• 한국태양에너지학회 논문집
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• 제29권3호
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• pp.19-27
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• 2009

In this study, Urban Climate Simulation was performed by 3-Dimensional Urban Canopy Model. The characteristics of urban climate were analyzed combining artificial land coverage, building size, heat production from the air conditioning and topographic conditions as physical variables which affects urban climate characteristics. The results are as follows. (1) The aspects of the urban climatal change is derived to be related to the combination of the building coverage ratio, building height and shading area. According to the building height, the highest temperature was increased by $2.1^{\circ}C$ from 2-story to 5-story building and the absolute humidity by 2.1g/kg maximum and the wind velocity by 1.0m/s was decreased from 2-story to 20-story building. (2) Whole heat generation was influenced by the convective sensible heat at the lower building height and by the artificial heat generation at the higher one over 20-story building influence to some extent of the building coverage ratio. The effect of the altitude is not more considerable than the other variables as below $1^{\circ}C$ of the air temperature. In the last, deriving the combination of building coverage and building height is needed to obtain effectiveness of the urban built environment planning at the point of the urban climate. These simulation results need to be constructed as DB which shows urban quantitative thermal characters by the urban physical structure. These can be quantitative base for suggesting combinations of the building and urban planning features at the point of the desirable urban thermal environment as well as analyzing urban climate phenomenon.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.44-49
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• 2009

In this study, we performed urrban climate simulation how both the factor of environmental land and artificial factors influence on the formation of urban temperature. With deducing quantitative data, this study could get more accurate results of the urban temperature using urban climate simulation system. In the case of natural land cover, it appeared that there are effects on the lowering temperature and the lower temperature rate appeared in the water land cover on the whole. This is considered as temperature in water land was low because of the characteristics of water land having evaporation latent heat was high and convective sensible heat was low. In case of building which has building coverage ratio, 5% with 10 floors and building coverage ratio, 15 % with 6 floors, it appears that the temperature in the water land is $33.6^{\circ}C$. In case of building coverage ratio 5%, temperature dropped when buildings has more than 4 stories. This is regarded as the size of building is bigger, the temperature dropped in relatively because of the fluctuation of the rate of solar heat from the land. At the present time, the urban temperature are higher because of various artificial factors in the city. With these results, this study supposed to be a basies of the future studies for considering both the composition of building coverate ratio and floor plan.

• 한국콘텐츠학회논문지
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• 제22권7호
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• pp.55-62
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• 2022

페로브스카이트 태양전지는 4차 산업혁명으로 사물인터넷, 가상환경 등의 증가에 따른 전력 수요가 급증하면서 점진적으로 고갈되어가는 석유, 석탄, 천연가스 등의 화석연료를 대체할 태양에너지, 풍력, 수력, 해양에너지, 바이오에너지, 수소에너지 등의 신재생 에너지 분야에서 연구가 활발한 부분이다. 페로브스카이트 태양전지는 페로브스카이트 구조를 가진 유-무기 하이브리드 물질을 사용하는 태양전지 소자로 고효율, 저가의 용액 및 저온 공정으로 기존의 실리콘 태양전지를 대체할 수 있는 장점들이 있다. 기존의 경험적 방법으로 예측한 광흡수층 박막을 최적화하기 위해서 소자 특성 평가를 통해 신뢰도를 검증해야 한다. 그러나 광흡수층 박막 소자 특성 평가 비용이 많이 소요되므로 시험 횟수에 제약이 따른다. 이러한 문제점을 해결하기 위하여 광흡수층 박막 최적화의 보조 수단으로 머신러닝이나 인공지능 모델을 이용하여 명확하고 타당한 모델의 개발과 적용 가능성이 무한하다고 본다. 이 연구에서는 페로브스카이트 태양전지의 광 흡수층 박막 최적화를 추정하기 위하여 서포트 벡터 머신의 선형 커널, 가우시안 커널, 비선형 다항식 커널, 시그모이드 커널의 회귀분석 모델을 비교하여 커널 함수별 정확도 차이를 검증하였다.

