• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.446-446
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• 2013

유기태양전지는 가벼운 무게와 우수한 유연성을 가져 플렉서블 태양전지 및 롤투롤(Roll-to-roll) 인쇄 공정에 대한 적용 가능성 때문에 많은 연구가 이루어지고 있다. 하지만 이종접합 유기태양전지를 상용화하기 위해서는 낮은 전력 변환 효율 (PCE)을 증진하는 연구가 필요하다. 본 연구에서는 간단한 용액공정을 통해 poly (3-hexylthiophene) (P3HT) 나노구조층을 사용하여 indium-tin-oxide 양극 전극/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) 정공수송층/P3HT 나노구조층/P3HT 복합체로 제작한 나노구조층/C60 전자수송층 /lithium quinolate 전자주입층/Al 음극 전극 구조의 유기태양전지를 제작하였다. 전류밀도-전압 곡선 결과는 P3HT 복합체 이용한 나노구조층를 가진 유기태양전지의 구조는 평면층을 가진 유기태양전지에 비해서 PCE가 향상됨이 관찰되었다. 유기태양전지는 짧은 엑시톤의 확산거리가 PCE 감소의 주요 원인이 된다. P3HT 복합체를 사용한 나노구조층을 가지는 유기태양전지는 광활성층과 전자수송층 사이의 계면이 넓어지는 효과를 가진다. 계면이 넓어지는 효과를 통해 생성된 엑시톤을 효율적으로 분리할 뿐만 아니라 더 많은 양의 전하를 생성할 수 있기 때문에 전하의 양이 증가되고 더 높은 전류를 생성하여 PCE를 효과적으로 높일 수 있다.

• Korean Journal of Organic Agriculture
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• v.10 no.4
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• pp.1-7
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• 2002

CODEX의 유기농업기준에 대하여 기본적으로는 공감하고 있으나, 아시아적 기후의 특성과 농가당 소유면적이 유럽이나 미주$\cdot$오세아니아 지역에 비하여 상대적으로 너무 협소한 점을 감안하여 아시아의 유기벼 재배농가들에게 과중한 부담을 주지 않을 수 있는 선에서의 유연성을 부여해야 할 것이다. 윤작이나 휴경의 경우, 지역에 따라 벼-딸기 등의 과채류-벼-토마토 등 과채류-벼 행태나, 병-보리 또는 호밀 등의 사료 또는 녹비작물-벼-자운영 등의 사료 또는 녹비작물-벼 행태의 윤작 또는 녹비작물 재배형태의 윤작 또한 유기재배로 인정해야 할 것이다. 완충지배 역시, 일정거리 보다는 경계선상에 주작물보다 상당히 키가 큰 다른 식용이나 녹비용 작물을 재배하면서 이웃 관행농장으로부터의 영농화학물질의 비산을 막아줄 수 있는 조처만으로도 유기재배 인증획득이 가능토록 해야 할 것이다. 제체작업 또한 오리를 이용할 경우, 기본적인 제초효과는 물론 해충포식이 이루어지며, 배설물에 의한 자연적인 시비가 원활히 이루어지게 볏대를 튼튼하게 자극시켜주며, 고랑사이의 공기유통 촉진과 흙탕물에 의한 잡초 발아억제 효과 등 다양한 부대효과를 올리 수 있게 된다. 왕우렁이 제초법 또한 논의 건조와 백로 등 조류의 접근만 차단해 주면 완벽한 제초가 이루어지고 있으며, 불시 경운에 의한 제초법도 유기농업 실천에 크게 기여할 수 있는 최선의 방안으로 활용되고 있는 중이다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2003.04a
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• pp.132-136
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• 2003

최근 셀룰로오스 섬유에 대해 위생적이고 건강성을 강조하는 항균 방취 가공을 부여하기 위한 연구가 활발히 진행되고 있다. 지구상에서 생물체에서 얻는 키틴은 셀룰로오스 다음으로 그 생산량이 많은 천연고분자 물질이다. 키토산은 키틴을 탈아세틸화 함으로써 얻어지는 다수의 아미노기를 갖는 천연다당계열의 생체적합성, 생분해성 고분자이다. 특히 키토산은 우수한 항균ㆍ방취 기능성 부여와 대전방지등의 효과를 나타내어 우수한 가공제로 사용된다. (중략)

