• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.3-3
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• 2003

고밀도 플라즈마를 생산할 수 있는 대면적용 플라즈마 소스의 개발은 미세전자구조 산업에서부터 FPD 산업에 이르기까지 많은 영역에 걸쳐 필수 불가결한 기술요소가 되어가고 있 다. 이러한 대면적용 고밀도 플라즈마에의 적용을 위하여 새로운 유도결합형 플라즈마 소오스의 개발이 진행되고 있으며, 차세대 반도체 식각 및 세정 공정을 위하여 여러 형태의 안 테나가 연구되어지고 있다. 그러나 TFT -LCD에 적용이 가능하게끔 기존의 ICP 소오스를 직 접적으로 대면적화 하는 데에는 여러 가지 문제점들로 인해 그 한계점이 들어났다. 그 예로 안테나의 길이가 길어짐에 따른 안테나 저항 값이 커지며, 안테나 소스 길이자체가 사용하는 인가전력(13.56MHz)의 반파장에 해당되는 길이가 되었을 경우 생기는 심각한 정상파 효과, 유전물질의 두께 증가 및 그에 따른 재료비의 상승 및 관리상의 어려움들이 바로 그것 이라 할 수 있겠다. 그러므로, 본 연구에서는 차세대 TFT -LCD 대면적 공정에 적용 가능한 고밀도 플라즈마 를 발생시키기 위해서 내장형 유도결합형 선혈 안테나를 사용하였다. 내장형 유도결합형 선 혈 안테나가 가지고 있는 고유의 정전기적 결합효과를 최소화시키기 위해 직사각형모앙의 플라즈마 댐버(830mm*1,020mm)에서 영구자석을 사용하여 multi-cusp 자장효과 및 다양 한 자장의 배열에 따른 플라즈마 특성변화를 살펴보았다. 영구자석을 사용하여 외부자장을 인가하였을 때가, 그럴지 않은 때보다 RF 안테나 코일의 전압을 낮춰주었으며, 영구자석의 배열에 따라 코일의 인덕턴스의 값이 크게 변함을 알 수 있었다. 그리고 최적화된 자장의 배열은 플라즈마의 이온밀도를 증가시켰으며, 플라즈마의 균일도도 10% 이내로 유지됨을 알 수 있었다. 또한 영구자석에 의한 자장의 유무 및 공정압력과 인가전력에 따른 P Photoresist Film의 식각특성에 관해 살펴보았다.증을 위한 실험.측정장비의 구입 및 업계와의 공동활용, 국내.외 최신기술 정보자료의 수집과 신속제공, 국내.외 전문가 초청 활 용, 미래 지향적 목적활용 기초연구사업 수행, 미래기술 동향예측 및 홍보 등을 통해 서 국내 도금기술의 기술자립 및 고도화를 위한 여건마련을 위하여 노력하고 있다.빛 이때의 부식속도(선형분극법), 인위적인 피막 파괴 전,후 의 전위 변화 및 부식속도 측정법에 의한 국부부식 발달 저지능 등을 평가하여 각 실험결과를 비교분석하여 보았다. 수록 민감하여 304 의 IGSCC 와 매우 유사한 거동을 보인다. 본 강연에서는 304 와 600 의 고온 물에서 일어나는 IGSCC 민감도에 미치는 환경, 예민화처리, 합금원소의 영향을 고찰하고 이에 대한 최근의 연구 동향과 방식 방법을 다룬다.다.의 목적과 지식)보다 미학적 경험에 주는 영향이 큰 것으로 나타났으며, 모든 사람들에게 비슷한 미학적 경험을 발생시키는 것 이 밝혀졌다. 다시 말하면 모든 사람들은 그들의 문화적인 국적과 사회적 인 직업의 차이, 목적의 차이, 또한 환경의 의미의 차이에 상관없이 아름다 운 경관(High-beauty landscape)을 주거지나 나들이 장소로서 선호했으며, 아름답다고 평가했다. 반면에, 사람들이 갖고 있는 문화의 차이, 직업의 차 이, 목적의 차이, 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응$\lrcorner$과 $\ulcorner$표현$\lrcorner$

• Journal of the Korean institute of surface engineering
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• v.45 no.3
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• pp.97-105
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• 2012

