• 한국진공학회지
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• 제7권3호
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• pp.187-194
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• 1998

저압 유기금속 화학기상증착법을 이용하여 $600^{\circ}C$와 $620^{\circ}C$에서 InP 기판 위에 격자 일치된 InGaAsP 에피층을 성장하였다. InGaAsP 에피층의 기상에서의 조성에 따른 고상에 서의 조성의 변화를 분석하여, 3족 원소의 경우에는 기상에서 반응이 일어나는 표면으로의 3족 원료의 확산에 의해 조성이 결정되었으며, 5족의 경우에는 As과 P의 증기압의 차이와 $AsH_3$, $PH_3$의 열분해 효율의 차이에 의해 조성이 결정되었다. 측정 온도에 따른 PL스펙트 럼의 변화를 분석하여 75K 이하의 저온에서 비정상적인 PL스펙트럼 피크의 거동을 관찰하 였다. 이러한 PL피크의 비정상적인 거동은 투과 전자현미경 분석과 투과 스펙트럼 분석을 통해 국부적인 ordering의 차이에 의한 에너지 갭의 공간적인 변화에 의해 나타나는 것으로 설명되었다.

• 대한산업공학회지
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• 제3권1호
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• pp.39-47
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• 1977

Most of the current literature on inventory theory has been devoted to the study of single stage models. A class of inventory problems which is of great interest is the multistage inventory system which involves a series and hierarchical sequence of stations. This study analyzes some aspect of the series type and multi-stage inventory system, using the fixed cycle ordering which bas a modificatory control function in the system equations. The objective of this study is to clarify the dynamic behavior of the system. The author has derived the theoretical formulas of variation of ordering quantity and stock fluctuation of each stage due to power spectral density function. Influence of parameters such as, (1) intensity of autocorrelation of demand sequence ($\lambda$), (2) forecasting exponential smoothing factors of each stage (${\alpha}_1,\;{\alpha}_2,\;{\alpha}_3$) and (3) production control factor of the 3rd stage ($\gamma$), as operators of the system on the variation of ordering quantity and stock fluctuation of the system. is also clarified. As a result of this study, the relations between the variation of ordering quantity, stock fluctuation and the parameters of the system, have been found. The principles and the theorical analysis presented here will be applicable to more complex type of discrete control systems in constructing the specific condition of the system to minimize inventory variances.

• Bulletin of the Korean Chemical Society
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• 제18권11호
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• pp.1210-1213
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• 1997

• 한국결정성장학회지
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• 제7권4호
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• pp.599-609
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• 1997

콜로이드 분산의 상거동 및 동적 운동 및 형성되는 침적체의 구조와 물성은 전산실험법으로 조사되었다. 다양한 물성과 공정조건들은 Peclet수를 사용하여 조사될 수 있다. 형성된 구조는 구조인자 및 반경방향 분포함수로서, 물성은 계면의 궤적선도를 사용하여 조사되었다. 침적체의 형성 조건과 구조가 조사되었으며 침적시간과 높이에 따른 구조와 물성이 조사되었다. 침적체가 결정구조를 갖는 최적 Peclet수의 범위가 있으며 결정화와 관련된 현상들은 공정조건에 크게 좌우됨을 알 수 있다. 현 방법과 결과들은 고밀도 침적체의 제조시 세라믹 미분체 공정을 설계하는데 사용될 수 있다.

• 대한영양사협회학술지
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• 제25권3호
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• pp.165-177
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• 2019

This study examined the perception and behavior of fast food restaurant customers toward ordering kiosk nutrition information. Specifically, the influence of nutrition information transparency and information quality on behavioral intention and revisit intention were identified. In addition, the difference in the nutrition information transparency and information quality was analyzed according to the health consciousness of the customers. The study employed a self-administered survey that was distributed both online and offline from November 8~22, 2018. The sample of the study was customers who had experienced ordering from the kiosk in a fast food restaurant in the six months prior to taking the survey. A total of 250 (98.0%) respondents completed the survey, which was used for data analysis. As a result, there was a significant relation between transparency and nutrition information quality (P<0.001). The higher the visibility and inferability of the nutrition information, the better the nutrition information quality. Nutrition information quality has a significant impact on the levels of customer satisfaction and revisit intention (P<0.001). For the differences in the transparency and nutrition information quality by health consciousness of customers, the results indicated that groups with high health consciousness (3.74 or higher) perceived a higher transparency and nutritional information quality than those with a lower health consciousness. These findings can form the basis of a strategy in developing nutrition information of ordering kiosks in restaurants. In addition, it can be applied to academia and industry.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2001년도 춘계 학술발표회 논문집
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• pp.15-18
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• 2001

• Applied Microscopy
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• 제27권4호
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• pp.473-481
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• 1997

Disorder-order transformation of nanocrystalline FeAl have been investigated by a combination of electron and X-ray diffraction analysis including high resolution electron microscopy and differential scanning calorimetry. Fe-50at.%Al powders mechanically alloyed for 90 hours consist of $5\sim10$ nm size grains haying either disordered b.c.c. structure or amorphous structure. X-ray and electron diffraction of mechanically alloyed FeAl powders show that disorder-order transformation occurs at the temperature range of $300^{\circ}C\sim320^{\circ}C$. Such a low-temperature ordering behavior exhibiting an exothermic reaction is attributable to the nm-scale grain structure with a large amount of defects accumulated during mechanical alloying process.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.553-557
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• 2005

The nature of the phase transition in nematic liquid crystalline elastomer is investigated using NMR and calorimetry. The balance between ordering and disordering effects of the polymer network is identified as crucial for the behavior of the order parameter near the phase transition. The change from supercritical to critical regime with adding low molecular weight liquid crystal to the elastomer is proven.

• Nuclear Engineering and Technology
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• 제37권3호
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• pp.293-298
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• 2005

We have performed the density functional theory calculations of $UO_2$ using the spin-polarized generalized gradient approximation (SP-GGA) and the SP-GGA+U approach. The SP-GGA+U approach correctly predicts the insulating electronic structure with antiferromagnetic ordering, but the SP-GGA calculations predict metallic behavior. The cohesive properties obtained from the SP-GGA+U calculations are in good agreement with the available experimental results and previous calculations. The spin-polarized local density of states shows that the antiferromagnetic ordering of $UO_2$ is governed by 5f orbitals of uranium ion. Our calculations demonstrate that the strong correlation of U 5f electrons should be taken into account for a reliable description of $UO_2$ physics.

• Journal of Magnetics
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• 제8권2호
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• pp.85-88
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• 2003

The magnetic and transport properties far single crystals of Ru-doped mono-layered manganites $La_{0.5}Sr_{1.5}-Mn_{1-x}Ru_xO_4$ (0$\leq$$\chi$$\leq$0.1) have been studied using neutron diffraction and magnetization measurements. Temperature dependent magnetization data reveal that with an increase in the Ru concentration the parent charge ordered antiferromagnetic state is gradually destroyed and new ferromagnetic phase evolves. In the low Ru-doped system spin glass behavior is apparent in low temperature region, which is confirmed by ac and do magnetization measurements. The competing magnetic interaction between Mn/Mn and Mn/Ru couples is the most likely cause of the spin glass transition.