• Journal of Adhesion and Interface
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• v.16 no.2
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• pp.55-62
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• 2015

It was investigated that the effect of surface modification and concentration of fumed silica on the adhesion properties and thermal stability of 2-EHA/AA pressure sensitive adhesive (PSAs) prepared by UV irradiation. The influence of repeating units of crosslinking agent on PSAs were also studied. From SEM analysis, PSAs synthesized with surface modified silica had finer dispersion of silica particles in polymer matrix due to the interfacial interaction. Results of the study showed that increase in tack and peel strength when under 0.3 wt% of silane treated silica were added in the reaction mixture. The addition of PEGDMA for crosslinking agent offers positive effect on adhesion properties in comparison with PSAs using EGDMA for crosslinker, which may be attributed to high mobility of ethylene oxide repeating units in PEGDMA. From the thermal degradation residue of PSAs, it was revealed that thermal stability was improved with silica addition due to the strong interfacial bonding between silane modified silica and polymer matrix, which may act as a thermal barriers into 2-EHA/AA PSAs.

• 재활복지
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• v.22 no.3
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• pp.1-22
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• 2018

The purpose of the study was to identify available evidence related to physical activity interventions that were effective to improve health-related physical fitness levels of children and youth with disabilities. Studies were accumulated from multiple databases (i.e., ERIC, Child Development & Adolescent Studies, MEDLINE, SPORTDiscus with Full Text, and CINAHL Plus with Full Text). From the initial process, 1195 articles were identified and of those, 13 studies (n = 13) were analyzed. Based on the results, community-based physical activities were the most common environment of interventions followed by school-based and home-based. Further, the most improved health-related physical fitness outcomes were muscular strength, muscular endurance, and cardiorespiratory endurance while limited evidence on weight reduction was available. There is a need for more research on physical activity intervention which particularly improves health related physical fitness of children and youth with disabilities.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.960-968
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• 2012

In this study, the measurement of physical properties of 3 different ethylene oxide adducted zwitterionic surfactants were measured such as critical micelle concentration, surface tension, interfacial tension, contact angle, viscosity and foam stability. Also, the dual function characteristics of the zwitterionic surfactants were investigated by determining an isoelectric point, which were obtained using zeta potential measurement and QCM (quartz crystal microbalance) experiments. The isoelectric point of the synthesized zwitterionic surfactant determined by zeta potential measurement was close to that obtained by QCM experiment and both results have shown almost the same trend as that determined by the frictional property measured using an automated mildness tester. In particular, it has been observed that all three surfactants used during this study provide better softening effect at a pH of neutral condition than at an acidic or an alkaline condition. This result indicates that the synthesized surfactants act as a cationic surfactant at a pH of neutral condition and thus provide good softening effect during a rinsing cycle in the detergency process.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.455-463
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• 2012

In this study, the measurement of physical properties of ethylene oxide-propylene oxide adducted zwitterionic surfactants were measured such as critical micelle concentration, surface tension, interfacial tension, contact angle, viscosity and foam stability. Also, the dual function characteristics of a zwitterionic surfactant were investigated by determining an isoelectric point, which were obtained using zeta potential measurement and QCM (quartz crystal microbalance) experiments. The isoelectric point of DEP-OSA82-AO zwitterionic surfactant determined by zeta potential measurement was close to that obtained by QCM experiment and both results have shown almost the same trend as that determined by the frictional property measured using an automated mildness tester. In particular, it has been observed that DEP32-OSA82-AO and DEP34-OSA82-AO surfactants provide better softening effect at a pH of acidic or neutral condition than at an alkaline condition. This result indicates that both surfactants act as a cationic surfactant at a pH of acidic or neutral condition and thus provide good softening effect during a rinsing cycle in the detergency process.

