• Journal of Navigation and Port Research
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• v.28 no.2
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• pp.141-148
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• 2004

The observations of rapid motion of bubbles under water for approximately 50ms or less in high . magnetic fields of 10 T have been carried out successfully for the first time. The observation system constructed is composed of a high-speed video camera, a telescope, a cryostat with a split-type superconducting magnet, a light source, a mirror and a transparent sample cell. Using this system, the influence of magnetic field on the path and shape of single bubbles of $O_2$(paramagnetism) and $N_2$ (diamagnetism) has been examined carefully. Experimental values describing the path are in good agreement with theoretical values calculated on the basis of the magneto-Archimedes effect, despite the effect of magnetism on the bubble. However, no effect of magnetism on the shape of the bubble is observed In addition, the influence of magnetic field on drag coefficient of the bubble is discussed.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2135-2137
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• 2005

This paper describes the features of electric and magnetic fields produced by lightning discharges. The measuring system consists of fast electric field sensor, crossed-loop magnetic field sensors, signal processing circuit, A/D converter and data acquisition equipment with a 12bit resolution and 10[MS/s] sampling rate. The frequency bandwidth and responsitivity of the electric field measuring system were 40[Hz]${\sim}$2.6 [MHz] and 2.08 (V/m/mV) and those of the magnetic field measuring system were 400[Hz]${\sim}$1[MHz] and 2.78[nT/mV], respectively. The electric and magnetic fields produced by lightning discharges were observed, and the features and parameters of the waveforms were analyzed.

• Journal of the Korean Magnetic Resonance Society
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• v.10 no.2
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• pp.188-196
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• 2006

A known theonellapeptolide Ie, previously reported in other research group, was isolated from the methanolic extract of the Philippine sponge Theonella swinhoei. The planar structure of this compound was determined on the basis of NMR methods including HMBC and selective HMBC experiments. This is fast and efficient for the dereplication of natural products compared with the MS studies of fragments obtained from complete and partial hydrolysis. The sequence of thirteen amino acids including six N-methyl amino acids in the compound was clearly determined from correlations of extensive HMBC experiments.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.455-458
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• 1997

Crude oils in the rhizoma of fresh and dried Gastrodia elata were obtained by a simultaneous steam distillation and extraction(SDE) method using n-pentane/diethyl ether (1 : 1) as solvent, and their volatile constituents were analyzed by gas chromatography-mass spectrometry(GC/MS) A total of 39 volatile flavor constituents (11 acids, 13 alcohols,6 hydrocarbons,7 carbonyls,2 esters) and 25 constituents (6 alcohols, 13 acids, 4 hydrocarbons, 1 carbonyl, ester) were identified in the fresh and dried Gastrodia elate respectively. The major volatile components of the fresh and dried sample were hexadecanoic acid(66.78%, 50.72%), 9-hexadecenoic acid(8.07%, 9.58%), heptadecanoic acid(2.01%, 0.13%), pentadecanoic acid(6.41%, 4.94%), p-cresol(1.43%,0.52%) and cyclododecene(1.83%, 6.00%).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.498-501
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• 2003

We investigated response characteristics of twisted nematic (TN) cell with different nematic liquid crystals (NLCs) and cell gap d on a rubbed polyimide (PI) surface. High transmittance and fast response time of the TN cell on the rubbed PI surface were achieved by using high birefringence (${\Delta}n$) and low cell gap d. The transmittance and response time of the TN cell on the rubbed PI surface decreased with decreasing ${\Delta}nd$. The fast response time of TN cell using high birefringence with ${\Delta}nd=0.363$ on the rubbed PI surface was measured 5.1 ms.

