• Korean Journal of Materials Research
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• v.23 no.3
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• pp.183-189
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• 2013

$Cu_2ZnSn(S,Se)_4$ material is receiving an increased amount of attention for solar cell applications as an absorber layer because it consists of inexpensive and abundant materials (Zn and Sn) instead of the expensive and rare materials (In and Ga) in $Cu(In,Ga)Se_2$ solar cells. We were able to achieve a cell conversion efficiency to 4.7% by the selenization of a stacked metal precursor with the Cu/(Zn + Sn)/Mo/glass structure. However, the selenization of the metal precursor results in large voids at the absorber/Mo interface because metals diffuse out through the top CZTSe layer. To avoid the voids at the absorber/Mo interface, binary selenide compounds of ZnSe and $SnSe_2$ were employed as a precursor instead of Zn and Sn metals. It was found that the precursor with Cu/$SnSe_2$/ZnSe stack provided a uniform film with larger grains compared to that with $Cu_2Se/SnSe_2$/ZnSe stack. Also, voids were not observed at the $Cu_2ZnSnSe_4$/Mo interface. A severe loss of Sn was observed after a high-temperature annealing process, suggesting that selenization in this case should be performed in a closed system with a uniform temperature in a $SnSe_2$ environment. However, in the experiments, Cu top-layer stack had more of an effect on reducing Sn loss compared to $Cu_2Se$ top-layer stack.

• The Research Journal of the Costume Culture
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• v.26 no.2
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• pp.233-250
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• 2018

This study examined images typical to this city and explored ways to develop cultural products using these images. Researchers reviewed literature about fashion cultural products and related previous research, and then conducted a closed-ended survey to analyze universal fashion preferences. For the examination material, such a way was used as information data base and network review inside and outside the country, dissertation screen, and published media including separate volumes. The following are considering points in the developing process. First, the study identified design, color, price, practicality and quality as factors that should be taken into consideration when using the image of Gangneung. In particular, it determined that the image needs to reflect a modern sensibility while maximizing its representation of local culture. Second, Gangneung's symbolic image should incorporate the sea, Gyeongpo, and coffee. In other words, the sea, Gyeongpo, and coffee should receive top symbolic priority. Third, from a development perspective, the most appropriate items for displaying the image include t-shirts, keychains, umbrellas, or other accessories, since these items are easily available in terms of price. In sum, this study highlighted the necessity of reconsidering Gangneung's currents ymbolic image, suggesting that a new image should be developed. Developing a typical fashion cultural product image will enrich Gangneung's cultural industry and the distribution of newly designed products will improve the localeconomy.

• Korean Journal of Materials Research
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• v.28 no.9
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• pp.506-510
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• 2018

Nitrogen is a serious contaminant in natural gas because it decreases the energy density. The natural gas specification in South Korea requires a $N_2$ content of less than 1 mol%. Thus, cost-effective $N_2$ removal technology from natural gas is necessary, but until now the only option has been energy-intensive processes, e.g., cryogenic distillation. Using porous materials for the removal process would be beneficial for an efficient separation of $CH_4/N_2$ mixtures, but this still remains one of the challenges in modern separation technology due to the very similar size of the components. Among various porous materials, metal-organic frameworks (MOFs) present a promising candidate for the potential $CH_4/N_2$ separation material due to their unique structural flexibility. A MIL-53(Al), the most well-known flexible metal-organic framework, creates dynamic changes with closed pore (cp) transitions to open pores (ops), also called the 'breathing' phenomenon. We demonstrate the separation performance of $CH_4/N_2$ mixtures of MIL-53(Al) and its derivative $MIL-53-NH_2$. The $CH_4/N_2$ selectivity of $MIL-53-NH_2$ is higher than pristine MIL-53(Al), suggesting a stronger $CH_4$ interaction with $NH_2$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.4
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• pp.231-238
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• 2004

The conditions are obtained for the decomposition of solid radioactive wastes, including ion exchange resin, zeolite, charcoal, and sludge from nuclear power plant. In the process of decomposing the radioactive wastes was used the microwave acid digestion method with mixed acid. The solution after acid digestion by the following method was colorless and transparent. Each solution was analyzed with ICP-AES and AAS and the recovery yield for 5 different elements added into the simulated radioactive wastes were over $94{\%}$. The elemental analysis of destructive low and medium level radioactive wastes by the proposed microwave acid digestion conditions concerning the chemical characteristics of each radioactive waste are expected to be useful basic data for development of optimal glass formulation.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.101-112
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• 2013

Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM) offers opportunities to make advances in many research areas including hydrology by providing near-global scale elevation measurements at a uniform resolution. Its wide coverage and complimentary online access especially benefits researchers requiring topographic information of hard-to-access areas. However, SRTM DEM also contains inherent errors, which are subject to propagation with its manipulation into analysis outputs. Sensitivity of hydrologic analysis to the errors has not been fully understood yet. This study investigated their impact on estimation of hydrologic derivatives such as slope, stream network, and watershed boundary using Monte Carlo simulation and spatial moving average techniques. Different amount of the errors and their spatial auto-correlation structure were considered in the study. Two sub-watersheds of Geum and Deadong River areas located in South and North Korea, respectively, were selected as the study areas. The results demonstrated that the spatial presentations of stream networks and watershed boundaries and their length and area estimations could be greatly affected by the SRTM DEM errors, in particular relatively flat areas. In the Deadong River area, artifacts of the SRTM DEM created sinks even after the filling process and then closed drainage basin and short stream lines, which are not the case in the reality. These findings provided an evidence that SRTM DEM alone may not enough to accurately figure out the hydrologic feature of a watershed, suggesting need of local knowledge and complementary data.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.273-282
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• 2005

The purpose of this study is how to apply to e-Commerce of parts procurement system in the Japanese Automobile Industry and examine the influence of that through the case studies of automobile makers. In the Japanese automobile industry, B2B e-Commerce of parts procurement system have a shifted from closed circuits through VAN to opened IP-VPN and eventually to the JNX of internet environment. The Japanese automobile industry depends mainly on IP-VPN and JNX, especially EDI on a one to one basis with parts procurement suppliers. As to the future direction of B2B e-Commerce of parts procurement in the Japanese automobile industry, many of commodity parts will be traded among established participants on internet websites owned by automobile maker groups. Finally, for improvement of B2B e-Commerce of parts procurement in the Japanese automobile industry I suggested that there are 'revitalize of e-Marketplace', 'improvement of IT and business process', 'extension of B2B e-Commerce among small and medium sized suppliers'.

• Journal of the Economic Geographical Society of Korea
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• v.8 no.2
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• pp.285-299
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• 2005

The economic reform in China since 1978 has been increasingly sped up and deepened. The recent development of private enterprises, especially, has significant economic and political implications, whereas its regional differentiation has considerable impacts on both the development potential of certain regions and overall regional growth pattern. This study aims to understand the regional pattern of private enterprise growth as well as the institutional change which has structured the growth process. The development of private enterprises turned out to be closely tied to the marketization strategy of dual-track system and policy needs to reduce the unemployment level in both urban and 겨ral China. The regional pattern of the private enterprise growth can be characterized as ever-increasing spatial differentiation. Based on the basic statistical analysis results, it is argued that the private enterprise growth is closed related with the marketization level of the regional economy. Therefore, the strategy of developing private sector will be more important in shaping the regional development path as well as potential.

• Journal of Korean Association for Spatial Structures
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• v.6 no.4 s.22
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• pp.73-80
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• 2006

It is an object of the present paper to investigate a electrochemical properties of Mg-based sacrificial anodes and the effect of calcium added from calcium chloride into magnesium on the melt protection during the melting. Electrochemical data will be correlated with processing control variables, and the microstructural change by the addition of CaCl2. Small addition of calcium into magnesium from CaCl2 imparts beneficial effect in electrochemical properties of Mg alloys, primarily, through microstructural modifications. In addition, the protection effect of the melts surface of Ca with low melting point modification is obtained by adding Ca not more than 0.6%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.984-987
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• 2013

In concept, such as the backup of wired network and disaster prevention network of water treatment measurement and control system, reliability and security of high level of sending and receiving data between the nodes must be ensured in Ad-hoc network construction. Rather than apply the common communication protocols of Ad-hoc network construction during the FA network of closed water treatment facility with the facility of a certain scale is concentrated contrast, and high characteristics of the water treatment system infrastructure, public facilities We have developed a specific protocol another that applies the OTP of communication frame of process control commands and H-ARQ with ZRP by applying the flexibility to time constraints such as precision industrial plants to ensure the safety and property of facility operation.

• Korean Institute of Interior Design Journal
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• v.26 no.6
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• pp.81-96
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• 2017

This study aims at establishing a basic theory for the combination of architecture and movies by comparing the long-take technique of movies and the continuity of space, one of space composition principles, which is important in digital architecture based on Jacques Lacan's visual-art theory and finding common features and differences of them. The following is a summary of the conclusions. First, analyzing the long-take technique on the basis of Lacan's visual-art theory found that the subject of representation is scenes of movies and that staring shows features of narrative. Second, the long-take technique can be thought as a cinematic technique which tries to realize the real order beyond the symbolic order in real life through the process of continuous replication of replication of replication of a scene in one shot. Third, in contemporary architecture, which is compared to the long-take technique in the past, the inclined space of opened gaze is similar to the method which tries to realize architectural space of the reality which belongs to the symbolic order close to the real order which belong to significant in human unconsciousness. Fourth, the freeform continuous space of closed gaze, which can be compared to contemporary long take combined with computer graphic technology, has more difficulty in realizing the real order than the long-take technique in the past and inclined, continuous space as the feature which belongs to $signifi{\acute{e}}$ in human consciousness has been strengthened through the circulation which repeats and expands along an observer's movement. Fifth, when the contemporary long-take technique and freeform continuous space expand gaze which opens from the inside to the outside, it is considered that the space which is closer to the real order than the classic long-take technique and inclined continuous space can be created.