• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.3
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• pp.125-132
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• 2011

Is very simple in tension work of screen mesh for effective printing if worker uses screen mesh of player who desire at screen print process. General method is methods that use mesh of player who want on screen frame as screen plate because tensioned. The single layer screen plate was made from one sheet screen mesh and the double layer screen plate was made from two sheets screen mesh overlapped. The thickness of sensitive emulsion applied to double layer screen plate is more thicker than two time s of thickness of emulsion applied to single layer screen plate. It seems that the sensitive emulsion inserted between an upper layer and a lower layer of double layer screen mesh.

• Journal of Surface Science and Engineering
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• v.51 no.1
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• pp.21-26
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• 2018

The $Cu_2(btc)_3$ metal-organic frameworks (MOF) coated anodic aluminum oxide (AAO) membrane was successfully prepared by layer-by-layer technique using hand spray method. It was confirmed that the $Cu_2(btc)_3$ layer, which has the pore sized in 2-3 nm, on surface of AAO exhibited the polycrystalline thin film structure by XRD analysis. More than 100 repetitive spray cycles were required to obtain more robust and thick MOFs on AAO and it was possible to uniformly coat both the top and bottom surfaces of the AAO. It should be noted that the MOFs also could be coated on surface of pores resulting in reduce the size of pore from 52 nm to 32 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.281-283
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• 2001

Bi$_2$Sr$_2$CuO$\_$x/(Bi-2201) thin films were fabricated layer-by-layer deposition using an ion beam sputtering method. 10 wt% and 90 wt% ozone mixed with oxygen were used ultraviolet light irradiation to assist oxidation. At early stages of the atomic layer by layer deposition, two dimensional epitaxial growth which covers the substrate surface would be suppressed by the stress and strain caused by the lattice misfit, then three dimensional growth takes place. Since Cu element is the most difficult to oxidize, only Sr and Bi react with each other predominantly, and forms a buffer layer on the substrate in an amorphous-like structure, which is changed to SrBi$_2$O$_4$ by in-situ anneal.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.310.2-310.2
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• 2013

For enhancement of dye-sensitized solar cell performance, TiO2 blocking layer has been used to prevent recombination between electron and hole at the conducting oxide and electrolyte interface. In solid state dye-sensitized solar cells, it is necessary to fabricate pin-hole free TiO2 blocking layer. In this work, we deposited the TiO2 blocking layer on conducting oxide by atomic layer deposition and compared the efficiency. To compare the efficiency, we fabricate solid state dye-sensitized solar cell with using CuSCN as hole transport material. We see the efficiency improve with 40nm TiO2 blocking layer and the TiO2 blocking layer morphology was characterized by SEM. Also, we used this blocking layer in TiO2/Sb2S3/ CuSCN solar cell.

• Journal of Mechanical Science and Technology
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• v.20 no.2
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• pp.271-277
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• 2006

A numerical study is made of the spin-up from rest of a three-layer fluid in a closed, vertically-mounted cylinder. The densities in the upper layer $\rho_1$, middle layer $\rho_2$ and lower layer $\rho_3\;are\;\rho_3\;>\;\rho_2\;>\;\rho_1$, and the kinematic viscosities are left arbitrary. The representative system Ekman number is small. Numerical solutions are obtained to the time-dependent axisymmetric Navier-Stokes equations, and the treatment of the interfaces is modeled by use of the Height of Liquid method. Complete three-component velocity fields, together with the evolution of the interface deformations, are depicted. At small times, when the kinematic viscosity in the upper layer is smaller than in the middle layer, the top interface rises (sinks) in the central axis (peripheral) region. When the kinematic viscosity in the lower layer is smaller than in the middle layer, the bottom interface rises (sinks) in the periphery (axis) region. Detailed shapes of interfaces are illustrated for several cases of exemplary viscosity ratios.

• New & Renewable Energy
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• v.6 no.1
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• pp.46-52
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• 2010

Membrane electrode assemblies (MEAs) for proton exchange membrane fuel cells (PEMFCs) have been extensively studied to improve their initial performance as well as their durability and to facilitate the commercialization of fuel cell technology. To improve the MEA performance, particularly at low Pt loadings, many approaches have been made. In the present study, MEA performance improvement was performed by adding $TiO_2$ particles into the catalyst layer of MEA. Most of previous studies have focused on the MEA performance enhancement under low humidity conditions by adding metal oxides into the catalyst layer mainly due to the water keeping ability of those metal oxides particles such as $Al_2O_3$, $SiO_2$ and zeolites. However, this study mainly focused on the improvement of MEA performance under fully humidified normal conditions. In this study, the MEA was prepared by decal method aiming for a continuous MEA fabrication process. The decal process can make very thin and uniform catalyst layer on the surface of electrolyte membrane resulting in very low interfacial resistance between catalyst layer and the membrane surface and uniform electrode structure in the MEA. It was found that the addition of $TiO_2$ particles into the catalyst layer made by decal method can minimize water flooding in the catalyst layer, resulting in the improvement of MEA performance.

