• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.18-18
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• 2003

• Journal of the Korean Chemical Society
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• v.47 no.5
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• pp.466-471
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• 2003

The effect of polyamines on the cabbage phospholipase D(PLD) activity was investigated. The PLD activity was determined by pH-stat titration of phosphatidic acid, one of the enzymatic reaction product, using phosphatidyl choline small unilamellar vesicles as a substrate. The cabbage PLD was activated approximately 4 fold by spermine at 1 mM concentration. This spermine effect appears to be similar to the previous report on the PLD activation of rat brain mitochondrial fraction. It was also found that cationic polypetides such as polylysine and polyhistidine exerted a marked enhancement effect on the cabbage PLD. Particularly polyhistidine exerted approximately 5.5 fold enhancement effect at 0.062 mM concentration. The polyamine effect on the cabbage PLD was reexamined in the phosphatidylcholine/sodium dodecyl sulfate mixed micellar system. The relevance of polyamine effect on PLD activity is discussed in relation to the active site of PLD.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.11
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• pp.1090-1099
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• 2004

In this paper a novel design of equilateral-triangular microstrip antenna using PIN diode fur switching the resonant frequency is presented and experimentally studied. The proposed antenna has changed the resonant frequency by length of spur-lines on the patch, and PIN diodes are utilized to switch the spur-line on and off. The shape of the spur-line is changed according to the on and off states of PIN diode and the equilateral triangular microstrip antenna has different resonant frequencies in accordance with them. The resonant frequency is 1.22 GHz with off states since the surface currents flow the periphery of T shape spur-lines, while the resonant frequency is 1.82 GHz with on states since the surface currents are little effect with the conventional equilateral triangular microstrip antenna. The radiation pattern of the proposed antenna has a good linear polarization with the cross polarization of -20 dB both with on and off states.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.299-305
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• 2010

Purposes: The purposes of this study were to investigate the optical, structural and electrical properties of the antimony doped tin oxide(ATO) thin films according to certain variable deposition conditions, such as RF input power and T-S (target-substrate) distance change, using transparent conducting oxide (TCO). Methods: ATO thin films of Sb concentration ratio with $SnO_2:Sb_2O_5$ = 95:5 wt% were deposited at room temperature by RF magnetron sputtering method. Results: ATO thin films were most sensitive to the RF input power: light transmittance was 78% at RF input power of 30W, and 0.56 nm for the surface roughness and 1007 $\Omega{\cdot}cm^{-2}$ for the sheet resistance as well. Conclusions: It was found that ATO thin films were showed the large change in its characteristics of structural, optical and electrical properties which were affected by T-S distance and RF input power.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.413-413
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• 2011

최근 전기, 전자, 반도체 산업의 발전으로 전 고상 박막리튬전지는 초소형, 초경량의 마이크로 소자의 구현을 위한 고밀도 에너지원으로 각광받고 있다. 현재 양극박막은 대부분LCO(LiCoO2)계열이 이용되고 있으나, 코발트는 높은 가격과 인체 유해성 뿐만 아니라 상대적으로 낮은 용량(~140 mAh/g)등의 단점을 갖고 있어 향후 보다 고용량의 양극박막이 요구된다. 3원계 양극활물질 LiMO2(M=Co,Ni,Mn,etc.)은 우수한 충방전 효율 과 열적 안정성 뿐 아니라 277mAh/g의 높은 이론용량을 갖고 있어 고용량 양극박막으로의 적용시 고용량 박막이차전지 제작이 가능하다. 본 연구에서는 전 고상 박막 전지의 구현을 위하여 RF 스퍼터링법을 사용하여 Li[Li0.2Mn0.54Co0.13Ni0.13]O2 박막을 증착하였다. Li/MnCoNi의 몰 비율을 변화시켜 높은 전기화학적 특성을 갖는 분말을 합성하여 제조한 타겟으로 Pt/TiO2/SiO2/Si 기판위에 RF 스퍼터법을 이용하여 박막을 성장시켰다. 박막 증착 시 가스의 비율은 Ar:O2=3:1로 하고 증착 압력의 조절(0.005~0.02 torr)을 통하여 박막의 두께와 표면 특성을 조절하며 성장시켰다. 또한 박막을 다양한 온도에서($400{\sim}550^{\circ}C$) 열처리하여 결정화도와 전기화학적 특성을 측정하였다. 증착 된 박막의 구조적 특성은 X-ray diffraction(XRD) 과 scanning electron microscopy(SEM)로 관찰되었다. 박막의 전기화학적 특성 평가를 위하여 Cyclic voltammatry를 측정하여 가역성의 정도를 확인하고 WBC3000 battery cycler를 이용한 half-cell 테스트를 통하여 박막의 용량을 평가하였다.

