• Proceedings of the KSME Conference
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• 2000.04b
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• pp.531-534
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• 2000

The objective of this investigation is to find effects of the pulsatile flow on the morphological changes of the endothelial cell(E.C.) in blood vessel. The shear flow experiment system is used to get the morphological changes of the E.C. The shapes of E.C. are simulated by the cosine curves and computer simulation is used to calculate the pressure and shear stress fields on the E.C. The inlet boundary condition is given from the measured velocity data of femoral artery. The endothelial cells reduce their heights in the flow field so as to reduce the pressure and wall shear stress on the surface. As the exposed time increases, the shear stress and pressure on the E.C. are reduced under the pulsatile flow. The shear stresses on the cell surface show the minimum values during the deceleration phase.

• Rapid Communication in Photoscience
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• v.1 no.2
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• pp.42-42
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• 2012

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.377-380
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• 2012

대피 및 인명피해 시뮬레이션 기술은 성능위주 설계의 핵심 기술 중 하나이다. 기존 해외에서 개발된 프로그램들은 단순한 인명피해 계산 방식과 비주얼의 조악으로 한계성을 나타내고 있다. 본 연구에서 개발된 대피 및 인명피해 평가 프로그램은 기존의 프로그램의 한계점을 극복함과 동시에 다음의 관련 기술을 향상시키고 실제 사례에 적용하여 현재 사용되고 있는 상용 대피 프로그램과 비교/검증하였다. 첫째, 피난계단 뿐만 아니라 엘리베이터를 이용하여 대피할 수 있는 알고리즘을 적용하였다. 둘째, 미국 표준연구소(NIST)의 화재해석 프로그램 (FDS, Fire Dynamics Simulator)과 연계(Coupled)를 통해 화재에 의한 인명피해 발생여부 판단이 가능한 프로그램이다. 마지막으로 그래픽 전용 모듈을 적용하여 현실에 가까운 3차원 가상현실을 구현하였다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.262-265
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• 2011

초고층 복합건물의 비상시에 대한 인적 피해 및 물적 피해를 최소화하기 위해 화재 위험성을 정량적으로 평가할 수 있는 기술이 요구된다. 본 연구에서는 비상시 초고층 건물의 화재 발생 및 발달에 대한 충분한 화재 안전성을 확보할 수 있도록 사전에 평가할 수 있는 기술을 개발하고자 한다. 특히 국내에서는 고층 건물에 대한 화재 시나리오가 명확히 제시된 바가 없기 때문에 정량적 화재 위험성 평가를 위한 신뢰할 수 있는 시나리오를 개발하고 이를 분류할 수 있는 하부모델을 도출하였다. 따라서 시간에 따른 화재의 발달과 연소 확대에 관한 각 하부모델의 적절한 시나리오 선택 기법을 제시하고자 한다.

• The Journal of Society for e-Business Studies
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• v.9 no.4
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• pp.1-17
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• 2004

We guarantee the significance of the provided prediction model and predicted figures from the experts consulting group and we product the prediction figures of the domestic e-commerce market size in future by business subjects, BtoB, BtoG and BtoC. Besides, we do predict by the high raked 6 merchandises in the case of BtoC market size prediction. We use the KNSO(Korea National Statistical Office) BtoB, BtoG and BtoC data to ensure the significance of data.

• Electrical & Electronic Materials
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• v.10 no.2
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• pp.156-165
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• 1997

D-E hysteresis loops have been measured for the 65/35 mole % copolymer of vinylidene fluoride and trifluoroethylene over wide temperature range. The remanent polarization and the coercive field at room temperature were estimated to be 75 mC/m$^{2}$ and 55 MV/m respectively. D-E hysteresis loops were observed even below the glass transition temperature(-20.deg. C) and the remanent polarization and the coercive field were larger, as the temperature lower. It seems that the remanent polarization and the coercive field depend on the amorphous region as well as crystalline region in this copolymer. And the ferroelectric-to-paraelectric phase transition was observed at 90.deg. C on heating and 80'C on cooling. Double hysteresis loops were observed at the temperature(85.deg. C) of paraelectric phase.

• Korean Journal of Mathematics
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• v.16 no.2
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• pp.215-231
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• 2008

Let E be a uniformly convex Banach space with a uniformly $G{\hat{a}}teaux$ differentiable norm, C a nonempty closed convex subset of E, and $T:C{\rightarrow}{\mathcal{K}}(E)$ a multivalued nonself-mapping such that $P_T$ is nonexpansive, where $P_T(x)=\{u_x{\in}Tx:{\parallel}x-u_x{\parallel}=d(x,Tx)\}$. For $f:C{\rightarrow}C$ a contraction and $t{\in}(0,1)$, let $x_t$ be a fixed point of a contraction $S_t:C{\rightarrow}{\mathcal{K}}(E)$, defined by $S_tx:=tP_T(x)+(1-t)f(x)$, $x{\in}C$. It is proved that if C is a nonexpansive retract of E and $\{x_t\}$ is bounded, then the strong ${\lim}_{t{\rightarrow}1}x_t$ exists and belongs to the fixed point set of T. Moreover, we study the strong convergence of $\{x_t\}$ with the weak inwardness condition on T in a reflexive Banach space with a uniformly $G{\hat{a}}teaux$ differentiable norm. Our results provide a partial answer to Jung's question.

