$ electron-injection layer is thought to be due to the lowering of an electron barrier height at the interface region between the cathode and the emissive layer. This is judged from an analysis of current density-voltage characteristics with a Fowler-Nordheim tunneling conduction mechanism model. In a study of lifetime of the device that depends on the thickness of $Li_2CO_3$ layer, the optimum thickness of $Li_2CO_3$ layer was obtained to be 1.1 nm. It is thought that an improvement in the lifetime is due to the prevention of moisture and oxygen by $Li_2CO_3$ layer. Thus, from the efficiency and lifetime of the device, we have obtained the optimum thickness of $Li_2CO_3$ layer to be about 1.0 nm.

• 패션비즈니스
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• 제16권5호
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• pp.39-56
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• 2012

The purpose of this study was to examine in influence on the effect of understanding their major and career self-efficacy on career indecision of the community college students majoring in fashion and is intended to provide useful resources on career education and guidance of students through this research. In order to achieve the objective of study, 349 college students in Gyeonggido were selected for the questionnaires for the understanding major, career self-efficacy, and career indecisions survey. The survey data was analyzed using the statistical program SPSS 12.0 and this was followed by the descriptive statistics, factor analysis, and hierarchical regression analysis. The results were as follows; First, career indecision factors of the college students majoring in fashion were extracted 5 valuables that were 'insufficiencies vocational information', 'an undeceivable character', 'the lack of self well-defined', 'the lack of needs for job' and 'external barrier for the career'. Second, the subordinate valuables of understanding major which is 'social cognition for the major', 'satisfaction on the major course', and 'satisfaction on the major skill', had positive effect on career self-efficacy. Third, understanding of major and the subordinate valuables of career self-efficacy which is 'making goal for the career', 'career information', 'career plan for the future', 'alternative searching', and 'overcoming difficulties' had negative effect on career indecision. Forth, understanding major and career self-efficacy had medicated in career indecision.

• 대한전자공학회논문지SD
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• 제39권3호
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• pp.9-19
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• 2002

본 논문에서는 thermionic emission 모델을 이용하여 SCH 양자우물 레이저 다이오드에 대한 L-I-V특성을 해석적으로 도출하였다. SCH의 bulk 캐리어와 양자우물 속박 캐리어의 관계를 도출하였고, 주입된 전류를 각 영역에서의 캐리어 재결합을 고려한 전류 연속 방정식을 만족하도록 하였다. 또한, high level injection과 전하 중성 조건하에 ambipolar 확산 방정식을 이용하여 캐리어 분포를 고찰하였다. 위 해석적인 모델을 이용하여 계산한 결과, 클래딩 영역의 전위장벽 변화가 전류 전압 특성 변화의 주요 원인으로 나타났다. 또한 thermionic emission에 의한 주입 전류의 forward flux 증가가 캐리어 주입을 증가시키고, 레이저 다이오드의 직렬 저항을 감소시키는 것을 보였다.

• 한국환경과학회지
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• 제29권1호
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• pp.1-13
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• 2020

Recently, a heavy rainfall with high spatial variation occurred frequently in the Korean Peninsula. The meteorological event that occurred in Busan on 3 May 2016 is characterized by heavy rain in a limited area. In order to clarify the reason of large spatial variation associated with mountain height and location of low level jet, several numerical experiments were carried out using the dynamic meteorological Weather Research and Forecasting (WRF) model. In this case study, the raised topography of Mount Geumjeong increased a barrier effect and air uplifting due to topographic forcing on the windward side. As a result, wind speed reduced and precipitation increased. In contrast, on the downwind side, the wind speed was slightly faster and since the total amount of water vapor is limited, the precipitation on the downwind side reduced. Numerical experiments on shifting the location of the lower jet demonstrated that if the lower jet is close to the mountain, its core becomes higher due to the effect of friction. Additionally, the water vapor convergence around the mountain increased and eventually the precipitation also increased in the area near the mountain. Hence, the location information of the lower jet is an important factor for accurately predicting precipitation.

