• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.195-201
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• 2006

In multicarrier code division multiple access(MC-CDMA), the total system bandwidth is divided into a number of sub-bands, where each subband may use direct-sequence(DS) spreading and each subband signal is transmitted using a subcarrier frequency. In this paper, the system performance analysis of MC-CDMA using to gain combining(EGC) and maximal ratio combining(MRC) method over frequency selective Nakagami-m fading channel is analyzed. In the proposed system, a data sequence is serial-to-parallel converted, and MC-CDMA is used on each of the parallel data streams. The data streams are spread at both the symbol fraction level and at the chip level by the transmitter. In this paper, the compare to analysis,two standard diversity combining techniques, EGC and MRC, The good performance of system using to MRC more than EGC

• Korean Journal of Medicinal Crop Science
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• v.15 no.4
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• pp.271-275
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• 2007

Naturally occurring substances are important biomedical resources with low toxicity and ethnopharmacology-based efficacy. Four out of 45 extracts (Celastrus orbiculatus, Cercis chinensis, Stephanadra incisa, and Weigela subsessilis) prepared from the bark of Korea Forest plants exhibited more than 50% of inhibition on $TNF-{\alpha}$ production in lipopolysaccharide (LPS)-activated RAW264.7 cells at $100\;{\mu}g/m{\ell}$. In particular, potential inhibitory components of 4 extracts showed more than 50% inhibition seemed to be concentrated in methylene chloride (MC) fraction from C. orbiculatus, in ethyl acetate (EtOAc) fraction from C. chinensis and in hexane (Hx) fraction from S. incisa, whereas inhibitory activities of W. subssilis were broadly seen in non-polar solvent fractions such as Hx, MC and EtOAc. Therefore, our results suggest that extracts from C. orbiculatus, C. chinensis, S. incisa and W. subsessilis may be developed as a therapeutic remedy against $TNF-{\alpha}-mediated$ diseases such as rheumatoid arthritis or further fractionated to isolate active components having $antiTNF-{\alpha}$ inhibitory activity.

• Korean Journal of Pharmacognosy
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• v.31 no.2
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• pp.190-195
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• 2000

In the previous reports, we selected 80% MeOH extract of 7 herbs including Scutellariae Radix(SR), Paeoniae Radix Rubra(PRR), Moutan Cortex(MC), Angelicae Gigantis Radix(AGR), Crataegi Fructus(CF), Bambusae Caulis in Taeniam(BCT) and Cinnamomi Ramulus(CR), which exhibited the inhibitory effect on HMG-CoA reductase and DPPH free radical scavenging effect in vitro, and antihyperlipidemic effects on antihyperlipidemic rats induced by Triton WR 1339 in vivo. Among them, SR, MC, AGR and BCT showed significant suppression of elevated serum LDL-cholesterol level, and AGR and CF showed significant liver weight increase on high cholesterol diet induced hyperlipidemic mice. And, SR, PRR, AGR, BCT and CR significantly suppressed the elevated serum total cholesterol and triglyceride levels on corn oil induced hyperlipidemic rats. Then, in order to research new antihyperlipidemic agents from the oriental medicinal herbs, we chose SR, AGR, CR and BCT which have the antihyperlipidemic effect in vitro and in vivo, and those herbs were systematically fractionated with organic solvent. EtOAc fraction of SR, hexane fraction of BCT, AGR and chloroform fraction of CR exhibited remarkably inhibitory effect on HMG-CoA reductase activity.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.2
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• pp.189-194
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• 2005

The morphological properties of various structure materials of domestic and foreign reconstituted tobacco products(RTP) were investigated by using the Bauer-McNett classifier and the image analyzer. The results of the fiber classification showed the fraction of the bigger size structure materials was larger in a domestic RTP than that in two foreign RTPs. In case of fine fraction, the domestic RTP had bigger fine fraction than two foreign RTPs. Images of each structure materials showed the scrap in the foreign RTPs kept the original shape which were rare in the domestic RTP fractions. Those results deduced that the raw materials in a foreign RTP process might be treated separately depending on the mechanical and morphological properties, which could reduce the amount of fine generation and increase the efficiency in raw material treatment.

• Journal of Korea Foundry Society
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• v.33 no.5
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• pp.193-203
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• 2013

The Ni-base superalloy CM247LC was directionally solidified (DS) using the Bridgman-type furnace to understand the effect of the chill plate on the microstructural evolution, such as dendrite arm spacing, microporosity, and MC-type carbide. The DS process was also modeled by the PROCAST to predict the solidification rate, thermal gradient, and resultant cooling rate in the entire length of the DS specimen. Due to the quenching effects of chill plate, four distinct areas were found to form in the specimen, in which the solidification rate was changed, during DS at a given withdrawal rate of 0.083 mm/s. Among the microstructural features investigated, the dendrite arm spacings and average size of the MC-type carbide near the chill plate were found to be influenced by the quenching effect of the chill plate. However, no significant influence was found on the size and volume fraction of microporosity, and the volume fraction of the MC-type carbide. The relationship between the microstructural features and the solidification variables was also analyzed and discussed on the basis of a combination of experimental and modeling results.

