• Transactions on Electrical and Electronic Materials
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• v.1 no.4
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• pp.1-6
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• 2000

The mechanical strength of silicon carbide dose nor permit the use of diffusion as a means to achieve selective doping as required by most electronic devices. While epitaxial layers may be doped during growth, ion implantation is needed to define such regions as drain and source wells, junction isolation regions, and so on. Ion activation without an annealing cap results in serious crystal damage as these activation processes must be carried out at temperatures on the order of 1600$^{\circ}C$. Ion implanted silicon carbide that is annealed in either a vacuum or argon environment usually results in a surface morphology that is highly irregular due to the out diffusion of Si atoms. We have developed and report a successful process of using silicon overpressure, provided by silane in a CAD reactor during the anneal, to prevent the destruction of the silicon carbide surface, This process has proved to be robust and has resulted in ion activation at a annealing temperature of 1600$^{\circ}C$ without degradation of the crystal surface as determined by AFM and RBS. In addition XPS was used to look at the surface and near surface chemical states for annealing temperatures of up to 1700$^{\circ}C$. The surface and near surface regions to approximately 6 nm in depth was observed to contain no free silicon or other impurities thus indicating that the process developed results in an atomically clean SiC surface and near surface region within the detection limits of the instrument(${\pm}$1 at %).

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.7
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• pp.1008-1019
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• 2007

The purpose of this study was to develop an appropriate jacket pattern for elderly women over sixty years old, providing a good fit and appearance. Results were as follows: The length of the jacket was made long enough to cover the area 22.0cm below the waistline. The waist back length was made 1.7cm longer than the actual size of the waist back length. The armhole length was made 0.5cm longer than B/4, enhacing the appearance and functionality while allowing freer movement of the arms. As for the front and back interscye breadths, the front interscye breadth was made 1.7cm larger than the actual size while the back interscye breadth was only 1.0cm larger, providing the front interscye breadth more space. The bust breadth was made 10.0cm larger than the bust circumference measure(B/4+2.5cm), the waist breadth was made 6.0cm larger than the waist circumference measure(W/4+1.5cm), The hip breadth was made 12.0cm larger than the him circumference measure(H/4+3.0cm). The sleeve length was made 3.0cm larger than the arm length measure, as the sleeve length of a jacket is usually long enough to cover the ulnar styloid. The sleeve width was made 5.0cm larger than the upper arm circumference measure, as the upper arm circumference measure of the model pattern was too large than necessary, worsening the overall appearance. The sleeve cap height was set at AH/4+4.7cm. The wrist circumference of 27.0cm was set, allowing 2/3 and 1/3 for the large sleeve and small sleeve respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.261-262
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• 2006

High temperature superconducting coated conductor has multi-layer structure of protecting layer/superconducting layer/buffer layer/metallic substrate. The buffer layer consists of multi layer, and the architecture most widely used in RABiTS approach is $CeO_2$(cap layer)/YSZ(diffusion barrier layer)/$CeO_2$(seed layer). Multi-buffer layer deposition required many times and process. Therefore single buffer layer deposition study reduce 2G HTS manufacture efforts. Evaporation technique for single buffer deposition method is used for the $CeO_2$ layer. $CeO_2$ single buffer film could be achieved in the chamber. Detailed deposition conditions (temperature and partial gas pressure of deposition) were investigated for the rapid growth of high quality $CeO_2$ single buffer film.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.12
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• pp.979-984
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• 2016

Recently, ball screws have been used in machine tools, robot parts, and medical instruments. The demand for ball screws of high precision and reduced size is increasing because of the growth of high value-added industries. Three types of ball screws are typically used: deflector type, end-cap type, and tube type. They are also classified from C0 to C9 according to the precision level. A deflector type ball screw can reduce the variation of rotational torque and the size of the nut of the ball screw is minimized. To ensure the reliable design of ball screws, it is important to perform a structural analysis. The purpose of this study is to perform a stability evaluation through analysis of a deflector type miniature ball screw for weapon systems. The analysis is performed through Finite Elements Method (FEM) simulation to predict characteristics such as deformation, stress, and thermal effects. The interference between the shaft and the deflector for smooth rotation are also studied. Based on the results of the analysis, the development of the deflector type miniature ball screw for weapon systems is performed.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.252-252
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• 2010

