• Publications of The Korean Astronomical Society
• /
• v.9 no.1
• /
• pp.111-166
• /
• 1994

I have developed a UV and visible spectroscopic database (UVSD) for atoms and molecules, which are found in interstellar medium, stars, galaxies, and in the atmospheres of the earth, planets, satellites, and comets. This UV and visible database, which is machine-readable, consists of three different sub-databases depending upon the characteristics of the sub-databases: (A) atomic and molecular line listings from laboratory observations or theoretical studies; (B) absorption spectra measured in laboratories; and (C) solar UV, visible, and infrared spectral atlases. The UVSD is in a very initial stage of development compared with other well organized and established infrared and microwave databases. In order to make a good quality and complete database, substantial efforts should be made for the acquisition of scattered important data from laboratories or institutions, and then the acquired heterogeneous data should be peer-reviewed and standardized.

• Korean Journal of Pharmacognosy
• /
• v.33 no.2 s.129
• /
• pp.92-95
• /
• 2002

Three diene-yn-diene chromophore type compounds were isolated from the flowers of Hemisteptia lyrata Bunge. On the basis of spectral data, isolated compounds were identified as heptadeca-1,7,9,13,15-pentaen-11-yne, 14-acetoxy-2,4,8,10-tetradecatetra-ene-6-yne and 14-hydroxy-2,4,8,10-tetradecatetraene-6-yn. They were first isolated from the genus of Hemisteptia.

• Korean Journal of Pharmacognosy
• /
• v.11 no.2
• /
• pp.69-74
• /
• 1980

The rhizome of Polygonatum robustum Nakai (Liliaceae) has been used as a crude drug for the purpose of tonic and thirst cure in Korea. The dried rhizomes were extracted with hot ether, then the residue was extracted with hot alcohol. 1) The three kinds of chemical constituents, substance, I, II and III were isolated by silicagel column chromatography from ether and alcohol extracts of the rhizomes. Substance I was confirmed as ${\beta}-sitosterol$, $C_{29}H_{50}O$ by mass and IR spectroscopy. Substance II was identified as stigmasterol by GLC. 2) Substance III was obtained by crystallization from the column chromatography of alcohol fraction. It was suggested as diosgenin based on chemical and spectral discussions. 3) The concentration of blood sugar was significantly decreased in the group administered the ether extract with 20% dextrose and adrenaline in comparison to that of 20% dextrose and adrenaline along.

• Korean Journal of Pharmacognosy
• /
• v.19 no.3
• /
• pp.174-176
• /
• 1988

From the stem barks of Tilia mandsurica, fraxin ( I ) and 1, 10-decanedicarboxylate ( II ) were isolated and characterized by spectral data. 1, 10-decanedicarboxylate was the first isolation from Tilia plants.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.1
• /
• pp.56-63
• /
• 2009

Cell migration is one of the essential mechanisms responsible for complex biological processes. Intensive researches have begun to elucidate the mechanisms and search intriguing conditions for efficient control of cell migration. One general mechanism that is widely applicable for cells including Escherichia coli, amoebae and endothelial cell is chemotaxis. The single cell study for bacterial chemotaxis has an advantage over studies with the population of cells in providing a clearer observation of cell migration, which leads to more accurate assessments of chemotaxis. In this paper, we propose a three-dimensional model considering a single bacterium to study its chemotaxis. The semi-implicit Fourier spectral method is applied for high efficiency and numerical stability. The simulation results reveal rich dynamics of cell migration and provide quantitative assessments of bacterial chemotaxis with various chemoattractant gradient fields.

