• Journal of Korea Foundry Society
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• v.22 no.6
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• pp.293-298
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• 2002

The effects of alloying elements added on the microstructure and high temperature oxidation behavior of the electro-slag remelted Fe-22Cr-5Al alloy were investigated. The amount of casting defect was makedly reduced by the electro-slag remelting. The electro-slag remelted ingot had a directionally solidified structure and cleaner surface than that of air-melted one. The high temperature oxidation reststance was greatly improved by the addition of Be and Zr.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.150-153
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• 2007

Apply electromagnetic stirring system to making rheology slurry of Al7075. This experiment has important element which is the relation between solid fraction percent and melt temperature of Al7075. The rheology slurry of Al7075 eliminated liquid phase to include alloying element of copper and zinc by squeeze casting process. In result the most structure was composed entirely of globular primary $\alpha$. Used this material for this study. This study made a comparison of mechanical property according to heat treatment T6 at each melt temperature ($619^{\circ}C$ and $615^{\circ}C$). The microstructure and component are observed how heat treatment T6 weight with the mechanical property by SEM-EDS.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1379-1381
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• 1994

In order to investigate the effects of crystal structure in electrical breakdown of polyethylene film. Low molecular materials in polyethylene are removed by the method as follow. Polyethylene was dissolved in xylene and filtered through a glass fiber filter. And then, a polyethylene thin films of thickness $0.5 - 0.9{\mu}m$ are prepared with heat treatment from solution casting. To evaluate the performance of PE film, Electrical breakdown of PE film are measured on M( Al) - I (PE)-M(Al) system.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.674-679
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• 2004

In this study, we investigated the cause analysis on fracture of diesel locomotive engine liner, which was trouble assuming the inflow of cooling water. In order to reveal the cause of fracture, we studied the use history of engine, the drawing of production appearance and the stress distribution of engine in use. Also, we conducted experiments such as tension strength test, bending test and hardness test. Next, we observed fractured sections by SEM for the purposed of explaining the fracture mechanism of engine liner. Test results showed that fracture mechanism was brittle fracture due to coarse casting structure and stress concentration caused by manufacturing badness.

• ETRI Journal
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• v.26 no.2
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• pp.136-148
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• 2004

It is expected that an intelligent broadcasting service (IBS) will be able to provide broadcast programs based on user preference and program-associated information (metadata) in order to assist users in easy navigation of the program content being broadcast. In this way, users will be able to access program content anytime, anywhere, and in the manner they wish. This type of IBS will be a basis for future broadcasting services such as customized broadcasting or personal casting. In this paper, we introduce an agent-based multimedia broadcasting framework using the Foundation for Intelligent Physical Agents (FIPA) and MPEG-7 technologies within MPEG-21. We use a FIPA implementation called FIPA open source as a platform for exchanging user preferences and program information as FIPA messages between a server and its clients. The user preference is modeled as the User Preference description scheme in MPEG-7 multimedia description schemes. We discuss a framework structure and implementation for the IBS.

• Journal of the Korean Ceramic Society
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• v.28 no.12
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• pp.943-952
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• 1991

Lead zirconate titanate(PZT) powders and thin films were prepared from an alkoxide-based solution by sol-gel method. Gelation of synthesized complex solutions, pyrolysis and crystallization behaviors of the dried powder were studied in accordance with a water content and a catalyst. PZT thin films were formed by spin-casting method on silicon and platinum substrates, and characterized. Ester produced from the reactions was completely removed when drying of the gel was finished. Pyrolysis property of the dried PZT gels were changed in order water content, class of catalyst, and quantity of catalyst. Crystalline Pb phase was transiently formed near 250$^{\circ}C$. Basic catalyst is good additive for a formation of perovskite phase in the films, and acidic catalyst for a densified film structure. By the analysis of RBS, Pb element in the PZT films were diffused into silicon substrate, and the pores, may be produced due to local densification around some grains in the films, make an origin of fault in microstructure when holding time goes to be longer at 700$^{\circ}C$.

• Korea Journal of Hospital Management
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• v.12 no.3
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• pp.20-46
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• 2007

Given the pressures to promote the efficient utilization of medical resources, hospitals have developed cost accounting systems in several countries. This study discusses the recent development and problems of hospital cost accounting practices in three countries: UK, US, and Japan. first, we discuss a cost accounting structure and detailed pictures of costing practices. Second, problems of current systems arc reviewed and then possible remedies are discussed. Third, we provide implications for implementing the systems(especially ABC). finally, we assert that infrastructure(hospital information systems, database, etc.) must be established and the target level of costing has to be considered before organization-wide application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.147-150
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• 1998

Since P-ELD(powders type electroluminescent device) phenomena were found by G.Destriau at first In 1936, lots of studying was performed in order to realize surface emission devices and flat panel display as a backlight. Due to the problem of low luminance and color and so on, it was delayed. Recently using electric field and thermal effect which can change it\`s molecular arrangement, it can be developed using photoelectric properties of P-ELD. P-ELD in this study was prepared by casting method. Basic structure is ITO/Phosphor/insulator/Al sheet, each layer was mixed by binder, which concentration 11p(poise) for phosphor, 8p(poise) fort insulator. Dielectric properties was investigated first and emission properties of P-ELD based on ZnS:Mn,Cu/ZnS:Cu,Br mixture. P-ELD prepared in this work exhibits about 100cd/㎡ 1-kHz simusoidal excitation.

• Applied Science and Convergence Technology
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• v.23 no.5
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• pp.254-260
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• 2014

Organic solar cells have attracted extensive attention as a promising approach for cost-effective photovoltaic devices. However, organic solar cell has disadvantage of low power conversion efficiency in comparison with other type of solar cell, due to the recombination ratio of hole and electron is too large in the active layer. Thus we have change the surface structure of PEDOT:PSS layers to improve the current density by colloidal lithography method using various-size of polystyrene sphere. The two types of coating method were applied to fabricate the different pattern shape and height, such as spin coating and drop casting. Using the organic solvent, we easily eliminate the PS sphere and could make the varied pattern shapes by controlling the wet etching time. Also we have measured the electrical properties of patterned PEDOT:PSS film to check whether it is suitable for organic photovoltaics.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.14-15
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• 2013

Green Frame is precast concrete column-beam structure. There are three types on column connection. The coupler type which is one of the three, need to be improved because of unstability caused by pre-installation of column before casting the slab, and quality deterioration caused by lack of workspace. Therefore, in this study, new coupler connection type with thread rebar is suggested. The result of this study shall be used for the efficiency analysis of the new coupler connection.