• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.453-458
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• 1994

Intestinal microbial flora comprise one third of the large intestinal contents in human. They play a significant effects through beneficial and harmful action on the human health. This is the first study which examined the composition of the microflora of the general population in Korea. Bacteroides, Bifidobacterium, Eubacterium, Peptostreptococcus, Lactobacillus, Streptococcus, Escherichia coli, Staphylococcus, Clostridium perfringens, total aerobic bacteria and total anaerrobic bacteria were counted using various selective and non-selective media. Among the bacteria studied the number of Bifidobacterium were greatest in breast-fed infants(30-90 days old), whereas Streptocuccus and Bifidobacterium in bottle-fed infants. In 20-40 age group Bacteroides were predominant followed by Bifidobacterium and Eubacterium. In early group(over 65 years old) Bacteroides were predominant followed by Eubacterium and bifidobacterium. The frequency and number of Cl. perfringens were highest in dlderly group. These results confirm that the microfloral pattern in large intestine change during the life cycle of humans.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.305-305
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• 2009

The carbon nano-structured materials could be applied to the fields of advanced fillers, templates, electrode materials, sensor, storage, and absorption materials. The polyacrylonitrile (PAN) based carbon nano-particles provide the remarkable properties of high specific surface area, large pore volume, chemical inertness, and good mechanical stability. In this study, well-defined carbon nano-particles were obtained through pyrolysis of polyacrylonitrile based particles. The precursor nano-particles were prepared by modified aqueous dispersion polymerization using hydrophilic poly(vinyl alcohol) in a water/ N,N-dimethylformamide mixture media. Synthesized precursor nanoparticles have relatively monodisperse particles ranging 80 ~ 250nm. Stable spherical particles are obtained without coagulum or secondary particles in our system. The characteristic of the carbon nanoparticles were investigated in terms of surface area, morphology, and size distribution.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.101-102
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• 2012

지수-골롬 부호는 데이터의 무손실 부호화를 위해 사용되는 대표적인 방법으로서 지수 함수 형태로 단일 모드 분포를 가지는 데이터의 부호화에 적합하다. 본 논문에서는 데이터의 분포가 단일 모드가 아닌 이중 모드를 가지는 경우에 적용하기 위해 변형된 지수-골롬 부호를 제안하고 모드의 높이와 모드 사이의 거리에 따른 부호화 성능을 살펴보았으며 실제 데이터에 적용한 실험결과를 제시하였다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.10a
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• pp.39-43
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• 1999

불포화대에서 LNAPL의 이동과 분포를 수치 모의를 통하여 예측하였다. 균질한 매질에서 LNAPL의 이동은 조립질 매질에서 빠르고, 세립질 매질에서 더 많은 면적으로 확산되며, 더 많은 LNAPL이 불포화대에 잔류한다. 조립질 매질내에 세립질층이 존재할 경우, 이 층이 지하수면으로부터 멀수록 LNAPL이 많이 포획된다. 조립질 매질에 세립질 또는 더 조립질인 매질이 렌즈 상으로 존재하는 환경에서는, LNAPL이 이들 렌즈를 통과하지 못한다. 불균질한 렌즈가 존재할 때의 LNAPL 분포를 초기조건으로 이용하여, 지하수 면의 수직 이동과 물의 침투에 따른 LNAPL의 이동을 모의하였다. 두 경우 모두 불포화대에 잔류되어 있던 LNAPL의 수직방향 이동이 증가되었다. 특히, 지하수면의 하강 시 LNAPL이 조립질 렌즈를 통해 이동하나, 세립질 렌즈를 통해서는 이동하지 못한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.368-370
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• 2012

본 논문에서는 이중 홉 무선 네트워크에서 누적분포함수(cumulative distribution function) 기반 중계기 선택 기법을 제안한다. 제안된 기법은 수신 신호대잡음비(signal-to-noise ratio)의 누적분포함수 값에 따라 중계기를 선택한다. 본 논문에서는 제안한 기법의 중계기 공정성에 대한 분석을 통해 제안된 기법이 엄격하게 공정성을 달성할 수 있음을 보인다. 그리고 모의 실험에서는 round-robin 기법과 기회적 중계 기법을 제안된 기법과 총 타임 슬롯에 대한 각 중계기별 타임 슬롯 분배율, 평균 공정성, 불능확률 비교를 통해 제안된 기법이 엄격하게 공정성을 달성하는 것과, 기회적 중계 기법과 거의 동일한 기울기로 불능확률이 떨어지는 것을 확인한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.183-188
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• 1998

This paper describes the concept of object-based coding for future broadcasting environments. Digital broadcasting uses the MPEG2 coding scheme which is regarded as a picture-based coding. An object-based coding scheme is a potential candidate for future broadcasting both for studio and distribution uses, and it offers a higher compression more flexible content handling. This paper also describes key technologies that we have been developing for the object-based coding, e.g., image analysis, object extraction and coding of objects.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.173-176
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• 2002

This paper proposes a new approach for digital watermarking and secure copyright protection of video. the principal aim being to discourage illicit copying and distribution of copyrighted material. The method presented here is based on the three dimensional discrete wavelet transform of video scene. The watermark is a copyright information encoded in the form of a spread spectrum signal to ensure the system security and is embedded in the 3D DWT magnitude of video chunks. The performance of the presented technique is evaluated experimentally.

• Nuclear Engineering and Technology
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• v.33 no.1
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• pp.62-72
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• 2001

The one-dimensional finite element program was developed to analyze the coupled behavior of heat, moisture, and air transfer in unsaturated porous media. By using this program, the simulation results were compared with those from the laboratory infiltration tests under isothermal condition and temperature gradient condition, respectively. The discrepancy of water uptake was found in the upper region of a bentonite sample under isothermal condition between numerical simulation and laboratory experiment. This indicated that air pressure was built up in the bentonite sample which could retard the infiltration velocity of liquid. In order to consider the swelling phenomena of compacted bentonite which cause the discrepancy of the distribution of water content and temperature, swelling and shrinkage factors were incorporated into the finite element formulation. It was found that these factors could be effective to represent the moisture diffusivity and unsaturated hydraulic conductivity due to volume change of bentonite sample.

• Journal of Plant Biology
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• v.28 no.4
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• pp.305-315
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• 1985

Morphological variations within the species of Scenedesmus in Korea, S. armatus and 2 strains of S. quadricauda were investigated. Taxonomic characters such as length of long spine, ridge, unicell-colony transformation, and colony types were compared. The length of long spine was constant, whereas the distribution of the spine varied with the age of culture. Ridge and short spine in S. armatus occurred constantly, whereas those in S. quadricauda varied with the composition of the media and age of culture. Strains CY-1 and CY-2 showed 6 different colony types in the stationary culture, whereas S. armatus formed only two types, armatus and armatus-longus types. All strains showed unicell-colony transformation. The cell became minimum when the daughter cell was released, and reached maximum at division.

• Journal of the Speleological Society of Korea
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• no.95
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• pp.1-13
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• 2009

The problems of Ondal cave have been analyzed by the lack of academic names and explanations compared to other caves. To improve the problems, there needs to be various and balanced distribution of names, increase explanations, specializing in the form of academic explanations and the information format.