• 컴퓨터교육학회논문지
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• 제21권6호
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• pp.105-115
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• 2018

서술형 문항은 수준 높은 사고능력 평가에 적합하나 채점이 쉽지 않다. 동일한 채점기준을 적용하더라도 채점자마다 서로 다른 채점을 할 수 있으므로 객관적인 채점 시스템이 필요하다. 그렇지만 채점 시스템을 구축하기 위해서는 표현 언어인 한국어 분석이 전제되어야 한다. 특히 서술형 문항의 답변은 단문형태가 아닌 복문이 내포된 복합 문장으로 표현되기 때문에 복합문의 한국어 분석이 이루어져야 한다. 본 연구는 이와 같은 서술형 문항의 자동 채점을 위해 한국어의 복합문을 구문의미 분석하는 시스템을 개발하고 시스템의 성능을 분석하였다. 이 시스템은 의미속성 사전을 활용하여 대상 구문의 의미적 제한조건을 검사하고 적합한 피수식 대상을 선별하여 구문의미분석을 실행한다. 실험 데이터에 대해 93%의 정확률을 얻어 제안한 시스템이 효과있음을 알 수 있었다. 본 연구의 시스템은 서술형 문항 채점에 활용할 수 있고 한국어 처리의 응용영역에 활용할 수 있을 것으로 기대된다.

• Journal of Forest and Environmental Science
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• 제40권2호
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• pp.123-140
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• 2024

More than half of the global distribution of the Rhododendron genus is found in China, with over 74% being endemic species. However, there is still insufficient data to chemically classify the Rhododendron genus native to China. Therefore, in this study, a chemotaxonomic study was conducted to determine the presence of taxifolin-3-O-arabinopyranoside, a flavonoid compound, in the Rhododendron genus native to China. Forty-three species of Rhododendron native to China-20 from across China, 8 from Beijing, 6 from Yanbian, and 9 from Yunnan-were utilized in the experiment. Through HPLC analysis, the retention time was compared with that of taxifolin-3-O-arabinopyranoside, a standard compound, and quantitative analysis was conducted. As a result, taxifolin-3-O-arabinopyranoside was detected in 22 out of 43 the Chinese Rhododendron species. Afterwards, LC-MS/MS analysis was performed on the 22 species in which taxifolin-3-O-arabinopyranoside was detected to determine whether the molecular weight was consistent with the standard compound. Under negative conditions, it was confirmed that all samples exhibited the same molecular weight as taxifolin-3-O-arabinopyranoside, 435-436 m/z. The same compound was detected in more than half of the Rhododendron species used in the experiment, and taxifolin-3-O-arabinopyranoside was determined to be an indicator compound for Rhododendron species native to China. In addition, the possibility of using the above results as basic data for chemical classification of Chinese Rhododendron genus was confirmed.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.183-188
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• 1997

Antimicrobial activity of various extracts of Xanthium strumarium L. was tested against 25 strains of bacteria, yeast and fungus. The crude ethylacetate extract exhibited strong growth inhibition to the tested strains with the exception of partial Gram-negative bacteria. The property of antimicrobial compound was very stable under heat treatment at $120^{\circ}C$, but it was unstable in acid (pH 3.0) and alkali (pH 10.0) treatment. The antimicrobial compounds were purified by boiling water extraction, ethylacetate extraction, charcoal column chromatography, silica gel column chro- matography and reverse phase HPLC. The purified compound A and B were detected in a single peak (each above 98% purity) through the HPLC analysis. The compound A and B showed a strong growth inhibition against Gram-negative and positive bacteria in the agar diffusion method. When tested by the FDA method using the esterase, compound A mainly inhibited the growth of bacteria and compound B showed the growth inhibition of both bacteria and yeasts.

• 한국공작기계학회논문집
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• 제14권4호
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• pp.96-103
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• 2005

We designed the compound CVT(Continuously Variable Transmissions) by combining power circulation mode and power split mode, which have been proposed for connecting 2K-H I differential gear to the V- belt type CVU(Continuously Variable Unit), as an input coupled type. With the designed compound CVT, we carried out theoretical analysis and performance experiments for efficiency, speed ratio, power flow, and power transmission ratio. We proved that the compound CVT had a better performance than either of the power circulation mode or power split mode.

