• 한국자동차공학회논문집
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• 제18권3호
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• pp.104-109
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• 2010

The fatality of pedestrian accounts for about 21.2% of all fatality at 2007 year in Korea. In car to pedestrian accident it is very important to inspect the throw distance of pedestrian after collision for exact reconstructing of the accident. The variables that influence on the throw distance of pedestrian can be classified into the factors of vehicle and pedestrian, and road condition. It was simulated by PC-CRASH, a kinetic analysis program for a traffic accident in sedan type vehicle and SPSS program was used for regression analysis. From the results, the throw distance of pedestrian increased with the increasing of vehicle velocity, and decreased with the increasing of impact offset. Also it decreased with the increasing of velocity of pedestrian at accident, and throw distance at the road condition of wet was longer than that at dry condition. Finally, the regression model of sedan type vehicle on the throw distance of pedestrian was as follows; $$dist_i=2.39-0.11offset_i+0.59speed_i-545height_i-0.25walk_i+2.78wet_i+{\epsilon}_i$$.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.37-41
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• 2004

Quenching phenomena is one of major concern in development of millimeter or sub-millimeter scale micro combustor for the size of the combustor is near extinction condition. In this work we focused on the effect of combustor wall condition that was parameterized by Perovskite LSC($La_{0.8}$$Sr_{0.2}$$CoO_3$) redox catalyst. The experiment was done by variable gap-width 2D wall equipment. The flame was produced by premixed methane-air jet issuing from millimeter-scale slot burner and it propagated through the narrow gap of the walls. By comparison of flame behaviour near catalyst-coated wall and simple glass wall, we investigated the effect of possible surface reaction on quenching phenomena. The flame between two plates was observed where the gap of the plates was reduced stepwise from 20mm to a distance of quenching occurrence. The two flames with and without surface modification were almost same by observation. But the gap for the occurrence of quenching was increased between catalyst-coated wall. So we concluded that surface reaction close to combustor wall has a negative effect on micro combustion.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 춘계학술발표회 초록집
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• pp.13-13
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• 2001

현재 초고속 가공 공구의 국내 시장은 150억원이며 향후 3년 내에 1500억원으로 급성 장활 전망이다. 무윤활 초고속 가공을 실현하기 위해서는 윤활특성이 우수한 초고경도 코팅의 개발이 필요하며 이를 통해 기계설비의 수명향상과 폐유문제 해결을 기대할 수 있다. 기존의 고체윤활 코팅은 초고경도 코팅의 상부에 $MoS_2$, Graphite 등 윤활성 박막을 합성하였으나, 이들은 Hexagonal 구조의 연질 박막이며 수분이 존재하는 대기중에서는 윤활 및 내마모 특성이 급격히 저하된다. 환경친화 대체소재 개발의 일원으로 TiN, ZrN 박막 등이 이미 개발되었고 기계적 특성이 우수하여 널리 응용되고 있으나 아직 경도(약 20GPa 내외) 및 윤활성의 한계 (마찰계수 $\mu=O.6$)를 극복하지 못하고 있다. TiN박막 위의 Cu의 첨가는 TiN의 구조와 성질을 크게 변화시키는 것으로 알려져 있다. 따라서 본 연구에서는 TiN 기지 위에 Cu를 도핑함으로써 경도의 상승을 통환 내구력의 향상과 마찰계수의 감소를 통한 윤활성의 향상을 보고자하였다. TiN합성의 안정화를 위하여 magnetron sputtering과 arc ion pIatingd을 병용한 hybrid 공정을 이용하였다. Cu첨가에 따른 결정 성장 거동의 변화를 보기 위해 XRD 분석을 실행하였고, EDS 분석을 통해 Cu target 전류밀도에 의한 기지내의 Cu의 함량변화를 고찰하였으며, 경도 및 윤활특성을 고찰하기 위해서 경도 시험과 마모 시험(ball-on disc type test)를 하였다.

• 환경위생공학
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• 제14권4호
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• pp.143-149
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• 1999

In the tungsten industry as light source material, tungsten filament which used as light source material could form after molybdenumwire which used as the center supporter for coil shape tungsten wire was removed. This process uses hydrogen peroxide, Ozone and UV(Ultraviolet)Lamp, for the quantity of hydrogen peroxide decrease. The results were as follows : 1. An incandescent electric Lamp type : FL(FL-20) type : A standard of commodity (P.W.: $19{\pm}1.0mg$, $C.R:4.5{\pm}0.3{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time : 65Min., P.W.: 18.60mg, $C.R.:4.60{\Omega}$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide; Reaction Time : 64Min., P.W.: 18.61mg, C.R.: $4.61{\Omega}$ 2. A Fluorescent Lamp Type : GLS(GLS-40) Type : A standard of commodity(P.W.: $11.8{\pm}0.2mg$$65{\pm}1.5{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time: 72Min, P.W.:11.88mg, C.R.: $65.62\Omega$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide;Reaction Time:71Min., P.W.:11.88mg, C.R.: $65.63\Omega$

• Tribology and Lubricants
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• 제19권4호
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• pp.203-210
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• 2003

