• Natural Product Sciences
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• v.14 no.3
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• pp.202-205
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• 2008

The antioxidant activity of Paeonia suffruticosa (Paeoniaceae) was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl). The methanolic extract of P. suffruticosa showed the strong antioxidant activity. The antioxidant activity of ethyl acetate soluble fraction was stronger than that of the others ($IC_{50}$, $1.2\;{\mu}g/mL$), and the fraction was subjected to purification by repeated silica gel and Sephadex LH-20 column chromatography. Suffruticosol A, suffruticosol B, methyl gallate, and gallic acid, were isolated from the ethyl acetate soluble fraction. Their structures were elucidated by physico-chemical and spectroscopic studies.

• Annual Conference of KIPS
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• 2017.04a
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• pp.50-52
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• 2017

클라우드 컴퓨팅 시장의 지속적 성장과 가상화의 인기로 세계적 VDI 시장은 꾸준한 성장률을 보이고 있다. 또한 의료, 교육, 금융 등의 폭넓은 분야에서 VDI 서비스가 활용될 전망이다. 하지만 기존 VDI 서비스는 고정적인 자원 할당으로 사용자 워크로드 맞춤형 자원이 제공되지 못하는 문제점이 있다. 따라서 본 논문에서는 기존 VDI에 비해 실행속도가 빠른 컨테이너의 장점을 살려 VDI를 컨테이너화 하고, 사용자 워크로드 맞춤형으로 자원을 분배하기 위해 VDI 컨테이너 자원 사용량 데이터로 K-means 알고리즘을 통한 군집 분석 기반의 워크로드 분류 방법을 제시하였다.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.374-377
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• 2010

HID 램프는 광원 1개당 방출되는 광속이 많고 광원효율 또한 높은 광원이며 긴 수명에 경제성까지 우수한 특징을 가지고 있어서 높은 밝기가 요구되는 대규모 공장등에 사용되고 있으며 자동차의 전조 등 등에도 많이 사용되고 있다. HID의 전원부에 압전 변압기를 적용하여 경량, 소형이며 고효율의 전원부를 구현하고자 하였다. 기존의 HID 및 압전 변압기는 시뮬레이션에서 일반 저항부하와 변압기를 이용하여 개략적인 동작을 확인하는데 만족하였다. 본 논문은 압전 변압기와 HID의 전기적 등가회로에 의한 정밀한 PSPICE 모델을 제시하였고, 손쉽게 변수값을 수정하여 다양한 모델에 적용할 수 있도록 구성하였다.

• Natural Product Sciences
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• v.11 no.4
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• pp.193-195
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• 2005

The chromatographic separation of methanolic extract from the twigs of Ilex macropoda (Aquifoliaceae) led to the isolation of three hemiterpenes, and their chemical were elucidated by physico-chemical and spectroscopic analysis. Their structures were characterized as 4,5-dihydroxyprenyl caffeate (1), $4-(6-O-caffeoyl-{\beta}-D-glucucopyranosyloxy)-5-hydoxyprenyl$ caffeate (2), and $4-{\beta}-D-glucucopyranosyloxy-5-hydroxyprenyl$ caffeate (3), respectively. Compound 1 was isolated for the first time from plant.

• Korean Journal of Pharmacognosy
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• v.19 no.4
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• pp.233-238
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• 1988

Angelica flaccida Kom. is a herbal plant growing wild in the marsh of valley in Korea. It has been used for sedative and analgesic as a folk medicine, but its constituents have not been clarified yet. Five known coumarins such as isoimperatorin, decursidin, (-) anomalin, decursin, decursinol and two sterols such as ${\beta}-sitosterol$ and stigmasterol were isolated from the root of this plant, Their structures were identified by the UV, IR, NMR, mass data and the physico-chemical properties.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.222-227
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• 2002

MR(Magneto-rheological) fluid is smart fluid that can change its characteristics then magnetic fields are applied. Recently, many researches have been performed on this MR fluid for the application in a vareity of areas including automobile shock absorbers. This paper describes the design procedure of a MR damper and the analysis results of its dynamic characteristics. MR fluid in the magnetic field shows initial yield shear stress and increasing resistive viscosity with final saturation thereafter. Herschel-Bulkley model is used to simulate the flow characteristics of MR fluid and magnetic analysis is used to identify the magnetic property of the MR fluid in the orifice of the damper. The dynamic characteristics of the damper was predicted and compared with the experimental results for typical sinusoidal excitations.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.207.3-208
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• 2003

Peroxisome proliferator-activated receptor (PPAR), a member of the nuclear hormone receptor superfamily, is a transcription factor activated by specific natural or synthetic ligands. It is involved in various cellular processes including adipogenesis, inflammation, cell cycle progression and carcinogenesis. Here, we report the production and characterization of a PPARgamma subtype-specific monoclonal antibody P${\gamma}$ 48.34A, which was raised against full-length human PPARgamma protein. (omitted)

• Korean Journal of Cleft Lip And Palate
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• v.6 no.2
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• pp.117-130
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• 2003

The prevalence of craniofacial cleft is reported to be 10-34 / 100,000 live birth of human. This case report describes the characteristics of the Tessier classification number 0, 5, 7, and 14 craniofacial cleft patients. Given the rarity and unique nature of the clinical expression of each of the craniofacial clefts, the treatment plans can not be standardized but must be based on the individual assessment of each case.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.54.3-55
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• 2016

We model the spectral energy distribution (SED) of the Class 0 protostar L1527 IRS using a dust continuum radiative transfer code RADMC-3D to study the initial condition of gravitational collapse. To constrain the envelope structure, we use the data obtained by Herschel /PACS, which covers the far-infrared regime ($55-190{\mu}m$) where the SED of L1527 IRS peaks. According to our modeling, a more flattened density profile fits the far-infrared SED of L1527 IRS better than the density profile of a rotating and infalling envelope. Thus, we employ the density structure of a Bonnor-Ebert sphere, which consists of the inner flat-topped and the outer power-law regions and is often used for describing the density structure of the youngest sources in the low mass star formation process. A Bonnor-Ebert sphere fits very well the observed SED at ${\lambda}$ > $10{\mu}m$, suggesting that L1527 IRS might collapse from an unstable Bonnor-Ebert sphere rather than a singular isothermal sphere.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.89.3-89.3
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• 2017

Recent interferometric observations toward embedded protostellar systems show a clear offset between the emission peaks of N2D+ and N2H+. However, the chemical model that con-siders solely freeze-out and desorption from the dust grains could not reproduce the ob-servations. This difference between two spe-cies in the depletion zone might be caused by the reduction of the deuterated molecules, due to the reactions on grain surfaces. We present that the abundance offset between N2H+ and N2D+ can be explained if the chemi-cal model includes the surface chemistry, especially for the deuterated.