• 재활복지공학회논문지
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• 제4권1호
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• pp.43-51
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• 2010

본 논문에서는 사용자의 훈련효과 향상을 위한 세계공인 전자호구 시스템에 기반한 디지털 태권도 트레이너 시스템을 개발하였다. 본 시스템은 전자호구용 모듈을 확장한 타격감지 모듈과 타격목표 지정을 위한 LED 인디케이터를 포함한 E-Kick Bag, 훈련 설정 및 훈련 관련 제어와 사용자의 훈련정보 및 통계 등을 분석하는 태권도 트레이너 프로그램, 그리고 E-Kick Bag과 트레이너 프로그램을 유/무선으로 연결하는 수신기로 구성된다. 태권도 트레이너 시스템은 사용자에게 6개의 LED 인디케이터를 이용하여 타격목표를 지정해 줌으로써 타격정확도 및 반응속도 등의 운동기능 및 훈련효과를 향상시키는 장점을 가진다. 트레이너 시스템은 또한 훈련결과로부터 사용자의 타격강도 및 정확도 분석을 통한 타격 패턴 및 장/단점을 파악하여 제공할 수 있다는 특징을 가진다. 본 논문에서는 시스템의 효율성을 판단하기 위해 국가대표선수를 포함한 다양한 체급, 나이, 성별의 선수 8명을 대상으로 임상 실전 평가를 실시하였고, 시스템의 만족도 및 가치를 설문조사하였다.

• 한국결정성장학회지
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• 제2권2호
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• pp.40-52
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• 1992

Titanium-iso-propoxide[$Ti(OC_3H_7)_4$]와 Tetra-ethyl-lead $[Pb({C_2}{H_5})_4]$를 사용한 MOCVD법으로 PbTi$O_3$박막을 55$0^{\circ}C$에서 증착하였다. Ar과 $O_2$를 각각 운반 및 반응기체로 사용하였으며, 열처리에 따른 박막의 두께와 굴절지수의 변화, Xtjs 회절 분석, CV 특성 측정등을 행하였다. 열처리에 따른 CV 특성 측정 결과 PbTi$O_3$는 Si기판과 계면 반응을 하는 것으로 생각되며, X선 회절 분석 결과 $PbTiO_3$의 특성 peak들이 관찰되었다. 열처리 시간 및 온도의 증가에 따라 박막의 두께는 감소하고, 굴절지수는 증가하는 경향을 보여 주었다.

• Corrosion Science and Technology
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• 제5권5호
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• pp.168-172
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• 2006

Alloy 600 having a superior resistance to a corrosion is used as a steam generator tubing in nuclear power plants. In spite of its high corrosion resistance, there are many tubings which experience corrosion problems such as a SCC under the high temperature and high pressure environments of nuclear power plants. The Alloy 600 tubing can be repaired by using a Ni electroplating having an excellent SCC resistance. In order to carry out a successful Ni electrodeposition inside a steam generator tubing, the effects of various parameters on the material properties of the electrodeposit should be elucidated. Hence this work deals with the effects of an applied current density, duty cycle($T_{on}/(T_{on}+T_{off})$) of a pulse current, bath temperature and solution pH on the material properties of Ni electrodeposit obtained from a Ni sulphamate bath by analyzing the current efficiency, potentiodynamic curve, hardness and stress-strain curve. Hardness, YS(yield strength) and TS(tensile strength) decreased whereas the elongation increased as the applied current density increased. This was thought to be by a concentration depletion at the interface of the electrodeposit/solution, and a fractional decrease of the hydrogen reduction reaction. As the duty cycle increased, the hardness, YS and TS decreased while the elongation increased. During an off time at a high duty cycle, the concentration depletion could not be recovered sufficiently enough to induce a coarse grain sized electrodeposit. With an increase of the solution temperature and pH, the YS and TS increased while the elongation decreased. The experimental results of the hardness and the stress-strain curves can be supplemented by the results of the potentiodynamic curve.

• 한국재료학회지
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• 제21권6호
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• pp.309-313
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• 2011

The power capacitors used as vehicle inverters must have a small size, high capacitance, high voltage, fast response and wide operating temperature. Our thin film capacitor was fabricated by alumina layers as a dielectric material and a metal electrode instead of a liquid electrolyte in an aluminum electrolytic capacitor. We analyzed the micro structures and the electrical properties of the thin film capacitors fabricated by nano-channel alumina and metal electrodes. The metal electrode was filled into the alumina nano-channel by electroless nickel plating with polyethylene glycol and a palladium catalyst. The spherical metals were formed inside the alumina nano pores. The breakdown voltage and leakage current increased by the chemical reaction of the alumina layer and $PdCl_2$ solution. The thickness of the electroless plated nickel layer was 300 nm. We observed the nano pores in the interface between the alumina layer and the metal electrode. The alumina capacitors with nickel electrodes had a capacitance density of 100 $nF/cm^2$, dielectric loss of 0.01, breakdown voltage of 0.7MV/cm and leakage current of $10^4{\mu}A$.

• 한국산업정보학회논문지
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• 제12권5호
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• pp.98-109
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• 2007

최종사용자 중심의 웹 플랫폼을 제공하는 웹 환경인 웹2.0시대가 도래했다. 또한 UCC(User Created Contents) 환경에 대한 관심의 증가로 사용자들의 멀티미디어 콘텐츠 참여가 급속도로 확산되고 있는 실정이다. "사용자의 능동적 참여"라는 웹2.0의 목적을 고려할 때, 노약자나 시각장애인과 같은 기반 정보접근에 있어 많은 어려움이 따르는 사용자들의 접근성 고려에 대한 인식과 필요성 역시 증가하고 있다. 본 연구에서는 시각장애 사용자들의 웹 기반 UCC 서비스 활용에 있어 문제점을 파악 분석하여 그들의 원활한 접근이 가능한 웹 기반 UCC 서비스에 대한 효율적인 구현방안을 제시한다. 특히 본 연구에서는 제시된 구현방안에 의한 테스트 페이지 구현을 통해 시각장애 사용자들의 반응시간을 기존 UCC 서비스와 비교.분석함으로써 제시한 방법론에 대한 타당성을 검증하였다.

