• TTA 저널
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• 통권178호
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• pp.8-13
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• 2018

최근 조선 및 해운경기가 급격히 위축되면서 해운사는 보다 많은 이익을 창출하기 위하여 첨단 ICT기술을 도입하여 최소 운항비 최대 이익 창출을 꾀하고 있다. IMO는 새로운 화두로서 자율운항선박이 운항 가능하도록 법적 개념 정립을 2020년까지 완료하도록 계획하고 있다. 산업계는 IMO의 NOx규제 Tier III(3.4 g/kWh, n<130), EEDI($CO_2$ 배출규제)의 Phase 1(Phase 0 대비 10%포인트 감소), Phase 2(Phase 1 대비 10%포인트 감소), EEOI 등 친환경선박 문제가 현안으로 대두되고 있는 상태에서 ICT와 결합하여 친환경 에코선박으로써 스마트선박이 문제를 해결하도록 기대하고 있다. 자율운항선박의 도입에 관해 많은 해운 전문가들 사이에 찬반의 의견이 분분하나 첨단 ICT를 도입하여 최소 운항비 최대 이익 창출을 추구하는 친환경 스마트선박의 도입에 대해서는 해운사 선주, 조선소 모두 앞을 다투고 있는 실정이다. 이러한 시점에서 세계 각 국가가 추진하고 있는 스마트자율운항선박의 연구와 기술 및 표준 동향과 우리나라가 추진하고 있는 연구와 산업계의 동향을 알아보고 새로운 전기를 맞이하게 될 글로벌 조선 산업의 미래를 조명해 보고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.110-112
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• 1995

In this paper, We have designed the new Two-Double 1-2 phase exciting method. And We have developed the chopper constant current drive circuit in order to apply Two-Double 1-2 phase exciting method to 4-phase Stepping Motor.

• 전기화학회지
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• 제4권1호
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• pp.14-20
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• 2001

단결정 Pt(100)/0.5M $H_2SO_4$ 및 0.5M LiOH수용액 계면에서 저전위 수소흡착(UPD H)과 과전위 수소흡착(OPD H)에 관한 Langmuir흡착등온식을 위상이동 방법을 이용하여 연구 조사하였다. 최적 중간주파수에서 위상이동 변화$({-\varphi}\;vs.\;E)$는 Langmuir흡착등온식$(\theta\;vs.\;E)$의 추정에 적용할 수 있는 유용한 실험 방법이다. 단결정 Pt(100)/0.5M $H_2SO_4$ 수용액 계면에서 과전위 수소흡착에 기인한 흡착평형상수(K)와 흡착표준자유에너지$({\Delta}G_{ads})$는 각각 $1.5\times10^{-4}$와 21.8kJ/mol이다. 단결정 Pt(100)/0.5M LiOH 수용액 계면에서 K는 음전위에 따라 1.9(UPD H)에서 $6.8\times10^{-6}$ (OPD H)또는 그 반대로 전이한다. 마찬가지로, ${\Delta}G_{ads}$는 음전위에 따라 -1.6kJ/mol (UPD H)에서 29.5kJ/mol (OPD H) 또는 그 반대로 전이한다. 전극속도론적 패러미터$(K,\; {\Delta}G_{ads})$의 전이는 단결정 Pt(100)전극표면의 UPD H와 OPD H에 기인한다. UPD H와 OPD H는 음극 $H_2$발생 반응을 위한 순차적 과정이 아니라 전극표면의 수소 흡착부위에 기인하는 독립적 과정이다.

• 멤브레인
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• 제26권5호
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• pp.381-390
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• 2016

본 연구에서는 고순도의 모데나이트(Mordenite) 입자를 합성하기 위하여 천연 제올라이트를 시드로 사용하여 시드의 농도 및 수열합성 시간에 따른 천연 제올라이트 시드가 합성에 미치는 영향을 고찰하였다. 그 결과 시드가 입자의 형성에 큰 영향을 끼치는 것을 확인할 수 있었고 시드를 3 g/100 g batch 주입하여 $140^{\circ}C$에서 72시간 동안 수열합성을 진행하였을 때 $1-2{\mu}m$ 사이즈의 고순도 모데나이트 입자를 합성할 수 있었다. 이를 통해 모데나이트 입자의 성장 기구를 규명할 수 있었으며, 모데나이트 입자 형성에 있어 시드는 첫째, 구형 모데나이트 전구체 형성 자리 공급의 역할과, 둘째 모데나이트 원료 물질 소스 역할을 한다는 것을 알 수 있었다. 합성된 모데나이트 입자의 가스 흡착량 분석 결과 $CO_2$ 기체의 흡착량이 97.19 mg/g로 다른 가스들에 비해 비교적 높은 흡착성능을 보였으며, $CO_2/H_2$의 선택도가 가장 우수한 것으로 나타났다. 따라서 이러한 결과들을 바탕으로 용도에 맞는 고순도 상의 모데나이트 입자를 합성할 수 있음을 확인하였고 보다 낮은 가격으로 우수한 분리성능을 갖는 분리막 소재개발에 활용할 수 있을 것이라 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6369-6374
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• 2012

