• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.4
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• pp.679-686
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• 1994

This paper describes an improved FES system to restorp paralyzed extremities in spinal-cord-injured patients. By using time-division method in the proposed FES system, we can reduce the size and weight of system despite of increasing channels. We designed a DC-DC converter to adapt the condition of each patient. We could reduce the cost by using easily available apparatus like an IBM-PC for the stimulus-pattern-creating system and standardized parts for the protable FES system.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.1
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• pp.25-37
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• 2002

The purpose of the study was to survey the distribution patterns of inorganic elements of PM-10 in the various indoor environments and analyze the pollution patterns of aerosol in various places of indoor environment using a pattern recognition method based on cluster analysis and disjoint principal component analysis. A total of 40 samples in the indoor had been collected using mini-vol portable samplers. These samples were analyzed for their 19 bulk inorganic compounds such as B, Na, Mg, Al, K, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, and Pb by using an ICP-MS. By applying a disjoint principal component analysis, four patterns of the indoor air pollutions were distinguished. The first pattern was identified as a group with high concentrations of PM-10, Na, Mg, and Ca. The second pattern was identified as a group with high concentrations B, Mg, At, Ca, Fe, Cu, and Ba. The third pattern was a group of sites with high concentrations of K, Zn. Cd. The fourth pattern was a group with low concentrations PM-10 and all inorganic elements. This methodology was found to be helpful enough to set the criteria standard of indoor air quality, corresponding pollutants, and classification of indoor environment categories when making an indoor air quality law.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.621-628
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• 2009

Because the Ultra-Precision Technology increase its competitiveness in the field of the design, precision of processing technology, confidence and fixation degree are major considerations. According to Pattern shapes using these processing technologies, Light Reflection has influence on the sense of sight about human being. Based on background of these studies, we draw a plan about a round workpiece using a 3D design program and analyze the effect on Light Reflection changing a pattern angle and a source of light through SPEOS program in this research. We make Pattern form as V-Shape, and compare the area distributed by Light Reflection by classifying angle into 4 and analyze changes according to a source of light. In order to measure and evaluate the data from simulation analysis we has manufactured Diamond Tool and has processed Pattern precision using a Ultra-Precision Machine. Based on the result of this study, we forecast that the field of design will achieve rapid growth due to Ultra-Precision Technology in the world market.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.5
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• pp.741-751
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• 2009

In order to design and develop the various silhouette of pants pattern for standardized pants patterns, this study is to classify the pants style by the silhouette and to characterize each pants pattern which are classified. Recent 37 ready-made pants patterns of various style were collected in order to analyze their silhouette from April to July 2007. Measurement of each region of the pants pattern were compared and analysed. After analyse the standard deviation, coefficient of variance, minimum, maximum, range about the measurement of each region of the pants pattern, major pattern design factors were extracted. Five major factors are the angle of center front line and center back line, the crotch extension, the position of center back line against center front line, the curvature of center back line, and amount of waist dart. As a result, pants style were grouped as the culottes, formal, basic and tight style after considering the extracted design factors, and analysing correlation, degree of dispersion of the measurement by part. As the silhouette of pants classification from culotte to tight, the fits are closer to the figure, crotch depth increases, crotch extensions are shorter, and angle of the center back increases. The shape of the connected front and back center lines is U-shape for culotte and is closer to V-shape as the silhouette becomes tight.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.133-133
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• 2011

최근 나노입자를 이용한 비휘발성 메모리 소자의 제작에 대한 연구가 진행되고 있다. 특히, 실리사이드 계열의 나노입자를 적용한 소자는 일함수가 크지만 실리콘 내의확산 문제를 가지고 있는 금속 나노입자와 달리 현 실리콘 기반의 반도체 공정 적용이 용이한 잇 점을 가지고 있다. 따라서 본 연구에서는 실리사이드 계열의 화합물 중에서 4.63 eV인 Vanadium Silicide ($V_3$Si) 박막을 열처리 과정을 통하여 수 nm 크기의 나노입자로 제작하였다. 소자의 제작은 p-Si기판에 5 nm 두께의 $SiO_2$ 터널층을 dry oxidation 방법으로 성장시킨 후 $V_3$Si 금속박막을 RF magnetron sputtering system을 이용하여 3~5 nm 두께로 tunnel barrier위에 증착시켰다. Rapid thermal annealing법으로 질소 분위기에서 $1000^{\circ}C$의 온도로 30초 동안 열처리하여 $V_3$Si 나노 입자를 형성 하였으며. 20 nm 두께의 $SiO_2$ 컨트롤 산화막층을 ultra-high vacuum magnetron sputtering을 이용하여 증착하였다. 마지막으로 thermal evaporation system을 통하여 Al 전극을 직경 200, 두께 200nm로 증착하였다. 제작된 구조는 metal-oxide-semiconductor구조를 가지는 나노 부유 게이트 커패시터 이며, 제작된 시편은 transmission electron microscopy을 이용하여 $V_3$Si 나노입자의 크기와 균일성을 확인했다. 소자의 전기적인 측정은 E4980A capacitor parameter analyzer와 Agilent 81104A apulse pattern generator system을 이용한 전기용량-전압 측정을 통해 전하저장 효과를 분석하였다.

