• Korean Journal of Materials Research
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• v.22 no.6
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• pp.316-320
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• 2012

$Co_3O_4$, $Al_2O_3$ and $Co_3O_4$/$Al_2O_3$ mesoporous powders were prepared by a sol-gel method with starting matierals of aluminum isopropoxide and cobalt (II) nitrate. A P123 template is employed as an active organic additive for improving the specific surface area of the mixed oxide by forming surfactant micelles. A transition metal cobalt oxide supported on alumina with and without P123 was tested to find the most active and selective conditions as a heterogeneous catalyst in the reaction of styrene epoxidation. A bBlock copolymer-P123 template was added to the staring materials to control physical and chemical properties. The properties of $Co_3O_4$/$Al_2O_3$ powder with and without P123 were characterized using an X-ray diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), a Bruner-Emmertt-Teller (BET) surface analyzer, and $^{27}Al$ MAS NMR spectroscopy. Powders with and without P123 were compared in catalytic tests. The catalytic activity and selectivity were monitored by GC/MS, $^1H$, and $^{13}C$-NMR spectroscopy. The performance for the reaction of epoxidation of styrene was observed to be in the following order: [$Co_3O_4$/$Al_2O_3$ with P123-1173 K > $Co_3O_4$/$Al_2O_3$ with P123-973 K > $Co_3O_4$-973 K>$Co_3O_4$/$Al_2O_3$-973 K > $Co_3O_4$/$Al_2O_3$ with P123-1473 K > $Al_2O_3$-973 K]. The existence of ${\gamma}$-alumina and the nature of the surface morphology are related to catalytic activity.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.3
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• pp.291-300
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• 2016

The emergence of smart devices and IoT leads to the appearance of O2O service to blur the difference between online and offline. As online services' merits were added to the offline market, it caused a change in the dynamics of the offline industry, which means the offline-space's digitization. Unlike these changing aspects of the offline market, exhibition industry grows steadily in the industry, however it is also possible to create a new value added by combining O2O service. We conducted a survey targeting 20 spectators in '2015 Seoul Design Festival' at COEX. The survey was used to analysis of the spatial structure and generate the dataset for machine learning. We identified problems with the analysis study of the existing spatial structure, and based on this investigation we propose a new method for analyzing a spatial structure. Also by processing a machine learning technique based on the generated dataset, we propose a novel evaluation model of exhibition-space cells for O2O service layout.

• Journal of the Korean Ceramic Society
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• v.34 no.8
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• pp.811-816
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• 1997

SiO2-P2O5-B2O3 glass soot was fabricated by flame hydrolysis deposition and their properties by SEM, XRD, TGA-DSC were investigated., The mechanism of consolidation process of a glass soot as a function of consolidation temperature was analyzed by SEM observations. In the XRD patterns, the crystalline peaks which seem to be generated from B2O3 and BPO4 were observed. When the temperature of heat treatment exceeded 105$0^{\circ}C$, the non-crystalline state of SiO2-P2O5-B2O3 glass was observed. In the TGA-DSC curves, the evaporation of water molecule by a sudden endothermic reaction was observed at 128$^{\circ}C$ and a broad endothermic peak was seen in the temperature range of 40$0^{\circ}C$-95$0^{\circ}C$, without any weight loss. Finally, this peak was began to recover its baseline at 953$^{\circ}C$. This point is equal to the temperature at which the densification begins. Furthermore, we observed that the addition of dopants such as P2O5 and B2O3 decrease the onset of consolidation temperature till 95$0^{\circ}C$.

• Korean Journal of Materials Research
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• v.9 no.6
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• pp.547-550
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• 1999

Optical and electrical properties of MgO-CaO films as a protective layer for AC plasma display panel were studied. When the [(CaO/(MgO+CaO)] ratio of evaporation starting materials was optimum composition, 0.1, firing voltage and memory margin of the film were 176V and 0.5, respectively. When [CaO/(CaO+MgO)] was 0, 0.1 and 0.2, memory margin was 0.39, 0.5 and 0.41, respectively, and surface roughness of films was $27.7\AA$, $21.1\AA$ and $40.3\AA$, respectively. It was thought that memory margin had a reverse-relation with surface roughness. The density of film was calculated by measuring the refractive index of film. The density of MgO film was 3.21g/㎤ and the density of film, when [CaO/(CaO+MgO)] was 0.1, was 3.632g/㎤. The mixture of MgO-CaO films showed a good transmittance property in the visual range.