• Journal of the Korean Chemical Society
• /
• v.24 no.4
• /
• pp.310-314
• /
• 1980

Some minor carotenoid pigments, luteints, lutein monoester, torulene, $\gamma$-carotene, and 5,6-monoepoxy-$\alpha$-carotene-like have been separated and identified from the abdominal skin of Bombina Orientalis. Their structures have been established through the physical and chemical properties, VIS-UV and IR spectral characteristics, and chromatographic behaviors.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 2003.04a
• /
• pp.182-186
• /
• 2003

일반적으로 영상은 공간, 분광 및 시간 해상력을 바탕으로 고해상과 저해상 영상으로 구분된다. 최근 IKONOS 와 QuickBird 등 공간해상력이 1m 이하인 위성 영상들이 국내에 공급되어 바야흐로 고해상 위성영상을 이용한 다양한 활용분야들이 연구되고 있다. 이에 반하여 고분광해상력을 갖는 하이퍼스펙트럴 영상에 대한 연구는 미흡한 실정이다. 국제적으로는 항공기탑재 센서들을 이용한 다양하고 광범위한 조사분석 연구가 이루어지고 있으나, 국내에서는 장비와 관심의 부재로 인하여 초기적인 연구 단계에 있는 실정이다 하이퍼스펙트럴 센서는 환경, 지질, 목표물 인식 분야에 있어 많은 관심을 받고 있으며 위성탑재 초다중분광센서가 운용되기 시작하면서 연구의 활성화가 더욱 기대되고 있다. 본 연구에서는 EO-1 위성의 Hyperion 센서 데이터를 이용하여 노이즈 제거를 위한 영상 전처리 과정을 실시하고 분광특성에 따른 무감독 분류를 통한 인덱싱 기법과 널리 알려진 분광 라이브러리를 활용한 대상물, 특히 인공지물 추출 기법을 실험하였다. 이를 위하여 MNF(Maximum/Minimum Noise Filtering) 변환 및 분광 매칭(Spectral Matching) 기법, 분광 라이브러리 처리 등을 수행하였다. 결과의 비교를 위하여 동일 지역의 Landsat ETM+ 데이터를 이용하여 상호비교를 통한 검증작업으로서 그 성과를 판단하였다.

• Korean Journal of Plant Resources
• /
• v.5 no.1
• /
• pp.49-56
• /
• 1992

In the preliminary antitumor screening tests of Crude Drugs and collected plants, the methanol ic extract of Forsythia Fruits in Korean marcket showed signif icant cytotoxic activity against Chinese hamster V-79 cells, but that in Japanese market did not. The former was identifid as Forsythia viridissima Lindley and latter as F.suspensa Vahl on the basis of the morphological observation. When an aqueous solution of the extract prepared from the fruits of F. viridissima (Oleaceae) was partitioned successively with n-hexane, methylene chloride, n-butanol, the cytoyoxic activitywas concetrated in the methylene chloride extract. Fractionation of the extract was made with the guidance of bioassay against V-79 cells to give cytotoxic lignans, matariresiol (1) and arctigenin (2). Their ICso values of compounds 1 and 2 were respectively $7.8{\;}\mu\textrm{g}/ml$ 1 and $1.65{\;}\mu\textrm{g}/ml$. Also, their structures were confirmed by comparison of physical and spectral data in the literature.

• Archives of Pharmacal Research
• /
• v.29 no.3
• /
• pp.195-198
• /
• 2006

Slavins A (1) and B (2), the new amyrin type triterpenes, have been isolated from the chloroform soluble fraction of Salvia santolinifolia and assigned structures on the basis of spectral studies including 2D NMR. Both the compounds displayed inhibitory potential against the enzyme butyrylcholinesterase.

• Archives of Pharmacal Research
• /
• v.15 no.1
• /
• pp.62-68
• /
• 1992

From the roots of Caragana sinica (Buc'hoz) Rehder (Leguminosae), a new saponin named caraganoside A was isolated and elucidated as 3-0-$\beta$-D-xylopyranosyl (1$\rightarrow$2)-[$\beta$-D-glucopyranosyl (1$\rightarrow$3)]-$\alpha$-L-arabinopyranosyl oleanolic acid 28-O-[$\beta$-D-glucopyranosyl ester by means of chemical and spectral studies. Kalopanax-saponin F, hemsloside Ma3 and araloside A were also isolated and characterized. The former two compounds were separated as their methylesters.