• Journal of the Korean Vacuum Society
• /
• v.7 no.3
• /
• pp.187-194
• /
• 1998

InGaAsP epitaxial layers lattice matched to InP were grown at 600 and $620^{\circ}C$ by low pressure metalorganic chemical vapor deposition. Solid phase composition of group III was controlled by the diffusion flux gas phase to the reachion surface. For the case of group V, the difference of As and P vapor pressure and pyrolysis efficiency of $PH_3$and $AsH_3$ mainly determined their in corporation into solid. An abnormal behavior of peak energy shift was observed below 75K in temperature variant photoluminescence study. This abnormal behavior was explained by the difference in order of ordering which makes spatial variation of energy gap in InGaAsP layer and this explanation was supported by the analyses of transmission electron microscopy and transmission spectroscopy.

• Journal of Korean Institute of Industrial Engineers
• /
• v.3 no.1
• /
• pp.39-47
• /
• 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
• /
• v.18 no.11
• /
• pp.1210-1213
• /
• 1997

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.7 no.4
• /
• pp.599-609
• /
• 1997

The phase behavior and dynamics of colloid suspensions and the resulting structures and properties of powder compacts were examined by a computer experimental method for cooperative packing processes. A wide range of properties and process conditions such as arbitrary particle size, medium densities, field strength, and temperature could be examined using the Peclet number (Pe). We demonstrated that an optimum range of Peclet number for the ordering of sediments was present and that the phenomena related to the ordering such as the onset of crystallization, the phase behavior, etc. strongly depend on process conditions. The present work appears to be useful to design the processing method of ceramic spherical submicron powders for the preparation of high-density green compacts.

• Journal of the Korean Dietetic Association
• /
• v.25 no.3
• /
• pp.165-177
• /
• 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.

• Proceedings of the Korean Society of Rheology Conference
• /
• 2001.06a
• /
• pp.15-18
• /
• 2001

• Applied Microscopy
• /
• v.27 no.4
• /
• pp.473-481
• /
• 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
• /
• 2005.07a
• /
• pp.553-557
• /
• 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
• /
• v.37 no.3
• /
• pp.293-298
• /
• 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
• /
• v.8 no.2
• /
• pp.85-88
• /
• 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.