• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.12
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• pp.1009-1014
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• 2012

Hydrogenated amorphous silicon (${\alpha}$-Si:H) layers deposited by plasma enhanced chemical vapor deposition (PECVD) are investigated for use in silicon hetero-junction solar cells employing n-type crystalline silicon (c-Si) substrates. The optical and structural properties of silicon hetero-junction devices have been characterized using spectroscopy ellipsometry and high resolution cross-sectional transmission electron micrograph (HRTEM). In addition, the effective carrier lifetime is measured by the quasi-steady-state photocoductance (QSSPC) method. We have studied on the correlation between the order of ${\alpha}$-Si:H and the passivation quality at the interface of ${\alpha}$-Si:H/c-Si. Base on the result, we have fabricated a silicon hetero-junction solar cell incorporating the ${\alpha}$-Si:H passivation layer with on open circuit voltage ($V_{oc}$) of 637 mV.

• Transactions of Materials Processing
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• v.19 no.8
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• pp.508-516
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• 2010

Thickening process in sheet metal forming is being increased to improve the strength as well as to reduce manufacturing process such as welding. This process can make it possible to obtain part locally thicker than that of initial sheet thickness. In this study, design method for manufacturing the component which has double sinks with local thickened wall is proposed. Deep drawing and upsetting processes are applied in order to form double sinks and thicken its walls. Used material is SPHC440 with the thickness of 2.0mm and initial blank size is determined on the basis of the final product. Distance between the center of double sinks and first drawing ratio to avoid fracture are the most significant factors during deep drawing. FE-analysis is implemented in order to determine the appropriate values. Progressive die is designed based on the proposed method and FE-analysis. As a result of experiment, locally thickened component can be manufactured, which has double sinks with the thickness about 3mm at the corner and wall.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.128-130
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• 2003

As toughness-investigation to improve brittleness of existing epoxy resin, elastic-factor of elastic epoxy using TMA (Thermomechanical Analysis), DMTA (Dynamic Mechanical Thermal Analysis) and FESEM (Field Emission Scanning Electron Microsope) for structure-images analysis were investigated. A range of measurement temperature of the TMA, DMTA was changed from -20[$^{\circ}C$] to 200[$^{\circ}C$]. When modifier was ratio of 0[phr], 20[phr], 35[phr], glass transition temperature (Tg) of elastic epoxy was measured through thermal analysis devices. Also, it was investigated thermal expansion coefficient ($\alpha$), modulus and loss factor through DMTA. In addition, it was analyzed structure through FSSEM and made sure elastic-factor of elastic epoxy visually. As thermal analysis results, 20[phr] was superior than 30[phr] thermally and mechanically. Specially, thermal expansion coefficient, modulus, damping properties were excellent. By structure-images analysis through FESEM, we found elastic-factor of elastic epoxy that is not existing epoxy, and proved high impact.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.43-50
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• 1998

Three hundred and fifty-two growing pigs were utilized in three growth trials to investigate the effects of crystalline amino acid supplementation on growing pigs' growth performance and feed consumption. In Exp. 1, diets were formulated on the basis of digestible amino acids. Utilization of rapeseed meal plus cottonseed meal (R + C) in diet supported similar average daily gain (ADG), feed/gain (F/G) and cost per gain (p > 0.05) to group of soybean meal (SBM). In Exp. 2, 14% CP diets containing equal amount of cottonseed meal and rapeseed meal were formulated with the addition of threonine and/or tryptophan. Supplementation with threonine improved ADG and F/G (p < 0.05). Supplementation with only tryptophan made no benefits for ADG of growing pigs. In Exp. 3, diets with different threonine level were formulated. Increasing dietary threonine to 0.54% improved (p < 0.05) ADG and F/G compared to 0.45% dietary threonine. Increase in dietary threonine did not improve ADG (p > 0.05) but decreased F/G (p < 0.05) because of a decrease in average daily feed intake. Pigs fed diet with dietary threonine/lysine ratio of 67.5% supported optimum growth performance.

• Agricultural and Biosystems Engineering
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• v.2 no.2
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• pp.59-62
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• 2001

The starch content of apples, which is related to the maturity and ripeness, was quantified by using a computer vision system. The stained area was measured by image analysis when an apple slice was stained with KI/I$_2$ solution. The ratio of stained area of the apple slice to its whole area, so called the starch index, was defined as an indicator of the starch content. When Tsugaru apples were manually sorted into immature, turing and mature groups, their starch indices were 0.374, 0.312 and 0.129, respectively. The starch index had relationships to various physicochemical properties of Tsugaru apples. At the statistically significant level of 0.1%, it was correlated with the pH value, bio-yield force, rupture force and color of intact and skin-removed apples. At the 1% significant level, it had the correlation with the density and moisture content.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.229-234
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• 1997

