• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.12
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• pp.1045-1057
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• 2009

The authors investigated the InGaN/GaN multi-quantum well blue light emitting devices with the implementation of the photonic crystals fabricated at the top surface of p-GaN layer and the bottom interface of n-GaN layer. The top photonic crystals result in the lattice-dependent photoluminescence spectra at the wavelength of 450 nm and however, the bottom photonic crystal shows a big shift of the photoluminescence peak from 444 nm to 394 nm. The sample with the bottom photonic crystal structure also shows the lasing effect at the wavelength of 468 nm. Furthermore, the quality enhancement for the crystal growth of GaN thin film on the bottom photonic crystal comes from the modulated compressive stress which was measured by the micro-Raman spectroscopy.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.481-485
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• 2006

분산 컴퓨팅 시스템에 관한 연구가 네트워크가 발달함에 따라 점차 다양한 분야에서 활발하게 이루어지고 있다. 하나의 컴퓨터의 성능으로는 처리하기 힘든 일을 여러 컴퓨터 시스템이 분산하여 처리함으로써 효율성을 극대화 시킬 수 있도록 하는 이 기술은 네트워크가 발달할 수록 점점 더 각광 받을 것이다. 본 논문에서는 분산 컴퓨팅 시스템에서 무결성, 기밀성을 보장하기 위해 인증 시스템을 이용한 보안 프로토콜을 제시한다.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.796-799
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• 2012

직류전원장치에 사용되는 계통연계형 컨버터는 전원의 위상을 기준으로 제어되어야 하므로 하드웨어 또는 소프트웨어적인 다양한 방법들이 사용되고 있다. 이러한 방법들은 복잡하거나 노이즈에 의한 오동작 등의 위해요소를 내포하고 있다. 이에 본 논문에서는 관측기를 이용하여 전원의 주파수 변동에도 사용할 수 있는 강인한 위상점지 방법에 대해 제안하고 실험을 통해 입증하였다.

• Microbiology and Biotechnology Letters
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• v.24 no.6
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• pp.652-656
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• 1996

The 80 strains which produce carrageenan degrading enzyme were isolated from soils, mud, seaweed, marine moluscus and echonodermata samples. Among them, one isolated strain, which showed the highest activity to produce carrageenan degrading enzyme, was used for this study. The isolated strain was identified as Pseudomonas alcaligenes through its morphological, biochemical, and physiological characteristics. The best conditions for enzyme production were 0.7% nutrient broth and 0.2% carrageenan as nitrogen and carbon source, respectively. The optimal pH, NaCl, temperature and culture time for carrageenan degrading enzyme were 7.0, 1.5%, 30* and 96hrs, respectively.

• Proceedings of the Ginseng society Conference
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• 2004.12a
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• pp.61-61
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• 2004

• Transactions on Electrical and Electronic Materials
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• v.11 no.5
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• pp.230-233
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• 2010

The authors investigated the anodization mechanism of aluminum in an oxalic acid solution, and the electrochemical reaction is very unique for pore formation via the dissolution process, which is very dependent on the surface geometry in nanoporous alumina templates. The cross-sectional nanochannels showed that the geometrical curvature of the initial surface can cause the branching of nanochannels to be adjusted in volume occupancy to be direct to the electric field normal to the surface. The nanoporous alumina with the crystalline $\gamma-Al_2O_3$ phase showed hexagonal ordering at a voltage of 40 V, with a nanohole distance of 102 nm from the charge density oscillation of the oxalic acid solution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.42-42
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• 2010

Deep-trenched photonic crystals passing through InGaN/GaN quantum well structural layer have been fabricated on the surface of GaN-based light emitting diode(LED) using by electron beam nanolithography. The lattice constant and hole diameter of the photonic crystals are 230nm and 140nm, respectively. The structural and electro-optical properties have been investigated by scanning electron microscope(SEM) and power-current-voltage(L-I-V). Electroluminescence from GaN-based LED with deep-trenched photonic crystal shows the higher intensity than that without photonic crystal.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.267-267
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• 2010

The structural and electrical properties of microcrystalline silicon films were investigated by hot wire chemical vapor deposition(HWCVD) often called catalytic chemical vapor deposition(Cat-CVD). The Si microcrystalline phase is easily controlled by changing the rate of the silane concentration of $SiH_4$ to $H_2$ during deposition. The Structural property was observed by Raman and SEM. Photo-conductivity and dark conductivity, and photo-sensitivity were observed by Sunsimulator (AM 1.5 illumination). The film color was changed by the variation of silane concentration. HWCVD is useful for the formation of Si thin films for solar cell and needs further commercialized development for mass production.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.268-268
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• 2010

AC anodizing on aluminum foil was investigated by the variation of AC voltage and frequency. The voltage and frequency were applied in the range of approximately 40~200V, 0~400Hz. The porous alumina film was formed and the growth rate of oxide film is increased with frequency. The structural property was analyzed by SEM and XRD. SEM results show the approximate relation between frequency, voltage and growth rate. The AC voltage effect on the structural modulation of porous alumina indicates that AC anodizing is useful for the application to nanocapacitor material.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.466-468
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• 2010

본 논문에서는 다양한 컬러모델 영상을 대상으로 히스토그램의 차이를 이용한 장면 전환 검출 결과를 비교한다. 임계값은 히스토그램의 변화에 따라 변화하는 적응적 임계값 설정 방법을 사용하여 오검출과 미검출의 확률을 줄였다. 점진적인 장면 전환에도 강인한 검출을 위하여 탐색 구간의 변화와 히스토그램의 변화가 급격하게 자주 일어나는 구간의 히스토그램의 변화율을 이용하여 장면 전환을 검출 하는 방법을 제안 하였다.