• 한국광학회지
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• 제9권1호
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• pp.5-8
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• 1998

비균일 단축결정(inhomogeneous uniaxal)매질 내에서 빛의 전파를 Berreman의 $4{\times}4$ 행렬을 사용하여 계산할 때, 광원이 단색광일 경우 매질 내의 불연속점에서 발생하는 다중 반사로 인한 Fabry-Perot 간섭효과에 의해, 투과광은 간섭효과가 나타나게 된다. 본 논문에서는 Berreman의 $4{\times}4$ 행렬 연산에서 Fabry-Perot 간섭효과를 제거하기 위한 apodization 방법을 제시하였다. 매질내에 k개의 불연속 경계면이 있을 경우, 새로운 apodization 방법은 최대 (k+1)개의 $4{\times}4$ 행렬을 부가적으로 곱하므로써 전체 전달행렬을 계산할 수 있다. 이를 twisted-nematic(TN) LC cell의 광투과 특성 계산에 적용한 결과 간섭 패턴을 효과적으로 제거할 수 있음을 확인하였다.

• 약학회지
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• 제41권4호
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• pp.473-479
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• 1997

New cephalosporin antibiotics, 7-[(3,4-dihydro-6-methoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl)acetamido]-3-substituted-3-cephem-4-carboxylic acid derivatives 2a-2d, 7 -[(3,4-dihydro-6-ethoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl)acetamido] -3-substituted-3-cephem-4-carboxylic acid derivatives 3a-3d and 7-[(3,4-dihydro-6-methoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl-1-(S)-oxide)acetamido]-3-substituted-3-cephem-4-carboxylic acid derivatives 4a-4d were synthesized. Antibacterial activities of these new cephalosporin derivatives and the relationship between their structures and their activities were examined. Among them, 7-[(3,4-dihydro-6-methoxycaronyl-2,2-dimethyl-2H-1,4-thiazin-3-yl-1-(S)oxide)-acetamido]-3-[(1,2,3-triazol-5-yl)thiomethyl]-3-cephem-4-carboxylic acid 4d exhibited the antibacterial activities against Gram(+)and Gram(-) bacteria.

• Transactions on Electrical and Electronic Materials
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• 제13권4호
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• pp.177-180
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• 2012

In this study, we prepared $LiFePO_4$- poly (sodium 4-styrenesulfonate) (PSS) composite by the hydrothermal method and ball-milling process. Different wt% PSS were added to $LiFePO_4$. The cathode electrodes were made from mixtures of $LiFePO_4$-PSS: SP-270: PVDF in a weighting ratio of 70%: 25%: 5%. $LiFePO_4$-PSS powders were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM). The electrochemical properties of $LiFePO_4$-PSS/Li batteries were analyzed by cyclic voltammetry, charge/discharge tests, and AC impedance spectroscopy. A Li/$LiFePO_4$-PSS battery with 4.75 wt% PSS shows the best electrochemical properties, with a discharge capacity of 128 mAh/g.

• 대한화학회지
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• 제58권4호
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• pp.377-380
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• 2014

A noval derivatives of 3-substituted[1,2,4]triazolo[4,3-b]pyridazine (4a-4o) and 7,8,9,10-tetrahydrobenzo[4,5] thieno[2,3-d][1,2,4]triazolo[4,3-b]pyridazine (7a-7l) is prepared by the reaction of heteroaryl hydrazone from the aldehyde and pyridazinohydrazine derivative, followed by subjecting the intermediate directly to oxidative cyclization employing the mixture of $Me_4NBr$ and Oxone. These derivatives were subjected to preliminary antimicrobial activities against microorganism. All these compounds exhibit good to moderate activity.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.209-220
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• 1996

In this paper, dynamic performance of 4WD/4WS Electric-driven vehicles is investigated. A coupled dynamic model is introduced for longitudinal, lateral and yawing motion of 4WD/4WS vehicles. Based on the coupled model, dynamic performance is analyzed for steady-state steering, acceleration steering and brake steering, respectively. These non steady-state cornering analysis is important for non-paved road maneuvering, trajectory projection for armored vehicle and future AVCS(Advanced Vehicle Control System) technology. Simulation results are obtained based on a simulink module for the introduced model.

