• Title/Summary/Keyword: Shading direction

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Series Resistance Change by Partial Shading in a-Si Thin Film Photovoltaic(PV) Module (부분 음영에 따른 a-Si Thin Film Photovoltaic(PV) Module의 직렬저항변화)

  • Shin, Jun-Oh;Jung, Tae-Hee;Kim, Tae-Bum;Woo, Sung-Chul;Yun, Na-Ri;Kang, Ki-Hwan;Han, Deuk-Young;Ahn, Hyung-Keun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.11
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    • pp.901-905
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    • 2010
  • PV module has many power loss factors, and series resistance is the most important elements of them. It is therefore easy to expect the partial shading decrease the lifetime of the semiconductor depletion layer in thin film PV module. Different shading losses could be related with the hot spot which is critical in expecting the reliability issue. In this paper we have modelled the series resistance of the PV module with both different direction of the cell line and shading area of the panel. From the results, thin film a-Si PV module has shown different properties by shading direction.

Studyies on the Shade Adsptation of Native Ground Cover Plants, Disporum spp. and Sedum sarmentosum. (자생지피식물인 애기나리속 식물과 돈나물의 내음성적응실험)

  • 박인환
    • Journal of the Korean Institute of Landscape Architecture
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    • v.21 no.1
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    • pp.1-12
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    • 1993
  • This studies were conducted to investigate on the shade adaptation of native Sedum kamchaticum and Disporum smilacinum. All plants were grow under the controlled light intensity conditions, which controlled by two shading materials, white and/or black shading net. The results obtained were as follow. 1. Daily changes of the shading area around of the building were various by building height, width and direction. 2. Upper canopy was composed to Pinus densiflora as dominant species in native sites of Disporum species. 3. Many branches of Disporum smilacinum were sprouted after pinching. However their growth were less elongated shorter than those of Disporum viridescens. 4. Sedum sarmentosum was poor growth under the low relative light intensity as 50%, however, the growth of this species closely was similiar as under the full sun condition.

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A Study of Fabrication of RF Control System for Building Sunshade (건물 차양을 위한 RF제어 시스템 제작에 관한 연구)

  • Park, Jung-Cheul;Chu, Soon-Nam
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.6
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    • pp.149-157
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    • 2014
  • This paper is based on the fabrication of wireless control system for the building shading device. RF Module was controlled by UHF wireless CC1020 chip which has low electrical power and low electrical voltage. Also 447.8625~447.9875 frequency, 4800Baud data rate and 12.5 kHz channel spacing was controlled by the use of SPDT switch and with Microcontroller program. Furthermore, the helical antenna was used. The starting production of 447.8625~447.9875 kHz wireless electrical power was used. As the result, it did not exceed 10dBm which is the standard of low power wireless system. Shading efficiency was measured at 25%, 50%, 75% direction with controlling the interior temperature and the intensity of illumination at the rate of 1 hour. As the result, the intensity of illumination was lowered to 82~87% at 25% direction with $0.6{\sim}1.4^{\circ}C$ lowered temperature. At 50% direction, the intensity of illumination was lowered to 60~68% with $2.3{\sim}4.1^{\circ}C$ lowered temperature. And at 75% direction, the intensity of illumination was lowered to 41~47% with $3.4{\sim}5.1^{\circ}C$ lowered temperature.

A Pen Drawing Method by Tensor-based Strokes Generation (텐서 기반 스트로크 생성에 의한 펜화기법)

  • Shin, Do-kyung;Ahn, Eun-young
    • Journal of Korea Multimedia Society
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    • v.20 no.4
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    • pp.713-720
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    • 2017
  • We present a non-photo realistic pen-ink drawing method for outlining and shading of the input image. Especially, we focus on the detailed illustration of the image of which stroke's direction is important. The pen-ink renderer is an alternative display models user can generate traditional illustration renderings of their photo realistic image. The previously proposed pen drawing methods produce feasible description in general image but it is difficult to express in detail for the sophisticated images that need to consider the direction of stroke for each image region. In order to overcome the disadvantages of the conventional method, a direction vector is extracted from a tensor field and we determine a stroke's direction in consideration of not only an edge area but also a gradient of a surrounding area in the image. For more detailed description for the sophisticated image, we generate white noises based on the light and shade of the input image and determine the direction and length of the stroke by using the tensor field for each generated white noise. The proposed method works particularly well for traditional architectural images where the direction and detailed description of the pen is important.

