• Computers and Concrete
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• v.19 no.6
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• pp.667-675
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• 2017

One of the main disadvantages of Ultra High Performance Concrete exists in the large suggested value of UHPC ingredients. The purpose of this study was to find the models mechanical properties which included a 7, 14 and 28-day compressive strength test, a 28-day splitting tensile and modulus of rupture test for Ultra High Performance Concrete, as well as, a study on the interaction and correlation of five variables that includes silica fume amount (SF), cement 42.5 amount, steel fiber amount, superplasticizer amount (SP), and w/c mechanical properties of UHPC. The response surface methodology was analyzed between the variables and responses. The relationships and mathematical models in terms of coded variables were established by ANOVA. The validity of models were checked by experimental values. The offered models are valid for mixes with the fraction proportion of fine aggregate as; 0.70-1.30 cement amount, 0.15-0.30 silica fume, 0.04-0.08 superplasticizer, 0.10-0.20 steel fiber, and 0.18-0.32 water binder ratio.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.540-551
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• 2005

In this research, We'll focus on warm environment and ventilation characteristics when utilizing intake ports, exhaust port and 4-way cassettes for removing heat and polluted air. Four way cassettes have been typical air conditioning units for offices since the multi air-conditioner was introduced. The following installation cases will also be discussed: 1) 4-way cassette's operation without intake ports and exhaust port. 2) Effect of the position of intake port and exhaust ports. 3) cooling air flow, temperature. distribution and local supply index according to the air flow rate from 4-way cassettes.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.181-186
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• 1994

The steel in concrete structures under the environment of seawater easily corrode as the seawater penetrate into concrete. The purpose of this study is to analysis the properties of chloride diffusion in mortar using mineral admixtures, as a part of study to examine the chloride penetration of concrete. The results show that the chloride diffusion in mortar increased with higher water-cement ratio. In the case of mortar using mineral admixtures the scope of diffusion coefficient$(\times10^{-8}cm^2/sec)$increased SF20(0.9), SG60(3.3), FA20(3.9), and OC(6.1) in order at the same water-cement ratio 50%.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.87-87
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• 2003

Three kinds of acrylic polymers containing silk protein were synthesized, which are (1) blending of silk fibroin (SF) fiber and polyacrylonitrile (PAN); (2) graft-copolymer of PAN onto SFs; (3) random-copolymer synthesized by copolymerization of acrylonitrile (AN) and silk fibroin peptide (SFP) with vinyl groups, and their solubility, thermal property, and moisture absorption was investigated, respectively. These polymers have difference solubility and attributable to their structure. Their excellent thermal stabilities and better moisture absorptions were indicated.

• Digital Contents
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• no.1 s.140
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• pp.19-19
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• 2005

어느덧 2005년의 숫자가 선명한 달력이 자리를 차지했다. 개인적으로 2004년을 돌아볼때, 그 어느해 보다 뜻 깊은 한해였다. 5년간 심혈을 기울여 준비했던 SF MMORPG RF온라인을 선보여 게이머를 비롯해 업계 관계자들의 성원이래 성공적으로 서비스를 진행했기 때문이다. 이와 같은 RF온라인의 성공은 2004년 계획을 수립하는데 있어 더욱 큰 기대와 긴장을 느끼게 한다.2005년 을유년을 상징하는 닭은 다섯 가지 덕이 있다고 했다. 머리에 있는 볏은 문을 상징하고, 발은 내치기를 잘한다 하여 무라했으며, 적과 맹렬히 싸우는 용이 있다고 했고, 먹이가 있으면 자식과 무리를 불러 먹인다하여 인이 있고, 하루도 거르지 않고 시간을 알려주니 신이 있다고 평가했다. 이와 같은 닭의 특징은 창으로 인상적이다. 앞서 언급했던 RF온라인은 캐주얼 게임으로 국민 게임이라 불릴만큼 기세를 떨쳤던 포트리스 2 블루가 정점을 달릴때 시작됐다. 한달 37억원까지 달했던 매출로 성공에 대한 기쁨에 취하기도 잠시, 바로 차기작 개발에 착수 했던 것이다.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.161-166
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• 1994

