• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제9권5호
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• pp.509-520
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• 2003

본 논문에서는 MPEG-4 비디오 부호화와 복호화 시스템의 실용성과 고효율의 압축을 위한 새로운 알고리즘을 개발하였다. MPEG-4 비디오 그룹에서는 실험과 경험을 통하여 비디오 검증 모델인 VM(Verification Model)을 개발하였다 또한 MPEG-4 표준화 과정을 통하여 ISO/IEC 14496-2 표준 문서와 VM에 기반하여 다양한 참조 소프트웨어가 개발되었다. MS-FDAM은 MPEG-4 참조 소프트웨어로서 표준 부호화와 복호화로 개발되었으나 고효율의 압축과 실용성에 제한이 있다. 이에 본 논문은 기본 MS-FDAM모델에 내용 기반 비디오 코딩의 핵심인 VOP 추출 알고리즘, 실시간 입력 시스템, 압축율을 높일 수 있는 움직임 감지 알고리즘을 추가하여 최대 180:1의 압축율을 보여주는 실시간 고압축 MPEG-4 시스템을 개발하였다.

• The Journal of Asian Finance, Economics and Business
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• 제5권4호
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• pp.201-211
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• 2018

The paper suggests making a policy and strategies for a way of exporting Korean ICT product effectively in the EU and Eastern area, and an effective preparation of 4^th industrial revolution through analysis of preparation status of 4^th industrial revolution of the Visegrad group. Analyze policy, status, what they want for 4^th preparation in the Visegrad group from comparing characteristics analysis of each country's official data, publication data, portal, paper, and etc. They have been preparing for 4^th industrial revolution long time ago as basic research and business before 4^th wave word. With these basic results, they are trying to apply such as, AI, S/W, security, ICT, etc. of 4^th wave core technology. For the development of new export market in EU, the Korean team should research with university and research center or venture company. Through these cooperation, they should understand their personal characteristic, lifestyle, and what consumers want to purchase in EU. And this results can be used in South Asia and India that give a big effect to all over the world ICT market. The external impact of the 4^th wave must have a long-term shift in manpower, and production policy is related to the EU's strategic role, or the preparation of the 4^th wave to the V4 country in the short term.

• The Korean Journal of Physiology and Pharmacology
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• 제4권6호
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• pp.463-469
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• 2000

It has been well known that 4-aminopyridine (4-AP) has an excitatory effect on vascular smooth muscle due to causing membrane depolarization by blocking $K^+-channel$. However, we observed that 4-AP had an inhibitory effect on the mesenteric artery of rat. Therefore, we investigated the mechanism of 4-AP-induced vasorelaxation. The mesenteric arcuate artery and its branches were isolated and cut into ring. The ring segment was immersed in HEPES-buffered solution and its isometric tension was measured. 4-AP $(0.1{\sim}10\;mM)$ induced a concentration-dependent relaxation, which was unaffected by NO synthase inhibitor, $N^G-nitro-L-arginine$ methylester $(100\;{\mu}M)$ or soluble guanylate cyclase inhibitor, methylene blue $(100\;{\mu}M).$ Glibenclamide $(100\;{\mu}M)$, ATP-sensitive $K^+$ channel blocker, did not exert any effect on the 4-AP-induced vasorelaxation. 4-AP relaxed the sustained contraction induced by 100 mM $K^+$ or $Ca^{2+}$ ionophore, A23187 $(100\;{\mu}M)$ in a dose-dependent manner. In addition, 4-AP significantly decreased the phasic contractile response to norepinephrine in the absence of extracellular $Ca^{2+}$. However, 4-AP did not block the $^{45}Ca$ influx of rat aorta. From the above results, we suggest that 4-AP may not block the $Ca^{2+}$ influx through $Ca^{2+}-channel,$ but act as a nonspecific vasorelaxant in arterial smooth muscle.

