• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.137-137
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• 2008

In-situ doped polycrystalline 3C-SiC thin films were deposited by APCVD at $1200^{\circ}C$ using HMDS(hexamethyildisilane: $Si_2(CH_3)_6)$) as Si and C precursor, and 0 ~ 100 sccm $N_2$ as the dopant source gas. The peak of SiC is appeared in polycrystalline 3C-SiC thin films grown on $SiO_2$/Si substrates in XRD(X-ray diffraction) and FT-IR(Fourier transform infrared spectroscopy) analyses. The resistivity of polycrystalline 3C-SiC thin films decreased from 8.35 $\Omega{\cdot}cm$ with $N_2$ of 0 sccm to 0.014 $\Omega{\cdot}cm$ with 100 sccm. The carrier concentration of poly 3C-SiC films increased with doping from $3.0819\times10^{17}$ to $2.2994\times10^{19}cm^{-3}$ and their electronic mobilities increased from 2.433 to 29.299 $cm^2/V{\cdot}S$, respectively.

• The Korean Journal of Ecology
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• 제6권2호
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• pp.114-127
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• 1983

The production and productivity of $C_3 and C_4$ type plants in Korea was studcied In the areas, in which the summer temperature is above $30^{\circ}C,;C_3$ type plants showed“M” type productivity curves exhibiting two peaks in spring and autumn, and C4 type plants showd “Bell” type productivity curves which show one peak in summer(Figs. 1,2,3,4,5). From the result of researching the standing crop of $C_3 and C_4$type plants dcuring August and September in which the standing crop reaches the highest peak, the dominant plants in the natural grass vegetation were almost all of $C_4$ type plants, showing the high standing crop, while the standing crop of $C_3$ type plants shows its high peak in the humid areas, riversides and dams.

• 태양에너지
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• 제9권1호
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• pp.70-77
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• 1989

Sodium pyrophosphate that melting point is $79-80^{\circ}C$ have been Studied on heat storage and heat discharge. In heat storage process, sodium pyrophosphate was kept up initial temperature $50^{\circ}C,\;60^{\circ}C,\;70^{\circ}C$ which melt by heated water at temperature $85^{\circ}C,\;90^{\circ}C,\;95^{\circ}C$. In heat discharge process, initial temperature of sodium pyrophosphate was maintained at temperature $85^{\circ}C,\;90^{\circ}C,\;95^{\circ}C$ which varied cooling temperature $50^{\circ}C,\;60^{\circ}C,\;70^{\circ}C$. The experiment has been reached conclusions as follows. 1) Heat transfer properties of phase change material is controlled by conduction during heating and cooling process. 2) The temperature increased rapidly at initial stage and transient region increase slowly because of characteristic of latent heat. 3) The lower cooling water temperature is the less the time that get to thermal equivalent state take during discharge process. 4) The higher cooling water temperature is the less temperature difference between top and bottom in P.C.M during discharge process.

• 자연과학논문집
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• 제15권1호
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• pp.79-88
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• 2005

효모에는 여러 가지 종류의 thiol peroxid se 동위 효소들인 cytoplasmic TPx I, cTPx II, cTPx III, mitochodrial TPx (mTPx), 및 nuclear TPx (nTPx)가 존재하고 있다. 특히 cTPx II는 다른 효모TPx와 비교해 볼 때 매우 낮은 peroxidase 활성을 보이나, cTPx II를 제거한 cTPx II mutant균주는 심하게 성장이 저해되는 특징을 보인다. 본 연구에서는 효모에서의 cTPx II의 생리학적 기능을 밝히는 연구의 첫 과정으로 cTPx II와 상호 작용하는 단백질을 탐색하였다. Sacchromyces cerevisiae genomic DNA library에서 yeast two-hybrid system을 이용하여 cTPx II와 상호 결합하는 단백질을 탐색하여 그 단백질들의 기능을 연구하여, 궁극적으로 cTPx II의 생리기능을 밝히는데 이 연구의 목적을 두었다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.158-161
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• 2006

SiC materials have been extensively studied for high temperature components in advanced energy conversion system and advanced gas turbine. However, the brittle characteristics of SiC such as law fracture toughness and law strain-to fracture impose a severe limitation on the practical applications of SiC materials. SiC/SiC composites can be considered as a promising candidate in various structural materials, because of their good fracture toughness. In this composite system, the direction of SiC fiber will give an effect to the mechanical properties. It is therefore important to control a properdirection of SiC fiber for the fabrication of high performance SiC/SiC composites. In this study, unidirection and two dimension woven structures of SiC/SiC composites were prepared starting from Tyranno SA fiber. SiC matrix was obtained by nano-powder infiltration and transient eutectoid (NITE) process. Effect of microstructure and density on the sintering temperature in NITE-SiC/SiC composites are described and discussed with the fiber direction of unidirection and two dimension woven structures.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.533-536
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• 2001