• Journal of Korea Port Economic Association
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• v.38 no.4
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• pp.45-64
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• 2022

Due to the recent and rapid globalization, logistics outsourcing has expanded globally and is seen as a means of creating a robust logistics system. However, many businesses continue to have difficulties with their logistics outsourcing contracts, which compels them to reinstate the logistics function for internal management. This study aims to investigate how organizational capabilities of logistics service providers (LSPs), notably flexibility, integration, innovation, and technological capabilities, impact on the logistics outsourcing success in Ugandan food processing firms. Using a structured questionnaire survey, cross-sectional data collected from 211 food processing firms in Kampala - Uganda were analyzed by partial least squares-structural equation modeling (PLS-SEM) using SmartPLS 3.3.7 software to examine the theorized relationships. The study findings revealed that whereas the technological and innovation capabilities positively and significantly influence logistics outsourcing success, the effects of flexibility and integration capabilities were insignificant. Additionally, the importance-performance map analysis (IPMA) reveals that the technological capability is a priority capability, followed by the innovation capability if logistics outsourcing success is to be achieved. Conversely, flexibility and integration capabilities are of low priority.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.116-120
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• 1994

최근 항공우주 및 생산자동화 분야의 급격한 발달에 따라 정밀도와 효율성을 향상시키기 위해 저중량, 고강도 구조물이 요구된다. 그러나 경량화 추세로 인해 수반되는 구조물의 유연성 증가로 외력에 대한 구조응답의 진폭이 커지고 구조물의 피로 수명이 단축되어 매우 위험한 상황에 이를 수 있다. 이런 바람직하지 않은 진동현상을 제어하기 위해 여러 제어이론을 응용한 진동억제시스템의 연구가 활발하며, 신소재인 압전재료의 개발로 새로운 방향이 제시되고 있다. 압전재료는 유연한 구조물에 부착되어 압전재료의 수축, 팽창 운동에 의해 발생된 에너지를 부착된 구조물에서의 제어력으로 사용되어, 진동 혹은 자세 및 형상 제어에 활용되고 있다. 압전재료에 대한 연구로는 Crawley, de Luis3가 보의 표면 혹은 내부에 압전세라믹을 부착하여 액튜에이터로 사용하는 경우 집중모멘트를 가하는 역할을 함을 밝혔고, Hanagud, obal은 압전재료를 센서와 액튜에이터로 사용해 복합재료 보에 대한 최적 진동제어 알고리즘을 개발, 그 성능에 대한 효과를 조사하였고 임의의 위치에 부착된 센서 및 액튜에이터를 고려한 복합재료 보의 운동방정식을 유한요소법을 이용 유도하였으며 변위율 피드백(rate feedback)과 모달피드백(modal feedback) 제어기를 적용하여 진동제어 효과를 고찰하였다. 그리고 Tomas, James, Hubbard는 압전필름을 액튜에이터로 사용해 복합재료 보에 Liapunov 제어기와 변위율 피드백 제어기를 사용하여 능동감쇠기를 설계하였고, Lee, Chaing, Sullivan은 압전필름을 센서와 액튜에이터로 사용해 평판에 변위율 피드백 제어기를 적용한 능동감쇠기를 설계하고 실험적으로 수행하였다. Base가 백색잡음가진을 지속적으로 받을 때 보끝의 움직임이 최소가 되도록 제어하고자 연구를 수행 중인 바 그 결과로소 본 논문에서는 적용시켰고 F-P-K 방정식을 이용해 확률영역으로 변환하여 LQR 제어기와 pole allocation 제어기를 시스템에 적용시켜 우수한 특성을 갖음을 제어 시뮬레이션의 결과를 통해 입증하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.180-190
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• 2019

This study aims to investigate the mediation effect of creativity in the relationship between the core competencies of lifelong educators and the life competencies of adult learners. A survey was conducted for adults participating in the lifelong education programs in lifelong education institutes in Gyeonggi-do. Consequently, a toows. First, among the life competencies of adult learners, the problem solving ability showed the highest correlations with the planning, action, and support competencies, which are the sub-factors of the core cotal of 520 questionnaires were used for research analysis. The main findings of this study are as follmpetencies of lifelong educators. Among the creativity factors of adult learners, unique flexibility showed high correlations with the life competencies of adult learners. Second, the core competencies and creativity of lifelong educators had a 74.6% effect on the life competencies of adult learners. Among them, creativity was a variable that had a greater effect on the life competencies of adult leaners than on the core competencies of lifelong educators. Third, the mediation effect of creativity in the relationship between the core competencies of lifelong educators and the life competencies of adult learners was verified. The results of this study proved that the creativity of adult learners is an important variable for improving life competencies and that qualitative improvement through the core competencies of lifelong educators is required.