• Journal of information and communication convergence engineering
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• v.18 no.2
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• pp.82-87
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• 2020

This paper discusses how to design a game server that is scalable, adaptable, and re-buildable with components. Furthermore, it explains how various implementation issues were resolved. To support adaptability, the server comprises three layers: network, user, and database. To ensure independence between the layers, each layer was designed to communicate with each other only via message queues. In this architecture, each layer can have an arbitrary number of threads; thus, scalability is guaranteed for each layer. The network layer uses input/output completion ports(IOCP), which shows the best performance on the Windows platform, it can handle up to 5,000 simultaneous connections on a typical entry-level computer, despite being built with a single-threaded user layer. To completely separate the database from the game server, the SQL code was not directly embedded in the database layer.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.11.1-11.1
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• 2011

We have developed a simple synthetic method for fabricating a wafer-scale colloidal crystal film of 2D crystals in a 1D stack based on a combination of two simple processes : the self-assembly of polystyrene (PS) nanospheres at the water-air interface and the layer-by-layer (LbL) scooping transfer technique. The main advantage of this approach is that it allows excellent control of the thickness (at a layer level) of the crystals and the formation of a vertical crack-free layer over a wafer-scale (4 inch). We investigate the optical and morphological properties of the PhC multilayers fabricated using various mono-sized colloidal crystals (250, 300, 350, 420, 580, 720, and 850 nm), and mixed binary colloidal crystals (300/350 and 250/350 nm).

• 한국전기화학회:학술대회논문집
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• 2001.06a
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• pp.179-184
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• 2001

The diffusion layer within MEA(membrane electrode assembly) has been evaluated important factor for improvement of cell performance in DMFC. The diffusion layer in MEA structure leads to the reduction of catalyst loss in active catalysts layer as well as prevention of water-flooding in cathode. Cell performance is directly affected by interior properties of diffusion layer materials. Acetylene Black and $RuO_2$ with large pore size and low porosity compared to Vulcan XC-72R gave better performance caused by vigorous methanol diffusion and water removal. And $RuO_2$ as diffusion layer materials showed different behavior in anode and cathode compartment, that is, diffusion layers in anode and cathode side make methanol diffusion and water removal facilitate, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1779-1783
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• 2006

The hybrid thin-film (HTF) passivation layer composed of the UV curable acrylate layer and MS-31 (MgO:SiO2=3:1wt%) layer was adopted in organic light emitting diode (OLED) to protect organic light emitting materials from penetrations of oxygen and water vapors. The moisture resistance of the deposited HTF layer was measured by the water vapor transmission rate (WVTR). The results showed that the HTF layer possessed a very low WVTR value of lower than $0.007g/m^2$ per day at $37.8^{\circ}C$ and 100% RH. Therefore, the HTF on the OLED was found to be very effective in protect what from the penetrations of oxygen and moisture.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1313-1316
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• 2005

In the present paper, it was investigated that adhesion layer on gate insulator could affect the electrical characteristics for the organic thin film transistors (OTFTs). The polyimide (PI) as organic adhesion layer was fabricated by using the vapor deposition polymerization (VDP) processing . It was found that electrical characteristics improved comparing OTFTs using adhesion layer to another. We researched adhesion layer as a function of thickness. For inverted-staggered top contact structure, field effect mobility, threshold voltage, and on-off current ratio of OTFTs using adhesion layer of PI 15 nm thickness on the gate insulator with a thickness of 0.2 ${\mu}m$ were about 0.5 $cm^2/Vs$, -0.8 V, and $10^6$, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1046-1049
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• 2006

We proposed a simplified fabrication structure and method which can provide separate Red (R), Green (G), Blue (B), and White (W) OLED pixels with 2 metal-mask changes in emitting layer fabrication inspired from the structure of multi-layer white OLED and carrier blocking mechanism. A red emission layer for the R and W pixel with 1st mask, and then a blue emission layer with hole blocking layer for the B and W pixel with 2nd mask, and finally a common green emission layer were deposited sequentially. We expect that this concept would be very useful to the actual fabrication of multi-color OLED display although additional optimization is needed.

• Publications of The Korean Astronomical Society
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• v.9 no.1
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• pp.21-38
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• 1994

We have developed a cylindrical mixing layer model of a stellar jet including cooling effect in order to understand an optical emission mechanism along collimated high velocity stellar jets associated with young stellar objects. The cylindrical results have been calculated to be the same as the 2D ones presented by Canto & Raga(1991) because the entrainment efficiency in our cylindrical model has been obtained to be the same value as the 2D model has given. We have discussed the morphological and physical characteristics of the mixing layers by the cooling effect. As the jet Mach number increases, the initial temperature of the mixing layer goes high because the kinetic energy of the jet partly converts to the thermal energy of the mixing layer. The initial cooling of the mixing layer is very severe, changing its outer boundary radius. A subsequent change becomes adiabatic. The number of the Mach disks in the stellar jet and the total radiative luminosity of the mixing layer, based on our cylindrical calculation, have quite agreed with the observations.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.163.2-163.2
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• 2014

We report catalytic decomposition of few-layer graphene on an $Au/SiO_x/Si$ surface wherein oxygen is supplied by dissociation of the native $SiO_x$ layer at a relatively low temperature of $400^{\circ}C$. The detailed chemical evolution of the graphene covered $SiO_x/Si$ surface with and without gold during the catalytic process is investigated using a spatially resolved photoelectron emission method. The oxygen atoms from the native $SiO_x$ layer activate the gold-mediated catalytic decomposition of the entire graphene layer, resulting in the formation of direct contact between the Au and the Si substrate. The notably low contact resistivity found in this system suggests that the catalytic depletion of a $SiO_x$ layer could realize a new way to micromanufacture high-quality electrical contact.

• Journal of the Korean Applied Science and Technology
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• v.20 no.2
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• pp.173-176
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• 2003

We have seen the effects of buffer layer in organic light-emitting diodes using poly(N-vinylcarbazole)(PVK). Polymer PVK buffer layer was made using static spin-casting method. Two device structures were made; one is ITO/TPD/Alq3/Al as a reference and the other is ITO/PVK/TPD/Alq3/Al to see the effects of buffer layer in organic light-emitting diodes. Current-voltage characteristics, luminance-voltage characteristics and luminous efficiency were measured with a variation of spin-casting speeds. We have obtained an improvement of luminous efficiency by a factor of two and half when the PVK buffer layer is used.

• ETRI Journal
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• v.34 no.2
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• pp.280-283
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• 2012

By inserting $H_2O$ treatment steps during atomic layer deposition of a ZnO layer, the turn-on voltage shift from negative bias stress (NBS) under illumination was reduced considerably compared to that of a device that has a continuously grown ZnO layer without any treatment steps. Meanwhile, treatment steps without introducing reactive gases, and simply staying under a low working pressure, aggravated the instability under illuminated NBS due to an increase of oxygen vacancy concentration in the ZnO layer. From the experiment results, additional oxidation of the ZnO channel layer is proven to be effective in improving the stability against illuminated NBS.