• 한국군사과학기술학회지
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• 제18권5호
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• pp.548-557
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• 2015

This paper is results on Chemisorption of organic compound for the sea water fire fighting line of naval vessels. The quantitative analysis of Chemisorption has been investigated in seawater after immersion in 0.1 % of NaDDTC solutions for 43 hours. The morphology and topography were investigated by FE-SEM and AFM. The chemical elements were analyzed by SEM-EDS, XPS and the depth of chemical elements was measured by depth profiles. The effect of NaDDTC comes from Chemisorption between Copper and Sulfur of NaDDTC. As a result, test results showed that sulfur is helpful to protect a corrosion of seawater line.

• 한국재료학회지
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• 제16권2호
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• pp.85-91
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• 2006

The fraction of $\varepsilon\;and\;\gamma$'-iron nitride in compound layer is predicted by x-ray diffraction using direct comparison method. The validity of formulation models was checked by comparing calculated results with metallographic analysis of iron nitride compound layer grown on steel S45C by gas nitriding. The fraction of $\varepsilon$ calculated by the three phase model, porous-$Fe_3N$/ dense-$Fe_3N$/ mixed layer with $Fe_3N\;and\;Fe_4N$, is 80 percent of that analyzed by etching technique. The $\varepsilon$ fraction predicted by mixed layer model is 122 percent of that measured by microscope.

• 대한본초학회지
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• 제28권5호
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• pp.95-101
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• 2013

Objectives : A quantitative method using high performance liquid chromatography with a photodiode array detector(HPLC-PDA) was established for the quantitative analysis of the four main compound and pattern analysis to classification Piiellia ternate, P. pedatisecta and Typhonium flagelliforme. Methods : The analytical procedure for the determination of P. ternata, together with the known main compounds uracil, uridine, guanosine and adenosine was established. Optimum HPLC-PDA separation of these P. ternata was possible on Luna C18(2) column material, using water and acetonitrile as mobile phase. The method was validated according to regulatory guidelines. In addition, this assay method were analyzed for the content of four main compound in P. ternata, P. pedatisecta and T. flagelliforme and by data obtained from the HPLC-PDA analysis was performed principal component analysis(PCA). Results : Validation results indicated that the HPLC method is well suited for the determination of the roots of P. ternata with a good linearity ($r^2$ > 0.999), precision and recovery rates. Analysis of HPLC-PDA, the average content of uracil, uridine, guanosine and adenosine was significantly higher in P. ternate>P. pedatisecta> T. flagelliforme order. The application of PCA to main compound data by HPLC-PDA permitted the effective discrimination among the three species. Conclusions : Analysis of both HPLC-PDA and PCA confirmed the fact that four main compound and pattern profiles of P. ternata, P. pedatisecta and T. flagelliforme were different from each other.

• 한국환경보건학회지
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• 제17권1호
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• pp.104-109
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• 1991

Carbamates are generally used as insecticide, thus 8-hydroxy-5-chloroquinolinyl-N-ethylcarbamate was newly synthesized. Its physical properties were determined and chemical structure was identified by means of IR, nmr in addition to elemental analysis. The effect of the compound on rat's ileum, and antibacterial activity against Staphylococcus aureus, Salmonella typhi, E. coli, and Pseudomonas aeruginosa were examined. It was observed that the dosage over 100 $\mu$g/ml of the compound relaxed rat's ileum and the same dosage of the compound inhibited growth of the above strains of bacteria.

• 약학회지
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• 제32권5호
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• pp.308-312
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• 1988

A phenolic compound isolated from the ethylacetate extract of Duchesnea indica (Andr.) Focke (Rosaceae) showed antimicrobial activities against Staphylococcus aureus, Shigella dysentriae and Pseudomonas aeruginosa. This compound was identified as ellagic acid by spectral analysis.

• 분석과학
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• 제36권4호
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• pp.198-203
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• 2023

The reaction of cis-protected (Me4en)Pd(II) species with potentially multidentate bis(benzylthio)methylenepropanedioate (L) was carried out to obtain a monometallic compound, [(Me₄en)Pd(L)], in O,O'-coordination mode. The bis(benzylthio)methylene group was bent strikingly from the palladium square plane at the dihedral angle of 70.40°. The physicochemical properties of the present palladium(II) compound were fully characterized by means of infrared and nuclear magnetic resonance spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction measurement.