Vitexicarpin (3', 5-dihydroxy-3, 4', 6, 7-tetramethoxyflavone), a polymethoxyflavone isolated from Viticis Fructus (Vitex rotundifolia Linne fil.), has long been used as an anti-inflammatory herb in traditional Chinese medicine. It has also been reported that vitexicarpin can inhibit the growth of various cancer cells. However, there is no report elucidating its effect on human prostate carcinoma cells. The aim of the present study was to examine the apoptotic induction activity of vitexicarpin on PC-3 cells and molecular mechanisms involved. MTT studies showed that vitexicarpin dose-dependently inhibited growth of PC-3 cells with an $IC_{50}{\sim}28.8{\mu}M$. Hoechst 33258 staining further revealed that vitexicarpin induced apoptotic cell death. The effect of vitexicarpin on PC-3 cells apoptosis was tested using prodium iodide (PI)/Annexin V-FITC double staining and flow cytometry. The results indicated that vitexicarpin induction of apoptotic cell death in PC-3 cells was accompanied by cell cycle arrest in the G2/M phase. Furthermore, our study demonstrated that vitexicarpin induction of PC-3 cell apoptosis was associated with upregulation of the proapoptotic protein Bax, and downregulation of antiapoptotic protein Bcl-2, release of Cytochrome c from mitochondria and decrease in mitochondrial membrane potential. Our findings suggested that vitexicarpin may become a potential leading drug in the therapy of prostate carcinoma.

• 대한한방부인과학회지
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• 제19권2호
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• pp.214-225
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• 2006

Purpose : This study was aimed to investigate the inhibitory effect of Corydalis Tuber on the proliferation of human uterine leiomyoma cell and the expression of gene related the mechanism of cell apoptosis. Methods : We counted the number of suvival cells treated with indicated concentration of Corydalis Tuber and investigated cell viability by MTS assay. Furthermore, flow cytometric analyis were used to dissect between necrosis and apoptosis related with cell cycle and then we observed the differential gene expression by western blot analysis. Results : 1) The inhibitory effect on the proliferation of uterine leiomyoma cell treated with Corydalis Tuber was increased in a concentration and time proportional. 2) The result of flow cytometry analysis, subG1 phase arrest related cell apoptosis was not investigated in uterine leiomyoma cell treated Corydalis Tuber but showed G2/M phase prolongation. 3) The gene expression of p27, p21 related cell cycle was increased according to increasing concentration, but p53 was not exchanged. 4) The dephosphorylation of pRb gene were increased dependent on treatment concentration and pro-caspase 3, CDK4 were not exchanged. Conclusion : This study showed that Corydalis Tuber have the inhibitory effect on the proliferation of human uterine leiomyoma cell but the effect was thoughted no relationship with apoptosis. The inhibitory effect was suggested that dephosphorylation of pRb gene induced with increasing p21, p27 prolonged cell division in G2/M phase.

• Journal of Periodontal and Implant Science
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• 제31권3호
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• pp.597-610
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• 2001

