• Journal of the Korean Applied Science and Technology
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• v.39 no.4
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• pp.488-498
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• 2022

The effects of 1,3-Butanediol, 1,2-Pentanediol, and 1,2-Hexanediol in surfactant solutions on cmc, surface tension, foaming and emulsifying properties were determined. The addition of diols in aqueous surfactant solution decreased cmc and surface tension, and enhanced the foaming and emulsifying power. This trend is more significant by the longer hydrocarbon chain length of the diols. This property was confirmed because the diol's alkyl chain and the hydrophobic interaction with the surfactant reduce the cohesive force of water and increase the interaction between the head groups of the surfactant at interface. In addition, MIC test was conducted to determine the preservative power of each diol, and as a result, the antibacterial activity was effective in the order of 1,2-HDO > 1,2-PDO > 1,3-BDO. The results of this study show that diol can be applied to cosmetics as an auxiliary surfactant and antibacterial agent.

• The Journal of Information Technology and Database
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• v.3 no.2
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• pp.25-38
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• 1996

병렬 데이타베이스 소프트웨어 구조 중 공유 디스크 구조는 트랜잭션간의 병렬도 향상, 적재 균형 용이, 데이타 재할당 용이 등의 장점을 가지고 있어 병렬 데이타베이스 구조 중 가장 효율적인 성능이 기대되고 있다. 그러나 공유 디스크 구조는 동시성/응집성 제어를 위한 추가적인 메세지의 증가로 네트워크 트래픽이 증가되는 문제를 가지고 있으며 이러한 문제를 완화시키고자 하는 연구가 계속되고 있다. 본 논문에서는 공유 디스크 구조의 동시성/응집성 제어를 위한 추가적인 메세지를 감소시키는 기법을 제안하고, 기존 기법과의 비교를 위해 성능 모델을 제시하였으며, 이를 통한 시뮬레이션을 수행하여 성능을 분석하였다.

• Current Industrial and Technological Trends in Aerospace
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• v.8 no.1
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• pp.96-103
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• 2010

The propulsion systems such as upper stages of launch vehicles, orbiters, spacecrafts have to operate in the zero gravity environment. Because the flight condition where the vehicle undergoes is different from the normal gravity state, many studies have been being in progress. Fluid behavior in the zero gravity condition is differently shown in the normal gravity state because the importance of the intermolecular force, such as adhesion, cohesion, and surface tension is enlarged. In this paper, we investigate the characteristic of fluid behavior and describe effects and problems on the liquid propulsion system due to these fluid behavior. We also check which studies are in progress in order to solve these problems.

• Polymer(Korea)
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• v.27 no.6
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• pp.596-602
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• 2003

A Polymeric emulsifier was synthesized by solution polymerization with 2-ethylhexyl acrylate, n-butyl acrylate, and acrylic acid. A series of polymeric emulsifier have been used in the emulsion copolymerization of 2-ethylhexyl actryacrylate and n-butyl acrylate. The size of the synthesized latex particles was around 145 nm and its distribution was very narrow. Emulsion with polymeric emusifier showed no coagulum after 7 cycles of freeze-thaw test, while the emulsion with traditional emulsifier exhibited coagulum after 2 cycles. The adhesion tests showed that the initial tackiness and peel strength decreased as the molecular weight and acrylic acid content of polymeric emulsifier increased, whereas the holding power increased.

• Journal of Korea Game Society
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• v.11 no.6
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• pp.193-199
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• 2011

Producing high density crowd simulation is time-consuming task as increasing the number of individuals in the crowds. In this paper, we propose a new control technique that can create realistic high density crowd simulation by using Smoothed Particle Hydrodynamics (SPH) method from fluid simulation field. Equations in SPH method are modified for evacuation, distance maintenance, and group maintenance forces for individual behaviors in the crowds. Experimental results showed that the proposed system could enable natural high density crowd simulation efficiently.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.573-576
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• 2010

The propulsion systems such as upper stages of launch vehicles, orbiters, spacecrafts have to operate in the zero gravity environment. Because the flight condition where the vehicle undergoes is different from the normal gravity state, many studies have been being in progress. Fluid behavior in the zero gravity condition is differently shown in the normal gravity state because the importance of the intermolecular force, such as adhesion, cohesion, and surface tension is enlarged. In this paper, we investigate the characteristic of fluid behavior and describe effects and problems on the liquid propulsion system due to these fluid behavior. We also check which studies are in progress in order to solve these problems.