The effects of pH, types of applied current, agitation method and time, additive on the amount of co-deposited $TiO_2$ particles in the matrix were investigated. The deposition rates increased with increasing pH values, while the volume fraction of $TiO_2$ particles and the size of agglomerated $TiO_2$ particles in the composite decreased. The volume fraction of $TiO_2$ particles in the composite decreased when pulsed current of 50% duty cycle was used. And the size of agglomerated $TiO_2$ particles in the nickel matrix of pulsed current was smaller than that of DC current specimen. The volume fraction of $TiO_2$ particles in the matrix decreased with longer time by air agitation, but in case of using magnetic bar, volume fraction in the same range of time was relatively constant. The volume fraction of the electrodeposited Ni-$TiO_2$ composite in the solution containing 0.01 M Dimethylamine borane (DMAB) increased slightly with increasing agitation time regardless of agitation methods. Thermal stability of the electrodeposited Ni-$TiO_2$ composite increased with lower pH at the temperature range of $200{\sim}800^{\circ}C$, and the results showed that the amount of co-deposited $TiO_2$ relies more on the deposition rate than zetapotential of $TiO_2$ particles.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.119-119
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• 2009

인버터 DC 저항용접의 적용성 증대 : 인버터 DC 저항용접 공법이 SPOT, PROJECTON, SEAM, BUTT 등의 공정에 다양하게 적용되어 저항용접 현장에서 고효율, 친환경적 용접 환경을 만드는데 일조 하고 있다. 특히 자동차의 경량화, 충돌내성 증대, 진동 및 내구성 증대, 공간활용 극대화, 새로운 Design 개념 적용 등의 산업전반에 걸쳐 나타나는 신 Trends로 고 장력 철재의 적용 범위가 확대되고 HSS(High Strength Steel), EHSS(Extra High Strength Steel), UHSS (Ultra High strength Steel ; Hot - Formed Steel )등 다양한 철판의 SPOT 저항용접이 필요하게 되었다. 기존의 AC 단상용접의 전력 특성 상 통전 중 무 통전 시간 과 높은 PEAK 전력, 단상 대 전력 소모로 인한 전력 DROP 등의 문제로 인하여 신소재의 용접 시 매우 많은 Spatter가 발생하고, 높은 용접품질의 확보가 어려워 지므로 이를 대체하기 위한 공법으로 MFDC ( 인버터 DC 저항용접공법 )이 적용되고 있다. 인버터 DC 저항용접의 적응제어 : MFDC라는 높은 효율의 용접 전력원이 확보 됨에도 불구하고 용접현장에서는 원 자재, 도금 등의 품질 산포, 프레스 물의 가공산포, 공기압 산포, 전극 과열 및 마모 등의 요인에 의하여 저항용접 산포가 발생하고 있다. 이는 인위적인 조작이 어렵고 불규칙적이며, 어디서나 산재하고 있는 문제이다. 이를 용접전력 제어 법으로 개선하여 일정한 용접성을 확보하기 위한 노력이 적응제어 기법이다. 정 전류, 정 전력 제어는 정량 제어로 용접 물을 비롯한 용접부의 변화와는 관계없이 설정된 일정량의 전력을 공급하기만 하는데 반하여 적응제어는 적절한 용접 작업 시의 용접 물의 상태, 전극의 가압, 표면 상태 등에 따른 변화 페턴을 기억하고 이후 진행되는 용접에 대하여 정상 페턴과의 차이를 감지 이를 보상하므로 고품질의 용접성을 보장하는 제어기법이다. 따라서 다양한 용접 산포 유발 요인에 의해 용접부의 변화가 발생한다 하여도 그 변화를 감지 하고 적절한 용접전력을 공급한다면 고품질의 용접성을 확보하는데 유용한 공법이 될 수 있다. 인버터 DC 저항용접의 SPC 관리 : SPOT 용접 시 획득할 수 있는 다양한 파라메터에 대하여 모니터링 하고 이 자료를 data 화 하여 품질 관리에 응용하게 되면 양산라인에서 반복적으로 발생되는 문제점을 확인 할 수 있고 이를 통계적 방법으로 추적 개선해 나간다면 용접 불량 감소 및 생산성 향상에 도움이 되며 작업자의 공정 능력 향상 및 기업의 기술축적에도 높은 기여를 할 수 있을 것이다. 용접 적응제어와 다양한 파라메터 모니터링이 한 system에서 이루어 질 때 높은 용접성 확보와 불량률 감소, 원가절감, 생산성 향상 등의 효과가 극대화 될 것이다.

