• 대한수학회지
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• 제50권5호
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• pp.1033-1050
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• 2013

We show the existence of smooth isolated curves of different degrees and genera in Calabi-Yau threefolds that are complete intersections in homogeneous spaces. Along the way, we classify all degrees and genera of smooth curves on BN general K3 surfaces of genus ${\mu}$, where $5{\leq}{\mu}{\leq}10$. By results of Mukai, these are the K3 surfaces that can be realised as complete intersections in certain homogeneous spaces.

• 대한수학회보
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• 제52권4호
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• pp.1213-1223
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• 2015

We examine a family of isolated complex surface singularities whose exceptional curves consist of two complex curves with high genera intersecting transversally. Topological data of smoothings of these singularities are determined. We use these computations to construct symplectic 4-manifolds by replacing neighborhoods of the exceptional curves with smoothings of the singularities.

• 한국구조물진단유지관리공학회 논문집
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• 제10권4호
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• pp.135-144
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• 2006

지진에 대한 구조물의 특성, 지반과의 상호작용, 현장 조건 등의 예측에 다수의 불확실성이 존재하는 경우 그 취약성 또는 손상도를 평가하는 방법이 필요하다. 본 연구에서는 범용구조해석 프로그램과 일반적인 확률밀도함수를 사용하여 면진 콘크리트 교량의 손상도 곡선을 구하는 방법을 제시하였으며, 제시된 방법을 교량에 적용하여 교량의 손상도를 평가하였다. 손상도 곡선을 작성하는 데에는 2변수를 갖는 대수정규분포를 사용하였으며, 지진의 여러 특성인 최대지반가속도(PGA), 최대지반속도(PGV), 스펙트럼가속도(SA), 스펙트럼속도(SV), 스펙트럼강도(SI) 등에 대해 납 면진받침(LRB)이 설치된 면진교량의 손상도 곡선을 구하였다. 또한 손상도 곡선의 합성 방법을 사용하여 합성된 면진교량의 손상도 곡선을 유도하였다.

• Journal of applied mathematics & informatics
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• 제29권1_2호
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• pp.451-457
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• 2011

The function f(z) = $e^{p(z)}$ where p(z) is a polynomial of degree n has 2n Julia lines. Julia lines of $e^{p(z)}$ divide the complex plane into 2n equal sectors with the same vertex at the origin. In each sector, $e^{p(z)}$ has radial limits of 0 or innity. Main results of the paper are concerned with maximum curves of $e^{p(z)}$. We deal with some properties of maximum curves of $e^{p(z)}$ and we give some examples of the maximum curves of functions of the form $e^{p(z)}$.

• 대한수학회지
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• 제53권2호
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• pp.461-473
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• 2016

Let C be a projective plane curve of degree d whose singularities are all isolated. Suppose C is not concurrent lines. P loski proved that the Milnor number of an isolated singlar point of C is less than or equal to $(d-1)^2-{\lfloor}\frac{d}{2}{\rfloor}$. In this paper, we prove that the Milnor sum of C is also less than or equal to $(d-1)^2-{\lfloor}\frac{d}{2}{\rfloor}$ and the equality holds if and only if C is a P loski curve. Furthermore, we find a bound for the Milnor sum of projective plane curves in terms of GIT.

• 한국지진공학회논문집
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• 제20권7_spc호
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• pp.435-441
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• 2016

The Korean peninsula has known as a minor-to-moderate seismic region. However, some recent studies had shown that the maximum possible earthquake magnitude in the region is approximately 6.3-6.5. Therefore, a seismic vulnerability assessment of the existing infrastructures considering ground motions in Korea is necessary. In this study, we developed seismic fragility curves for a continuous steel box girder bridge and two typical transmission towers, in which a set of seven artificial and natural ground motions recorded in South Korea is used. A finite element simulation framework, OpenSees, is utilized to perform nonlinear time history analyses of the bridge and a commercial software, SAP2000, is used to perform time history analyses of the transmission towers. The fragility curves based on Korean ground motions were then compared with the fragility curves generated using worldwide ground motions to evaluate the effect of the two ground motion groups on the seismic fragility curves of the structures. The results show that both non-isolated and base-isolated bridges are less vulnerable to the Korean ground motions than to worldwide earthquakes. Similarly to the bridge case, the transmission towers are safer during Korean motions than that under worldwide earthquakes in terms of fragility functions.

• The Korean Journal of Physiology
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• 제23권2호
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• pp.225-236
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• 1989

1) At the isolated perfused guinea-pig and rat heart heterometric autoregulation of the myocardium and myogenic autoregulation of the coronary vessels were induced by means of stepwise increases of perfusion pressure. 2) According to this loading test Frank-Starling function curves of the left ventricle and pressure-flow curves of the coronary vessels can be drawn. This graphic evaluation gives more information about the condition of the heart and the coronary vessels than simple evaluation under hemodynamic equilibrium. 3) There are significant differences in both curves between animal species and between different perfusate Mg concentration. 4) Myogenic autoregulation is not affected by the cyclooxygenase inhibitors indometacin and me- clofenamate. Thus it appears unlikely that prostanoides are involved in myogenic autoregulation. 5) Ca antagonists (Gallopamil, prenylamine) depress myogenic autoregulation dose-dependently. Enhanced myogenic autoregulation, induced by low extracellular magnesium, can be reduced effectively by Gallopamil. 6) Ginsenosides from Panax ginseng as well as the ginsenoside 'Rg' are effective inhibitors of myogenic autoregulation without major negative inotropic effects.

