• Clean Technology
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• v.6 no.2
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• pp.101-106
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• 2000

A new nonvolatile and nonflammable soldering flux was developed. This flux was synthesized with dichloropropane as its solvent instead of VOC solvents such as isopropanol and methanol etc. which had been used in the conventional flux. It was confirmed that the nonflammable and nonvolatile flux(NFV-flux) was better in insulation resistance, workability, and reliability and that it was better in the enviromment and safety of the working place and more economic in comparison with the conventional flux.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.1385-1388
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• 2012

국가R&D사업의 추진결과와 활동현황에 대한 종합적이고 다각적인 분석을 위해 1999년도부터 매년 모든 국가R&D사업에 대해 주요 연구 성과인 논문, 특허, 기술료 등에 대한 국가R&D 조사분석 자료 수집이 실시되고 있다. 국가R&D 표준정보 수집을 위해 2003년도에 '국가연구개발사업 종합관리시스템(CORDI, 현재 SIMS)'이 구축되었고, 매년 국가R&D 조사분석 자료들의 수집 분석이 실시되고 있으나, 전자기록의 속성을 갖는 국가R&D 조사분석 자료, 특히 조사분석의 검증자료에 대한 장기적 보존을 위한 관련 연구는 전무한 상태이다. 따라서 본 연구는 국가R&D 조사분석의 검증자료에 대한 장기적 보존과 나아가서는 평가의 활용 및 정보 시스템간의 상호운용성을 높이기 위한 국가R&D 조사분석 검증자료의 보존 메타데이터 모델을 제안한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.3
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• pp.127-137
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• 2003

Contingency analysis is one of the most important tasks encountered by planning and operation of lafe scale power systems. This paper describes a new contingency analysis methods for small signal security assessment based on the eigen-sensitivity/perturbation of the electromechanical oscillation modes. The eigen-sensitivity/perturbation with respect to line suceptances and controller parameters can he used to find possible sources of the system instability, and to select contingency for small signal stability. Also, the contingency selection to identify critical generators for MW changes can be obtained by computing the relative movement of the system oscillation modes. The proposed algorithm has been successfully tested on the KEPCO systems which is comprised of 791-bus, 1575-branch and program PSS/E

• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.81-85
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• 2012

As business environment and complex work conditions are rapidly changing, large financial institutions are doing research on various fields to build a system that will efficiently and accurately process the production and modification of financial information and minimize the error in data-processing. In this paper, we have built a metadata system that, among various research areas, gives stability, accuracy and convenience in financial data modelling, analyze its effect and when adapting new models, provide mapping information from existing model to efficiently connect models and databases. If we manage modelling and standard data through this metadata system, the data standardization and database can process the model modification work in an unitary system and consistent high quality data model can be maintained and managed when data modification occurs.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.27 no.1
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• pp.59-85
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• 2016

The purpose of this study was to synthesize the effects of the information literacy instruction using meta-analysis. Results using random-effect models were as follows. First, the overall average effect size (ES) of information literacy instruction (Hedges'g) was 0.72, which could be interpreted based on Cohen's guidelines as moderate to large. Second, the two types of information literacy instruction, demonstrating more than medium ESs, did not show significant differences in their ESs. Third, the ESs of information literacy instruction differed depending on the measuring variables. Fourth, grade, study design and the form of the measurement tool were moderator variables that explain the differences in ESs. In sum, the effects of information literacy instruction, having more than medium effect size, seem quite stable across instruction types and study designs.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.268-276
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• 2021

As wireless communication devices become more common, interests in how to control the electromagnetic waves generated from the devices are increasing. One of the most commonly used electromagnetic wave control materials is magnetic one, but due to the features that make the product heavy and thick when applied to the product, it is difficult to use them in curved electronic devices. Therefore, a polymer flexible meta electronic device has been presented to sort out the problem, which is thin and can have various curvatures. However, it requires an additional evaluation of curvature reliability. In this study, we developed a method to predict electromagnetic wave control characteristics through the resistance/length of the conductive ink line patterns of polymer flexible meta electronic devices, which is inversely proportional to the electromagnetic wave control characteristics. As the radius of curvature decreased, the resistance/length increased, and there was little variations with the duration times of curvature. We also found that both permanent and recoverable changes along with the removal of curvature were occurred when the curvature was applied, and that the cause of these changes was newly created vertical cracks in the conductive ink line pattern due to the tensile stress applied by applying curvature.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.285-288
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• 2000