• Korean Journal of Social Welfare
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• v.59 no.1
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• pp.27-53
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• 2007

Until now, the strategies for increasing community participation has been focusing on the administrative legal institutionalization, but these have not brought substantive effects. So, the need of strategies utilizing the community culture which was formed by the residents and community has been issued on recently. The purpose of this study is to explore the strategies utilizing the community culture. So, it was identified the socio-demographic variables affected the community cohesion (community social networks, community solidarity, place-attachment), that is called community spirit and culture. And through path analysis, it was analyzed the relationship among residents' socio-demographic background, community cohesion, and community participation. The findings are as follows. : the community cohesion's three elements altogether affected positively to the community participation. When regarding the residents characteristics, the strategies for increasing the participation relating to community solidarity was most relevant. the socio-demographics affecting to community solidarity are gender, age, the beneficiary, religion, job type, household income, the length of residence. the women was low at level of participation. The most important variables affecting the community cohesion are the age, the residence duration. Based on these results, the relevant strategies or approaches for increasing community participation are as follows. : using and sharing of the aged's community knowledge, making the long term living and final settlement of community residents, increasing and creating the income for the low-income residents, increasing of religious organization and its members' responsibility to community, and the purposeful extension and relevancy of women's participation. Ultimately, this study is to contribute to fomulate the residents- cultural asset driven's community welfare planning.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.587-593
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• 1995

Lectin was purified by using $(NH_4)_2SO_4$, DEAE-cellulose ion-exchange chromatography and Sephadex G-150 column chromatography from Alismatis Rhizoma(AR). The specific activity of AR lectin was 50, 441units/mg, and purification folds were 114. The AR lectin agglutinated human erythrocytes of all types(A, B, O, AB). The molecular weight of AR lectin was estimated about 90, 500 daltons by gel filtration and each subunits were 42,000, 27,000 and 22,500 daltons on SDS-PAGE respectively. The hemagglutinating activity of the lectin was inhibited by sialic acid, glucose, ribose, galactose, sucrose, and lactose. It was also inhibited by cations such as $Hg^{++},\;Fe^{++},\;Cu^{++}\;and\;Pb^{++}$.

• KSBB Journal
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• v.23 no.1
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• pp.48-53
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• 2008

Lectin was isolated from locular fluid of tomato by affinity chromatography using Sephadex G-200, and studied its some biochemical properties. SDS-PAGE of the isolated lectin revealed a tetramer composed of two identical subunits with molecular weights of 39 and 23 kDa. The isolated lectin was agglutinated by trypsin-treated human ABO type blood erythrocytes with similar potency, and the most activity of agglutination was found at B type blood erythrocyte. This lectin showed maximum thermal stability at $70^{\circ}C$, and was relatively stable to heat with the higher activity at $40-80^{\circ}C$. The optimal temperature and pH of this lectin were $50^{\circ}C$ and pH 7.0, respectively.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1997.10a
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• pp.67-67
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• 1997

정수공정은 "원수 -1 침사지 1 전염소 -1 전오존 -1 침전지 1 여과지 1 후오존 1 GAC 4 후염소 1 가정수"로 이루어져 있으며 전처리 공정으로 염 소와 오존을 주입하게 되는데, 여기서 전염소 처리 공정으로 인해 잔류 유리염 소가 수중의 유기물질과 반웅하여 유해성 유기염소 화합물 (i.e.. Trihalomethane, Haloacetonitriles, Chlorophenol 등)을 생성하는 것으로 알려져 있다. 이러한 이유로 고도 정수처리 공정에서는 강한 산화력을 지닌 대체 산화 제로서 오존을 이용하고 있다. 전오존 처리공정은 OOC와 탁도 제거에 있어 응 집제 주입량을 감소시키는 것과 더불어 전오존 효과 (산화, 생분해 증대, 살균 등)를 얻을 수 있는 것으로 알려져 왔다. 그러나 낙동강과 같이 유기물이 많은 원수에 과다한 오존이 주입되면 수중 의 유기물이 저분자화 또는 응집이 어려운 오존 산화물로 변화하여 응집제의 소비가 많아지게 된다. 실제, 오존을 응집 효과에 대해서 pilot plant로 운전한 결과 전오존에 의해 입자성 물질의 제거 효율은 향상된 반면에 유기물 제거는 뚜렷한 효과를 볼 수 없었다고 보고되었다 (류, 1997). 본 연구에서는 물금 지역의 원수와 응집-침전 공정까지 거치는 각각의 처 리수에 대해서 전처리가 응집에 미치는 영향을 천연유기물질 (NOM)의 조성 변화로 파악하였다. 그 방법으로 천연유기물질 (NOM)을 XAD-1, -4 수지를 이 용하여 소수성 물질 (hydrophobic components)과 친수성 물질 (hydrophilic components)로 분리 및 농축하여 용존 유기물이 처리 과정에서 어떻게 변화하 는지를 조사하여 개선된 상수 처리 시스템을 설계하는데 기초 자료를 제공하고 수질 관리 분야에서도 적용하고자 하였다. 상수원수인 물금 지역의 소수성 물질(hydrophobic components)은 75~80%, 친수성 물질(hydrophilic components)은 30~33%정도의 분포를 보였고, 전염소 및 전오존 공정을 거친 처리수에서는 각각 62.2-62.8%, 43.9~49.0% 및 50~ 55%, 40~57% 정도의 분포를 보였다. 그리고 웅집-침전을 거친 처리수에서는 그 분포가 77~82%, 24-48%였다. 전주리 공정을 통하여 소수성 물질(byoghobic components)의 분포가 감 소하는 것을 볼 때 전염소 및 전오존 처리가 용존유기물의 응집에는 오히려 역 효과를 나타내는 것으로 판단된다. 것으로 판단된다.