• Advances in concrete construction
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• 제7권3호
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• pp.183-189
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• 2019

In this study, it has been tried to prepare an analytical fragility curves for isolated straight continues highway bridges by considering different spectral intensity measures. A three-span concrete isolated bridge has been selected and the seismic performance of the bridge has been improved by Lead Rubber Bearing (LRB). Incremental Dynamic Analysis (IDA) is applied to the bridge in longitudinal direction. A suite of 14 earthquake ground motions from medium to sever motions are scaled and used for nonlinear time history analysis. Fragility function considers the relationship of earthquake intensity measures (IM) and probability of exceeding certain Damage State (DS). A full three dimensional finite element model of the isolated bridge has been developed and analyzed. A wide range of different intensity measures are selected and the optimal intensity measure which has the less dispersion is proposed.

• 한국식품영양학회지
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• 제9권3호
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• pp.341-347
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• 1996

Growth curves of seven strains of lactic acid bacteria isolated from Kimchi were graphed, when they were cultivated at 3$0^{\circ}C$ in filter sterilized Chinese cabbage juice containing 0, 2, 4 and 6% salt, and then lag time and generation time were calculated. The shapes of growth curves were changed differently among strains, as salt concentrations were increased. The addition of 2~4% salt resulted in prolongation of lag time were most omspicuous in Leu. Paramesenteroides and Leu. Mesenteroides subsp. Dextranicum, and the next in Leu. Mesenteroides subsp. Mesenteroides,m Lac. Bavaricus and Lac. Gomohiochii, and the least in Lac. Plantarum and Lac. Brevis. And then the prolongations of generation time were most remarkable in Lac. bavaricus and Lac. Homohiochii, and the next in Leu. Mesenteroides subsp. Mesenteroides, Leu. Mesenteroides subsp. Dextranicum and Leu. Paramesenteroides, and the least in Lac. Plantarum and Lac. brevis. By increasing salt concentrations from 0 to 2%, the generation times of Leu. Cesenteroides subsp. Dextranicum and Leu. Mesenteriodes subsp. Mesenteroides were prolonged slightly, while those of Lac. Homohiochii and Lac. Brevis were not changed, and those of Lac. Plantarum, Lac. Bavaricus and Leu. Paramesenteroides were shortened slightly. As salt concentrations were increased from 2% to 4%, inversions in the order of generation time occurred among strains. As a whole, lower salt concentrations were more favorable for the growth of Leuconostoc strains, while higher salt concentrations were for Lactobacillus strains.

• The Korean Journal of Pain
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• 제27권3호
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• pp.229-238
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• 2014

Background: A toxic dose of bupivacaine produces vasodilation in isolated aortas. The goal of this in vitro study was to investigate the cellular mechanism associated with bupivacaine-induced vasodilation in isolated endothelium-denuded rat aortas precontracted with phenylephrine. Methods: Isolated endothelium-denuded rat aortas were suspended for isometric tension recordings. The effects of nifedipine, verapamil, iberiotoxin, 4-aminopyridine, barium chloride, and glibenclamide on bupivacaine concentration-response curves were assessed in endothelium-denuded aortas precontracted with phenylephrine. The effect of phenylephrine and KCl used for precontraction on bupivacaine-induced concentration-response curves was assessed. The effects of verapamil on phenylephrine concentration-response curves were assessed. The effects of bupivacaine on the intracellular calcium concentration ($[Ca^{2+}]_i$) and tension in aortas precontracted with phenylephrine were measured simultaneously with the acetoxymethyl ester of a fura-2-loaded aortic strip. Results: Pretreatment with potassium channel inhibitors had no effect on bupivacaine-induced relaxation in the endothelium-denuded aortas precontracted with phenylephrine, whereas verapamil or nifedipine attenuated bupivacaine-induced relaxation. The magnitude of the bupivacaine-induced relaxation was enhanced in the 100mM KCl-induced precontracted aortas compared with the phenylephrine-induced precontracted aortas. Verapamil attenuated the phenylephrine-induced contraction. The magnitude of the bupivacaine-induced relaxation was higher than that of the bupivacaine-induced $[Ca^{2+}]_i$ decrease in the aortas precontracted with phenylephrine. Conclusions: Taken together, these results suggest that toxic-dose bupivacaine-induced vasodilation appears to be mediated by decreased calcium sensitization in endothelium-denuded aortas precontracted with phenylephrine. In addition, potassium channel inhibitors had no effect on bupivacaine-induced relaxation. Toxic-dose bupivacaine-induced vasodilation may be partially associated with the inhibitory effect of voltage-operated calcium channels.