• Journal of the Korean Ceramic Society
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• v.33 no.6
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• pp.672-678
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• 1996

The relationship between domain switching and acoustic emission (AE) during poling was investigated using the tetragonal ferroelectric ceramics with composition of (Pb,La)TiO3+0.01MnO2 The amount of AE generation during poling increased with increasing dc electric field and raising temperature. It was confirmed that the change of the amount of AE generation with poling condition resulted from the difference of the amount of 90$^{\circ}$ domain switching and total amount of AE generation for 10 minutes was approximately proportional to the amount of 90$^{\circ}$domain switching. The A generations of two specimens which have different tetragonality rations(c/s rations) 15 at% and 24at% La-doped were also investigated. The sample with c/a ratio of 1.012 where 90$^{\circ}$ domains are dominate had larger amount of AE generation and 90$^{\circ}$ domain switching compared with the sample with c/a ratio of 1.004 where 180$^{\circ}$ domains are dominant.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2001.06a
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• pp.139-142
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• 2001

국지기온 결정인자 가운데 특히 고도의 영향이 현저하므로 비관측점과 공간내삽에 사용되는 주변 관측점간 표고편차를 기온감율에 의해 보정해주는 간단한 방법은 상대적으로 복잡한 다른 기법들에 비해 우수한 결과를 보인다 (Nalder and Wein, 1998). 지구대기의 건조단열감율은 -0.0098$^{\circ}C$m$^{-1}$로 상수이지만, 수증기로 포화된 대기의 기온감율은 지표 부근의 -0.004$^{\circ}C$m$^{-1}$부터 대류권 중간의 -0.007$^{\circ}C$m$^{-1}$를 거쳐 권계면 부근에서는 건조단열감율과 거의 같아진다 (Wallace and Hobbs, 1997).(중략)

• Journal of Ecology and Environment
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• v.37 no.1
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• pp.31-34
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• 2014

The effectiveness of N-acetyl-L-cysteine (NAC) to protect blood cells against Mitomycin C (MMC) induced genotoxicity was investigated in human chronic myeloid leukemia cells (KCL22) using the alkaline comet assay. The comet assay was selected as sensitive and rapid method for analysis of DNA damage and repair in individual cells. NAC treatment alone did not produce any damage in KCL22 cell. But NAC was found to be effective in reducing genotoxic damage in KCL22 cells exposed to MMC. These results confirm the literature data that, given the safety and ability to reduce DNA damage. NAC may be useful to prevent drug-mediated genotoxicity.

• East Asian mathematical journal
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• v.29 no.1
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• pp.39-52
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• 2013

Let (X, S) be an association scheme where X is a finite set and S is a partition of $X{\times}X$. The size of X is called the order of (X, S). We define $\mathcal{C}$ to be the set of positive integers m such that each association scheme of order $m$ is commutative. It is known that each prime is belonged to $\mathcal{C}$ and it is conjectured that each prime square is belonged to $\mathcal{C}$. In this article we give a sufficient condition for a scheme of order pq to be commutative where $p$ and $q$ are primes, and obtain a partial answer for the conjecture in case where $p=q$.

• Journal of Astronomy and Space Sciences
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• v.22 no.3
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• pp.187-196
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• 2005

From the line ratios of Si III] 1892 to C III] 1909 (Feibelman & Aller 1987), we estimated the BLR electron densities and their changes of Seyfert 1 galaxy NGC 7469 using IUE spectra observed from June 11 to July 29, 1996 (Wanders et al. 1997). We separated blended Si III] and C III] lines using the STARLINK/DIPSO and measured their fluxes within the error of $12.4\%\;and\;6.6\%,$ respectively. Electron density fluctuated from $10^{9.69}\;to\;10^{10.93}$ during about two month period, i.e. 17.3 times density variation within 50 days. We also derived time delays from UV emission line variations .elative to the continuum $(at\;1315{\AA}):$ 2 days for C IV, 4 days for C III], 8 days for Si III]. This suggests that their stratified UV line emission regions are at 0.002 pc, 0.004 pc and 0.006 pc, respectively, from the central region. Based on the BLR sizes and their rotation velocities deduced from the line profiles, we estimate the central black hole mass as about $10^6M_{\odot}$

• The Korean Journal of Food And Nutrition
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• v.32 no.2
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• pp.138-147
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• 2019

In this study, we examined antioxidative effects and the anti-adipogenesis effect of different parts of Cudrania tricuspidata (C), and Morus alba (M). Total polyphenol contents were highest in M-root ($34.56{\pm}0.045mg\;GAE/g$), and there was no significant difference, between C-root and M-leaf. Total flavonoid contents of C-root were highest ($23.07{\pm}0.004mg\;QE/g$). To examine antioxidant activities of C and M extracts, DPPH and ABTS radical scavenging activity, and FRAP assay, was used. Results show that antioxidant activities of C and M extracts increased, in a dose-dependent manner. Adipocytes are generated by preadipocyte differentiation, during adipogenesis. Matured adipocytes accumulate in abnormal and cause obesity. We investigated effects of leaf and root extracts of C and M, on lipid accumulation, in 3T3-L1 adipocytes. Changes in cell morphology, and degrees of lipid accumulation in adipocytes, were evaluated by Oil Red O staining. Root extracts of C and M, reduced lipid content in a dose-dependent manner. Therefore, root extracts of C and M, may be good candidates for managing obesity.