• 열처리공학회지
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• 제15권2호
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• pp.76-81
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• 2002

The melt-spun amorphous $Fe_{77-X}P_{13}C_4B_4Al_2Mo_X$(x=4~10) and $Fe_{82-X}P_XC_4B_4Al_2Mo_8$(x=9~15) alloys were found to exhibit a large supercooled liquid region(${\Delta}T_x$) exceeding 40 K before crystallization. The largest ${\Delta}T_x$ for the glassy alloys containing Mo reaches as large as 65 K for the $Fe_{69}P_{13}C_4B_4Al_2Mo_8$ alloy. The corrosion behavior of the amorphous $Fe_{77-X}P_{13}C_4B_4Al_2Mo_X$(x=4~15) and $Fe_(82-X)P_XC_4B_4Al_2Mo_8$ (x=9~17) alloys were examined by electrochemical measurements in 9M $H_2SO_4$ solution at 303 K. The addition of Mo(or P) for replacing some portion of Fe is effective in improving the corrosion resistance of the investigated Fe-based glassy alloys. They are spontaneously passivated and have a wide passive region with low passive current density.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2006년도 추계학술대회
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• pp.19-24
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• 2006

Mothers against decapentaplegic homolog 4 (SMAD4) is a tumor suppressor gene associated with gastrointestinal carcinogenesis. The aim of the present study was to characterize more precisely its role in the development and progression of human gastric carcinoma. In this study, using tissue microarray analysis of 283 gastric cancers and related lesions, we found loss of SMAD4 protein expression in the cytoplasm (36/114, 32%) and in the nucleus (46/114, 40%) of gastric cancer cells. The loss of nuclear SMAD4 expression in primary tumors correlated significantly with poor survival, and was an independent prognostic marker in multivariate analysis. We also found a substantial decrease in SMAD4 expression at both the RNA and protein level in several human gastric carcinoma cell lines. To identify the genetic and/or epigenetic mechanisms of altered SMAD4 expression in gastric carcinoma, loss of heterozygosity (LOH), promoter hypermethylation, and exon mutations were examined. We found that LOH (20/70, 29%) and promoter hypermethylation (4/73, 5%) were associated with the loss of SMAD4 expression. SMAD4 protein levels wore also affected in certain gastric carcinoma cell lines following incubation with Mc132, a proteasome inhibitor. Taken together, our results indicate that the loss of SMAD4, especially loss of nuclear SMAD4 expression, is involved in gastric cancer progression. The loss of SMAD4 in gastric carcinomas is due to several mechanisms, including LOH, hypermethylation, and proteasome degradation.

• Archives of Pharmacal Research
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• 제27권5호
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• pp.507-511
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• 2004

From the flowers of Chromolaena odorata (Eupatorium odoratum) four flavanones, isosakuranetin (5,7-dihydroxy-4'-methoxyflavanone) (1), persicogenin (5,3'-dihydroxy-7,4'-dimethoxyflavanone) (2), 5,6,7,4'-tetramethoxyflavanone (3) and 4'-hydroxy-5,6,7-trimethoxyfla-vanone (4), two chalcones, 2'-hydroxy-4,4',5',6'-tetramethoxychalcone (5) and 4,2'-dihydroxy-4',5',6'-trimethoxychalcone (6), and two flavones, acacetin (5,7-dihydroxy-4'-methoxyflavone) (7) and luteolin (5,7,3',4'-tetrahydroxyflavone) (8) were isolated and identified. Compound 1 exhibited moderate antimycobacterial activity against Mycobacterium tuberculosis with the MIC value of 174.8 $\mu$M, whereas compounds 4,7, and 8 exhibited weak activity with the MIC values of 606.0, 704.2 and 699.3 $\mu$M respectively. Compound 7 showed moderate cytotoxicity against human small cell lung cancer (NCI-H187) cells with the MIC value of 24.6 $\mu$M, whereas compound 8 exhibited moderate toxicity against NCI-H187 cells and week toxicity against human breast cancer (BC) cells with the MIC values of 19.2 and 38.4 $\mu$M respectively.

• 한국재료학회지
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• 제27권4호
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• pp.199-205
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• 2017

In this study, (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate acrylate was synthesized by reacting (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate with acrylic acid to minimize hardening shrinkage and to improve heat resistance, which are known as disadvantages of photopolymers for 3D printing application. Urethane acrylate was synthesized by reacting 1,3,5-triazine-2,4,6-triamino alcohol, 2-hexylethyl acrylate, and isophorone diisocyanate in order to improve the mechanical properties without deteriorating the heat resistance. The physical properties before and after the synthesis of the acrylate and the mechanical properties when the urethane acrylate was applied were investigated. The reaction progress of the composite was examined by FTIR and $^{13}C$ NMR. The heat deflection temperature, flexural strength, and surface hardness of the molding were measured. The curing behavior by Photo-DSC ultraviolet irradiation was also examined.