• Journal of Welding and Joining
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• v.28 no.3
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• pp.92-98
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• 2010

Ferritic stainless steels, which have relatively small thermal expansion coefficient and excellent corrosion resistance, are increasingly being used in vehicle manufacturing, in order to increase the lifetime of exhaust manifold parts. But, there are limits on use because of the problem related to cosmetic resistance, corrosions of condensation and high temperature salt etc. So, Aluminum-coated stainless steel instead of ferritic stainless steel are utilized in these parts due to the improved properties. In this investigation, Al-8wt% Si alloy coated 409L ferritic stainless steel was used as the base metal during Gas Tungsten Arc(GTA) welding. The effects of coated layer on the microstructure and hardness were investigated. Full penetration was obtained, when the welding current was higher than 90A and the welding speed was lower than 0.52m/min. Grain size was the largest in fusion zone and decreased from near HAZ to base metal. As welding speed increased, grain size of fusion zone decreased, and there was no big change in HAZ. Hardness had a peak value in the fusion zone and decreased from the bond line to the base metal. The highest hardness in the fusion zone resulted from the fine re-precipitation of the coarse TiN and Ti(C, N) existed in the base metal during melting and solidification process and the presence of fine $Al_2O_3$ and $SiO_2$ formed by the migration of the elements, Al and Si, from the melted coating layer into the fusion zone.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1626-1632
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• 2018

In this paper, we describe the fabrication and characterization of a hydrogen peroxide ($H_2O_2$) sensor based on palladium and copper (PdCu) electroplated laser induced graphene (LIG) electrodes. $CO_2$ laser was used to form LIG electrodes on a PI film. This fabrication method allows simple control of the LIG electrode size and shape. The PdCu was electrochemically deposited on the LIG electrodes to improve the electrocatalytic reaction with $H_2O_2$. The electrochemical performance of this sensor was evaluated in terms of selectivity, sensitivity, and linearity. The physical characterization of this sensor was conducted using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), which confirmed that PdCu was formed on the laser induced graphene electrode. In order to increase the sensor sensitivity, the Pd:Cu ratio of the electroplated PdCu was varied to five different values and the condition of highest amperometric current at an identical of $H_2O_2$ concentration was chosen among them. The resulting amperometric current was highest when the ratio of Pd:Cu was 7:3 and this Pd;Cu ratio was employed in the sensor fabrication. The fabricated PdCu/LIG electrode based $H_2O_2$ sensor exhibited a sensitivity of $139.4{\mu}A/mM{\cdot}cm^2$, a broad linear range between 0 mM and 16 mM of $H_2O_2$ concentrations at applied potential of -0.15 V, and high reproducibility (RSD = 2.6%). The selectivity of the fabricated sensors was also evaluated by applying ascorbic acid, glucose, and lactose separately onto the sensor in order to see if the sensor ourput is affected by one of them and the sensor output was not affected. In conclusion, the proposed PdCu/LIG electrode based $H_2O_2$ sensor seems to be suitable $H_2O_2$ sensor in various applications.

• Journal of Institute of Convergence Technology
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• v.8 no.1
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• pp.33-39
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• 2018

The screen printing method for forming the electrode by applying the existing pressure is difficult to apply to thin wafers, and since expensive Ag paste is used, it is difficult to solve the problem of cost reduction. This can solve both of the problems by forming the front electrode using a plating method applicable to a thin wafer. In this paper, the process conditions of electrode formation are optimized by using LIEP (Light-Induced Electrode Plating). Experiments were conducted by varying the Ni plating bath temperature $40{\sim}70^{\circ}C$, the applied current 5 ~ 15 mA, and the plating process time 5 ~ 20 min. As a result of the experiment, it was confirmed that the optimal condition of the structural characteristics was obtained at the plating bath temperature of $60^{\circ}C$, 15 mA, and the process time of 20 min. The Cu LIEP process conditions, experiments were conducted with Cu plating bath temperature $40{\sim}70^{\circ}C$, applied voltage 5 ~ 15 V, plating process time 2 ~ 15 min. As a result of the experiment, it was confirmed that the optimum conditions were obtained as a result of electrical and structural characteristics at the plating bath temperature of $60^{\circ}C$ and applied current of 15 V and process time of 15 min. In order to form Ni silicide, the firing process time was fixed to 2 min and the temperature was changed to $310^{\circ}C$, $330^{\circ}C$, $350^{\circ}C$, and post contact annealing was performed. As a result, the lowest contact resistance value of $2.76{\Omega}$ was obtained at the firing temperature of $310^{\circ}C$. The contact resistivity of $1.07m{\Omega}cm^2$ can be calculated from the conditionally optimized sample. With the plating method using Ni / Cu, the efficiency of the solar cell can be expected to increase due to the increase of the electric conductivity and the decrease of the resistance component in the production of the solar cell, and the application to the thin wafer can be expected.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.62-77
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• 2011

