• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.546-549
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• 1990

This study introduces the three-dimensional information about moving objects. Relative motion between textured objects and observer generates a time varying optic array at the image, from which image motion of contours can be extracted. Closed-form solutions are proposed for the structure and motion of planar and curved surface patches. The analytic solution for curved surface patches combines the transformation of Longuet-Higgins with the planar surface solution of Subbarao and Waxman. Ovoid patches are shown to construct a unique transform angle. Thus, ovoid patches almost always yield a unique 3D interpretation.

• 한국표면공학회지
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• 제48권4호
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• pp.149-157
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• 2015

We investigated the effects of the fabric structure or the kinds of plated metals on the electromagnetic interference shielding effectiveness (EMI SE) by means of electroless plating on polyester fabric. We found that the weight of deposited metal, EMI SE, and flexibility of the conductive fabric for EMI shield is affected by morphology of fabric and structure of fiber. The EMI SE of conductive fabric plated Ni/Cu/Ni by electroless plating method on draw textured yarn (DTY) polyester was in the practically useful range of above 70 dB over a wide frequency range of 10 MHz to 1.0 GHz at the surface resistivity of $0.05{\Omega}/{\square}$. Au or Ag plated conductive fabric by immersion plating method is not able to provide for a good EMI SE.

• 한국재료학회지
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• 제16권7호
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• pp.449-454
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• 2006

Al-doped zinc oxide (ZnO:Al) films for transparent electrodes in thin film solar cells were deposited on glass substrates at a low temperature of $200^{\circ}C$ by rf magnetron sputtering. The transmittance of the ZnO:Al films in the visible range was 87%. The lowest resistivity of the ZnO:Al films was about $5.8{\times}10^{-4}{\Omega}$ cm at the Al content of 2.5 wt%. After deposition, the surface of ZnO:Al films were etched in dilute HCl (0.5%) for the investigation of the change in the electrical properties and the surface morphology due to etching.

• 드라이브 ㆍ 컨트롤
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• 제9권4호
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• pp.26-31
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• 2012

Friction reduction between sliding hydraulic machine components is required to improve efficiency and reliability of hydraulic machineries. It is recently reported that surface texturing on sliding bearing surfaces can reduce the friction force highly. In this paper, numerical analysis is carried out to investigate the effect of dimple numbers and inlet boundary pressures on the lubrication characteristics of a parallel sliding bearing using a commercial computational fluid dynamics (CFD) code, FLUENT. The results show that the pressure distribution, load capacity, dimensionless friction force and leakage with dimple number and their locations, and inlet pressures. The overall lubrication characteristics are highly affected by dimple numbers and boundary pressure. The numerical method adopted and results can be used in design of efficient hydraulic machine components.

• 반도체디스플레이기술학회지
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• 제12권2호
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• pp.57-61
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• 2013

This paper presents adaptive neuro-fuzzy inference based defect detection method for various defect types, such as micro-crack, fingerprint and contamination, in heterogeneously textured surface of polycrystalline solar wafers. Polycrystalline solar wafer consists of various crystals so the surface of solar wafer shows heterogeneously textures. Because of this property the visual inspection of defects is very difficult. In the proposed method, we use local binary feature and fuzzy reasoning for defect detection. Experimental results show that our proposed method achieves a detection rate of 80%~100%, a missing rate of 0%~20% and an over detection (overkill) rate of 9%~21%.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.24-32
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• 2018

Nanocellulose was surface-functionalized toward the applications in enhanced oil recovery (EOR) as a green alternative. The focus of this paper is on the effect of this material based nanofluid (NF) on foam lamella stabilization through studying its bubble breakup dynamics and flow behaviors in constricted mircofluidic devices. The NF stabilized foam produced an improved flow resistance across the capillary largely due to the capillary trapped bubbles at the contraction. The "snap-off" caused the NF stabilized foam to produce finer textured bubbles, which can migrate readily forward to the deep porous media, as revealed by the pressure profiles.