• Journal of Korean Biological Nursing Science
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• 제18권1호
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• pp.27-35
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• 2016

Purpose: The purpose of this study was to identify the assertive behavior of asking smokers not to smoke and investigate the factors related to assertive behavior in patients with vascular diseases. Methods: Participants were 203 adult Korean patients with vascular diseases such as cerebral infarction and myocardial infarction. Data were collected using questionnaires that included the characteristics of secondhand smoke (SHS), secondhand smoke-related variables (Health belief model factors, health promotion model factors) and level of assertive behavior. Descriptive statistics, t-test, ANOVA and multiple regression using SPSS/WIN 18.0 were performed. Results: Participants who never ask smokers not to smoke was 39.9%, whereas participants who always ask was 7.4%. There was a weak positive relationship between assertive behavior and susceptibility to disease (r=.18), severity of disease (r=.19), benefit of assertive behavior to SHS exposure (r=.10), barrier of assertive behavior to SHS exposure (r=.24), and self-rated health (r=.21) respectively. There was a moderate positive relationship between assertive behavior and self-efficacy of assertive behavior to SHS exposure (r=.49). Health belief model factors explained 15.7% variance and health promotion model factors explained 27.0% of assertive behavior. Conclusion: The findings of this study suggest that self-efficacy of assertive behavior to SHS exposure is a very important factor. Therefore the development of a program to foster self-efficacy of assertive behavior regarding SHS exposure in patients with vascular diseases is needed.

• 한국환경보건학회지
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• 제39권3호
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• pp.289-299
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• 2013

Objectives: For the field application of the dielectric barrier discharge plasma reactor, scale-up of the plasma reactor is needed. This study investigated the possibility of inactivation of microorganisms in sewage using pilot multi-plasma reactor. We also considered the possibility of degradation of total organic carbon (TOC) and nonbiodegradable matter ($UV_{254}$) in sewage. Methods: The pilot plasma reactor consists of plasma reactor with three plasma modules (discharge electrode and quartz dielectric tube), liquid-gas mixer, high voltage transformers, gas supply equipment and a liquid circulation system. In order to determine the operating conditions of the pilot plasma reactor, we performed experiments on the operation parameters such as gas and liquid flow rate and electric discharge voltage. Results: The experimental results showed that optimum operation conditions for the pilot plasma reactor in batch experiments were 1 L/min air flow rate), 4 L/min liquid circulation rate, and 13 kV electric discharge voltage, respectively. The main operation factor of the pilot plasma process was the high voltage. In continuous operation of the air plasma process, residual microorganisms, $UV_{254}$ absorbance and TOC removal rate at optimal condition of 13 kV were $10^{2.24}$ CFU/mL, 56.5% and 8.6%, respectively, while in oxygen plasma process at 10 kV, residual microorganisms, $UV_{254}$ absorbance and TOC removal rate at optimal conditions were $10^{1.0}$ CFU/mL, 73.3% and 24.4%, respectively. Electric power was increased exponentially with the increase in high voltage ($R^2$ = 0.9964). Electric power = $0.0492{\times}\exp^{(0.6027{\times}lectric\;discharge\;voltage)}$ Conclusions: Inactivation of microorganisms in sewage effluent using the pilot plasma process was done. The performance of oxygen plasma process was superior to air plasma process. The power consumption of oxygen plasma process was less than that of air plasma process. However, it was considered that the final evaluation of air and oxygen plasma must be evaluated by considering low power consumption, high process performance, operating costs and facility expenses of an oxygen generator.

• Toxicological Research
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• 제32권2호
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• pp.109-114
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• 2016

Allergic skin inflammation such as atopic dermatitis is characterized by skin barrier dysfunction, edema, and infiltration with various inflammatory cells. The anti-inflammatory effects of Apo-9'-fucoxanthinone, isolated from Sargassum muticum, have been described in many diseases, but the mechanism by which it modulates the immune system is poorly understood. In this study, the ability of Apo-9'-fucoxanthinone to suppress allergic reactions was investigated using a mouse model of atopic dermatitis. The Apo-9'-fucoxanthinone-treated group showed significantly decreased immunoglobulin E in serum. Also, Apo-9'-fucoxanthinone treatment resulted in a smaller lymph node size with reduced the thickness and length compared to the induction group. In addition, Apo-9'-fucoxanthinone inhibited the expression of interleukin-4, interferon-gamma and tumor necrosis factor-alpha by phorbol 12-myristate 13-acetate and ionomycin-stimulated lymphocytes. These results suggest that Apo-9'-fucoxanthinone may be a useful therapeutic strategy for treating chronic inflammatory diseases.