In order to enhance the thermal stability of binder materials of bonded type solid lubricants, several metal-alkoxide based sol-gel materials such as methyltrimethoxysilane(MTMOS), titaniumisopropoxide (Ti(Opr$\^$i/)$_4$), zirconiumisopropoxide (Zr(Opr$\^$i/)$_4$) and aluminumbutoxide (Al(Obu$\^$t/)$_4$) were modified chemically by both epoxy and acrylic silane compounds. Friction and wear characteristics of the bonded solid lubricants, whose binders were of several hybrid ceramic materials, were tested with a reciprocating tribo-tester. Wear life was evaluated with respect to the heat-curing temperature, friction temperature, type of supplement lubricants, and ratio of binder materials. Test results showed that the Si-Zr hybrid ceramic materials modified by epoxy-silane compounds had a higher wear life compared to others. Sb$_2$O$_3$ was the most effective supplement lubricants in the high temperature, and BUS analyses revealed that it was caused mainly by a strong anti-oxidation effect to MoS$_2$ particles. The higher heat-curing temperature resulted in the higher wear life, and the higher friction temperature resulted in the lower wear life.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2007년도 춘계 학술발표회 발표논문집
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• pp.289-291
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• 2007

본 연구의 대상해역은 여수반도 남단에 위치한 가막만은 굴을 비롯한 패류양식 생산활동에 기여하는 자연환경의 실질적인 가치와 인간경제 시스템에 대한 EMERGY 분석법으로 평가하고자 한다. 이를 기초로 넙치생산의 지속적인 발전방향을 제시하고자 했다. 2004년 통계를 기준으로 가막만 양식에 유입되는 총 EMERGY의 양은 33.42E+19 sej/yr이고, 이 중 자연환경으로부터 영속성 에너지는 2.95E+20 sej/yr 이며, 주 경제로부터 유입되는 비영속성 에너지는 3.92E+19 sej/yr이다. 자연환경으로부터의 유입이 전체 에너지원의 88%이고, 주 경제로부터의 유입은 12%로서 환경자원에 대한 의존도가 높은 1차 산업의 구조적 특징을 나타내고 있다. Net EMERTY yield ratio는 8.52으로 이는 주 경제로부터 투입된 에너지(비영속성 에너지)에 대해 8배 만큼 수산물을 얻을 수 있는 자원으로서의 가치를 가진다. EMERGY Investment Ratio 0.13은 주 경제로부터 유입된 에너지의 약 7배에 해당하는 에너지를 자연환경에서 얻을 수 있음을 의미한다. EMERGY량이 모두 현재의 EMERGY 생산비대로 생산이 된다는 가정하면 가막만의 패류(굴) 생산량은 환경수용량의 50%정도에도 못 미치는 것으로 나타났다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1443-1446
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• 2005

We have synthesized thin multi-walled carbon nanotubes (t-MWCNTs) using a catalytic chemical vapor deposition (CCVD) method with FeMoMgO catalyst. The number of tube walls were 2 ${\sim}$ 6 with the corresponding diameters of 3 ${\sim}$ 6 nm. We obtained high production yield of over 3000 wt% compared to the weight of the supplied catalyst. These t-MWCNTs revealed the intermediate structural characteristics between single- and multi-walled carbon nanotubes (SWCNTs and MWCNTs). We have also characterized the field emission properties such as turn-on field and emission current, and current degradation from these t-MWCNTs together with SWCNTs and MWCNTs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1264-1267
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• 1998

$Cu(In_xGa_{1-x})Se_2$ thin films were prepared and characterized with various Ga contents. As the Ga content increased, the grain size of CIGS film became smaller. The 2 $\theta$ values in XRD patterns were shifted to larger values and the overlapped peaks were splitted. The energy bandgap increased from 1.04 to 1.67 eV and the resistivity decreased. The solar cell fabricated with ZnO/CdS/$Cu(In_{0.7}Ga_{0.3})Se_2/Mo$ structure yielded an efficeincy of 14.48% with an acitive area of 0.18 $cm^2$. The efficiency decreased with further increase of Ga content.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.82-82
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• 2008

One-dimensional (1D) nanowires have been received much attention due to their potential for applications in various field. Recently some logic applications fabricated on various nanowires, such as ZnO, CdS, Si, are reported. These logic circuits, which consist of two- or three field effect transistors(FETs), are basic components of computation machine such as central process unit (CPU). FETs fabricated on nanowire generally have surrounded shapes of gate structure, which improve the device performance. Highly integrated circuits can also be achieved by fabricating on nano-scaled nanowires. But the numerical and SPICE simulation about the logic circuitry have never been reported and analyses of detailed parameters related to performance, such as channel doping, gate shapes, souce/drain contact and etc., were strongly needed. In our study, NAND and NOT logic circuits were simulated and characterized using 2- and 3-dimensional numerical simulation (SILVACO ATLAS) and built-in spice module(mixed mode).

• 대한전자공학회논문지TC
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• 제37권6호
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• pp.36-43
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• 2000

두 개의 마이크로 스트립 선로를 이용하여 결합한 유전체 공진기를 유한 차분 시간 영역(FDTD)법을 적용하여 3차원 해석을 하였다. 유전체 공진기의 표면은 곡면으로서, Noriaki model을 이용하여 정확하게 모델링 하였다. 일반적인 FFT에 의해 106.46 MHz의 주파수 해상도를 얻었지만 공진 주파수를 결정할 수가 없다. 따라서 1.00 MHz의 높은 주파수 분해능을 갖기 위해서 Pad 근사법과 Stoer-Bulirsch법을 적용하고 측정치와 비교하였다. 그 결과 Pad 근사법을 통하여 매우 정확한 공진주파수를 얻었다. 그리고 정현파를 인가하여 전자계 분포를 도시하였으며, 공진 모드가 TE/sub 01δ/ 모드임을 알 수 있었다.