• Korean journal of food and cookery science
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• v.2 no.1
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• pp.65-70
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• 1986

Total pectin content of Korean apple varieties at optimum harvest time was deter-mined by carbazole reaction method and pectin fraction content in each variety was also determined. Properties of pectin extracted ty 2a Sodium hexa metaphesphate were compared with commercial pectin. Among apple varieties, pectin contents varied in the range of 0.26-0.48％ on fresh basis and 1.76-4. 0% on dry basis. Ball's was the highest and then high in order of Spur early blaze, Golden delicious, Fuji. , Jonathan. In each pectin fraction, soluble pectin fractions in Rall's was the lowest and in both Spur early blaze and Golden Delicious were highest but insoluble fractions in the latter were lowest. Thub the changes in poetic substances in Spur early blaze and Golden delicious seem to he occurred: during early ripening. In the analysis of properties of isolated pectin, ash, anhydrogalacturonic arid7(AUA) content and methoxyl content were different among apple varieties. Ash and methoxyl content in all isolated pectin were higher and AUA content lower than in commercial pectin. Degree of esterification (DE) in all apple varieties were above 70％.

• Journal of Convergence for Information Technology
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• v.12 no.4
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• pp.143-157
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• 2022

The aim of this study is to design Spudsville, an immersive game environment in Minecraft that can effectively help learners acquire the English language. To create a successful learning experience using Minecraft, the researchers adopted the Agile Model and the Design Thinking approach. The researchers first conducted an analysis through an extensive literature review in order to assess the learners' needs. Afterwards, they designed and developed a Minecraft world based on the data collected during the analysis phase. The researchers learned that implementing constructivist and behaviorist approaches has benefits, even though applying a cognitivist-learning model to Spudsville could have provided the researchers with more insight on how learner processes information. Making these adjustments could improve Spudsville's effectiveness and could potentially help the ways in which gamified learning aids with language acquisition.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.2
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• pp.121-130
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• 2023

Finite element analysis is widely used to predict the structural stability and tooth contact performance of gears. This study focused on the effect of finite element modeling conditions of a spur gear on the simulation result and the model simplification. The gear body and teeth, teeth width, configuration of mesh, frictional coefficient, and simulation time interval (gear mesh cycle division) were selected for model simplification for gear analysis. The static transmission error during a single-gear mesh cycle was calculated to represent the performance of the gear, and the elapsed time was measured as a simplification factor. Contact stress distribution was also checked. The differences in maximum transmission error and elapsed time depending on the model simplification methods were analyzed. After all simplification methods were estimated, an optimal combination of the methods was defined, and the result was compared with that of the most detailed modeling methods.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.2
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• pp.147-157
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• 2023

Centella asiatica extract is widely used as a raw material for cosmetics due to its various effects, but it is difficult to expect penetration into the skin due to its high molecular weight and low solubility. In order to solve these problems, lipid-based liposomes of various types were developed to increase skin absorption. Therefore, in this study, we tried to increase the skin absorption rate by preparing transfersomes using surfactants as edge activators in existing liposomes. Liposome and transfersomes containing Span 80 and Tween 20, 60, 80, and 85, respectively, were prepared using a high-pressure homogenizer, and we evaluated the particle size, polydispersity index, zeta potential, and skin absorption rate. As a result, there was almost no change in the physical properties of particle size, polydispersity index and zeta potential from 25 ℃ to 60 d, and the particle size of transfersomes containing Tween 20, 60, and 80 increased after 60 d at 45 ℃. Madecassoside, main substances of the Centella asiatica extract was used as an standard and madecassoside was measured and calculated when measuring the skin absorption rate using Franz diffusion cells. As a result, formulations containing Tween 20 were the most, whereas formulations containing Span 80 were the least. According to the skin absorption coefficient (Kp) value, all formulations showed 'very fast', and the absorption rate was similar or greater than that of liposomes, except for formulations containing Span 80. Through this, it was confirmed that the larger the HLB value of the nonionic surfactant, the smaller the particle size of the transfersome, and the increased skin absorption rate due to the increased flexibility of the vesicle membrane. Through this study, transfersome using surfactant as an edge activator can be expected to solve local skin problems not only as a cosmetic raw material or product, but also by increasing skin absorption.

• Journal of the Korea Convergence Society
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• v.5 no.4
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• pp.137-146
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• 2014

This study investigated the effects of response prompting through 3-steps compliance training to reaction time for child with Asperger's syndrome(AS). The participant was 3 and 8 year-old boy who was diagnostic As with non-compliant, delayed receptive language. Study design was multiple-baseline across behaviors. Target Behaviors were hands-up, following direction, and answering behavior. Dependent variable was latency reaction time during compliance training. This results mean that reaction time was increased raise hands-up behavior, compliance behavior and response ask questions. During intervention, the participant improve the rate on-task behavior as well as reduce off-task behaviors.