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블록 근사화식의 적응적 선택을 이용한 프랙탈 영상 부호화
박용기(Park Yong Ki),박철우(Park Chul Woo),김두영(Kim Doo Young) 한국정보처리학회 1997 정보처리학회논문지 Vol.4 No.12
This paper suggests techniques to reduce coding time which is a problem in traditional compression and improve fidelity of reconstructed images by determining fractal coefficient through adaptive selection of block approximation formula. First, to reduce coding time, we construct a linear list of domain blocks of which characteristics is given by their luminance and variance and then we control block searching time according to the first permissible threshold value. Next, when employing three-level block partition, if a range block of minimum partition level cannot find a domain block which has a satisfying approximation error, we choose new approximation coefficients using a non-linear approximation of luminance term. This boosts the fidelity. Our experiment employing the above methods shows enhancement in the coding time more than two times over traditional coding methods and shows improvement in PSNR value by about 1-3dB at the same compression rate.
목단피(牧丹皮) Methyl Gallate 성분의 항염증효능에 대한 연구
박용기 ( Yong Ki Park ),민지영 ( Ji Young Min ),이제현 ( Je Hyun Lee ) 대한본초학회 2009 大韓本草學會誌 Vol.24 No.4
Objectives: In this study, we investigated the effect of methyl gallate of Paeonia suffruticosa(Moutan Cortex Radicis) on inflammatory response in activated macrophages. Methods: RAW264.7 cells were incubated with different concentrations of methyl gallate of Paeonia suffruticosa for 30 min and then stimulated with or without LPS at indicated times. Cell toxicity was determined by MTT assay. The concentrations of nitric oxide (NO), prostaglandin E2 (PGE2) and inflammatory cytokines (TNF-α, IL-6) were measured in culture medium by Griess assay, enzyme-immuno assay, and ELISA, respectively. The expressions of iNOS, COX-2 and cytokine mRNA and protein were determined by RT-PCR and Western blot, respectively. The Iκ-Bα degradation in cytosol and NF-κB p65 translocation into nuclear of the cells were determined by Western blot. Results: Methyl gallate was significantly inhibited LPS-induced production of NO and PGE2 in RAW264.7 cells. Methyl gallate was also suppressed LPS-induced expression of iNOS and COX-2 mRNA and protein in the cells. Methyl gallate was inhibited LPS-induced production of TNF-α and IL-6 via suppression of their mRNA expressions. Methyl gallate blocked the NF-κB pathway in LPS-stimulated RAW264.7 cells. Conclusions: This study suggests that methyl gallate of Paeonia suffruticosa may have an anti-inflammatory property through suppressing inflammatory mediator production in activated macrophages.
허혈성뇌졸중 흰쥐모델에서 가미보양환오탕(加味補陽還五湯)와 주요 구성약재인 황기(黃?), 단삼(丹蔘)의 뇌신경보호효과에 대한 연구
박용기 ( Yong Ki Park ),손혜영 ( Hye Young Son ) 대한본초학회 2010 大韓本草學會誌 Vol.25 No.2
Objectives: In this study, the neuroprotective effects of modified Boyanghwano-Tang (mBHT) and the major medicinal plants, Astragali Radix(AR) and Salviae Miltiorrhizae Radix(SMR) were investigated in transient middle cerebral artery occlusion (tMCAO)-induced ischemic stroke of rats. Methods: mBHT(400㎎/㎏) and AR(154㎎/㎏) or SMR(62㎎/㎏) water extract orally injected in rats after 90 min occlusion of MCA and then allow reperfusion to 24 h. Brain infarction was measured by TTC staining and the expressions of NOS isoforms and apoptotic molecules were determined in ischemic brain by Western blot. Results: The results showed that mBHT has stronger neuropreotective property through inhibitions of the PARP cleaved and caspase-3 activation in ischemic rats, and could reduced infarction volumes comparison of those of AR or SMR, respectively. While, AR extract has an angiogenic property through increasing the expressions of eNOS and VEGF, and SMR extract has a strong anti-inflammatory effects through inhibition of iNOS expression in ischemic brains. Conclusions: These results suggest that mBHT has multifactorial therapeutic advantages through anti-apoptosis, anti-inflammation and angiogenesis for ischemic stroke based on a synergistic combination of ingradients rather than monotherapy.
박영철,박용기,Park, Young-Chul,Park, Yong-Ki 동국대학교 한의학연구소 2008 東國韓醫學硏究所論文集 Vol.11 No.-
Objectives: The study was designed to evaluate the single dose toxicity of modified Bo-yang-Hwan-o-Tang (mBHT) in Sprague-Dawley (SD) rats. Methods: The mBHT was once administrated orally to both sexes of rats at dose 2,000 mg/kg body weight which are the recommended maximum limit dose for acute toxicity. We recorded clinical signs of toxicity, body weight, gross and histological changes in target organs for all rats. Results: Neither significant changes of body weight not death was observed during the observation period in mBHT-administrated rats. Neither significant toxic signs not histopathological changes were shown during the observation period. There were not observed significant gross abnormality between the control and mBHT-administrated rats. Conclusions: These results indicated that the toxicity of mBHT is greater than 2,000 mg/kg body weight in SD rats.
