• Clean Technology
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• v.17 no.3
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• pp.244-249
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• 2011

We synthesized low molecular-weight polymers bearing hydrophobic and hydrophilic parts in a chain through $CO_2$/propylene oxide copolymerization. When hydrophilic poly (ethylene glycol) bearing -OH group (s) at the end group (s) was added as a chain transfer agent in the $CO_2$/propylene oxide copolymerization catalyzed by a highly active catalyst, block polymers were formed. If poly (ethylene glycol) (PEG) bearing -OH group only at an end was fed, PEG-block-PPC diblock copolymer was obtained. When PEG bearing -OH group at both ends was fed, PPC-block-PEG-block-PPC triblock copolymer was obtained. We confirmed formation of block copolymers by $^1H$-NMR spectroscopy and GPC studies.

• Korean journal of communication and information
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• v.21
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• pp.114-146
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• 2003

The purpose of this study is to explore and explain how organization-public relations influence organizational reputation, accounted for by the moderating effect of level of involvement. For this purpose, a survey was conducted to 100 residents in a metropolitan city of Korea with the following five Korean organizations studied: two Korean domestic companies, a sports association, a non-profit organization, and a multinational company. Results of multiple regression analysis indicated that organization-public relationships and publics' level of involvement were significant predictors to account for organizational reputation by non-chance amount, and that level of involvement played a moderating variable role between organization-public relationships and organizational reputation.

• Journal of Korean Library and Information Science Society
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• v.31 no.4
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• pp.259-283
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• 2000

본 연구의 목적은 공중보건의들이 환자 치료와 학술적인 연구를 하기 위해 요구하는 정보를 효율적으로 제공하는데 그 목적이 있다. 2000년 10월 23일부터 11월 11일까지 3주 동안 공중보건의 298명을 대상으로 조사하였으며 이용자들의 정보요구와 이용행위로 정보수집방법과 정보원, 그리고 도서관 이용정도와 만족도를 평가한 결과는 다음과 같다. 1) 공중보건의들은 환자치료와 최근의 연구동향을 알고자할 때 정보를 가장 많이 필요로 하는 것으로 나타났다. 가장 많이 이용하는 정보원은 단행본(교과서)과 학술지로 인쇄본을 더 선호하는 것으로 나타났다. 2) 공중보건의들이 그들의 정보요구를 충족시키기 위해 선호하는 정보수입방법은 인터넷 검색과 동료들로 그 이유는 정보접근의 편이성과 정확성 최신성인 것으로 나타났다. 3) 이용자의 50.3%가 정보이용에 어려움을 느낀다고 하였는데 그 이유는 주로 지역적인 문제와 문헌전달의 지연에 있는 것으로 나타났다. 4) 공중보건의들은 정보가 필요할 때 주로 도서관을 이용하여 필요한 정보를 얻는 경향이 있으나 대체적으로 보아 도서관 이용빈도수는 매우 적은 것으로 나타났다.

• Journal of the Korean Chemical Society
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• v.17 no.5
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• pp.371-377
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• 1973

The low temperature anionic copolymerization of p-tolylisocyanate ($M_1$) with n-hexylisocyanate ($M_2$) in DMF was carried out with NaCN. Copolymers were characterized by osmometry and I. R. spectrophotometry. Also copolymer composition was analyzed by spectral measurements. The behavior of this copolymerization system was the type of less ideal, that is the $M_2$ prefers to react exclusively with the same kind of species. The stress-strain behavior of the copolymer obtained from equimolar comonomer feed exhibited somewhat brittle or rigid character.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.351-351
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• 2002

새로운 LCST 형 블록 공중합체를 설계하기 위하여 LCST 블렌드 계를 선정하고, 이로부터 대응되는 블록 공중합체를 고안하였다 고안된 블록 공중합체의 분자 변수와 자기 집합에 의한 나노 미세 상 발현 거동과의 관계를 Cho의 압축성 random-phase approximation (RPA) 이론을 이용하여 구하였다. 본 연구의 대상 물질은 polystyrene (PS)과 poly(vinyl methyl ether) (PVME), PS 와 Poly(cyclo hexyl methacrylate) (PCHMA)의 블록 공중합체이다. (중략)

