• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.666-669
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• 2002

Vertically aligned carbon nanotubes (CNTs) have been produced using various type of plasma enhanced chemical vapor deposition (PECVD). Catalysts such as Ni, Co, and Fe are used for growth of CNTs. To explain the effect of catalysts on the growth characteristics of CNTs, carbon species of $C_2H_2$ was observed in different catalysts using optical emission spectroscopy (OES) with theoretical calculation on the surface reaction in different catalysts.

• 한국응용과학기술학회지
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• 제22권4호
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• pp.299-305
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• 2005

In this study, we designed color of tunable and high efficient organic materials using the quantum dynamics and the semi-empirical calculation, and applied this results to the fabrication of organic light-emitting diodes. Also we optimized the molecular structure of phosphorescent materials and the energy transfer from a host to a dye which makes organic light-emitting diodes improve. Using quantum dynamics method, the molecular structures of ligand only and the whole metal chelate were optimized, and these energy levels were calculated. From this test results, we could understand the emission mechanism of phosphors with various ligands as well as design the proper ligands reducing the T-T annihilation and the carrier lifetime. We also could design ligands with various colors using this test method.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2002년도 춘계학술대회 논문집
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• pp.47-48
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• 2002

LNG보일러는 과거 기름을 주요 연료로 하던 보일러와는 달리 황산화물이나 매연이 거의 배출되지 않는다. LNG연소는 상대적으로 다른 연료에 비하여 오염물질 배출이 적지만 질소산화물을 비롯한 일부오염물질은 배출될 수밖에 없다 본 연구의 목적은 LNG보일러 시설에서 발생되는 주요 대기오염물질에 대한 국내 실정에 맞는 배출계수를 개발하고 배출되는 오염물질의 특성을 파악하여 정확한 대기오염 배출량 산출에 관한 기초를 마련하고자 함에 있다. (중략)

• Journal of Astronomy and Space Sciences
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• 제19권3호
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• pp.173-180
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• 2002

Images taken with the Chandra X-ray telescope have for the the first time revealed the central, wind-driven, hot bubble (Chu et al. 2001), while Hubble Space Telescope (HST) WFPC2 images of the Cat's Eye nebula, NGC 6543, show that the temperature of the halo region of angular radius ~ 20", is much higher than that of the inner bright H II region. With the coupling of a photoionization calculation to a hydrodynamic simulation, we predict the observed 〔O III〕 line intensities of the halo region with the same O abundance as in the core H II region: oxygen abundance gradient does not appear to exist in the NGC 6543 inner halo. An interaction between a (leaky) fast stellar wind and halo gas may cause the higher excitation temperatures in the halo region and the inner hot bubble region observed with the Chandra X-ray telescope.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.139-140
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• 2000

The origin of the display current in the surface conduction electron emitter displays has been verified in the calculation of the electron trajectory. Some electrons move directly toward the display surface as an anode current which is generated due to the inertial force of electron motion along the curved electric field lines with a small curvature near the fissure area..

• Journal of the Optical Society of Korea
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• 제3권2호
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• pp.41-46
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• 1999

Spatial and temporal dynamics arising in a photorefractive crystal(BaTiO3) during the process of double phase conjugation was studied experimentally. We studied the dynamical effects caused by the buildup of the diffraction grating and turn on of phase conjugated beams, as well as the spatial effects caused by the finite transverse coupling of beams and the propagation direction of beams. We observed conical emission in DPCM. We believe that various temporal and spatial instabilities are due to movement of the nonlinear grating. For a real beam coupling and constructive interaction of interference fringes in the crystal, we observed steady, periodic, irregular temporal behavior. And, by the calculation of the correlation index, we found that the spatial correlation decreased as the transverse interaction region was increased.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 춘계학술대회
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• pp.625-633
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• 2011

전 세계적인 기후변화 협약과 정부의 저탄소 녹색성장 정책으로 물류기업은 탄소배출량 감축을 위한 노력을 해야 할 시대에 직면하고 있다. 특히 화주기업에 대한 서비스제공과 화주의 경영 가치 실현에 공헌해야 할 제3자 물류기업은 기업자체의 경쟁력뿐 아니라 화주기업의 탄소경영에 이바지하기 위해서라도 이산화탄소 배출량을 감축하는 노력을 해야 한다. 탄소 배출량을 감축하기 위해서는 제3자 물류기업의 특성에 맞는 탄소배출량을 산정해야 하고 이러한 산정방법이 공정하고 일관성 있는 체계로 실행되어야 한다. 이산화탄소 배출량을 산출하기 위해서는 탄소경계 설정과 연료별, 연비법, 톤-킬로미터법 등 다양한 계산방식을 적용해야 하는데, 본 연구에서는 제3자 물류기업의 현실에 맞는 이산화탄소 배출량 산정 모형에 대하여 연구하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1125-1127
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• 2008

Recently, the tilting train has been developed to increase speed in conventional line. Due to global environmental changes, it is necessary to investigate quantitatively the environment of tilting train. This study evaluated the environmental impacts of tilting train to grasp a key issue environmentally. The related data were collected from bill of material (BOM). The system boundary of tilting train was determined by its cumulative weight. In addition, the $CO_2$ emission in the operation phase of tilting train was calculated. Based on this basic study, the environment of tilting train will be assessed exactly through the establishment of life cycle inventory database for its main components.

• 한국분무공학회지
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• 제5권3호
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• pp.9-16
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• 2000

In a SI engine, three-way catalyst converter has the best efficiency when A/F ratio is near the stoichiometry. The feedback control using oxygen sensors in the commercial engine has limits caused by the system delays. So it is necessary to control fuel quantity in accordance with intake air amount in order to reduce exhaust emission and improve the specific fuel consumption. Precise A/F ratio control requires measurement of air amount with respect to the cylinder and injection fuel according to the air amount In this paper, we applied nonlinear fuel injection model and developed the algorithm of A/F ratio control. This algorithm includes the methods of measurement of transient air mass flowing into each cylinder, of calculation of injection pulse width for measured air mass, and the method of feedback and engine control by using lambda sensor. Also we developed control program for IBM-PC by using C++ Builder, and tested it in the commercial engine.

• 전기학회논문지
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• 제57권12호
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• pp.2249-2254
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• 2008

A non-thermal micron size plasma needle is applicable for medical treatment because it includes radicals, charged particles, ultraviolet emission, and strong electric fields. The electric fields around the plasma needle device driven by a radio frequency wave are investigated in order to calculate the power delivered to the cell. A commercial multi-physics code, CFD-ACE, was utilized for the calculation of electric fields for the optimization of the needle structure. The electric field and energy absorption profiles are presented with the variation of the device structure and the distance between the needle and tissues. The living tissues effectively absorb the radio frequency power from the plasma needle device with the covered pyrex structure.