• 대한지구과학교육학회지
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• 제10권1호
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• pp.62-75
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• 2017

본 연구는 생태교육 기반 Eco-STEAM 프로그램을 개발하고 초등학교 6학년 학생들에게 적용하여 환경 소양과 STEAM 태도에 미치는 효과를 분석하였다. 이를 위해 먼저 Eco-STEAM 프로그램 교수 학습과정안과 학생활동지를 개발하였다. 효과검증을 위해 수업 전 후로 환경 소양과 STEAM 태도 검사를 실시하여 그 결과를 분석하였고, 수업 후 만족도 설문과 학생 소감문을 통해 학생들의 반응을 분석하였다. 연구 결과는 첫째, Eco-STEAM 프로그램을 적용한 수업이 학생들의 환경소양 향상에 긍정적인 효과가 있었다(p<.05). 둘째, Eco-STEAM 프로그램은 STEAM 태도 전반에 걸쳐 유의미한 향상 효과가 있었다(p<.05). 셋째, 학생들은 Eco-STEAM프로그램 수업에 대해 긍정적으로 인식하고 있는 것으로 나타났으며, 탐구주제인 황새에 대한 이해 및 관심도 변화가 크게 증가한 것을 알 수 있었다. 따라서 Eco-STEAM프로그램을 적용한 수업은 초등학생의 환경소양 및 STEAM 태도에 긍정적인 영향을 미치고 있으며, 초등학교 환경교육에서 STEAM을 기반으로 한 융합적 접근 방법이 가치가 있다고 볼 수 있다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.395-401
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• 2008

Since metallic foam will increase the performance of heat exchanger, it have caused many researcher's attention recently. Our research base on the model that metallic foams applied to heat exchanger. In this case, there is three kind of heat transfer mechanisms, heat conduction in fibers, heat transfer by conduction in fluid phase, and internal heat change between solid and fluid phases. In this paper we study both the hydraulic and thermal aspect performance. Pressure drop along air flow direction will be presented. As thermal aspect, we first discuss the acceptance of applying thermal equilibrium among the two phases. then to calculate the dimensionless temperature profile, the heat transfer coefficient and Nu number in 14 metallic foams(7 Aluminium foams, 7 FeCrAlY foams). All these discussion is based on the same velocity u=2 m/s.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.239-243
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• 2008

In many literatures the researchers pointed out that the using metal foam will significantly enhance the performance of heat exchanger. This paper focuses on theory study of metal foam, including calculation method of properties of foam (permeability ��K, inertial coefficient f, fiber diameter $d_f$, and effective conductivity $k_e$), model of pressure drop and model of heat transfer. Theory analysis on the performance of heat exchanger will be presented here. Finally the optimal material will be obtained from theory calculation.

• Environmental Engineering Research
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• 제14권2호
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• pp.102-110
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• 2009

Application of artificial intelligence (AI) approaches in eco-environmental modeling has gradually increased for the last decade. Comprehensive understanding and evaluation on the applicability of this approach to eco-environmental modeling are needed. In this study, we reviewed the previous studies that used AI-techniques in eco-environmental modeling. Decision Tree (DT) and Artificial Neural Network (ANN) were found to be major AI algorithms preferred by researchers in ecological and environmental modeling areas. When the effect of the size of training data on model prediction accuracy was explored using the data from the previous studies, the prediction accuracy and the size of training data showed nonlinear correlation, which was best-described by hyperbolic saturation function among the tested nonlinear functions including power and logarithmic functions. The hyperbolic saturation equations were proposed to be used as a guideline for optimizing the size of training data set, which is critically important in designing the field experiments required for training AI-based eco-environmental modeling.

• 전기전자학회논문지
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• 제17권4호
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• pp.505-510
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• 2013

본 논문에서는 Electrocorticogram(ECoG) 신호를 이용하여 손과 팔꿈치의 움직임을 추론하는 방법을 제안한다. 환자로부터 다수의 채널을 이용하여 표면 근전도 신호와 ECoG 신호를 동시에 취득하였다. 추론하는 동작은 손을 쥐었다 펴는 동작과 팔꿈치를 안으로 굽히는 동작이며, 외부 자극에 의해 동작을 수행하는 방법 대신 환자의 자유의지에 의해 동작을 수행하게 하였다. 표면 근전도 신호를 이용하여 동작을 수행한 운동 시점을 찾고, ECoG 신호를 이용하여 동작을 추론한다. 각 동작의 특징을 추출하기 위하여 ECoG 신호를 전체 대역을 포함한 ${\delta}$, ${\Theta}$, ${\alpha}$, ${\beta}$, ${\gamma}$ 총 6개의 대역을 나누어 정보 엔트로피를 구하고, 최대우도추정법을 사용하여 동작을 추정하였다. 실험 결과 감마대역의 ECoG를 사용할 경우 다른 대역을 사용할 때 보다 높은 평균 74%의 성능을 보이며, 다른 대역보다 감마 대역에서 높은 추정 성공률을 보였다. 또한 운동 시점을 기준으로 3개의 시간 구간으로 나누어 준비전위를 포함하는 'before' 구간과 'onset' 구간을 비교하였다. 'before' 구간과 'onset' 구간에서 추정 성공률은 각각 66%, 65%로 준비전위를 이용할 수 있다는 것을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1824-1828
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• 2016

AcrR, the toxic-compounds-response regulator, regulates motility in microorganisms, presumably to escape from toxic environments. In this study, the genome-wide target genes of AcrR were investigated in a ΔacrR mutant strain by microarray analysis. In the absence of AcrR, the transcription of most flagella/motility genes was highly increased. In addition, flagella formation was increased in this mutant strain. Motility assays revealed that AcrR modulates swimming motility, but not swarming.