• Parasites, Hosts and Diseases
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• v.32 no.1
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• pp.27-34
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• 1994

The results of fecal examination for helminth eggs and protozoan cysts in Seoul Paik Hospital during 1984-1992 are reported. Fecal specimens of a total of 52,552 out- or in- patients were examined by formalin-ether sedimentation and/or direct smear method. The overall egg Positive rate of helminths was 6.5% and the cyst Positive rate of Protozoa 2.5%. The egg positive rate (number of positive cases) for each species of helminth was; Clonorchis sirensis 3.2%(1,667) , Trichuris trichiura 2.0%(1,089), Metqsonimw yokogawai 1.2% (613), Ascaris lumbricoides 0.2% (100), Trichostrongylus orientalis 0.1% (34), Taenin spp. 0.05% (28), Hymenolepis nana 0.03% (181), hookworms 0.03% (17), Poragonimlrkf westermani 0.02% (12), Echinostoma spp. 0.03% (12), Enterobius uermiculans 0.02% (10), Strongyloides stercora;is (larvae) 0.01% (6) , and Diphyllobothrium latum 0.004% (2). The cyst positive rate (number of positive casesl for each protozoan was; Entamoebc coli 1.1% f5881, Snnolimox nana 0.8% (402), Ginrdin lomblia 0.3% (173) , Entamoeba histo;utoca 0.3% (164), and Trichomonos hominis (trophozoites) 0.004% (2). Viewing from the data of 9 years, it was evident that the prevalence of soil-transmitted helminths such as A. Lumbricoines and T. trichiuro has been decreasing remarkably, while that of snail transmitted helminths such as C. sinenris and intestinal protozoans has not.

• Nuclear Engineering and Technology
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• v.44 no.6
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• pp.697-708
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• 2012

The majority of instrumentation and control (I&C) systems in today's nuclear power plants (NPPs) are based on analog technology. Thus, most existing I&C systems now face obsolescence problems. Existing NPPs have difficulty in repairing and replacing devices and boards during maintenance because manufacturers no longer produce the analog devices and boards used in the implemented I&C systems. Therefore, existing NPPs are replacing the obsolete analog I&C systems with advanced digital systems. New NPPs are also adopting digital I&C systems because the economic efficiencies and usability of the systems are higher than the analog I&C systems. Digital I&C systems are based on two technologies: a microprocessor based system in which software programs manage the required functions and a programmable logic device (PLD) based system in which programmable logic devices, such as field programmable gate arrays, manage the required functions. PLD based systems provide higher levels of performance compared with microprocessor based systems because PLD systems can process the data in parallel while microprocessor based systems process the data sequentially. In this research, a bistable trip logic in a reactor protection system (RPS) was developed using very high speed integrated circuits hardware description language (VHDL), which is a hardware description language used in electronic design to describe the behavior of the digital system. Functional verifications were also performed in order to verify that the bistable trip logic was designed correctly and satisfied the required specifications. For the functional verification, a random testing technique was adopted to generate test inputs for the bistable trip logic.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.3
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• pp.17-26
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• 2002

The pressure distributions on a semi-span wing 1/12 scale mode and sic component aerodynamic forces and moments on a complete 1/16 scale advanced trainer model were measured. To reduce wing-tip vortex strength, 3 wing-tip jet slot shaped(forward $35{^{\circ}C}$ direction, straigt direction, backward $35{^{\circ}C}$ direction) and 3 blowing coefficents (0.004, 0.009, 0.017) were considered. From experiment results, the case of straight direction and blowing coefficent of 0.017 was the best effective in the reduction of drag and in increase of lift-drag ratio and A rate of drag decrease and a rate of lift-drag ratio increase were of most effective on angle of attack 8 degree.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1769-1774
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• 2004

Jun/Fos, a crucial factor in transmitting the tumor-promoting signal from the extracellular environment to the nuclear transcription machinery, has a dimerization interface possessing several coiled structural properties. Jun and Fos can interact with the DNA regulatory region, AP-1 (Activator Protein-1), which is composed of 5'-TGAC/GTCA-3'.$^1$ Curcumin is a well-known anticancer and anti-inflammatory compound.$^{2,3}$ It also acts as an inhibitor of the Jun-Fos function. c-Fos and c-Jun with a bZIP region are overexpressed in BL21 E. coli and purified with an $Ni^{2+}$ affinity column. The inhibitors of Fos-Jun-AP-1 complex formation were searched through the EMSA (electrophoresis mobility shift assay) experiment, and new curcuminoids were synthesized and investigated as to their inhibitory effect on the same system. Two curcuminoids showed a stronger inhibitory effect than curcumin. This inhibitory activity was quantified with EMSA. 1,7-bis(4-methyl)-1,6-heptadiene-3,5-dione (BJC003) and 1,7-bis(4-hydroxy-5-methoxy-3-nitrophenyl)-1,6-heptadiene-3,5-dione (BJC005) showed remarkably high inhibitory activities. $IC_{50}$ of 1,7-bis(4-methyl)-1,6-heptadiene-3,5-dione (BJC003) and 1,7-bis(4-hydroxy-5-methoxy-3-nitrophenyl)-1,6-heptadiene-3,5-dione (BJC005) are 8.98 ${\mu}M$ and 5.40 ${\mu}M$, respectively. However, 1,7-bis(4-methyl-3-nitrophenyl)-1,6-heptadiene-3,5-dione (BJC004) did not show inhibitory activity.