• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.369-369
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• 2012

The present work deals with selective deposition of copper on fluoropolymers patterned silicon (111) surfaces. The pattern of fluoropolymer was fabricated by nanoimprint lithography (NIL) and plasma reactive ion etching (RIE) was used to remove the residuals layers. Copper was electrochemically deposited in bare Si regions which were not covered with fluoropolymers. The patterns of fluoropolymers and copper have been investigated by scanning electron microscopy (SEM). In this work, we used two deposition methods. One is galvanic displacement method and another is electrodeposition. Selective deposition works in both cases and it shows applicability to other materials. By optimization of the deposition conditions can be achieved therefore this process represents a simple approach for a direct high resolution patterning of silicon surfaces.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.559-564
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• 2006

최근에 들어서 생체신호분석을 통하여 여러 가지 사용자 상태를 파악하려는 연구가 많이 진행되고 있다. 대표적인 것이 GSR(전기피부반응, galvanic skin response), BVP(blood volume pressure), 호흡 등의 생체신호가 사람의 흥분 정도, 정신적 부담, 감정변화에 따라 달라지는 특성을 활용하는 것이다. 본 연구에서는 디지털 TV, 혹은 IPTV 의 컨텐츠를 감상하는 환경 하에서 시청자의 생체신호의 변화 패턴을 분석하여, 그 분석 결과로부터 TV 프로그램이나 디지털 컨텐츠에 대해 시청자가 느끼는 만족도, 집중도, 흥미 여부 등을 추론하고자 하였다. 즉, 주어진 컨텐츠를 감상하는 동안 시청자로부터 얻어낸 생체신호를 분석한 시청 정보 데이터가 프로그램에 대한 선호도와 관련을 가질 수 있는지 검증한 기초 연구 결과를 제시한다. 또한 이 결과를 통해 프로그램에 대한 시청자의 반응을 객관적으로 측정하고 실시간으로 반영할 수 있도록 하는 TV 프로그램 추천 시스템의 구현 가능성을 검증한다.

• Corrosion Science and Technology
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• v.2 no.5
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• pp.247-251
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• 2003

The corrosion forms of automotive body panels are various. One of the representations is a corrosion pitting and its propagation on the lapped portion by galvanic corrosion. But it has been difficult in correlation analysis about the corrosion propagation rate and mechanism of pitting and the actual automotive body in field. This present study interprets experimentally the rust pitting occurrence mechanism on the lapped panels through experimental methods. And field car investigation was executed for correlation analysis with experimental results. This paper compares corrosion propagation rate by pitting on hot-dip galvannealed steel sheets with corrosion forms in the automotive field condition. The research fundamentals which make it possible to predict the pitting occurrence and propagation on the lapped panels in the actual vehicles are given.

• Corrosion Science and Technology
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• v.3 no.2
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• pp.67-71
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• 2004

Galvanized Steel pipes have been widely used in industries and apartments, Unexpected early leakage has been found in an apartment. Tunneling corrosion or penetration was found in the water supply pipes. The chemical compositions of the pipes and properties of coating layer were evaluated. The pipes met the specification of KS D 3507. The cause of early failure was analyzed through the examination of macrostructures and microstructures, It was found that the pipes were failed by grooving corrosion, which resulted from galvanic corrosion of weld bead and matrix.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1402-1408
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• 2015

A MOSFET's gate driver based on magnetic coupling is investigated. The gate driver can meet the demands in applications for wide range of duty cycles and high frequency. Fully galvanic isolation can be realized, and no auxiliary supply is needed. The driver is insensitive to the leakage inductor of the isolated transformer. No gate resistor is needed to damp the oscillation, and thus the peak output current of the gate driver can be improved. Design of the driving transformer can also be made more flexible, which helps to improve the isolation voltage between the power stage and the control electronics, and aids to enhance the electromagnetic compatibility. The driver's operation principle is analyzed, and the design method for its key parameters is presented. The performance analysis is validated via experiment. The disadvantages of the traditional magnetic coupling and optical coupling have been conquered through the investigated circuit.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.211-215
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• 2006

This paper present the Half-Bridge converter for low current output. In converter system, magnetic components are important devices used for energy storage, energy transfer, galvanic isolation and filtering. The proposed Half-Bridge converter is to reduce the number of magnetic components. The secondary rectification was discussed by comparison of center-tap type with primary center-core transformer winding and primary side-core transformer winding. A prototype featuring 400V input, 10V output, 400kHz switching frequency, and 100W output power.

• Proceedings of the KWS Conference
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• 1997.05a
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• pp.35-38
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• 1997

In order to investigate quantitative behavior of galvanic corrosion in the weld joint between stainless steel and carbon steel, electrochemical polarization experiments are performed for various pH, water temperature with boric acid concentration 4000ppm. The corrosion rate of stainless steel was almost independent of the variation of pH. The significant corrosion rates of carbon steel and the weld joint of carbon-carbon steel were observed at pH 4. The corrosion rates in the weld joint of the carbon-stainless steel were observed depending on the variation of pH level.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.4
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• pp.185-192
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• 2020

In this study, materials characterization of pure copper and copper based carbon nano-tube composite prepared by powder metallurgy method were investigated. Prior to evaluate materials characterization, spark plasma sintering processing variables such as sintering temperature, pressure, thickness and diameter of compacts was optimized to ensure the microstructure and materials property of pure Cu and Cu-CNT composite. In addition, corrosion behavior of Cu-based CNT composite produced by powder sintering method was investigated. It was confirmed from this study that the corroded surfaces of the composite shows less dissolution compared with pure copper in 3.5 wt% NaCl solution. The measured corrosion current density (I_corr) indicates improved corrosion property of Cu based composite containing small additions of CNTs in chloride containing media. Micro-galvanic activity between Cu and CNT was not observed in given sintering condition.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.05a
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• pp.120-122
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• 2003

In this study, an experiment was conducted in order to investigate the feasibility and effectiveness of and on-line subjective assessment (OLSA) system. The present study compared Galvanic Skin Response (GSR) with the OLSA by presenting 28 subjects in their 20s with pictures arousing either positive or negative sensibility. According to the correlation coefficients, changes in subjective sensibility caused by the positive visual stimulus were related more closely to GSR, from the positive visual stimulus, and changes in subjective sensibility caused by the negative visual stimulus were related more closely to GSR from the negative visual stimulus. In conclusion, the most remarkable characteristic of the present system is that it not only assesses the average sensibility when stimuli are presented, but also shows the changing strength of sensibility over time.

• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.141-145
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• 1998

The electrical properties of the mixed conducting yttria(8 mol%) stabilized zirconia(YSZ)-nickel oxide(NiO) composites were examined by a.c. impedance, 4-probe d.c. conductivity between 400 and $1000^{\circ}C$. The oxygen partial pressure dependence of conductivity, and electromotive force measurement of galvanic cell enabled to determine the electronic contribution to the conduction. Up to 6 vol% NiO addition, the conductivity decreased since the electronic NiO acted as an insulator in ionic matrix. However the ionic transport was dominant until NiO content reaches 26 vol%. Mixed conduction was observed between 26 and 68 vol% of NiO. The effect of composition on the electrical property was explained by the microstructure and thus by the distribution of two phases.