Yi Sunsin's artifacts had been exhibited at Hyeonchungsa in Asan-si, Chungchungnam-do. These artifacts include Janggeom(Long swords), Okno(Jade ornament of Korea traditional hat), Yodae(Waist belt) and Dobae(Peach shaped wine cups) Gudae(Yodae's saucers). These were covered with dust and corroded due to long term display. Condition of these artifacts was examined for a re-opening of Yi Chungmugong Memorial Pavilion on 28 March 2011. Before conservation treatment of the artifacts, scientific analysis was conducted to identify the material of the artifacts. The result showed that the red paint on the hilt of the sword is composed of two layers. Pigments of two layers were found to be hematite and cinnabar mixed with red lead respectively. Mixed layer was assumed to have been applied recently. Also it was found that the blade of the sword was repainted using chrome yellow($PbCrO_4$). Considering the time limit, conservation treatment focused on stabilization of damaged area and prevention of futher risk during display.

• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.92-107
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• 2018

In 2013~2016, gilt-bronze shoes were excavated from the ancient tombs in Jeongchon Village located at Bogam-ri, Dasi-myeon in Naju. They are estimated to have been made in the late 5th or early 6th centuries. The gilt-bronze shoes are significant in that they serve to explicate the relationship between the center of Baekje and the local forces in the Yeongsan River Basin. This study's specific focus was the gilt-bronze shoes from the ancient tombs in Jeongchon Village. Based on the findings, a restoration drawing was designed and restored products were manufactured by considering metalwork techniques used to manufacture the original ones. At first, manufacturing techniques were tested by using a scientific analysis and visual observation. The manufacturing method, structures, and patterns of the gilt-bronze shoes were closely examined. Then, a design drawing of gilt-bronze shoes was created through field measurement and they were recreated on the basis of the analysis. The original form of the restored products were manufactured through cutting out the outward form, bore carving, engraving, molding, plating, and an assembly process. In the restoration process, this study examined the formal characteristics of gilt-bronze shoes, manufacturing techniques, and archetypes during Baekje's late Hanseong era. Products restored from this study are expected to be used as achievements for more easily understanding the culture of Baekje.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.67-74
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• 2018

Thermoelectric thin film modules were fabricated by electroplating p-type $Sb_2Te_3$and n-type $Bi_2Te_3$ thin film legs with the same thickness of $20{\mu}m$ and different diameters of $100{\mu}m$, $300{\mu}m$, and $500{\mu}m$, respectively. The output voltage and output power of thin film modules were measured and compared as a function of the leg diameter. The modules processed with thin film legs of $100{\mu}m$, $300{\mu}m$, and $500{\mu}m$-diameter exhibited open circuit voltages of 365 mV at ${\Delta}T=36.7K$, 142 mV at ${\Delta}T=37.5K$, and 53 mV at ${\Delta}T=36.1K$, respectively. Maximum output powers of $845{\mu}W$ at ${\Delta}T=36.7K$, $631{\mu}W$ at ${\Delta}T=37.5K$, and $276{\mu}W$ at ${\Delta}T=36.1K$ were obtained for the modules fabricated with the thin film legs of $100{\mu}m$, $300{\mu}m$, and $500{\mu}m$-diameter, respectively.

• Conservation Science in Museum
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• v.26
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• pp.119-142
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• 2021

The gilt-bronze-and-silver shoes, excavated from the Tomb of King Muryeong, revealed many defective parts, which constantly raised in-depth re-investigation and reporting. In that point, scientific treatment and analysis were conducted to investigate the manufacturing techniques applied. The conservation treatment was carried out with an emphasis on the restoration of the original form and joining parts. As a result, the upper part of the right shoe and some part of the back heel were joined, confirming the joining method and the number of rivet used for instep bonding. From the component analysis, it is presumed that the outer plate was gilded with mercury amalgam on pure copper, and pure silver was used for the inner plate. The main pattern of the gilt-bronze-and-silver shoes includes designs of phoenix, lotus, and six-petal flower, while the lotus pattern is high in terms of ratio. Thus, youngnaksa(twisted gilt-bronze thread), geumdongsa(gilt-bronze thread), wondujeong (rivet), and samyeonjeong(quadrangular cleats) were used for bonding each plate. Twisted gilt-bronze thread was used to join the inner and outer plates, while the center and rear of the inner plate were combined with only gilt-bronze threads. From the fact, it is presumed that the joining method was different whether the function was decoration or just bonding. Regarding the manufacturing process, traces of burnishing were confirmed on the outer surface of the gilt-bronze and silver shoes, but no burnishing traces were identified on the inner surface of the silver plate, which is likely to prove more importance put on the finishing of the outer plates rather than that of the inner.