• Title/Summary/Keyword: Li Chan

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Mesh Segmentation With Geodesic Means Clustering of Sharp Vertices (첨예정점의 측지거리 평균군집화를 이용한 메쉬 분할)

  • Park, Young-Jin;Park, Chan;Li, Wei;Ha, Jong-Sung;Yoo, Kwan-Hee
    • The Journal of the Korea Contents Association
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    • v.8 no.5
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    • pp.94-103
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    • 2008
  • In this paper, we adapt the $\kappa$-means clustering technique to segmenting a given 3D mesh. In order to avoid the locally minimal convergence and speed up the computing time, first we extract sharp vertices from the mesh by analysing its curvature and convexity that respectively reflect the local and global geometric characteristics from the viewpoint of cognitive science. Next the sharp vertices are partitioned into $\kappa$ clusters by iterated converging with the $\kappa$-means clustering method based on the geodesic distance instead of the Euclidean distance between each pair of the sharp vertices. For obtaining the effective result of $\kappa$-means clustering method, it is crucial to assign an initial value to $\kappa$ appropriately. Hence, we automatically compute a reasonable number of clusters as an initial value of $\kappa$. Finally the mesh segmentation is completed by merging other vertices except the sharp vertices into the nearest cluster by geodesic distance.

Characterization and Immunopotentiating Effects of the Glycoprotein Isolated from Dioscorea Batatas

  • Huong, Pham Thi Thu;Lee, Chan-Ho;Li, Mei-Hong;Lee, Min-Young;Kim, Joon-Ki;Lee, Sun-Mee;Seon, Jong-Heum;Lee, Dong-Cheol;Jeon, Young-Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.2
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    • pp.101-106
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    • 2011
  • We demonstrate that glycoprotein isolated from Dioscorea batatas (GDB) has immunostimulatory effects including macrophage activation. Analysis of infiltration of inflammatory cells into peritoneal cavity showed GDB treatment significantly increased the recruitment of macrophages, lymphocytes, neutrophils, and monocytes into the peritoneal cavity. Treatment of spleen cells isolated from C57BL/6 mice with GDB significantly increased the proliferation of B cells and T cells induced by LPS and ConA, respectively. Treatment with GDB significantly increased the cytolytic capacity of NK cells and macrophages against YAC-1 and B16 cells, respectively. In order to further confirm and investigate the mechanism of GDB on macrophage activation, we analyzed the effects of GDB on the cytokine expression including iNOS, IL-1${\beta}$, and TNF-${\alpha}$ in mouse macrophage cell line, RAW 264.7 cells. RT-PCR and ELISA showed that GDB increased the expression of IL-1${\beta}$, and TNF-${\alpha}$, whereas iNOS was not induced by GDB. Collectively, this series of experiments indicates that GDB stimulates immune system including macrophage activation.

Effects of Polysaccharide Fraction from Euonymus alatus Sieb on T-, B-Lymphocytes and Macrophages in Mice (귀전우 다당류 분획이 생쥐의 T 및 B 임파구와 대식세포의 활성에 미치는 영향)

  • Kang, Jae-Woo;Shin, Ji-Seop;Bang, Jun-Sung;Jang, Sung-Hoon;Li, Ri-Hua;Jeon, Hoon;Kim, Dae-Geun;Oh, Chan-Ho;Cho, Hyoung-Kwon;Eun, Jae-Soon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.5
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    • pp.1270-1275
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    • 2008
  • Effects of polysaccharide fraction from Euonymus alatus Sieb(EPF) on the immune response of T-, B-lymphocytes and macrophages were examined in vitro and in vivo system. EPF (500 mg/kg) were administered p.o. twice a day for 5 days to C57BL/6 mice, and then the cells were separated from mice. EPF decreased the viability of thymocytes, but increased the viability of splenocytes in vitro and in vivo system. Also, the administration of EPF enhanced the population of helper T cell and cytotoxic T cell in thymocytes and did not affect the population of splenocytes. Furthermore, EPF enhanced the phagocytic activity and the production of nitric oxide in peritoneal macro phages in vivo system. These results suggest that EPF regulates an immune response via the enhancement of mature T lymphocytes and B lymphocytes viability and phagocytic activity of macrophages.