• Journal of Korea Multimedia Society
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• v.14 no.7
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• pp.872-883
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• 2011

SVC is an emerging video coding standard as an extension of H.264/AVC. This standard uses inter prediction, intra prediction and a new inter-layer prediction to improve coding performance of enhancement layers. However, it has high computational complexity. In this paper, we propose an efficient intra prediction mode decision method in the spatial enhancement layer to reduce the computational complexity. The proposed method consists of two phases. In the first phase, Intra_BL mode is selected using the RD cost of Intra_BL in advance. We exploit the fact that the RD cost and prediction mode are similar to those of neighbor macroblocks. In the second phase, we predict the enhancement layer mode using correlation between intra mode of enhancement layer and that of the base layer. Experimental results show that the proposed method could save from 48.15% to 56.32% in encoding time while degradation in video quality is negligible.

• Tribology and Lubricants
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• v.18 no.3
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• pp.194-203
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• 2002

This paper is the first step fur thermo-mechanical stress analyses of part with coated layer under contact load. A lot of coated material is applied in many structures to endure severe situation, like thermal stresses, high temperature gradients, irradiation, impacts by microscopic meteorites, and so on. In this part we are going to apply the FEM to analyze space parts with a coated layer subjected to a contact load thermo-mechanically. Coating layer is very thin in comparision with the structure, therefore it should take more times and behaviors to analyze whole model. In these reason we develop the FEM method of analyzing part with coated layer under contact load using partial model. Steady state temperature distribution of the part is obtained first, and then we apply quasi-static external load on the part. To obtain the final stage of solution, we compute the total solution, and by subtracting the thermal strain from the total ones we get the mechanical strains to compute stresses of the parts. In using the FEM, one has to discretize the model into many sub-domain, finite elements. The method is consisited of two steps. First step is to analyze the whole model with rather coarse meshes. Second step we cut a small region near the loading point, and analyze with very fine meshes. This method is allowable by the Saint-Venant's principle. And then, we finally shall check the therma1 load on the stresses of the space part with coating layer with or without substrate cracks. Then, we predict the actual behaviors of the part used in space.

• Journal of Broadcast Engineering
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• v.20 no.5
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• pp.756-769
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• 2015

In this paper, we propose a scalable coding method for high dynamic range (HDR) and standard dynamic range (SDR) videos based on Scalable High Efficiency Video Coding (SHVC). The proposed method has multi-layer coding architecture that consists of base layer for SDR videos and enhancement layer for HDR videos to support the backward compatibility with legacy codec and display devices. Also, to improve coding efficiency of enhancement layers, a global inverse tone mapping is applied to the reconstructed SDR video and the compensated frames are referred for coding of the enhancement layer. The proposed method is found to achieve BD-Rate gain of 43.0% on average (maximum 76.3%) for the enhancement layer and 15.7% on average (maximum 31%) for dual-layer against the SHM 7.0 reference software.

• Korean Journal of Materials Research
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• v.22 no.11
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• pp.626-630
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• 2012

The properties of SOFC unit cells manufactured using the decalcomania method were investigated. SOFC unit cell manufacturing using the decalcomania method is a very simple process. In order to minimize the ohmic loss of flattened tube type anode supports of solid oxide fuel cells(SOFC), the cells were fabricated by producing an anode function layer, YSZ electrolyte, LSM electrode, etc., on the supports and laminating them. The influence of these materials on the power output characteristics was studied when laminating the components and laminating the anode function layer between the anode and the electrolyte to improve the output characteristics. Regarding the performance of the SOFC unit cell, the output was 246 $mW/cm^2$ at a temperature of $800^{\circ}C$ in the case of not laminating the anode function layer; however, this value was improved by a factor of two to 574 $mW/cm^2$ due to the decrease of the ohmic resistance and polarization resistance of the cell in the case of laminating the anode function layer. The outputs appeared to be as high as 574 and 246 $mW/cm^2$ at a temperature of $800^{\circ}C$ in the case of using decalcomania paper when laminating the electrolyte layer using the in dip-coating method; however, the reason for this is that interfacial adhesion was improved due to the dense structure, which leads to a thin thickness of the electrolyte layer.