• Natural Product Sciences
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• v.22 no.1
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• pp.41-45
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• 2016

Extraction and fractionation of Pulsatilla koreana flowers followed by, repeated open column chromatography for EtOAc and n-BuOH fractions yielded four flavonoid glycosides, namely, astragalin (1), tiliroside (2), buddlenoide A (3), and apigenin-7-O-(3"-E-p-coumaroyl)-glucopyranoside (4). The chemical structures of these flavonoid glycosides were elucidated on the basis of various spectroscopic methods including electronic ionization mass spectrometry (EI-MS), 1D NMR ($^1H$, $^{13}C$, DEPT), 2D NMR (gCOSY, gHSQC, gHMBC), and infrared (IR) spectrometry. This study represents the first report of the isolation of the flavonoid glycosides from the flowers of P. koreana.

• Korean Journal of Pharmacognosy
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• v.31 no.4
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• pp.459-461
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• 2000

From the n-hexane layer of the MeOH extract of the roots of Polygala tenuifolia, three compounds (2-hydroxy-4,6-dimethoxy benzophenone, 3,4,5-trimethoxycinnamic acid ethyl ester and 1,2,3,6,7- pentamethoxyxanthone) were isolated. 2-Hydroxy-4,6-dimethoxybenzophenone and 3,4,5-trimethoxycinnamic acid ethyl ester were first isolated from Polygala genus. Their structures were elucidated employing 2D-NMR, IR, UV, and MS techniques.

• Journal of Plant Biotechnology
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• v.41 no.1
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• pp.33-37
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• 2014

Lychnis wilfordii (Regel) Maxim is a rare and valued ornamental plant. Germination rate reached 46.6% when seeds were treated with $100mg{\cdot}l^{-1}$ GA (Gibberellic acid). The highest callus induction was observed in the leaf explants of the seedlings on MS medium containing specific concentrations of $0.5mg{\cdot}l^{-1}$ BA ($N^6$-benzyladenine) and $3.0mg{\cdot}l^{-1}$ NAA (a-naphthalene acetic acid). The adventitious shoot was formed in 97.3% of calli on 1/2 WPM (Woody Plant Medium) medium. Shoot elongation of in vitro propagated plantlets was no difference among various medium. The plantlets grew well after transferring to the pot. This in vitro propagation protocol should be useful for conservation of this endangered plant.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.320-322
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• 2012

코 내부의 복잡한 기하학적 형상으로 인해 nasal airway의 분리는 많은 어려움을 겪고 있다. 본 논문은 velocimetry of nasal airflow 와 코 수술 계획을 위하여 3차원 공간에서 nasal airway를 interactive semiautomatic으로 분리하고 시각화하는 방법을 제안한다. 제안하는 방법은 ROI(Region-Of-Interest)와 multi-seed 3d region growing(MS3RG)기법을 적용하여 비강을 분리하며 볼륨렌더링 기법을 이용하여 분리된 영역을 3차원 공간에서 직관적으로 확인 할 수 있다. 또한 분리된 3차원 비강 모델은 유동흐름 실험을 위하여 3차원 프린터를 통해 실제 모형으로 제작 가능하다. 그리하여 CT dataset(512*512*175)을 가지고 매뉴얼 세그멘테이션에서 5시간 정도 걸리던 작업을 반자동 세그멘테이션 방법을 이용할 경우 최대 3분 이내에 분리 작업을 완료할 수 있으며 수치해석 실험 및 물리 실험에 이용할 수 있다.

• Bulletin of the Korean Chemical Society
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• v.16 no.7
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• pp.595-600
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• 1995

The kinetics of the reaction between O(3P) and C2H4 was investigated by measuring time-dependent concentrations of OH resulting from the reaction by using the LIF detection. Oxygen atoms were generated by titrating microwave discharged N2/He with NO to the chemiluminescent end point. The operating pressures in the flow reactor ranged from 5 to 15 torr and the mixtures consisted of He/O(3/P)/C2H4 in the approximate ratios from 100/1/0.1 to 100/1/1. The controlled residence time prior to the detection were estimated to be 0.8-17 ms at the reactor pressure of 7 torr. Experimentally determined profiles both in shape and magnitude were compared with the computed OH density for a specified set of experimental parameters, allowing us to arrive at a complete mechanism for the reaction of O(3P) with ethylene.