In vitro Screening of Medicinal Plants with Estrogen Receptor Modulation Activity (생약의 여성호르몬 수용체 조절 활성 검색)

  • Lee, Chang-Min;Kang, Se-Chan;Oh, Joa-Sub;Choi, Han;Li, Xue-Mei;Lee, Jae-Hyun;Lee, Mi-Hyun;Choung, Eui-Su;Kawk, Joung-Hwan;Zee, Ok-Pyo
    • Korean Journal of Pharmacognosy
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    • v.37 no.1 s.144
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    • pp.21-27
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    • 2006
  • Yeast based estrogenicity assay is the simplest and useful for the assay and the discovery of novel estrogenic substances in natural specimens, The estrogen receptor(ER) modulation activity of 50% EtOH extracts of 101 traditional medicinal herbs was assessed using a recombinant yeast assay system with both a human estrogen receptor expression plasmid and a receptor plasmid. Among them, 14 species proved to be active. Pureariae Flos (flower of Puerraria thunbergiana BENTH.) had the highest estrogenic relative potency$(7.75{\times}10^{-3})$ $(EC_{50}=9.39\;{\mu}g/ml)$. The $EC_{50}$ value of $17{\beta}-estradiol$ used as the positive control was $0.073\;{\mu}g/ml)$ (Relative Potency=1.00). There results demonstrated that some of the traditional medical herb may be useful in the therapy of estrogen replacement.

Characterization of the in vitro Activities of the P1 and Helper Component Proteases of Soybean mosaic virus Strain G2 and Tobacco vein mottling virus

  • Lim, Hyoun-Sub;Jang, Chan-Yong;Nam, Ji-Ryun;Li, Meijia;Hong, Jin-Sung;Bae, Han-Hong;Ju, Ho-Jong;Kim, Hong-Gi;Ford, Richard E.;Domier, Leslie L.
    • The Plant Pathology Journal
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    • v.28 no.2
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    • pp.197-201
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    • 2012
  • Potyviruses express their RNA genomes through the production of polyproteins that are processed in host cells by three virus-encoded proteases. Soybean plants produce large amounts of protease inhibitors during seed development and in response to wounding that could affect the activities of these proteases. The in vitro activities of two of the proteases of Soybean mosaic virus (SMV) and Tobacco vein mottling virus (TVMV) were compared in the rabbit reticulocyte lysate in vitro translation system using synthetic RNA transcripts. Transcripts produced from SMV and TVMV cDNAs that included the P1 and helper component-protease (HC-Pro) coding regions directed synthesis of protein products that were only partially processed. Unprocessed poly-proteins were not detected from transcripts that included all of the P1, HC-Pro, P3 and portions of the cylindrical inclusion protein coding regions of either virus. Addition of soybean trypsin inhibitor to in vitro translation reactions increased the accumulation of the unprocessed polyprotein from TVMV transcripts, but did not alter the patterns of proteins produced from SMV. These experiments suggest that SMV-and TVMV-encoded proteases are differentially sensitive to protease inhibitors.

Effect of Additive of the Encapsulated Amounts and Solubility of Poorly Water-soluble Ibuprofen in Gelatin Microcapsules

  • Li, Dong Xun;Park, Jung-Gil;Han, Hong-Hee;Yang, Chan-Woo;Choi, Jun-Young;Oh, Dong-Hoon;Yong, Chul-Soon;Choi, Han-Gon
    • Journal of Pharmaceutical Investigation
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    • v.37 no.5
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    • pp.269-273
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    • 2007
  • Poorly water-soluble ibuprofen and ethanol can be encapsulated in gelatin microcapsule by spray drying technique. To select an optimal formula of ibuprofen-loaded gelatin microcapsule which increased the ethanol content and ibuprofen solubility with the decreased amount of gelatin in the microcapsules, in this study, the effect of gelatin, ibuprofen and sodium lauryl sulfate on the ibuprofen solubility and the amount of ethanol and ibuprofen encapsulated in the gelatin microcapsule were investigated. Ibuprofen solubility and the amount of ethanol encapsulated increased as gelatin and sodium lauryl sulfate increased, reached maximum at 4% and 0.6%, respectively and then followed a rapid decrease. Furthermore, the ibuprofen solubility and the encapsulated ibuprofen content increased as the amount of ibuprofen increased, reaching maximum at 0.5% and beyond that, there was no change in the solubility and ibuprofen content. However, the encapsulated ethanol content remained same irrespective of the amount of ibuprofen. On the basis of increased ibuprofen solubility, our results showed that the formula of ibuprofen-loaded gelatin microcapsule at the ratio of gelatin/ibuprofen/sodium lauryl sulfate/water/ethanol of 4/0.5/0.6/30/70 with ibuprofen solubility of about $290\;{\mu}g/mL$ and ethanol content of about $160\;{\mu}g/mg$ could be a potential oral delivery system for poorly water-soluble ibuprofen.