• 대한공간정보학회지
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• 제24권3호
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• pp.67-73
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• 2016

본 연구에서는 하의도 남쪽 연안지역을 대상으로 자연적 및 인공적 지형에 의한 일조차단의 영향을 평가하였다. 지리정보시스템 자료를 이용하여 대상지역의 지형공간자료를 생산하고, 태양의 방위각과 고도각을 기반으로 3차원 일조환경평가 모델링을 수행하였다. 주간시간대에는 대상지역의 약 80~90% 이상의 영역에서 일조가 형성되었으며, 특히 하지(여름철)의 경우가 일조환경이 가장 우수한 것으로 평가되었다. 산악지형에 의한 일조차단의 영향은 일몰에 가까운 늦은 오후 시간대에 북쪽 주거지역에서 나타났다. 성토건설에 따라 형성되는 인공지형의 경우, 이른 오전 시간대에는 남쪽 주거지역의 일조환경에 영향을 미쳤으며, 늦은 오후 시간대에는 염전의 남서쪽 지역에 영향을 미치는 것으로 평가되었다.

• 한국조경학회지
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• 제29권1호
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• pp.161-167
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• 2001

The purpose of this study is to find out the difference of Zoysia matrella's evaporation in between 100 percent soil and mixed soil with 50 percent of perlite to create green spaces on the artificial ground. It is believed that the weight against the artificial ground will be reduced, provided the vegetation is possible in the circumstance of the mixed sol with 50 percent of perlite. The study employed a modified Makkink's model by Iwasa who had developed the model for estimating Zoysia matrella's evaporation in the natural ground using the Makkink's formula in 1997 at Chiba University, Japan. The parameter of Makkink's formula is the solar radiation. For that reason, the Makkink's formula is simple and easy to measure the parameter and has a high utility. If the outcomes from mixed soil are close to modified Makkinks formula, the modified Makkink's formula will be applied to estimate in the artificial ground with mixed soil with 50 percent of perlite. Weather observation and actual amount of evaporation of Zoysia matrella have been measured, and the relation between weather condition and actual amount of evaporation had been also investigated. In line with this, we found out that there is a relevant relationship between daily average temperature, the modified Makkink's model by Iwasa, and the actual amount of evaporation. As the results of the experiment, the outcomes from mixed soil with 50 percent of perlite have very high relation to 100 percent soil. In addition, mixed soil has more adhesion with water than natural soil. However, it needs to be adequately maintained in terms of fertilization and damage from disease and harmful insects until the gras fastens its roots into the soil. By using mixed soil with 50 percent of perlite, the load from soil on the artificial ground can be reduced. The study on the growth of the grass throughout the plant vegetation and the actual amount of evaporation in the mixed soil with 50 percent of perlite should be performed in the future.

• 한국전자통신학회논문지
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• 제9권2호
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• pp.231-242
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• 2014

지구 온난화로 인한 급격한 기후 변화로 인해 단위 면적당 작물의 생산성 향상 및 고품질 작물 재배에 관심이 고조되고 있다. 따라서 본 논문에서는 기존의 담액 수경방식이나 인공광원을 이용한 수경재배 방식이 아닌 광원 트래킹 기법을 적용한 양액 순환 방식의 수경재배기 제어 관리 시스템을 제안한다. 제안하는 수경재배기는 일정한 양의 양액과 물을 수로로 흘려보내 순환시키는 형태인 양액 순환 방식과 수경재배기 하단 부분의 작물도 지속적인 광합성 작용이 가능 하도록 피라미드 형태의 다단구조식으로 설계한다. 아울러 광원 트래킹 기법은 기존 2축, 4축 센서 방식이 아닌 태양광의 그림자를 추적하기 위한 중심축 센서 방식의 5축 센서 방식으로 설계한다. 본 논문에서 제안한 수경재배기를 통해 기존 연구에서 소개되지 않은 광원 트래킹 기법은 작물에 지속적인 광합성 작용으로 작물의 생장 속도를 단축시킬 수 있었으며, 피라미드형태의 다단식구조로 상, 하단 구분 없이 모든 작물이 동일한 형태의 생육환경을 제공받을 수 있어 단위 면적당 높은 작물 생산량이 예상된다.

