• Ocean Systems Engineering
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• v.3 no.3
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• pp.167-180
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• 2013

Hydrodynamic characteristics of a bluff cylinder oscillating along transverse direction in steady flow were experimentally investigated at Reynolds number of $2{\times}10^5$. The effects of non-dimensional frequency, oscillating amplitude and Reynolds number on drag force, lift force and phase angle are studied. Vortex shedding mechanics is applied to explain the experimental results. The results show that explicit similarities exist for hydrodynamic characteristics of an oscillating cylinder in high and low Reynolds number within subcritical regime. Consequently, it is reasonable to utilize the test data at low Reynolds number to predict vortex induced vibration of risers in real sea state when the Reynolds numbers are in the same regime.

• Archives of Pharmacal Research
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• v.27 no.11
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• pp.1106-1108
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• 2004

A new benzofuran derivative, named gymnastone [5-hydroxy-6-acetyl-2-(2-propane-1,2,3-triol)-benzofuran (1)], was isolated from the aerial part of Gymnaster koraiensis, together with viscidone (2) by repeated column chromatography. The structures of both compounds were identified by physico-chemical and spectral analysis including COSY, HMQC, and HMBC experiments.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.863-868
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• 1995

Electroacupuncture therapy was performed in 2 dogs with thoracolumbar disc disease. Case was a 3-year-old female chihuahua with a calcified disc between the 13th thoracic and 1st lumbar vertebrae. Treatment was done by electroacupuncture at San sho yu, Shen yu, Huan tiao and Fu yang-San yin jiao with the current of 0.5~8 volts, 30 Hz for 30 min. She could pass feces and urine 2 days, and walk 9 days after the beginning of the therapy. Case 2 Was a 6-year-old male cocker spaniel with 4 calcified discs(T12-T13, T13-L1, L2-L3 and L6-L7) and spondylosis(lumbosacral junction). Treatment was done by electroacupuncture at Tian ping, Bai hui and Pung kung yu with the current of 2~4 volts, 30 Hz for 20 min. He could pass feces 6 days, urine 8 days, and stand 21 days, after the beginning of the therapy.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.55.4-55.4
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• 2016

We observed 10 Class I sources as part of the IGRINS (Immersion GRating INfrared Spectroscoph) Legacy Program, "IGRINS Survey of Protoplanetary Disks (PI: Jeong-Eun Lee)". Unlike other Class I sources, IRAS 16316-1540 shows broad absorption features in the near-infrared spectra (H and K bands). The broadened absorption features have been detected toward FU Orionis-type objects. Boxy or double-peaked absorption profiles can be produced by a Keplerian disk that has the hot mid-plane heated by a burst mass accretion. We could fit the broad absorption features of IRAS 16316-1540 with a K5 V template stellar spectrum convolved with a disk rotation profile of 45 km s-1. Therefore, rotationally broadened absorption features detected in this Class I source suggest that the episodic accretion process occurs from the early stage of star formation.

• ETRI Journal
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• v.34 no.5
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• pp.696-705
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• 2012

Accurate synthesis models based on artificial neural networks (ANNs) are proposed to directly obtain the physical dimensions of an asymmetric coplanar waveguide with conductor backing and substrate overlaying (ACPWCBSO). First, the ACPWCBSO is analyzed with the conformal mapping technique (CMT) to obtain the training data. Then, a modified genetic-algorithm-Levenberg-Marquardt (GA-LM) algorithm is adopted to train ANNs. In the algorithm, the maximal relative error (MRE) is used as the fitness function of the chromosomes to guarantee that the MRE is small, while the mean square error is used as the error function in LM training to ensure that the average relative error is small. The MRE of ANNs trained with the modified GA-LM algorithm is less than 8.1%, which is smaller than those trained with the existing GA-LM algorithm and the LM algorithm (greater than 15%). Lastly, the ANN synthesis models are validated by the CMT analysis, electromagnetic simulation, and measurements.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.4-5
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• 2004

• Journal of applied mathematics & informatics
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• v.27 no.5_6
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• pp.1061-1071
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• 2009

For real generalized reflexive matrices R, S, i.e., $R^T$ = R, $R^2$ = I, $S^T$ = S, $S^2$ = I, we say that real matrix X is (R,S)-symmetric, if RXS = X. In this paper, an iterative algorithm is proposed to solve the least-squares problem of matrix equation AXB = C with (R,S)-symmetric X. Furthermore, the optimal approximation solution to given matrix $X_0$ is also derived by this iterative algorithm. Finally, given numerical example and its convergent curve show that this method is feasible and efficient.

• Journal of Magnetics
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• v.5 no.3
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• pp.73-75
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• 2000

Undoped and Cr-doped samples of electrooptic material KTiOPO$_4$ were studied by $^{31}$P nuclear magnetic resonance (NMR). Spin-lattice relaxation time ($T_1$) measurements manifested phase transition behaviors that are attributed to changes in the dominant charge carriers in different temperature ranges.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.199-201
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• 2010

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3317-3321
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• 2013

A series of new 3-alkylamino-6-allylthio-pyridazine derivatives was synthesized through allythiolation and amino-de-halogenation and were expected to have anti-proliferative activity. 6-Allylthio-3-chloropyridazine was prepared from the reaction of 3,6-dichloropyridazine with allylmercaptan and sodium hydroxide. The alkylamines such as methylamine and the dialkylamines such as dimethylamine were introduced into the 3-position of the pyridazine ring. These new compounds showed anti-proliferative activities against MCF-7 human breast cancer cells in CCK-8 assays. These compounds are thus promising candidates for chemotherapy of breast cancer. Two compounds, 14 and 15, showed higher potencies for inhibiting growth of breast cancer cells than did 5FU. This suggests the potential anti-proliferative activity of these compounds.