• Korean Journal of Crystallography
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• v.5 no.2
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• pp.108-112
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• 1994

C19H20O5, Mr=314.337, triclinic,PI, a=10.291(2)A, b=11.218(3)A, c=3.059(1)A, α=74.54(2)°, β=1148.84(1)°, r=109.84(2)°, V=883.283(2)A3, λ(Mo Kα)=0.71069A, μ=0.47 mm-1, F(000)=324, 296K, Z=2, Dx=1.18Mgm-3. Final R=0.0580 for 1637[F>3σ(F)]unique refledtions. α,β-diphenylsuccinic acid, C16H14O4, are connedted with the solvent actone by hydrogen bond O(4)-H˙˙˙O(5), forming a dimer related by related by centrosymmentry thorough intermolecualr carboxylic hydrogen bond O(1)-H˙˙˙O(2)(-x,-y,-z). The nearest distance 3.288A[O(2)˙˙˙O(2)(-x,-y,-z)] between the dimers shows that the packing of the dimer is govermed by van der Waals'force.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1471-1474
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• 1998

ZnO Varistor with composition of ZnO, $Bi_2O_3$, $Sb_2O_3$, CoO, NiO, $MnO_2$, $Cr_2O_3$, $Al_2O_3$ was fabricated by sintering methods. The purpose of this paper is to present certified voltage-current test data and a summary of electrical characteristics of the ZnO varistors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.480-483
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• 2001

Epitaxial rutile-$TiO_2$ and anatase-$TiO_2$ films were grown at $800^{\circ}C$ on $Al_2O_3$ (1102) and $LaAlO_3$ (001), respectively, using pulsed laser deposition. The formation of different phases on different substrates could be qualitatively explained by the atomic arrangements at the interfaces. We also successfully deposited epitaxial rutile-$TiO_2$ and anatase-$TiO_2$ films on conductive $RuO_2$ and $La_{0.5}Sr_{0.5}CoO_{3}$ electrodes, respectively. Using a Kelvin probe, we measured the photovoltaic properties of these multilayer structures. A rutile-$TiO_2$ film grown on $RuO_2$ showed a very broad peak in the visible light region. An epitaxial anatase-$TiO_2$ film grown on $La_{0.5}Sr_{0.5}CoO_{3}$ showed a strong peak with a threshold energy of 3.05 eV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.480-483
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• 2001

Epitaxial rutile-TiO$_2$ and anatase-TiO$_2$ films were grown at 80$0^{\circ}C$ on $Al_2$O$_3$ (1102) and LaAlO$_3$ (001), respectively, using pulsed laser deposition. The formation of different phases on different substrates could be qualitatively explained by the atomic arrangements at the interfaces. We also successfully deposited epitaxial rutile-TiO$_2$ and anatase-TiO$_2$ films on conductive RuO$_2$ and La$_{0.5}$Sr$_{0.5}$CoO$_3$ electrodes, respectively Using a Kelvin probe, we measured the photovoltaic properties of these multilayer structures. A rutile-TiO$_2$ film grown on RuO$_2$ showed a very broad peak in the visible light region. An epitaxial anatase-TiO$_2$ film grown on La$_{0.5}$Sr$_{0.5}$CoO$_3$ showed a strong peak with a threshold energy of 3.05 eV 3.05 eV

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.21-32
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• 2007

The households to be surveyed are usually huge number at the level of a city or metropolitan survey, not to mention a nationwide travel survey. Therefore, household travel surveys to figure out true origin-destination (O/D) trip patterns (population O/D) are conducted through a sampling method rather than by surveying all of the population in the system. Therefore, the population O/D pattern can only be estimated by expanding the sampled O/D patterns to the population. It is very difficult to avoid the errors involved in the process of sampling, surveying and expanding O/D data. In order to minimize such errors while estimating the true O/D patterns of the population, the validation and adjustment process should employed by doing a comparison between the expanded sample O/D data and observed link traffic volumes. This study suggests a method of validation and adjustment of the expanded sample O/D data by comparing observed link volumes at several screenlines. The study also suggests a practical technique to modify O/D pairs which are excluded in the screenline validation process by comparing observed traffic volume with the results of traffic assignment analysis. An empirical study was also conducted as an example applying the suggested methods of validation and adjustment with Korea's nationwide O/D data and highway network.

• Management & Information Systems Review
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• v.38 no.2
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• pp.29-46
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• 2019

O2O services, a form of mobile commerce, are increasing due to the widespread use of smartphones and the rational consumption trend of young consumers. In addition, the introduction of Social Commerce's O2O service has transformed customer experience into innovation. Therefore, the purpose of this study is to investigate the effect of O2O service characteristics and social commerce provider characteristics on the social commerce 's O2O service as a social psychological image that consumers have at the point of purchase and use time, as a smart shopper feeling and a cheapness shopper feeling. And the relationship between consumer satisfaction and intention to use through Structure Equation Modeling, and to suggest the implications for O2O service management that can provide greater satisfaction to consumers by identifying the process of creating satisfaction of O2O service. The results of the study show that price discounts and scarcity of social commerce's O2O service characteristics have shown that it increases smart shopper feeling. Also, it was confirmed that brand awareness and ease of purchase, which are characteristics of social commerce, confirms the increase of cheapness shopper feeling. We also confirmed the effect of smart shopper feeling and cheapness shopper feeling on satisfaction. This satisfaction has a positive effect on the intention to use. The result of this study is that it is necessary to reduce the cheapness shopper feeling of consumers and to emphasize the price discount and scarcity so that the smart shopper feeling occurs in order to satisfy the consumers who purchase O2O service products.