• Advances in Computational Design
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• 제3권4호
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• pp.319-338
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• 2018

High-performing architecture should be designed by taking into account the mutual dependency between the new building and the local context. The performative architecture plays an important role to avert any unforeseen failures after the building has been built; particularly ones related to the microclimate impacts that affect the human comfort. The use of the concept of solar envelopes helps designers to construct the developable mass of the building design considering the solar access and the site obstruction. However, the current analysis method using solar envelopes lack in terms of integrating the detailed information of the existing context during the simulation process. In architectural design, often the current site modelling not only absent in preserving the complex geometry but also information on the surface characteristics. Currently, the emerging applications of point clouds offer a great possibility to overcome these limitations, since they include the attribute information such as XYZ as the position information and RGB as the color information. This study particularly presents a comparative analysis between the manually built 3D models and the models generated from the point cloud data. The modelling comparisons focus on the relevant factors of solar radiation and a set of simulation to calculate the performance indicators regarding selected portions of the models. The experimental results emphasize an introduction of the design approach and the dataset visibility of the 3D existing environments. This paper ultimately aims at improving the current architectural decision of support environment means, by increasing the correspondence between the digital models for performance analysis and the real environments (context of design) during the conceptual design phase.

• 에너지공학
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• 제20권4호
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• pp.353-357
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• 2011

본 연구에서는 AVR 마이크로 컨트롤러를 사용하여 임베디드 태양추적장치를 개발하였다. 본 시스템은 Atmega128 마이크로 컨트롤러, 스텝 모터, 스텝 드라이브 모듈, CdS 센서 그리고 GPS 모듈 및 기타 부품들로 구성되어 있다. 태양추적장치는 광학적 방법과 천문학적인 방법에 의해 작동된다. 최초 태양추적은 천문학적인 계산방법에 의해 얻어진 결과에 따라 이루어지고 CdS에 의해 미세 조정이 이루어진다. 태양추적장치가 설치된 지점에서 GPS는 UTC(Universal Time Coordinated)와 위도 및 경도 데이터를 마이크로 컨트롤러에 전송한다. 전송되어진 데이터에 의해 실시간으로 태양위치, 일출 및 일몰시간이 계산되어 진다. 태양 추적에 필요한 데이터들은 범용 비동기화 송수신기(UART)를 통하여 컴퓨터로 전송 받을 수 있다.

• 천문학회보
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• 제37권2호
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• pp.112.2-112.2
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• 2012

For the study of fine-scale structure and dynamics in the solar chromosphere, the Fast Imaging Solar Spectrograph (FISS) was installed in 1.6m New Solar Telescope at Big Bear Solar Observatory in 2010. The instrument, installed at a vertical table of the Coude lab, is properly working and producing data for science. From the analysis of the data, however, we noticed that a couple of problems exist that deteriorate image quality : lower light level and poorer resolution of the CaII band data. After several tests, we found that the relay optics at the right position is crucial role for the spatial resolution of raster-scan images. By using resolution target, we re-aligned relay optics and other components of the spectrograph. Here we present the result of optical test and new data taken by the FISS.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.62-67
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• 2009

This paper describes the characteristics of scroll type stirling engine receiver. Scroll type stirling engine operated scroll compressor and expander instead of piston. Pass dimension of the receiver was $14(W){\times}14(H)$ mm and total pass length was 5,049 mm. External dimension of the receiver was $300{\times}300mm$. The experimental facility consisted of parabolic dish concentrator, compressor to supply air, triplex air filter, and flowmeter. In this study, basic experimental conditions were set at a inlet pressure of 5 bar and volume flow rate of $25m^3/hr$. As a result, air temperature in receiver at each measuring position of point 1, 2, 3 were $241^{\circ}C$, $465^{\circ}C$, and $542^{\circ}C$ respectively at inlet pressure of 5.5 bar and volume flow rate of $24.6m^3/hr$. As DNI increasing, heat transfer coefficient of the receiver changed from $695W/m^2K$ to $827W/m^2K$. Average heat transfer coefficient of receiver in the experiment was $798W/m^2K$. In addition, receiver efficiency became about 83%.

• 한국컴퓨터정보학회논문지
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• 제22권9호
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• pp.33-40
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• 2017

In this paper, we propose a sink-location management and data-routing scheme to effectively support the mobile sink in solar-powered WSN. Battery-based wireless sensor networks (WSNs) have a limited lifetime due to their limited energy, but solar energy-based WSNs can be supplied with energy periodically and can operate forever. On the other hand, introduction of mobile sink in WSNs can solve some energy unbalance problem between sink-neighboring nodes and outer nodes which is one of the major challenges in WSNs. However, there is a problem that additional energy should be consumed to notify each sensor node of the location of the randomly moving mobile sink. In the proposed scheme, one of the nodes that harvests enough energy in each cluster are selected as the cluster head, and the location information of the mobile sink is shared only among the cluster heads, thereby reducing the location management overhead. In addition, the overhead for setting the routing path can be removed by transferring data in the opposite direction to the path where the sink-position information is transferred among the heads. Lastly, the access node is introduced to transmit data to the sink more reliably when the sink moves frequently.

