• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.251-254
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• 2009

A new type of dye-sensitized solar cells(DSCs) based on Ti-mesh electrode without using TCO layer is fabricated for high-efficient and low-cost solar cell application. The TCO-Iess DSCs sample is composed of a [glass/ dye sensitized $TiO_2$ layer/ Ti-mesh electrode/ electrolyte/ metal counter electrode]. The Ti-mesh electrode with high conductivity can collect electrons from the $TiO_2$ layer and allows the ionic diffusion of $I^-/I_3{^-}$ through the mesh hole. Thin Ti-mesh (${\sim}40{\mu}m$ in thickness) electrode material is processed using rapid prototype method. Electrical performance of as-fabricated DSCs is presented and discussed in detail.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1074_1075
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• 2009

A new type of dye-sensitized solar cells(DSCs) based on Ti-mesh electrode without using TCO layer is fabricated for high-efficient low-cost solar cell application. The TCO-less DSCs sample is composed of a [glass/ dye sensitized $TiO_2$ layer/ Ti-mesh electrode/ electrolyte/ metal counter electrode]. The Ti-mesh electrode with high conductivity can collect electrons from the $TiO_2$ layer and allows the ionic diffusion of $I^-/I_3^-$ through the mesh hole. Thin Ti-mesh ($\sim40{\mu}m$ in thickness) electrode material is processed using rapid prototype method. Electrical performance of as-fabricated DSCs is presented and discussed in detail.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.896-901
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• 2002

The sound absorption coefficients for multiple layer perforated plate systems containing several compartments with airspaces and porous absorbing materials are estimated using the transfer matrix method developed in the previous paper. The absorption coefficients from transfer matrix method agree well with the values measured by the two-microphone impedance tube method for various combinations of perforated plates, airspaces or porous materials. Based on these results, a guidance for the design of multiple layer perforated plate systems combined with airspaces and porous absorbing materials is discussed in detail.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.326-328
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• 1999

We investigated the effects of residual gas partial pressure on the property of a CeO$_2$ buffer layer on a textured Ni tape, where the buffer layer was deposited by e-beam evaporation. The oxygen partial pressure were varied from 10$^{-7}$ to 10$^{-4}$ Torr. we also changed the surface condition for the surface oxygenation. We'll describe the detail of the resultant textures of the buffer layers and effects of YBCO growth on them

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.3
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• pp.346-351
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• 2016

Titanium dioxide ($TiO_2$) films are deposited by atomic layer deposition (ALD) using titanium isopropoxide (TTIP) and $H_2O$ as precursors. The operating instructions for the ALD equipment are described in detail, along with the settings for relevant parameters. The thickness of the $TiO_2$ film is measured, and thereby, the deposition rate is quantitatively estimated to verify the linearity of the deposition rate.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.69-74
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• 2004

In scramjet engines with sidewall compression inlet, it is well known that a non-uniform flow appears since a separated region is generated near the flow centerline on the body side. The separated region is caused by shock-boundary layer interaction and likely to cause un-start phenomena since the flow in the separated region is subsonic and acts as a communication path between the isolator and the combustor. In the present study, the non-uniform flow characteristics in the scramjet inlet-isolator region are numerically studied in detail. Effect of flow suction from body sidewall surface on the non-uniform flow field numerically examined to clarify the flow mechanism to suppress the un-start transition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.209-209
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• 2010

Multiferroic properties of $BaTiO_3-CuFe_2O_4$ thin films grown on highly-textured Pt(111)/$TiO_2/SiO_2$/Si(100) substrates were studied. $CuFe_2O_4$ ceramic target was synthesized by mixing oxide powders of CuO, $Fe_2O_03$, $BaTiO_3$ ceramic target was also prepared separately. The film structure was of bi-layer type, where $BaTiO_3$ layer lies underneath of $CuFe_2O_4$ layer, where both layers were grown by pulsed laser deposition technique. We will report the ferroelectric and magnetic properties of $BaTiO_3-CuFe_2O_4$ bi-layer films in some detail.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2577-2583
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• 2009

Presented are the formation of iron oxide layers on evaporator tubes in an actual fossil power plant operated under all volatile treatment (AVT) condition and an experimental simulation of iron oxide formation in the presence of ferrous and ferric ions. After actual operations for 12781 and 36326 hr in the power plant, two iron oxide layers of magnetite on the evaporator tubes were found: a continuous inner layer and a porous outer layer. The experimental simulation (i.e., artificial corrosion in the presence of ferrous and ferric ions at 100 ppm level for 100 hr) reveals that ferrous ions turn the continuous inner oxide layer on tube metal to cracks and pores, while ferric ions facilitate the production of porous outer oxide layer consisting of large crystallites. Based on a comparison of the oxide layers produced in the experimental simulation with those observed on the actually used tubes, we propose possible routes for oxid layer formation schematically. In addition, the limits of the proposed corrosion routes are discussed in detail.

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.677-688
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• 2017

In order to solve the undetected probability of multiple targets in ultra-wideband (UWB) through-the-wall radar imaging (TWRI), a time-delay and amplitude modified back projection (BP) algorithm is proposed. The refraction point is found by Fermat's principle in the presence of a wall, and the time-delay is correctly compensated. On this basis, transmission loss of the electromagnetic wave, the absorption loss of the refraction wave, and the diffusion loss of the spherical wave are analyzed in detail. Amplitude compensation is deduced and tested on a model with a single-layer wall. The simulating results by finite difference time domain (FDTD) show that it is effective in increasing the scattering intensity of the targets behind the wall. Compensation for the diffusion loss in the spherical wave also plays a main role. Additionally, the two-layer wall model is simulated. Then, the calculating time and the imaging quality are compared between a single-layer wall model and a two-layer wall model. The results illustrate the performance of the time-delay and amplitude-modified BP algorithm with multiple targets and multiple-layer walls of UWB TWRI.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.143-149
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• 2008

A numerical study was performed for a vane of a compressor with a high-turning angle and meridional divergence. At first, the effect of the suction position was discussed. Then, the optimal suction position was applied to the cascades with the aspect ratio of 2.53 and 0.3, respectively, to get the knowledge of the effect of the endwall boundary layer removal on the secondary flow along the blade height. At last, using the critical principles of the three-dimensional separation, the topological structures of the flow patterns of the body surfaces and the separation configurations were discussed in detail. The results show that the largest reduction of the total loss can be achieved when the suction slot is near the suction side. The topological structure as well as the separation configuration varies due to boundary layer removal, which restrains the flow separation at the corner and delays or depresses the separation on the suction surface. Compared with the original cascade, the cascade with the endwall boundary layer removal has a higher blade loading along the most span. Furthermore the flow loss decreases and distributes uniformly along the span.