본 논문에서는 카메라 플랫홈의 흔들림 등으로 인한 외부 영향으로 출렁이는 비디오를 전자적으로 안정화시키는 방법을 제안한다. LOG operator〔1〕을 이용하여 특징점을 잡고 그 특징점을 중심으로 일정크기의 subblock에 대해서만 correlation을 구한다. Least Square를 이용하여 모션 파라메타를 측정하고 모션 보상을 행하는데 현재의 영상을 기준 좌표계로 변환하고 명암값 보간을 하게된다. 이 때 기존 연구에서 많이 사용한 bilinear 보간법의 단점인 대비가 첨예한 곳에서의 averaging 효과를 없애기 위해 본 연구에서는 대비가 첨예한 곳에서는 nearest neighbor 보간을 사용하고 그렇지 않은 곳에서는 bilinear 보간을 사용하는 hybrid한 방법을 채택하였다. 그 결과 사람이 카메라를 손에 들고 움직일 때 생기는 출렁이는 비디오에 대해 대부분의 카메라 움직임을 안정화시킬 수 있었다.

• Broadcasting and Media Magazine
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• v.27 no.3
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• pp.36-44
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• 2022

NFT의 등장으로 디지털 자산의 가치 관점이 변화하며 생태계가 빠르게 확장하고 있다. 2017년 크립토키티를 시작으로 NFT가 대중에게 알려지기 시작하였고, 이를 시작으로 게임, 디지털 예술, 엔터, 콘텐츠 산업 등에서 부각을 나타내고 있다. 2020년의 NFT 시장 규모는 약 3,936억 원으로 성장하였으며, 메타버스 시대가 가속화되면서 NFT 기반의 생태계가 빠르게 발전할 것으로 보인다. 이에 본 고에서는 아직 안정적인 법제도 환경이 마련되어 있지 않은 상황에서 NFT 거래 참여자가 안전하게 거래에 참여할 수 있도록 거래 참여자 관점에서 고려해야 할 주요 이슈 5가지를 도출하고 이에 대해 논하고자 한다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.16 no.5
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• pp.463-476
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• 1987

주기적으로 작동하는 흡수식 장치가 부착된 직접 연소식 고효율 난방기기를 특정 공간 난방 목적으로 설계하여 제작하였다. 작동 유체는 메타놀/물-리치움브로마이드이다. 네개의 구성품으로 된 이 기기에는 동작부품이 없다. 제 1 시제품의 결과와 경험에 기반을 두고 개선형 시제품을 설계, 제작하였다. 현재까지 발생기-응축기 모듈이 설치되어 보일러 운전모드 결과가 확립되어 있다. 또한 난방기기의 경제성과 작동 유체의 안정성 연구가 중요한 부수 조건을 확립하기 위하여 수행되고 있다.

• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.216-223
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• 2006

To increase the stability of liposomes in blood circulation, surface modification of liposomes by incorporating a lipid-polymer derivative in the lipid bilayer or conjugating a hydrophilic polymer to the liposomal surface has been developed. In this study, the comblike copolymer, poly(HEMA-co-HPOEM), having multiple polyethyleneoxide side chains was prepared by free radical polymerization of hydroxyethylmethacrylate (HEMA) and hydroxypolyoxyethylenemethacrylate (HPOEM) as vinyl monomers. Poly(HEMA-co-HPOEM) was conjugated to the liposomal surface and the characteristics of the modified liposomes in serum were investigated. Conjugation of poly(HEMA-co-HPOEM) to liposomes increased the particle size of the liposomes by 30 nm and decreased the absolute value of zeta potential of the liposomes by shielding the negative charge of liposomal surface. Loading efficiency of model drug, doxorubicin, in liposomes was about 90% and the efficiency was not affected by conjugation of poly(HEMA-co-HPOEM) to liposomes. The particle size of poly(HEMA-co-HPOEM)-conjugated liposomes in serum did not changed and the protein adsorption was lower than that of control liposomes or liposomes containing polyethyleneoxide-lipid derivative (PEG-liposomes). These results suggest that poly(HEMA-co-HPOEM) is efficient for the stabilization of liposomes in blood circulation.