Normal gingival fibroblasts functioning is fundamental for the maintenance of periodontal connective tissue as well as wound healing. Nicotine have been found to affect DNA synthesis and cell proliferation, which appear to depend on the type of cells. This in vitro study was done to determine the effects of nicotine, a major component of tobacco, on cell proliferation, viability, activity, cell cycle distribution, and expression of cell cycle regulatory proteins in human gingival fibroblasts. Nicotine has been tested for 2 days or 4 days in 5 different concentrations; $0.1{\mu}g/ml$; $1{\mu}g/ml$; $10{\mu}g/ml$; $100{\mu}g/ml$; $1000{\mu}g/ml$. To assess cell proliferation and viability, viable and non-viable cells were counted by hemocytometer; to evaluate cellular activity, MTT assay was employed; to analyze cell cycle distribution, fluorescent propidium iodide-DNA complex were measured using fluorocytometer; to determine the expression of cell cycle regulatory proteins, western blot analysis was performed. After 2 days and 4 days incubation respectively, at concentrations of $1{\mu}g/ml$ - $1000{\mu}g/ml$, nicotine significantly inhibited proliferation comparing to non-supplemented controls. The cell viability was significantly decreased after 2 days and 4 days at concentrations of $1{\mu}g/ml$ - $1000{\mu}g/ml$ and at $10{\mu}g/ml$ - $1000{\mu}g/ml$ respectively. After 2 days and 4 days, the cellular activity was significantly decreased at concentrations of $10{\mu}g/ml$ - $1000{\mu}g/ml$. Treatment with $100{\mu}g/ml$ nicotine for 48 hours caused an increase in the proportion of G1-phase cells (from 46.41% to 53.46%) and a decrease in the proportion of S-phase cells (from 17.80% to 14.27%). The levels of cyclin $D_1$ and CDK 4 proteins in nicotine-treated fibroblasts were lower than that of controls, whereas the levels of p16 and pRB were higher than that of controls. These results suggest that the decrease of cell proliferation and lengthened Gap phases (G1) by nicotine may due to the increased expression of p16 and pRB as well as decreased expression of cyclin $D_1$ and CDK 4 in human gingival fibroblasts.

• 한국세라믹학회지
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• 제23권5호
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• pp.93-101
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• 1986

Microporous glasses were prepared from the 50 $SiO_2-44$ $B_2O_3-6$ $Na_2O$(wt%) parent glass by the phase eparation technique and were characterized by SEM, BET, and Gas Adsorption methods to investigate the possiblity of their use as salt-rejection membranes for reverse osmosis. The conditions of the phase separation for the possible glass membranes were optimized for the given parent glass. The temperature and duration of heat-treatment were desired to be lower(853K) and shorter (1/2~1 hr) respectively. The specific surface areas of porous glasses prepared in this study were about 80~120$m^2$/g and their pore size distribution had a unimodal shape(peak pore radius less than 15$\AA$) It was suggested that the porous glass obtained in this work could be effective for salt-rejection in point of pore size distributions but the way to increase its surface area for the high flux must be studied.

• Journal of Magnetics
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• 제7권4호
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• pp.156-159
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• 2002

We have investigated the escape rate of nano-magnetic particle with a magnetic field applied along the easy axis. The model studied here is described by the Hamiltonian H=$K_1\hat{S}{_z^2}$ ＋ $K_2\hat{S}{_y^2}$ ＋ $g{\mu}_bB$ $\hat{S}_x(K_1>K_2>0)$ and the escape rate was calculated with in the semiclassical approximation. We have obtained a diagram for orders of the phase transition depending on the anisotropy constant and the external field. For $K_2$/$K_1>$0.85 the present model reveals the existence of the first order transition within the quantum regime.

• Reproductive and Developmental Biology
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• 제32권4호
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• pp.211-215
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• 2008

The HMG box containing protein (HBP) has a high mobility group domain and involved in the regulation of proliferation and differentiation of tissues. We screened HBP2 in glioblastoma using Suppression Subtractive Hybridization (SSH) and isolated human spermatogonial stem cell-like cells (hSSC-like cells) derived from patients of nonobstructive azoospermia (NOA). Expression of HBP2 was analyzed by RT-PCR in undifferentiated stem cells (human Embryonic Stem Cells, hSSC-like cells 2P) and spontaneous differentiated stem cells (hSSC-like cells 4P). It was overexpressed in hESC and hSSC-like cells 2P but not in hSSC-like cells 4P. Also, the expression level of HBP2 was downregulated in colon tumor tissues compared to normal tissues. Specifically in synchronized WI-38 cells, HBP2 was highly upregulated until the G1 phase of the cell cycle and gradually decreased during the S phase. Our results suggest that HBP2 was downregulated during the spontaneous differentiation of hSSC-like cells. HBP2 was differently expressed in colon tissues and was related to G1-progression in WI-38 cells. It may playa role in the maintenance of an undifferentiated hSSC-like cell state and transits from G1 to S in WI-38 cells. This research was important that it identified a biomarker for an undifferentiated state of hSSC-like cells and characterized its involvement to arrest during cell cycle in colon cancer.