• Proceedings of the Korean Information Science Society Conference
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• 2002.10d
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• pp.433-435
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• 2002

본 논문은 공중작전에 대한 신속하고 정확한 상황인식을 위한 3차원 가시화 시스템을 제안한다. 공군의 전략, 전술을 수립, 시행하는 공군 지휘관에게는 전장 전반에 걸쳐 아군기, 적기, 민항기 등 공중 항적에 대한 정확한 정보를 신속하게 전달할 수 있는 공중작전 상황인식 3차원 가시화 시스템이 요구된다. 이를 위해 본 논문에서는 대용량의 디지털 지형 데이터의 가시화와 수많은 공중 항적의 데이터베이스 자료를 연계시킨 시스템을 구현하였다.

• Clean Technology
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• v.18 no.4
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• pp.366-372
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• 2012

Three acrylic copolymers containing tris(8-hydroxyquinoline) aluminum (AlQ3) pendant group (25 wt%), acrylateco-HEMA-$AlQ_3$ (25 wt%), were successfully synthesized by free radical polymerization from acrylates [methyl methacrylate (MMA), acrylonitrile (AN) or 2-hydroxyethyl methacrylate (HEMA)] with HEMA functionalized with AlQ3 pendant groups (HEMA-p-$AlQ_3$). The glass transition temperatures ($T_g$) of MMA-co-HEMA-p-$AlQ_3$ (copolymer 1), AN-co-HEMA-p-$AlQ_3$ (copolymer 2) and HEMA-co-HEMA-p-$AlQ_3$ (copolymer 3) were found to be 158, 150 and $126^{\circ}C$, respectively. They have good thermal stability: a very desirable feature for the stability of OLEDs. Their solubility, thermal properties, UV-visible absorption and photoluminescence behaviors were investigated. They were found to be soluble in various organic solvents such as tetrahydrofuran (THF), dimethylformamide (DMF), toluene and chloroform. It was also found that the UV-visible absorption and photoluminescence behaviors of these copolymers were similar to those of pristine $AlQ_3$. Green organic light-emitting diodes (OLEDs) have also been fabricated using these copolymers as light emission/electron transport components obtained easily by spin coating, and their current density voltage (J-V) curves were compared. The OLED device of the copolymer 3 had the lowest turn-on voltage of about 2 V compared to other copolymer types devices.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.162-173
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• 2013

This study was to examine the effect of trust, stigma, optimistic bias on risk perception of nuclear power plants. For this study, we carried out a survey targeting residents, total of 383, living in Seoul. The findings showed that trust of general public on nuclear power plants influenced negatively on stigma. Second, trust of general public on nuclear power plants influenced not significantly on optimistic bias. Third, stigma of general public on nuclear power plants influenced positively on risk perception. Fourth, optimistic bias of general public on nuclear power plants influenced negatively on risk perception.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.4
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• pp.367-378
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• 2008

The study is the establishment of spaceborne monitoring plan for land management. Spaceborne monitoring is land use change detection, tracking and forecasting process. For land management spaceborne monitoring plan are First, land monitoring system and long-term planning. Secondly, the spaceborne monitoring agency dedicated to specify. Thirdly, to educate the spaceborne monitoring the area of professional manpower. Fourth, data sharing and distribution systems to be prepared. Fifth, to establish real-time airborne monitoring systems. Sixth, to improve the relevant legal and institution. Seventh, continuing research and development of related technologies, and support.

• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.481-489
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• 1996

D,L-lactide (2-LA) was copolymerized with ${\beta}$-methyl-${\delta}$-valerolactone (MVL) using tetraphenyltin as a catalyst and the properties of the copolymers were investigated. The composition of the repeating unit of lactic acid in the copolymers was higher than that in the monomer feeds. The composition of the lactic acid unit in the copolymers decreased with increasing copolymerization time. The yield and the molecular weight of the copolymer increased with increasing 2-LA in the feed composition. These results suggest that the reactivity of 2-LA is larger than that of MVL. The number average molecular weight was in the range of 54,000 to 63,000 and the polydispersity index was in the range of 1.7 to 2.1. The copolymers did not show melting point, but glass transition temperature. The degradable tendency of the copolymers with lipase was almost equal to that of L-lactide-MVL copolymer.