• BMB Reports
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• v.28 no.1
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• pp.51-56
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• 1995

Thioredoxin is a small redox protein with an active-site disulfide/dithiol, and is ubiquitous in bacteria, plants, and animals. To investigate the structure-function relationship of thioredoxin, the genes encoding Escherichia coli thioredoxin and Corynebacterium nephridii thioredoxin C3 were fused via a common restriction site in the nucleotide sequence coding for the active site of the proteins to generate two chimeric thioredoxins, designated E-C3(N to C-terminal) and C3-E. The hybrid thioredoxin genes were put under the T7 promoter and their productions were confirmed. The two hybrid thioredoxins complemented phenotypes of a thioredoxin-deficient E. coli strain. A strain containing the C3-E hybrid thioredoxin supported growth of the T7 phage, whereas a strain expressing the E-C3 hybrid thioredoxin did not. However, both hybrids supported growth of M13 phages. The two hybrid thioredoxins were also characterized in other aspects. Differences in activity between the hybrid thioredoxins were attributed to altered interactions of the N- and C-terminal domains of the molecule, which produced changes in the three-dimensional structure of the active site region.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.1
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• pp.8-18
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• 1988

In the composite structures or the concrete structures, to analyze stress concentration factor, stress distributions and fracture mechanics of them under forces by photoelastic experiment, it is natural that to develope photoelastic model material for them is surely necessary. Thus, the orthotropic photoelastic model material for the transparent type photoelastic device was developed in the paper, it is called Copper Fiber Epoxy Composite and abbreviated as E.F.E.C. It was found that C.F.E.C. developed in this paper was satisfied with the properties of photoelastic model material that the photoelastic model material should have and that C.F.E.C. had completely properties of composite material. It is thought that C.F.E.C. can be applied to both medical engineering for modeling biological tissue and to the aerospace industry as orthotropic photoelastic material.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.39-45
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• 1995

The plywoods commonly used as decorative interior materials for the construction are inflammable and so it is a causative factor for making fire accidents, resulting in the destruction of human life and personal properties. Indeed, it is, therefore, required to produce fire-retardant plywoods. In this study, a special grade of defect-free, Kapur plywood was used. Specimens were cut into 3- by 20cm dimensions from 120- by 240- by 0.33-cm panels(thin panel) or 120- by 240- by 0.5-cm panels(thick panel). Some specimens were treated with diammonium phosphate(DAP), but some were not treated with diammonium phosphate to use as control panels. Chemical absorption, drying curves, drying rates and dynamic Young's modulus were investigated. The results were summaries as follows; 1. The specimens were soaked into 19% diammonium phosphate solution by a full cell pressure process and the diammonium phosphate retained in the thin and thick plywoods was 1.409kg/$(30cm)^3$, 1.487kg/$(30cm)^3$, respectively. 2. Diammonium phosphate-treated plywoods were redried with press-drying process at one of either condition dried on the platen($115^{\circ}C$) for a period of time or dried on the platen($50^{\circ}C$) for 3 hrs plus in a dry-oven($30^{\circ}C$) for 24 hrs. or dried on the platen($60^{\circ}C$) for 2 hrs plus in a dry-oven($30^{\circ}C$) for 24 hrs. The drying rate of treated thin specimens dried at $60^{\circ}C$ plus $30^{\circ}C$ and $115^{\circ}C$ only was found to be 0.04 %/min. and 8.53 %/min. Similarly, the drying rate of treated thick specimens were 0.03 %/min. and 6.77 %/min. respectively. 3. It was evident that highly-significantly different drying rate of treated plywoods was observed between plywood thicknesses and platen temperatures and the rate was increased by elevating the platen temperature up to $115^{\circ}C$. Based on the two-way variance analysis, highly significant drying rate was observed from the interaction between plywood thicknesses and platen temperatures. 4. After redrying, the specimens were weighed and reconditioned to a constant weight in a facility maintained temperature ($20^{\circ}C$) and relative humidity(65%) prior to test dynamic Young's modulus. The test revealed that the thin specimens dried at the platen temperature of $50^{\circ}C$, $60^{\circ}C$, $115^{\circ}C$ and untreated specimens showed 1.070E+09 dyne/$cm^2$, 1.156E+09 dyne/$cm^2$, 1.243E+09 dyne/$cm^2$, and 1.052E+09 dyne/$cm^2$, respectively. Likewise, the thick specimens revealed 5.647E+09 dyne/$cm^2$ 5.670E+09 dyne/$cm^2$, 6.395E+09 dyne/$cm^2$ and 5.415E+09 dyne/$cm^2$, respectively. 5. It was evident that significantly different dynamic Young's modulus was observed between the plywood thickness and the platen temperature, but not in the two-way interaction between the plywood thickness${\times}$the platen temperature.