• Bulletin of the Korean Chemical Society
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• v.18 no.1
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• pp.70-75
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• 1997

A wide range (10 < Si/V) of mesoporous vanadium silicate molecular sieves with the MCM-41 structure have been synthesized using vanadyl sulfate as the source of vanadium and characterized by XRD, 51V MAS NMR and 29Si MAS NMR. The increase of the unit cell parameter and the decrease of Q3/Q4 ratio of 29Si spectra with the vanadium content suggest the incorporation of vanadium in the framework of MCM-41 structure. 51V MAS NMR demonstrates that vanadiums in as-synthesized V-MCM-41 are present in the chemical environment of octahedra and octahedral vanadium is decreased and tetrahedral vanadium is increased inversely with raising the calcination temperature. Though the thermal treatment in rotor of hydrated sample resulted in the change from tetrahedral environment to octahedral one and the steaming and the acid treatment affect to the chemical environment of vanadium, the spectrum similar to originally calcined sample is regenerated after recalcination. This indicates that the vanadium is belong to the framework in a relatively exposed site. The best quality XRD pattern of the product of Si/V=27 may be attributable to heterogeneous nucleation mechanism. V-MCM-41's having the Si/V ratio lower than 20 are completely collapsed after calcination.

• Proceedings of the KIEE Conference
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• 2008.10a
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• pp.95-96
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• 2008

We constructed an on-line PD monitoring system for the 380kV U/G Cable project at the Riyad 9012 substation in Saudi-arabia. The system will be monitoring the termination of the two 380kV XLPE Cables to prevent unexpected failure of the cable insulation. The system had been tested in the laboratory and on-site for detection of various PD signals and reliability of operation. The system distinguish the existence and nonexistence of the partial discharge and then judge the source of partial discharge using automatic PD pattern recognition software.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.179-181
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• 2005

There is asymmetric in horizontal and vertical side of PDP cell. Every vertical line has BM(Black Mask) to improve luminance contrast. When error diffusion is processed in PDP system, these problems make an error bigger. In 4 inch PDP system, every red, green, blue color of test pattern is presented and each luminance is measured. That is called horizontal(H), diagonal right(R), diagonal left(L) and vertical(V). In red channel, high luminance descending order is V-H-R-L. In green channel, V-H-L-R. In blue channel, V-M-R=L. After average luminance of each direction is calculated. new weighted error diffusion(Weighted ED) is proposed. In digital image signal processing, the error in weighted ED is differ from ED's. The image of weighted ED is more less error compare to conventional ED and close to original image. As the gray level linearity and big size panel is adopted, weighted ED could produce good image.

• Korean Journal of Materials Research
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• v.12 no.8
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• pp.669-675
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• 2002

CrN film coated by AIP method, improved the mechanical properties (Hardness, Roughness, wear and fatigue) of Ti-6Al-4V alloy. The properties were studied using GXRD, XPS, Hardness, Roughness, wear and fatigue testers. CrN thin film thickness was about 7.5$\mu\textrm{m}$ and grew with (111) orientation. Hardness of CrN thin film was very high (Hv 1390) and roughness of the surface layer was greatly improved (Ra=0.063$\mu\textrm{m}$) compared with matrix alloy (Ra=0.321$\mu\textrm{m}$). Such changes of hardness and roughness could be contributed to improving the wear resistance and fatigue life. Striation like pattern with dimples and voids, a typical fatigue fracture mode, was observed throughout the specimen.

• Journal of Ship and Ocean Technology
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• v.8 no.1
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• pp.10-30
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• 2004

High-fidelity RANS simulations are presented for a ducted marine propulsor, including verification ＆ validation (V＆V) using available experimental fluid dynamics (EFD) data. CFDSHIP-IOWA is used with $\textsc{k}-\omega$ turbulence model and extensions for relative rotating coordinate system and Chimera overset grids. The mesh interpolation code PEGASUS is used for the exchange of the flow information between the overset grids. Intervals V＆V for thrust, torque, and profile averaged radial velocity just downstream of rotor tip are reasonable in comparison with previous results. Flow pattern displays interaction and merging of tip-leakage and trailing edge vortices. In interaction region, multiple peaks and vorticity are smaller, whereas in merging region, better agreement with EFD. Tip-leakage vortex core position, size, circulation, and cavitation patterns for $\sigma=5$ also show a good agreement with EFD, although vortex core size is larger and circulation in interaction region is smaller.