• 한국세라믹학회지
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• 제55권3호
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• pp.185-202
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• 2018

Photoelectrochemical (PEC) cells can convert solar energy, the largest potential source of renewable energy, into hydrogen fuel which can be stored, transported, and used on demand. In terms of cost competitiveness compared with fossil fuels, however, both photocatalytic efficiency and cost-effectiveness must be achieved simultaneously. Improvement of cost-effective, scalable, versatile, and eco-friendly fabrication methods has emerged as an urgent mission for PEC cells, and solution-based fabrication methods could be capable of meeting these demands. Herein, we review recent challenges for various nanostructured oxide photoelectrodes fabricated by solution-based processes. Hematite, tungsten oxide, bismuth vanadate, titanium oxide, and copper oxides are the main oxides focused on, and various strategies have been attempted with respect to these photocatalyst materials. The effects of nanostructuring, heterojunctions, and co-catalyst loading on the surface are discussed. Our review introduces notable solution-based processes for water splitting photoelectrodes and gives an outlook on eco-friendly and cost-effective approaches to solar fuel generation and innovative artificial photosynthesis technologies.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.522-528
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• 2012

Currently, the energy consumption of electric lighting in an office building is accounted for more than 30% of the total energy consumption. In order to reduce the energy consumed by the indoor lighting, the daylight as a natural energy resource can play an important role in energy savings. The daylight can have positive impacts on improvement of work efficiency and productivity, and also make people feel more psychologically stable. Moreover, by using the daylight, we can definitely reduce the energy consumption in office buildings. Thus, the purpose of this study is to determine the LED dimming ratio depending on the ratio by calculating the amount of artificial illumination required according to the change of daylight by using the light simulation software that can quantify and visualize the performance of daylight. As a result, the energy savings could be obtained up to 30%.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.25-30
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• 2011

In this paper, we analyzed the electrical characteristics with Micro-cracks in Photovoltaic module. Micro cracks are increasing the breakage risk over the whole value chine from the wafer to the finished module, because the wafer or cell is exposed to mechanical stress. And The solar cells have to with stand the stress under out door operation in the finished module. Here the mechanical stress is induced by temperature changes and mechanical loads from wind and snow. So, we experimentally analyze the direct impact of micro-cracks on the module power and the consequences after artificial aging. The first step, we made micro-cracks in PV module by mechanical load test according to IEC 61215. Next, PV modules applied the thermal cycling test, because micro-cracks accelerated aging by thermal cycling test, according to IEC61215. Before every test, we checked output and EL image of PV module. As the result of first step, we detected little power loss(0.9%). But after thermal cycling test increased power loss about 3.2%.

• 청정기술
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• 제17권3호
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• pp.280-282
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• 2011

광에너지를 이용하여 바이오원료 및 바이오케미컬을 생산하려는 새로운 시도가 많은 관심을 받고 있다. 특히, 광합성기작을 이용한 다양한 바이오유래 물질을 생산하려는 연구가 진행되고 있다. 본 연구에서는 광합성기작을 갖고 있는 해양 미생물인 Salinibacter ruber의 세포막에서 retinal과 salinixanthin의 작용으로 광전자를 흡수하는 역할을 하는 잔토로돕신을 수성 이상계 계면 농축법을 이용하여 효율적으로 분리하였다. 분리된 잔토로돕신을 생물학적 세포막인 레시틴으로 리포좀을 생성하여 잔토로돕신의 광전자흡수 활성을 그대로 갖는 인위적인 잔토로돕신-레시틴 리포좀을 제작하였다.