적외선 센서는 빛의 유무에 관계없이 주 야간 전방의 물체에서 발산하는 미약한 적외선(열선)을 감지하여 영상으로 재현하는 열상시스템은 자동차 야간 운전자 보조용 나이트 비젼, 핵심 시설의 감시 관리, 군수 등의 분야에 적용되어지고 있는 최첨단, 고부가가치를 지니고 있는 기술이다. 양자형은 센서 특성은 좋으나 냉각기(작동온도: $-196^{\circ}C$) 및 고진공 패키지인 dewar를 사용하는 반면에, 열형은 대부분 상온에서 동작되는 온도안정화를 위한 전자냉각모듈만을 구비하면 되므로 저가형으로 제작이 가능한 비냉각형 적외선 센서이다. 본 연구에서는 적외선 센서용 진공패키지 조립공정 및 패키지된 센서의 측정기술을 개발하였다. 금속 메탈패키지를 제작하였으며, 금속 진공패키지는 소자냉각용 TE Cooler와 장수명 진공유지를 위한 getter, 그리고 센서칩, 온도센서를. 장착하여 칩을 조립하였다. Cap ass'y와 base envelop의 솔더링 공정을 수행하였으며, 진공패키지의 진공유지를 위해 TMP를 이용하여 진공을 유지하고, 약 5일동안 패키지 bake-out을 수행하였다. 진공압력은 $10^{-7}\;torr$ 이하를 유지하였으며, getter를 활성화시키고, pinch-off 공정으로 조립 ass'y를 완성하였다. 진공 패키지의 기밀성은 He leak tester를 이용하여 측정하였으며, ${\sim}10^{-9}\;std.cm^3/sec$로 기밀성을 유지하였다. TE cooler를 작동한 온도안정성은 0.05 K 이하였다. 볼로미터 센서의 반응도는 $10^2\;V/W$ 이상을 나타내었으며, 탐지도는 $2{\times}10^8cm-Hz^{1/2}/W$를 나타내었다. 본 연구를 통하여 얻어진 결과는 향후 2차원 열영상용 어레이 검출기 및 웨이퍼수준의 패키징 공정에 유용하게 응용될 것으로 판단된다.

• Journal of Korean Society on Water Environment
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• v.34 no.4
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• pp.382-390
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• 2018

In this study, the LIDMOD3 was developed to design and evaluate low impact development (LIDMOD). In the same fashion, the LIDMOD3 employs a curve number (NRCS-CN) method to estimate the surface runoff, infiltration and event mean concentration as applicable to pollutant loads which are based on a daily time step. In these terms, the LIDMOD3 can consider a hydrologic soil group for each land use type LID-BMP, and the applied removal efficiency of the surface runoff and pollutant loads by virtue of the stored capacity, which was calculated by analyzing the recorded water balance. As a result of Model development, the LIDMOD3 is based on an Excel spread sheet and consists of 8 sheets of information data, including: General information, Annual precipitation, Land use, Drainage area, LID-BMPs, Cals-cap, Parameters, and the Results. In addition, the LIDMOD3 can estimate the annual hydrology and annual pollutant loads including surface runoff and infiltration, the LID efficiency of the estimated surface runoff for a design rainfall event, and an analysis of the peak flow and time to peak using a unit hydrolograph for pre-development, post-development without LID, and as calculated with LID. As a result of the model application as applied to an apartment, the LIDMOD3 can estimate LID-BMPs considering a well spatical distributed hydroloic soil group as realized on land use and with the LID-BMPs. Essentially, the LIDMOD3 is a screen level and simple model which is easy to use because it is an Excel based model, as are most parameters in the database. This system can be expected to be widely used at the LID site to collect data within various programmable model parameters for the processing of a detail LID model simulation.