• 멤브레인
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• 제27권6호
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• pp.506-510
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• 2017

계면중합법은 혼합되지 않은 두 용액에 용해되어 있는 반응성 단량체들이 계면에서 중합되는 기술로 다양한 분야에 응용되고 있다. 이 중, 수처리 분리막의 경우 m-phenylene diamine과 Trimesoyl chloride를 반응물로 사용하고 있다. 분리막의 성능은 다양한 중합 성능에 의해 영향을 받고 있으며, 본 연구에서는 유기 용액의 퍼짐 속도가 어떻게 분리막 표면 및 구조에 영향을 주는지를 주사전자현미경을 통해 고찰하였다. 퍼짐 속도는 7.6과 25 mm/sec로 조절하였으며, 유기상 용액은 1~3방울까지 조절하였다. 관찰된 결과는 퍼짐 속도가 7.6 mm/sec에서는 한 방울 떨어트릴 경우, 25 mm/sec에서는 두 방울 떨어트릴 경우 폴리아마이드 막에 균열을 발견할 수 없었다. 반면 나머지 경우에 모두 균열이 발생하였다. 따라서, 초기 유기용액의 퍼짐 속도는 폴리아마이드 분리막의 성능에 영향을 줄 것으로 관찰되었다.

• 한국세라믹학회지
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• 제49권6호
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• pp.659-662
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• 2012

Yttrium (Y) and niobium (Nb) doped spherical $Li_4Ti_5O_{12}$ were synthesized to improve the energy density and electrochemical properties of anode material. The synthesized crystal was $Li_4Ti_5O_{12}$, the particle size was less than $1{\mu}m$ and the morphology was spherical and well dispersed. The Y and Nb optimal doping amounts were 1 mol% and 0.5 mol%, respectively. The initial capacity of the dopant discharge and charge capacity were respectively 149mAh/g and 143 mAh/g and were significantly improved compared to the undoped condition at 129 mAh/g. Also, the capacity retention of 0.2 C/5 C was 74% for each was improved to 94% and 89%. It was consequently found that Y and Nb doping into the $Li_4Ti_5O_{12}$ matrix reduces the polarization and resistance of the solid electrolyte interface (SEI) layer during the electrochemical reaction.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2000년도 추계학술발표회 초록집
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• pp.1-2
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• 2000

In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the onventional rotating barrel, vibrational barrel(vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components. The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed thatbthe average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value. Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components. However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. 2H20 + e $\rightarrow$M/TEX> 20H + H2.. Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure there by resulting to bad plating condition.

• Nuclear Engineering and Technology
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• 제41권6호
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• pp.785-796
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• 2009

A KALIMER-600 concept which is a type of sodium-cooled fast reactor, has been developed at KAERI. It uses sodium as a primary coolant and is a pool-type reactor to enhance safety. Also, a supercritical carbon dioxide ($CO_2$) Brayton cycle is considered as an alternative to an energy conversion system to eliminate the sodium water reaction and to improve efficiency. In this study, a simplified model for analyzing the thermodynamic performance of the KALIMER-600 coupled with a supercritical $CO_2$ Brayton cycle was developed. To develop the analysis model, a commercial modular modeling system (MMS) was adopted as a base engine, which was developed by nHance Technology in USA. It has a convenient graphical user interface and many component modules to model the plant. A new user library for thermodynamic properties of sodium and supercritical $CO_2$ was developed and attached to the MMS. In addition, some component modules in the MMS were modified to be appropriate for analysis of the KALIMER-600 coupled with the supercritical $CO_2$ cycle. Then, a simplified performance analysis code was developed by modeling the KALIMER-600 plant with the modified MMS. After evaluating the developed code with each component data and a steady state of the plant, a simple power reduction and recovery event was evaluated. The results showed an achievable capability for a performance analysis code. The developed code will be used to develop the operational strategy and some control logics for the operation of the KALIMER-600 with a supercritical $CO_2$ Brayton cycle after further studies of analyzing various operational events.

• 한국진공학회지
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• 제7권2호
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• pp.82-87
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• 1998

$O_2$기체에 $NH_3/O_2$기체를 첨가하여 실리콘 표면에 산화막을 형성하는 $NH_3/O_2$산화법 에 의한 산화공정시 반응석영관 외부에 방출하는 기체는 $N_2,O_2$및 $H_2O$이며 극소량의 $CO_2$, NO 및 $NO_2$가 검출되었다. 두 종류의 산화제($O_2$ 및 $H_2O$)가 산화에 기여하며 성장률은 $NH_3$및 $O_2$ 의 부분압과 온도에 의해 결정되며, 그 기울기는 건식 및 습식 산화법의 중간에 평행 하게 위치함을 확인하였다. Auger Electron Spectroscopy(AES) 측정결과 $NH_3/O_2$ 산화막은 정확한 $SiO_2$의 화학량론을 가지며 $SiO_2/Si$계면에 발생하는 결합을 억제하며 고정전하의 발 생을 최소화함을 알 수 있었다. $NH_3/O_2$ 산화막(470$\AA$)의 항복전압을 57.5Volt이며, C-V특성 곡선을 축정한 결과 플랫밴드 전압은 0.29Volt이며 곡선의 형태는 이상곡선과 일치하였다.