• 한국대기환경학회지
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• 제12권4호
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• pp.389-398
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• 1996

In order to understand the relative importance of various pathways leading to the production and transformation of aerosols under different atmospheric conditions, the behavior of atmospheric aerosols have been investigated using a high volume tape sample in Seoul for a week period during August 1990. The concentrations of anion $(SO^{2-}_4, NO^-_3, CI^-)$ and cation $(Ca^{2+}, Na^+, NH^+_4)$ species of aerosol samples were analyzed to identify the ionic composition of aerosols and to estimate their relative contributions to aerosol formation. The concentrations of aerosol species were calculated by a multiple regression model. The results of our calculations indicate the existence of various chemical species such as $(NH_4)_2SO_4, Na_2SO_4, CaSO_4, NH_4NO_3, NaNO_3, Ca(NO_3)_2, NH_4Cl$, and NaCl salts. According to our calculations, the most dominant species of aerosol was $(NH_4)_2SO_4$ with the mean concentration of 23.3 $/mu g/m^3$ (66.9%). The proportion of different componts with aerosol (e.g., $NH_4NO_3$ and $NH_4Cl$) was strongly affected by temperature, relative humidity, and partial presure of gases.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.34-34
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• 2018

본 연구는 예산지역에서 현지외보전을 하는 매실나무(220여점) 및 살구나무(9점) 유전자원에 대한 개화 특성평가를 위하여 개화기를 지난 만개기를 연차별로 조사하였다. 대한민국에서 수집한 매실나무의 만개기는 이식 초기의 2012년에 4월 중순이었으나 이식 3년 후부터 4월 초순으로 약간 앞당겨졌다. 만개기는 2012년의 경우 모두 4월 11일 이후이었으나 2015년 이후는 4월 1~10일까지 70% 이상이었다. 연도별 보면 2015년과 2016년은 4월 1~5일에 가장 많이 만개하였고, 2017년과 2018년은 4월 6~10일에 가장 많이 만개하였다. 또한 일본에서 수집한 매실나무의 만개기도 대한민국 수집의 자원처럼 4월 초순이 대부분이었는데, 연도별로는 2015년, 2016년 및 2017년의 경우 4월 1~5일에 가장 많이 만개하였고, 2018년은 4월 6~10일에 가장 많이 만개하였다. 그러나 일본 수집의 매실나무 만개기는 3월말에서 4월 초순에 집중되어 3월 중순에서 4월 중순까지의 범위를 나타낸 대한민국 수집 자원과 약간의 차이를 보였다. 그리고 예산지역 현지외보전 살구나무(대한민국 수집)의 만개기는 2015년부터 2018년까지 모두 4월 1일부터 10일까지이었으며, 3월 및 4월 중순 이후에 만개한 꽃이 나타나지 않았다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제17권1호
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• pp.23-32
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• 2011

Recently, with the advent of high risk infectious agent such as the Ebola virus, SARS, special research facilities dealing with such dangerous pathogenic are drawing attention gradually. Especially, this kind of facilities can be called BL4(Biosafety Level 4) facility. At the moment, Korean government is going to construct BL4 institute in order to handle efficiently such kind of pathogen. However, there are no proper design guidelines for BL4 facility. This paper proposes circulation system of BL4 facility on the basis of analysis of existing BL4 guidelines of Canada, and Korean BL3 facilities. The outcomes of this study are as follows. At first, functional areas of BL4 facilities have been divided into three categories according to the hazard level ; dangerous area, transitional area, and ordinary area. Secondly, circulation system of BL4 facility has been explored as a form of diagram according to the circulating subjects. These include human, laboratory animals, hazardous pathogen, equipments and cloth. This study has some limitations in that it lacks empirical evidences and concrete SOPs(Standard Operating Procedure). Despite of some weaknesses, it is expected to give some preliminary guidelines for the design of circulation system in BL4 facilities.