• Korean Journal of Materials Research
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• v.30 no.12
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• pp.678-686
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• 2020

Microstructural characteristics of directionally solidified René 80 superalloy are investigated with optical microscope and scanning electron microscope; solidification velocity is found to change from 25 to 200 μm/s under the condition of constant thermal gradient (G) and constant alloy composition (Co). Based on differential scanning calorimetry (DSC) measurement, γ phase (1,322 ℃), MC carbide (1,278 ℃), γ/γ' eutectic phase (1,202 ℃), and γ' precipitate (1,136 ℃) are formed sequentially during cooling process. The size of the MC carbide and γ/γ' eutectic phases gradually decrease with increasing solidification velocity, whereas the area fractions of MC carbide and γ/γ' eutectic phase are nearly constant as a function of solidification velocity. It is estimated that the area fractions of MC carbide and γ/γ' eutectic phase are determined not by the solidification velocity but by the alloy composition. Microstructural characteristics of René 80 superalloy after solid solution heat-treatment and primary aging heat-treatment are such that the size and the area fraction of γ' precipitate are nearly constant with solidification velocity and the area fraction of γ/γ' eutectic phase decreases from 1.7 % to 0.955 %, which is also constant regardless of the solidification velocity. However, the size of carbide solely decreases with increasing solidification velocity, which influences the tensile properties at room temperature.

• Journal of Ginseng Research
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• v.15 no.1
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• pp.13-20
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• 1991

Ginseng components were examined for their ability to modify immunotoxicity of cyclophosphamide. Ginseng polysaccharide fraction (FO, 300 mg/kg) inhibited decreases in the ratio of spleen to body weight, white blood cells (WBC) count and the number of plaque forming cells (PFC) induced by cyclophosphamide (50 mg/kg, i.p.), and increased these variables in normal mice. Ginseng saponin fraction (50 mg/kg) showed to increase hemoglobin content as well as the number of PFC/spleen in normal mice. on the other hand, Panaxytriol (20 mg/kg) Prevented decrease in mc count by cyclophos phamide. Neither saponin fraction nor panaxytriol had any significant effect on the number of PFC and antibody titers in cyclophosphamide-treated mice. These results suggest that ginseng polysaccharine fraction may reduce the immunotoxicity of cyclophosphamide and may be effective in stimulating immune function in normal mice.

• Natural Product Sciences
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• v.18 no.2
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• pp.137-140
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• 2012

The aim of this research was to investigate the industrial application of Zanthoxylum schinifolium. Antibacterial activities of the n-hexane, methylene chloride (MC), ethyl acetate, and butanol fractions of Z. schinifolium were tested against Escherichia coli, Staphylococcus aureus and Helicobacter pylori. Among the fractions, the n-hexane and MC fractions showed the stronger antibacterial activity against H. pylori, with an inhibition zone greater than 10 mm in disc assays. Further testing of bergapten and lupeol from the MC fraction of Z. schinifolium revealed the antibacterial effects against E. coli, S. aureus and H. pylori, suggesting their potential use as antibacterial agents.

• Korean Journal of Medicinal Crop Science
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• v.17 no.5
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• pp.357-362
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• 2009

Compounds of isolated from roots extract of Pueraria thunbergiana were tested their inhibitory effects on $\alpha$-glucosidase and $\alpha$-amylase. Inhibitory activity of methylene chloride (MC) fraction and ethyl acetate (EA) fraction against $\alpha$-glucosidase showed more than 60% at a concentration of $500{\mu}g/m{\ell}$. Among the nine compounds tested on $\alpha$-glucosidase, biochanin A, (-)-tuberosin and calycosin from MC fraction and daidzein from EA fraction were stronger inhibitors than acarbose ($IC_{50}=530{\mu}g/m{\ell}$), and their $IC_{50}$ were 9, 144, 328 and $20{\mu}g/m{\ell}$, respectively. Biochanin A and (-)-tuberosin also inhibited $\alpha$-amylase activity as like as acarbose $IC_{50}=20.5{\mu}g/m{\ell}$), and their $IC_{50}$ were 22 and $348{\mu}g/m{\ell}$, respectively. Although daidzein was already known $\alpha$-glucosidase inhibitory effects, it was newly evaluated that biochanin A and (-)-tuberosin inhibited $\alpha$-glucosidase as well as $\alpha$-amylase, and that calycosin did $\alpha$-glucosidase.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.1
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• pp.55-62
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• 2005

Very little research has been carried out on safflower seed for the prevention and treatment of the bone deficiency diseases, including osteoporosis, which are supported by scientific evidences. In the present study, $3{\mu}l$ of 0.1% dried crude extract or $2{\mu}l$ of 0.1% dried aqueous fraction were shown to significantly accelerate the rate of differentiation of osteoblast. Also, the crude extract and aqueous fraction increased the $[Ca^{2+}]_i$ of the cultured osteoblast cells: $3{\mu}l$ of 0.1% dried crude extract and $2{\mu}l$ of 0.1% dried aqueous fraction significantly increased the $[Ca^{2+}]_i$ of the cultured osteoblast cells ($8{\times}10^{-4}$) to the extent that it deserves a considerable attention. Furthermore, the crude extract and aqueous fraction increased the $[Ca^{2+}]_i$ of the cultured osteoblast cells, and $300{\mu}M$ $Cd^{2+}$, specific calcium channel blocker, completely blocked the increase. Therefore, the increased $[Ca^{2+}]_i$ of the cultured osteoblast cells by safflower seed component continued to activate calcium channel.