• Korean Journal of Materials Research
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• v.10 no.10
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• pp.698-702
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• 2000

The characteristics of optical absorption in $Al_{0.24}Ga_{0.76}As/GaAs$ multi-quantum wells(MQWs) structure were investigated by using the surface photovoltage(SPV). The Spy features near 1.42 eV showed two overlapping signals. By chemical etching, we found associated with the GaAs substrate and the GaAs cap layer. The Al composition(x=24 %) was determined by Kuech's composition formula. In order to identify the transition energies. the experimentally observed energies were compared with results of the envelope function approximation for a rectangular quantum wells An amplitude variation of the relative Spy intensity from the GaAs substrate, llH, and llL was observed at different light intensities. A variation in the SPY line shape of the transition energies were observed with decreasing tempera­t ture.

• The Korean Journal of Mycology
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• v.26 no.3 s.86
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• pp.314-320
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• 1998

A 0.4 kb cDNA fragment was isolated from mRNA of UV or mechanical wound damaged Pleurotus sajor-caju by the differential display method. Expression of the gene corresponding to this cDNA fragment was highly induced by mechanical wound damage or UV treatment. This gene showed only basal level expression in mycelia, stipe, and cap under normal growth conditions. Sequencing analysis showed that this cDNA fragment contains partial open reading frame. Homology search using genbank database revealed that although this gene do not have homology with already reported wound induced genes, it has a significant sequence homology in defined region with the cdc2-related protein kinase gene which is known to be involved in negative regulation of meiotic maturation in Xenopus oocytes.

• Korean Journal of Organic Agriculture
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• v.7 no.2
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• pp.99-106
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• 1999

In order to acquire microbial agents that can be utilized for biological control of bitter rot(Glomerella cingulata), the major airborne disease to apple, the effective microorganisms were isolated, tested for antagonistic activity to the pathogen. Through the screening of more than 1,000 species of microorganisms collected in nature, 11 species of antagonists were selected. On of the 11 species, one species designated as CH141 demonstrated outstanding activity. The bacterial strain, CH1141 exerted antagonistic efficiency of 65% on Glomerella cingulata. The CH1141 was identified as a bacterial strain to Bacillus subtilis based on morphology, culture conditions, and physiobiochemical characteristics.

• Journal of Fashion Business
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• v.17 no.2
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• pp.46-62
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• 2013

This thesis aims to provide basic resources for the development of various uniform designs of cheerleaders by investigating the currently favoured uniform designs. The 13 professional cheerleader teams were existed among the 25 professional sports teams-9 baseball, 10 basketball and 6 volleyball teams. In each sports teams, four cheerleader's uniform were chosen and evaluated in terms of the cheerleader uniform design by analyzing the forms, colors, decorations and accessories. The result shows that the common kinds of design representing the symbolic color and the emblem were generally prevalent, instead of particular types of uniform design and subject in accordance with different kinds of the professional baseball, basketball and volleyball respectively. Throughout all the kinds of the sports, the combination of the sleeveless top and hot-pants were most frequently observed. In case of the skirts, the mini flare, wrap, and pleats skirts were the most prevalent, because it gave free to motion for cheerleading. The one-piece style were rather infrequent, comparing with the two-pieces, with the hourglass and fitted silhouette the most frequent type, and all those were mini in length. The sleeve in top were generally absent or short, however the bare top style was never found that the top would have a risk of being taken off downwardly during cheerleading. The accessories and the cheering tools were not so much used. The cap and headdresses were not many in kinds. The pompom, megaphone, tube stick, towel, umbrella and musical instruments would not be sufficient to play a role of tools for cheering, which suggests that the rather advanced tools or instruments for cheering in the sports need to be developed, not alone the uniform design.