Production of high strength concrete requires a low water-cement ratio and this leads to the high cement content. Mineral admixture like fly ash(FA) is often cheaper than ordinary portland cement(OPC) and this factor in combination with possible improvement in workability and moderation of the heat evolution of the cement-rich mixes tends to encourage its use. The other mineral admixture that its use has been widly advocated is silica fume that increases compressive strength due to its pozzolanic reaction. The objective of this study is to assess the contribution of mineral admixtures(FA, SF) to the workability and the strength of concrete with low water-binder ratios. In this experimental study that investigates and analyzes the properties of fresh concrete, it is presented that using admixtures like flysh and silica fume as binding material increases properties of high strength flowing concrete having very low water cementitious ratios of 0.25 and 0.30.

• Research in Community and Public Health Nursing
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• v.20 no.4
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• pp.522-530
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• 2009

Purpose: This study was performed to investigate the effects of lower urinary tract symptoms on depression and quality of life among women in urban areas. Methods: The participants in this study were 306 women in P city. Data were collected using a questionnaire from May 1 to June 6, 2008. Lower urinary tract symptoms (LUTS) were measured with BFLUTS-SF and categorized into voiding, filling and incontinence. The data were analyzed through t-test, one-way ANOVA, Fisher exact test, and multiple regression. Results: Age, filling and incontinence, and all of the subcategories of LUTS explained 16% of variance in depression. Older women, LUTS with incontinence, filling and incontinence, and all the problems including filling, voiding and incontinence lowered the quality of life. Conclusion: In order to develop nursing interventions for women with urinary tract symptoms, comprehensive understanding of LUTS is needed.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1358_1359
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• 2009

가스 절연 개폐장치(Gas Insulated Switchgear : GIS)의 고체 스페이서에 경사기능성 재료(Functionally Graded Material : FGM)를 적용할 때, 전계의 완화를 예상할 수 있다. 특히, 균일 유전율 분포를 가지는 스페이서에서 양극 근처에 집중된 높은 전계가 FGM 스페이서를 사용할 때, 스페이서와 $SF_6$ 가스의 접촉부로 옮겨지며, 그 크기가 완화됨을 확인할 수 있었다[1]. 본 연구에서는 상용 고체 스페이서의 양극 부근에서의 전계 집중을 감소시키기 위해 전극 형상의 최적화를 수행하였다. 최적화 기법으로는 완전계승계획법(Full Factorial Design : FFD)과 결합된 반응표면법(Response Surface Method : RSM)을 이용하였으며, 균일 유전율 스페이서에서 양극 형상을 최적화하였다. 또한 타원형 유전율 분포를 가지는 FGM 스페이서를 이용함으로써, 상용 GIS 모델에 비해 최대 전계가 크게 완화될 수 있음을 확인하였으며, 상용 GIS의 외함부의 크기를 줄여 실제 소형화 가능 여부를 확인하였다.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.57-62
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• 2002

Cationic liposomes complexed with DNA have been extensively utilized for the delivery of reporter or therapeutic genes both in culture and in vivo. We investigated and determined the optimum conditions of a cationic liposome, composed of dimethyldioctadecy-lammonium bromide (DDAB) and dioleoyl phosphati-dylethanolamine UOPE), mediated a reporter plasmid expressing luciferase into insect cell lines (Sf-21 and Bm-N) and silkworm larvae. Together the data demonstrated that Bombyx mori nuclear polyhedrosis virus (BmNPV) genomic DNA (128 kb) was successfully transfected into Bm-5 cells using this liposome. These results suggest that DDAB/DOPE liposome will be useful as delivery agents for gene transfer to insect cells both in vitro and in vivo.

• Journal of Microbiology and Biotechnology
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• v.4 no.3
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• pp.200-203
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• 1994

Spodoptera frugiperda IPLB-SF-21-AE cells were cultivated in a spin-filter bioreactor with continuous perfusion for the recombinant $\beta$-galactosidase production. At the perfusion rate of 0.06 $hr^{-1}$, the maximum cell density of insect cells in this bioreactor system reached 3.5$\times$$l0^6$ viable cells/ml using the Grace media containing 5% FBS and 0.3% Pluronic F-68. The recombinant $\beta$-galactosidase production of 8, 100 units per reactor volume was also achieved at this perfusion rate.