• Fisheries and Aquatic Sciences
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• 제4권1호
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• pp.25-31
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• 2001

4-Aminobutyrate aminotransferase plays an essential role in the 4-aminobutyric acid shunt, converting 4-aminobutyrate to succinic semi aldehyde. We isolated and sequenced' a fish cDNA fragment that encodes 4-aminobutyrate aminotransferase. A brain cDNA library from flounder (Paralichthys olivaceus) was constructed using the ZAP- III XR vector and screened for the fish 4-aminobutyrate aminotransferase gene using a probe derived from the conserved sequences of known mammalian 4-aminobutyrate aminotransferases. A partial cDNA for 4-aminobutyrate aminotransferase was cloned and found to be 700 bp in length corresponding to 66 amino acids. Nucleotide sequence of the clone was aligned with NCBI (National Center for Biotechnology Information) DNA sequence data base. The result showed high sequence identity with previously reported mammalian 4-aminobutyrate aminotransferases. The trans­criptional level of flounder 4-aminobutyrate aminotransferase was detected with the presence of mRNA at different flounder tissues by reverse transcription-polymerase chain reaction (RT-PCR). The expression of flounder 4-aminobutyrate aminotransferase was also tested and detected from the flounder tissues of the brain, liver, kidney and pancreas.

• 약학회지
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• 제36권1호
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• pp.36-39
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• 1992

In a continuous study for the developing of the anticariogenic agents, 3,3'-diacyl-4,4'-biphenol derivatives (Fig. 2, 2 and 3) and 3,3'-bis-(1-hydroxyalkyl)-4,4'-biphenol (Fig. 3, 4 and 5) derivatives are synthesized successively from 4,4'-diphenol (Fig. 2, 1). The synthesized compounds are tested for their antibacterial activity against a cariogenic bacterium, Streptococcus mutans OMZ 176. The acyl derivatives, 2 and 3, do not show antibacterial activity, but the hydroxyalkyl derivatives, 4 and 5, reduced from the acyl group of 2 and 3, show the activity. The antibacterial activity of 2 and 3 may be inhibited due to intramolecular hydrogen bonding between the acyl group and the hydroxyl one (Fig. 4).

• 통합자연과학논문집
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• 제11권2호
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• pp.61-68
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• 2018

New 4,4'-[6-(o-carboranylalkoxy)-1,3,5-triazine-2,4-diyl]dimorpholine derivatives have been prepared by reacting 4,4'-[6-(alkynyloxy)-1,3,5-triazine-2,4-diyl]dimorpholines with decaborane and N,N-dimethylaniline as base. The intermediate compounds, 4,4'-[6-(alkynyloxy)-1,3,5-triazine-2,4-diyl]dimorpholines, have been prepared by reacting 4,4'-[6-chloro-1,3,5-triazine-2,4-diyl]dimorpholines with prop-2-yn-1-ol, but-3-yn-1-ol, and pet-4-yn-1-ol, and potassium tert-butoxide (t-BuOK) as base. The structure of these compounds has been confirmed by IR, $^1H$, $^{11}B$, and $^{13}C$ NMR and X-ray crystallographic studies.

• 한국환경보건학회지
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• 제7권2호
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• pp.107-111
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• 1981

Thirteen Carbanilides, P-chloro, bromo, methyl, ethyl, methoxy and ethoxy carbanilides, 4,4'-dichlorocarbahilide, and 4-bromo, methyl, ethyl, methoxy and ethoxy 4'-chlorocarbanilides have been newly synthesized by reacting P-phenetidime, P-anisidime, anilime, P-chloroanilime, P-bromoanilime, P-methoxy aniline, and P-ethoxy anilime with phenyl and P-chlorophenyl isocyanate, respectively. The compounds generally exhibited antibacterial activity against Escherichia coli, and staphylococcus aureus. The results obtained were as follows 4-chlorocarbanilide and 4,4'-clichlorocarbanilide were active against Eschrichia Coli, and Staphylococcus aureus at the concentration of 50 ug/ml. 4-methyl-4'-chloro carbanilide, and 4-ethoxy-4'-chloro carbanilide were active against Escherichia Coli at the concentration of 100ug/ml. 4-methyl-4'-chloro canbanilide were active against Staphylococcus aureus at the concentration of 50ug/ml.

• 한국콘텐츠학회논문지
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• 제2권3호
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• pp.105-112
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• 2002

다양한 형태의 차세대 오디오/비디오 서비스를 위한 멀티미디어 데이터를 유연성 있게 부호화하기 위한 국제 표준 규격인 MPEG-4에서는 저작된 멀티미디어 컨텐츠를 저장하기 위한 포맷으로 XMT (eXtensible MPEG-4 Textual ferret)와 MPEG-4 파일 포맷 (MP4)를 제공하고 있다. 이들 중 XMT 포맷은 사람이 컨텐츠의 내용을 읽을 수 있는 가독성을 가지고 있는 장점이 있으며, XML을 기반으로 하고있기 때문에 여러 가지 응용에 사용될 수 있다. 본 논문에서는 인터렉티브 멀티미디어 컨텐츠를 저작할 수 있는 국제 표준인 MPEG-4를 따르는 컨텐츠를 XMT-A를 이용하여 저작하는 방법에 대하여 기술한다.