Performance analysis for the Characteristics of Double Stage Evaporator/Absorber for Large temperature Difference Absorption System (흡수식 대온도차 시스템에서 2단 증발/흡수기의 성능 특성에 관한 수치적 연구)

  • Park, Chan-Woo;Kang, Yong-Tae;Im, Ick-Tae;Moon, Sang-Done
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.304-308
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    • 2008
  • The optimal design of two stage evaporation & absorption system which is related to the large temperature difference system was investigated numerically in the absorption refrigeration system. The concentrations at inlet & oulet of absorber are 62.9% and 56.9%, but in two stage absorption system the values are 62.2% and 56.2%. Therefore strong solution & weak solution became diluted than the standard value. The amount of weak solution circulation can be reduced in absorption refrigeration system, and the sensible heat load is more reduced to enhance the COP of system. As UAR is increased, COP becomes larger, and this means the role of top section is more important than bottom section in two stage evaporation & absorption system. But the increase of COP becomes slower at 0.7 of UAR ratio. The performance of Type2 is higher than Type1 in COP with the flow direction of cooling waters. This phenomena is due to the active absorption of vapor -absorption & lower temp. cooling water is more effective. The pressure at bottom section becomes higher & that at top section becomes lower and therefore the circulation rate can be diminished more.

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Effects of Annealing Temperature on the Local Current Conduction of Ferromagnetic Tunnel Junction (열처리에 따른 강자성 터널링 접합의 국소전도특성)

  • Yoon, Tae-Sick;Tsunoda, Masakiyo;Takahashi, Migaku;Li, Ying;Park, Bum-Chan;Kim, Cheol-Gi;Kim, Chong-Oh
    • Korean Journal of Materials Research
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    • v.13 no.4
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    • pp.233-238
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    • 2003
  • Ferromagnetic tunnel junctions, Ta/Cu/Ta/NiFe/Cu/$Mn_{75}$ $Ir_{25}$ $Co_{70}$ $Fe_{30}$/Al-oxide, were fabricated by do magnetron sputtering and plasma oxidation process. The effect of annealing temperature on the local transport properties of the ferromagnetic tunnel junctions was studied using contact-mode Atomic Force Microscopy (AFM). The current images reflected the distribution of the barrier height determined by local I-V analysis. The contrast of the current image became more homogeneous and smooth after annealing at $280^{\circ}C$. And the average barrier height $\phi_{ave}$ increased and its standard deviation $\sigma_{\phi}$ X decreased. For the cases of the annealing temperature more than $300^{\circ}C$, the contrast of the current image became large again. And the average barrier height $\phi_{ave}$ decreased and its standard deviation $\sigma_{\phi}$ increased. Also, the current histogram had a long tail in the high current region and became asymmetric. This result means the generation of the leakage current that is resulted from the local generation of a low barrier height region. In order to obtain the high tunnel magnetoresistance(TMR) ratio, the increase of the average barrier height and the decrease of the barrier height fluctuation must be strictly controlled.led.

Retrogradation Behavior of Rice Starches Differing in Amylose Content and Gel Consistency (아밀로오스 함량과 Gel Consistency의 차이에 의한 품종별 쌀전분의 노화특성)

  • Kum, Jun-Seok;Lee, Sang-Hyo;Lee, Hyun-Yu;Lee, Chan
    • Korean Journal of Food Science and Technology
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    • v.28 no.6
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    • pp.1052-1058
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    • 1996
  • The effect of varietal differences of rice starches by amylose content and gel consistency on the retrogradation behavior was studied. Setback viscosity of rice flour measured in a Brabender amylograph was significantly affected by amylose content as well as gel consistency. Increase in the rigidity modulus (E) of rice starch gels during storage determined by using texture analyzer indicated that amylose content was an important factor in terms of hardness increase. Kinetics of retrogradation showed that time constant of rice starch gels was influenced by amylose content, but not by gel consistency.

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The X-Ray Fluorescent Spectrographic Analysis of Silicate Minerals (X線螢光分析에 依한 珪酸鹽鑛物의 分析)

  • Chan Kuk Kim;Ki Nam Sang;Hwang Am Kim
    • Journal of the Korean Chemical Society
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    • v.13 no.1
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    • pp.49-55
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    • 1969
  • X-ray Fluorescence Spectrographic method has been applied for the rapid determination of main components, such as $SiO_2$, $Al_2O_3$, $Fe_2O_3$, CaO, MgO and $K_2O$ in Silicate Minerals. In this method, Boric Acid was used as a binder after fusion with Lithium Tetraborate in the briquet-making process. The Lithium Flubride, Ammonium di-Hydrogen Phosphate and Ethylene Diamine d-Tartrate crystals were used with Scintillation counter and Gas Flow counter as the detectors. Several influences on this method were discussed, including the particle size of samples and reducing of the matrix effects by dilution with Boric Acid and addition of Lanthanum Oxide with the diluent. In order to test the reproducibility of this method described above, the determination of the same kind of samples were carried out repeatedly, and the results obtained were presented in the table. Calibration curves for each element were presented, and the application of the method was tested with International Rock Standard T-Ⅰ. All the results obtained by X-Ray Fluorescence Spectrographic method were compared with the results by conventional chemical method.

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