• 한국주거학회논문집
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• 제25권6호
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• pp.49-56
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• 2014

In this study, there is a purpose of using the GIS DB built in DEM, by analyzing the physical characteristics of the building site Yangdong village, to determine the spatial structure of the village. In order to understand the targeted spatial structure of Yangdong Village, the building site was analyzed separately by type and position. Through analysis it is clear the selection of building site relates to the slope and aspect that aquires the most solar radiation in Yangdong Village. This study shows that the amount of solar radiation in the terrain is unfavorable in parts of the village because slope and elevation affect the selection of the building site. That is, this village is confirmed to be influenced by solar radiation, according to slope and elevation, based on how the Yangdong Village is configured. And, while overcoming the adverse conditions to make the most, the village is formed according to the natural environmental conditions.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.111.1-111.1
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• 2011

The solar energy is dramatically increasing as the alternative energy source and the silicon(Si) solar cell are used the most. In this study, the improved process and equipment for the metallurgical refinement of multicrystalline Si were evaluated for the inexpensive solar cell. The planar plane and columnar dendrite aheadof the liquid-solid interface position caused the superior segregation of impurities from the Si. The solidification rate and thermal gradient determined the shape of dendrite in solidified Si matrix solidified by the directional solidification(DS) method. To simulate this equipment, the commercial software, PROCAST, was used to solve the solidification rate and thermal gradient. Si was vertically solidified by the DS system with Stober process and up-graded metallurgical grade or metallurgical grade Si was used as the feedstock. The inductively coupled plasma mass spectrometry (ICP) was used to measure the concentration of impurities in the refined Si ingot. According to the result of ICP and simulation, the high thermal gradient between the two phases wasable to increase the solidification rate under the identical level of refinement. Also, the separating heating zone equipped with the melting and solidification zone was effective to maintain the high thermal gradient during the solidification.

• 한국연초학회지
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• 제22권2호
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• pp.138-142
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• 2000

The effects of stalk cutting time and environmental factors such as air temperature, leaf temperature, solar radiation and leaf moisture content during harvesting and curing in burley tobacco(Nicotiana tabacum L.) on weight loss of fresh stalks and sunburning in leaves were investigated at Chonju Experiment Station, Korea Ginseng & Tobacco Research Institute in 1996 and 1997. Twelve to fifteen percent of the fresh weight was lost in 3 to 4 hours after stalk-cutting, and sunburned leaves could be observed in case of stalk cutting between 11:00 and 15:00 O'clock on a clear sunny day, when the air temperature was 34 to 35$^{\circ}C$, leaf temperature 52 to 54$^{\circ}C$, and solar radiation 700 to 940 w/$m^2$. The leaves exposed to this weather condition were sunburned within 1 hour after stalk cutting. But low temperature (below $25^{\circ}C$) with high solar radiation(above 700w/m2) or high temperature(above 3$0^{\circ}C$) with low solar radiation (below 600w$m^2$) did not induce the sunburn damage in leaves. As the leaf temperature and leaf moisture content were higher, the sunburned leaves increased. The leaves at the higher stalk position were more easily sunburned than those at the lower. This result indicates that the immature leaves with higher chlorophyll content might be more susceptible to sunburning.

• 한국태양에너지학회 논문집
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• 제30권6호
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• pp.102-107
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• 2010

a-Si solar cell has relatively dominant drift current when compared with crystalline solar cell due to the high internal electric field. Such drift current make an impact on the PV module in the local shading. In this paper, the a-Si PV module output characteristics of shading effects was approached in terms of process condition, because of the different deposition layer of thin film lead to rising the resistance. We suggested design condition to ensure the long-term durability of the module with regard to the degradation factors such as hot spot by analyzing the module specification. The result shows a remarkable difference on module uniformity for each shading position. In addition, the unbalanced power loss due to power mismatch of each module could intensify the degradation.

• 생물환경조절학회지
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• 제8권1호
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• pp.49-55
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• 1999

플라스틱온실의 생산비용 절감을 위하여 2단 재배를 시도할 때, 그 생육환경의 적정성을 검토하고자 주요 생육환경 요소인 온도, 습도, 광, 양액온도, 공기속도를 비교하였다. 특히 2단 베드의 구성과 광환경과의 관계로부터 광환경 적정화 방법을 제시하고자 하였다. 그 연구 결과를 요약하면 다음과 같다. 상.하 베드 주요 생육환경의 측정결과를 보면, 상단베드의 최고온도는 38.3$^{\circ}C$, 하단베드의 최고온도는 35.5$^{\circ}C$로 나타났다. 양액 온도는 상.하단 모두 20~$25^{\circ}C$ 범위였으며 하단의 온도가 1$^{\circ}C$ 정도 낮은 것을 알 수 있다. 상대습도는 상 하단 모두 야간에는 95% 정도로 높게 나타났으며 주간에는 상단 60~70% 범위, 하단 65~80% 범위로 하단이 10%정도 높게 측정되었다. PPFD는 상.하 베드 모두 200$\mu$mol.m$^{-2}$ .s$^{-1}$ 정도의 값을 보였고 하단의 경우는 100$\mu$mol.m$^{-2}$ .s$^{-1}$ 이하의 값을 보였다. 상.하 베드 일사량을 보면 상단은 200W.m$^{-2}$ 정도이고 하단은 85 W.m$^{-2}$ 이하가 측정되었다. 공기속도는 상.하 베드에서 주간에는 0.1~0.2m.s$^{-1}$ 정도가 측정되었고, 야간에는 0.05m.s$^{-1}$이하로서 거의 정지 상태였다. 온실방위별 하단베드의 광입사 면적을 이론적으로 해석해 보면, 동서동의 경우는 평균 49.9%이고 남북동의 경우는 평균 43%였다. 광입사 면적을 증대하기 위하여 베드를 재구성하면 동서동은 74.3%, 남북동은 60.8% 정도로 각각 25% 및 17.7% 정도의 광입사 면적의 증대효과를 가져왔다.