Shizandra chinensis(SC) and Pinus regida(PR) showed antimicrobial activity against 3 strains(B-5, D-1, A-1) of lactic acid bacteria(LAB) isolated from kimchi among eight kinds of plant extracts such as Shizandra chinensis, Phellodendron amurense, ornus officinalis, Pinus regida, Allium tuberosum, Machilus thunbergii, Cyperus rotundus and Schizonepeta tenuifloia. The growth of LAB was inhibited apparently in modified MRS broth containing 1% Schizandra chinensis at $35^{\circ}C$. Pinus regida showed weaker inhibitory effect on the growth of isolated LAB than Shizandra chinensis. pH of SC added kimchi did not change greatly compare with control during 25 days of fermentation. Degree of titratable acidity change and ratio of reducing sugar utilization in control were more higher than in SC added kimchi during fermentation. Growth of total bacteria and lactic acid bacteria was inhibited about 1 to 2 $log_10$ cycle by addition of SC extracts during kimchi fermentation for 10 days at $10^{\circ}C$. Fermentation of kimchi was delaved about 5 to 7 days by addition of 1 or 2% of SC. extract, but sensory quality (falvor, taste and overall acceptability) of SC added kimchi was lower than that of control (p>0.05).

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.227-229
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• 1997

A new phased-array quadrature RF coil for one or two RF acquisition channels is developed for spine MR imaging. Quadrature RF coils for MRI have been useful to improve the signal-to-noise ratio (SNR) by $"\sqrt{2}"$ using two orthogonal RF coils in combination [1]. More recently, the phased-array RF coil has been proposed for more improvement of SNR by using an array of RF coil elements with a reduced size and coverage for each element. Two new schemes are proposed for the new phased-array quadrature RF coil as follows : (1) Proper overlapping of two quadrature RF coils thus removing the mutual inductance and (2) Attaching preamplifiers right after the coil section and combining the signal with proper phase delays. The coil has been implemented for receive- only mode. It has been tested through phantom and volunteer imaging. The experimental results show the utility of the proposed RF coil.

• Journal of the Korean Dietetic Association
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• v.13 no.4
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• pp.368-378
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• 2007

This study was conducted to develop a optimal composite recipe of a functional muffin including Sweet pumpkin powder and to have the high preference to all age groups. Wheat flour was partically substituted by Sweet pumpkin powder to reduce the content of wheat flour. This study has produced the sensory optimal composite recipe by making muffin, respectively, with each 5 level of Sweet pumpkin powder($\X_1$), sugar($\X_2$), butter($\X_3$), by C.C.D(Central Composite Design) and conducting sensory evaluation and instrumental analysis by means of RSM(Response Surface Methodology). Sensory items showed very significant values in appearance, flavor, texture, overall quality(p<0.05), color(p<0.01), and instrumental analysis showed significant values in lightness, redness(p<0.01), yellowness(p<0.001), hardness, gumminess(p<0.05). Also sensory optimal ratio of Sweet pumpkin muffin was calculated as Sweet pumpkin powder 29.5g, sugar 72.6g, butter 79.3g, and it was revealed that the factors of influencing muffin aptitude were in order of Sweet pumpkin powder, butter, sugar.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.281-285
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• 2006

Recently LG.Philips LCD (hereafter "LPL") has announced the development of the world's largest 100-inch TFT-LCD with Advanced Super IPS technology. This magnificent LCD achieves the feature of a full high definition resolution $1920{\times}1080(16:9)$, 600nit brightness, 3000:1 dynamic contrast ratio, 92% color gamut, 180 degree viewing angle, and 5msec response time at all grays, targeted for HDTV and public display applications. Some unique technologies such as Cu bus line, advanced wide view polarizer, and high color gamut lamp were applied. A new stitching free technology was developed to overcome the size limitation of photo mask in both the TFT and CF processes. The size of the panel (100-inch) based on the wide format (16:9) is determined by the maximum efficiency of world's $1^{st}$ seventh generation line (glass size:$1950{\times}2250mm$) in LPL's Paju display cluster. In this paper, we will discuss the issues of 100-inch TFT-LCD.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.149-153
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• 2001

This paper describes on the fabrication of Fe-Co hydrophilic magnetic fluids from the waste pickling liquor of steel. By adding with HNO$_3$in the waste liquor oxidation is proceeded from Fe$^{3+}$ion at 6$0^{\circ}C$ with air blowing. Ultra-fine Co-ferrite particles with the mean particle size of 50 $\AA$ were produced at pH 12 after adjusting the ratio of Fe$^{3+}$Co$^{2+}$=7/3(wt%) and Fe-Co particles with the mean particle size of 94 $\AA$ were produced by reducing the Co-ferrite particle with H$_2$at the temperature of 50$0^{\circ}C$. After triple adsorption of oleic acid dodecyl benzene sulfonate(D.B.S.) and tetra methyl ammonium(T.M.A.) ions on the surface of Fe-Co particles Fe-Co hydrophilic magnetic fluid was produced by dispersing the Fe-Co particles in ethylene glycol solution. The magnetization of the Fe-Co hydrophilic magnetic fluid increased with increasing the Fe-Co concentration. The magnetic fluid containing 70% (g/cc) Fe-Co showed 73 emu/g in magnetization at the magnetic intensity of 10 kOe.kOe.e.