Single crystal cubic silicon carbide(3C-SiC) thin film were deposited on Si(100) substrate up to a thickness of $4.3{\mu}m$ by APCVD(atmospheric pressure chemical vapor deposition) method using hexamethyildisilane(HMDS) at $1350^{\circ}C$. The HMDS flow rate was 0.5 sccm and the carrier gas flow rate was 2.5 slm. The HMDS flow rate was important to get a mirror-like. The growth rate of the 3C-SiC films was $4.3{\mu}m/hr$. The 3C-SiC epitaxical layers on Si(100) were characterized by XRD(X-ray diffraction), raman scattering and RHEED(reflection high-energy electron diffraction), respectively. The 3C-SiC distinct phonons of TO(transverse optical) near $796cm^{-1}$ and LO(longitudinal optical) near $974{\pm}1cm^{-1}$ were recorded by raman scattering measurement. The deposition films were identified as the single crystal 3C-SiC phase by XRD spectra($2{\theta}=41.5^{\circ}$). Also, with increase of films thickness, RHEED patterns gradually changed from a spot pattern to a streak pattern.

• 한국통신학회논문지
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• 제29권5A호
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• pp.484-491
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• 2004

L-band EDFA는 작은 평균밀도 반전율에서 동작하기 때문에 C-b란d에서 상대적으로 높은 흡수율로 인해 펌프 효과를 가지게 된다. 본 논문에서는 980nm의 펌프 입력 광 파워, C-band 펌프 파장 및 입력 광 파워에 따라 펌프 효과에 대해 논하고자 한다. 즉, C-band 펌프광의 흡수 또는 후방 자연방출광의 흡수라는 두 가지 다른 메카니즘을 통해 펌프 효과를 야기 시키게 된다. 또한 동일한 소 신호 이득 조건 하에서 L-band 신호 입력 광에 의한 포화 특성 (포화 광출력, 잡음지수에 있어서 장파장의 C-band 펌프가 양호한 것으로 나타난다. 전광 고정이득 L-band EDFA에서 C-band발진의 효과를 검토한 결과 L-band발진에 비해서 개선된 특성은 없는 것으로 나타난다.

• 한국동물위생학회지
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• 제37권3호
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• pp.157-164
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• 2014

Clostridium chauvoei is the etiologic agent of blackleg, a high mortality rated disease infection mainly cattle. In the present study, the partial sequences of 16S rRNA and flagellin gene of C. chauvoei isolated in Jeonbuk, Korea were determined and compared with those of reference strain. Oligonucleotide primers were designed to amplify a 811 bp fragment of 16S rRNA gene and 1229 bp fragment of flagellin gene. Sequencing analysis of 16S rRNA gene showed high homology to the reference strains ranging 82.3% to 100%, while flagellin gene were different from published foreign clostridia, showing 98.7% to 72.0% nucleotide sequence homology. Phylogenetic analysis based on 16S rRNA gene revealed the close phylogenetic relationship of C. chauvoei and C. septicum in cluster I, which includes C. carnis, C. tertium, C. quinii, C. celatum, C. perfringens, C. absonum, C. botulinum B. Phylogentic analysis also revealed that flagellin gene formed a single cluster with C. chauvoei, C. septicum, C. novyi A, C. novyi B, C. tyrobutylicum, C. acetobutylicum. The genetic informations obtained from this study could be useful for the molecular study of C. chauvoei.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권5호
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• pp.1801-1816
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• 2014

Because HTTP-related ports are allowed through firewalls, they are an obvious point for launching cyber attacks. In particular, malware uses HTTP protocols to communicate with their master servers. We call this an HTTP-based command and control (C&C) server. Most previous studies concentrated on the behavioral pattern of C&Cs. However, these approaches need a well-defined white list to reduce the false positive rate because there are many benign applications, such as automatic update checks and web refreshes, that have a periodic access pattern. In this paper, we focus on finding new discriminative features of HTTP-based C&Cs by analyzing HTTP activity sets. First, a C&C shows a few connections at a time (low density). Second, the content of a request or a response is changed frequently among consecutive C&Cs (high content variability). Based on these two features, we propose a novel C&C analysis mechanism that detects the HTTP-based C&C. The HAS-Analyzer can classify the HTTP-based C&C with an accuracy of more than 96% and a false positive rate of 1.3% without using any white list.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.452-455
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• 2002

Single crystal 3C-SiC(cubic silicon carbide) thin-films were deposited on Si(100) substrate up to a thickness of $4.3{\mu}m$ by APCVD method using HMDS(hexamethyildisilane) at $1350^{\circ}C$. The HMDS flow rate was 0.5 sccm and the carrier gas flow rate was 2.5 slm. The HMDS flow rate was important to get a mirror-like crystal surface. The growth rate of the 3C-SiC films was $4.3{\mu}m/hr$. The 3C-SiC epitaxical films grown on Si(100) were characterized by XRD, AFM, RHEED, XPS and raman scattering, respectively. The 3C-SiC distinct phonons of TO(transverse optical) near $796cm^{-1}$ and LO(longitudinal optical) near $974{\pm}1cm^{-1}$ were recorded by raman scattering measurement. The heteroepitaxially grown films were identified as the single crystal 3C-SiC phase by XRD spectra$(2{\theta}=41.5^{\circ})$.