뇌 신경교세포에서 가미보양환오탕(加味補陽還五湯) 분획물의 항염증 효과 비교 연구
손혜영 ( Hye Young Son ),박용기 ( Yong Ki Park ) 대한본초학회 2009 大韓本草學會誌 Vol.24 No.4
Objectives: In this study, the effects of different fractions isolated from modified Boyanghwano-tang(mBHT) extract on LPS-induced inflammation in BV2 microglial cells were investigated. Methods: mBHT was extracted with water, and then fractionated with n-hexane, methylene chloride, ethylacetate and n-butanol. BV2 cells, a mouse microglia line were incubated with different concentrations of each fraction of mBHT for 30 min, and then stimulated with LPS for 24 h. Cell toxicity was determined by MTT assay. The concentration of nitric oxide (NO) was measured in culture medium by Griess reagent assay. The expression of inducible nitric oxide synthease (iNOS) protein was determined by Western blot. Results: Four fractions of mBHT were significantly inhibited LPS-induced NO productions in BV2 cells in a dose-dependent manner. The methylene chloride fraction of mBHT was most strongly inhibited the NO production compared with those of the others. The methylene chloride fraction of mBHT was also suppressed LPS-induced iNOS expression comparison of other fractions at same concentration (50 ㎍/㎖) in BV2 cells. Conclusions: The results showed that the methylene chloride fraction of mBHT may have an strong anti-inflammatory property through the inhibition of NO production and iNOS expression in activated microglia, and could a therapeutic potential for the treatment of various brain inflammatory diseases.
KMnO<sub>4</sub>/실리카-알루미나 상에서 에틸렌 제거: 합성 방법과 반응온도의 영향
조민휘,윤성훈,박용기,최원춘,김희영,박승규,이철위,Cho, Min-Whee,Yoon, Songhun,Park, Yong-Ki,Choi, Won Choon,Kim, Hee Young,Park, Seungkyu,Lee, Chul Wee 한국공업화학회 2009 공업화학 Vol.20 No.4
실리카-알루미나의 Si/Al 조성이 1:5, 1:10 및 0:1 (100% 알루미나)에 $KMnO_4$를 18~20중량% 담지시킨 $KMnO_4$/실리카-알루미나와 $KMnO_4$/알루미나를 용매증발법으로 제조하였다. 이 촉매를 사용하여 GHSV = $1125h^{-1}$, 에틸렌이 포함된 혼합가스(에틸렌 0.2%, 공기 99.8%, 상대습도 50%)를 $30^{\circ}C$, $40^{\circ}C$, $60^{\circ}C$, $150^{\circ}C$에서 고정층 반응기를 사용하여 각 촉매들에 대해 에틸렌 제거율을 비교하였다.그 결과 실리카-알루미나 담체를 사용한 촉매가 알루미나 담체를 사용한 촉매보다 $30{\sim}150^{\circ}C$ 온도 범위에서 우수한 성능을 보여주었는데, $30{\sim}40^{\circ}C$에서는 170~210%, $60^{\circ}C$ 및 $150^{\circ}C$에서는 약 60% 우수한 성능을 보여주었다. 18~19 wt% $KMnO_4$/$SiO_2-Al_2O_3$ with Si/Al = 1/5 and 1/10, and 20 wt% $KMnO_4$/$Al_2O_3$ were prepared by solvent evaporation method. Catalytic activity of ethylene abatement over those samples were evaluated and compared under the conditions of GHSV $1125h^{-1}$, ethylene gas (ethylene 0.2%, air 99.8%, relative humidity 50%) at 30, 40, 60 and $120^{\circ}C$ using a fixed-bed reactor. $KMnO_4$/$SiO_2-Al_2O_3$ was showed better performance than $KMnO_4$/$Al_2O_3$ by 170~210% at 30, $40^{\circ}C$, and by 60% at 60, $150^{\circ}C$, respectively.
속단(續斷)의 RAW264.7 세포에서 LPS에 의해 유도되는 염증반응에 대한 효과
민지영 ( Ji Young Min ),박용기 ( Yong Ki Park ) 대한본초학회 2009 大韓本草學會誌 Vol.24 No.4
Objectives: In this study, the effect of Dipsaci Radix(DR, Dipsacus asperoides C.Y. Cheng et T. M. Ai) water extract on LPS-induced inflammatory response in RAW264.7 cells were investigated. Methods: Dried roots of DR was extracted with water for 3 h(DR-W extract). RAW264.7 cells, a mouse macrophage line, were incubated with different concentrations of DR-W extract for 30 min and then stimulated with LPS at indicated times. Cell toxicity was determined by MTT assay. The concentrations of nitric oxide (NO) and prostaglandin E2 (PGE2) were measured by Griess assay and enzyme immunoassay (EIA), respectively. The expression of inducible nitric oxide synthease (iNOS) and cyclooxyganase (COX)-2 mRNA and protein was determined by RT-PCR and Western blot, respectively. Results: DR-W extract was significantly inhibited LPS-induced productions of NO and PGE2 in RAW264.7 cells. DR-W extract was not suppressed the expressions of iNOS mRNA and protein in LPS-stimulated RAW264.7 cells. Conclusions: This study suggests that DR-W extract can attenuate inflammatory response via inhibition of the NO and PGE2 production in activated macrophages.