• 한국가정과교육학회지
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• 제27권4호
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• pp.141-154
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• 2015

본 연구는 중학생의 라이프스타일이 친환경적인 의생활 실천과 효능감에 미치는 영향을 알아보기 위하여 대구지역 중학생 215명을 대상으로 자기기입식 설문조사로 실시되었다. 친화경적인 의생활 실천 점수는 남학생이 $2.95{\pm}.49$점, 여학생 $3.19{\pm}.55$점으로 여학생의 실천점수가 유의적으로 높았다(p<0.01). 1학년의 실천점수가 $3.23{\pm}.56$점, 2학년 $3.09{\pm}.53$점, 3학년 $2.94{\pm}.58$점으로 3학년 학생의 실천 점수가 유의적으로 낮았다(p<0.01). 친환경적 의생활 실천 효능감도 여학생이 남학생보다 유의적으로 높았고(p<0.05), 3학년이 1, 2학년보다 유의적으로 낮았다(p<0.05). 친환경 의생활 실천 효능감과 라이프스타일 요인은 친환경 의생활 실천에 유의적인 영향을 미치는 것으로 나타났고(p<0.05), 특히 라이프스타일의 계획된 구매요인이 친환경적인 의생활 실천 및 효능감에 유의적인 영향을 미치는 것으로 나타났다(p<0.05). 따라서 중학교 가정교과의 녹색생활 단원의 교육에서 학생의 라이프스타일이 반영되고, 친환경적인 의생활 실천 효능감을 높일 수 있으며, 의복의 재사용과 재활용 교육을 강화할 수 있도록 융합교육을 통한 보다 적극적인 창의성 교육이 요구되었다.

• 한국환경교육학회지:환경교육
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• 제24권3호
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• pp.34-43
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• 2011

Project-based learning is an innovative approach to learning that teaches a multitude of strategies critical for success in the twenty-first century. Students drive their own learning through inquiry activity, as well as work collaboratively to research and create projects that reflect their knowledge. The purpose of this study was to investigate the effects of eco-friendly school project activity which is applied from one of project-based learning approach on learning outcomes of students in ninth-grade environment course in middle school. The participants were given a questionnaire before and after the environmental project activities. In solving the school environment issues themselves, students have practiced invaluable problem solving skills. This study indicates that school students' awareness about the environment has positively changed by experiencing the eco-friendly school project. In addition, this project affects students' variety of environmental awareness. This project could be applied to school environmental education programs and to environment lessons, developmental activities or club activities for a positive impact on students' environmental awareness.

• Carbon letters
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• 제24권
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• pp.1-9
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• 2017

We studied the basic properties and fabrication of reduced graphene oxide (rGO) prepared using eco-friendly reduction agents in the graphene solution process. Hydrazine is generally used to reduce graphene oxide (GO), which results in polluting emissions as well as fixed nitrogen functional groups on different defects in the graphene sheets. To replace hydrazine, we developed eco-friendly reduction agents with similar or better reducing properties, and selected of them for further analysis. In this study, GO layers were produced from graphite flakes using a modified Hummer's method, and rGO layers were reduced using hydrazine hydrate, L-ascorbic acid, and gluconic acid. We measured the particle sizes and the dispersion stabilities in the rGO dispersed solvents for the three agents and analyzed the structural, electrical, and optical properties of the rGO films. The results showed that the degree of reduction was in the order L-ascorbic acid ${\geq}$ hydrazine > glucose. GO reduced using L-ascorbic acid had a sheet resistance of $121k{\Omega}/sq$, while that reduced using gluconic acid showed worse electrical properties than the other two reduction agents. Therefore, L-ascorbic acid is the most suitable eco-friendly reduction agent that can be substituted for hydrazine.

• 한국환경교육학회지:환경교육
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• 제20권2호
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• pp.78-92
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• 2007

The purindicator and its application through the application of the eco-city concept. To achieve this aim, this study execute to erect eco-city concept, to develop urban evaluation indicator for the fifth and sixth graders of elementary school, to survey for elementary school teacher in Daegu and to develop application of urban evaluation indicator for the fifth and sixth graders of elementary school. The result of study can be summarized as follow. First, erecting the eco-city concept and urban evaluation indicator for the fifth and sixth graders of elementary school was developed with 14 objects, such like that saving and sound circulation of water resource, sound atmosphere. Second, The result of survey, generally, teachers evaluated that Daegu has problems. The degree of interest of urban environmental problem of Daegu showed that each problem had relatively equal distribution. Teachers had positive response that the ecocity concept applied to environmental education of elementary school. Selection of educational contents had distinct tendency with application of the concept of ecocity. Teachers indicated several problems in environmental education of elementary school. Third, We develop application of indicator for the fifth and sixth graders of elementary school. We concluded that developing application of indicator will offer as follows: First, student and teacher can logically understand urban environmental problems. Second, application of indicator had role of useful tool for environmental education of elementary school.