• 한국전기전자재료학회논문지
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• 제21권2호
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• pp.99-103
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• 2008

To improve efficiency of solar cells, it is important to make a light trapping structure to reduce surface reflectance for increasing absorption of sun light within the solar cells. One of the promising methods that can reduce surface reflectance is isotropic texturing with acid solution based on hydrofluoric acid(HF), nitric acid($HNO_3$), and organic additives. Anisotropic texturing with alkali solution is not suitable for multicrystalline silicon wafers because of its different grain orientation. Isotropic texturing with acid solution can uniformly etch multicrystalline silicon wafers unrelated with grain orientation, so we can get low surface reflectance. In this paper, the acid texturing solution is made up of only HF and $HNO_3$ for easy controlling the concentration and low cost compared to acid solution with organic additives. $HNO_3$ concentration and dipping time were varied to find the condition of minimum surface reflectance. Textured surfaces were observed Scanning Electron Microscope(SEM) and surface reflectance were measured. The best result of arithmetic mean(wavelength from 400 nm to 1000 nm) reflectance with acid texturing is 4.64 % less than alkali texturing.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.16-17
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• 2007

To improve efficiency of solar cells, it is important to make a light trapping structure to reduce surface reflectance for increasing absorption of sun light within the solar cells. One of the promising methods that can reduce surface reflectance is isotropic texturing with acid solution based on hydrofluoric acid(HF), nitric acid($HNO_3$), and organic additives. Anisotropic texturing with alkali solution is not suitable for multicrystalline silicon wafers because of its different grain orientation. Isotropic texturing with acid solution can uniformly etch multicrystalline silicon wafers unrelated with grain orientation, so we can get low surface reflectance. In this paper, the acid texturing solution is made up of only HF and $HNO_3$ for easy controling the concentration and low cost compared to acid solution with organic additives. $HNO_3$ concentration and dipping time were varied to find the condition of minimum surface reflectance. Textured surfaces were observed Scanning Electron Microscope(SEM) and surface reflectance were measured. The best result of arithmetic mean(wavelength from 400nm to 1000nm) reflectance with acid texturing is 4.64% less than alkali texturing.

• Progress in Superconductivity
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• 제6권2호
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• pp.133-137
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• 2005

We fabricated the Au/Ni template for YBCO coated conductors and evaluated texture formation and the microstructural evolution. The cube textured Ni substrate was fabricated by rolling and recrystallization annealing, and subsequently Au layer formed on the substrate by electroless-plating method. The texture was evaluated by pole-figure with x-ray goniometer with orientation distribution function (ODF) analysis. The surface roughness and grain boundary morphology of template were characterized by atomic force microscopy (AFM) We observed that Au layer deposited epitaxially on Ni substrate and formed a strong cube texture when plating time was optimized. The full-width at half-maximum (FWHM) was $8.4^{\circ}$ for out-of-plane and $9.98^{\circ}$ for in-plane texture for plating time of 30 min. Microstructural observation showed that the Au layer was homogeneous and dense without formation of crack/microcrack. In addition, we observed that root-mean-square (RMS) and depth of grain boundary were 14.6 nm and 160 $\AA$ for the Au layer, respectively, while those were 27.0 nm and 800 $\AA$ for the Ni substrate, indicating that the electoless-plated Au layer had relatively smooth surface and effectively mollified grain groove.

• 한국결정성장학회지
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• 제4권2호
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• pp.157-168
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• 1994

APCVD에 의한 $SnO_2(:F)$ 박막 형성시 HF와 $H_2O$량의 변화에 따른 증착 조건이 전기적, 광학적 특성 그리고 textured $SnO_2(:F)$ 박막의 표면형상에 미치는 영향을 관찰하였다. HF의 bubbling량이 0.9 slm 이상일 경우에는 전자농도(electron concentration)가 $3{\Times}10^{20}/cm^3$에 도달 하였으며, 비저항값은 $7{\Times}10^4~9{\Times}10^4{Omega}cm$ 범위이었고, mobility 값은 $18~25 cm^{-2}/V.sec$이었다. 결정 grain의 형태는$H_2O$를 첨가시키지 않으며 증착시킨 경우 끝이 뾰족한 예각을 가진 pyramid 형태였으며, $H_2O$를 첨가시키며 증착시킨 경우에는 끝이 둥근 hemispherical 형이었다.