CFD Analysis for Microclimate of Venlo Type Glasshouse with the Screen Height and Air-inflow Quantity (스크린설치높이·공기유입량 차이에 따른 벤로형 유리온실 미기상 CFD 유동해석)

  • Yang, Won Mo
    • Journal of Bio-Environment Control
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    • v.29 no.1
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    • pp.52-61
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    • 2020
  • The natural change of winter night temperature from 00:00 to 04:30 O'clock with the different height of thermal screen in a venlo type glasshouse (W59×L68×H5.9 m) was studied using computational fluid dynamics (CFD). At the early stage of CFD analysis, the room temperature decrease of glasshouse with the 5.9 m height of thermal screen were faster than it with the 4.1m height of thermal screen, but at 2 hr after analysis it was slower than in it with the 4,1m, the temperature difference was 0.6℃ after 4 hr. If we consider that turn on the heater when the temperature were decrease below 13℃ at 1hr after CFD analysis, it is good for energy saving in the glasshouse with the 4.1 m height of thermal screen rather than in it with the 5.9 m height, because of the temperature decrease were slow during 2 hrs after analysis. The airflow at the height of 2 m which were grown tomato were fast and wide in the glasshouse with the 5.9 m height thermal screen rather than in it with the 4.1 m, the speed difference was 0.034m·s-1 at 1hr after CFD analysis. The effect of temperature decrease in summer season were compared with the different height of shading screen from 12:00 to 14:30 O'clock. The height of shading screen were 5.7, 3.9 m, the gap of it were 30%. The air-inflow quantity by the fan with duct at lower part of venlo glasshouse was 0.67 ㎥·s-1 until 1hr and to increase 3 times of it from 1hr after analysis. The roof window were open 100%. Until 1hr of CFD analysis, the temperature in the 30% open of shading screen was 0.9℃ higher than in the none shading screen. From 13:00 O'clock when the air-inlet quantity to increase 3 times, the temperature in case 30% gap of shading screen were decreased compare with the none shading screen, the temperature difference was 0.5℃ at 14:30 O'clock. The temperature on the floor surface in case 30% gap of shading screen were lower with it's height increase, the temperature difference was 8℃ compare with none shading screen. The relative humidity difference were insignificant by the height and gap of shading screen.

A Study on the Analysis of Architectural Environments in Medium and Small Scale Elderly Care Facilities (고령화에 따른 중소규모 노인요양원의 건축환경 분석에 관한 연구)

  • Kim, Heung-Gee;Kim, Yong-Gee
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.1
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    • pp.65-72
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    • 2015
  • Recently the concerns of aging & care according to the aged Society were on the increase about Home for the elderly facility. In order to moment, the purpose of this study is to analyze planning direction and Architectural Environments in medium and small scale Elderly Care Facilities. This survey are used to investigate with latest building data, which is Long-term Care Insurance Code for the Elderly was started on July 2008 in Korea. The results of this paper are as follows. First, various type of home for the elderly and the elderly group homes are spread out, attached to day care center type, nursing home type, city region type, countryside rural type, near the university and remodeling type. Secondly, per capita room area-$6.32m^2$ are sufficient in regal comparison with $6.6m^2$. Thirdly, Sunlight environments is inappropriate condition as south direction proportion-41.95%. According to the present situation various facility type and model for our baby boomers generation should be more developed with preemptive systems of senior welfare concept.

A Comparison of Offshore Met-mast and Lidar Wind Measurements at Various Heights (해상기상탑과 윈드 라이다의 높이별 풍황관측자료 비교)

  • Kim, Ji Young;Kim, Min Suek
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.1
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    • pp.12-19
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    • 2017
  • There is a need to substitute offshore met-mast with remote sensing equipment such as wind lidar since the initial installation and O&M costs for offshore met-mast are quite high. In this study, applicability of wind lidar is verified by intercomparison test of wind speed and direction data from offshore met-mast and wind lidar for simultaneous operational period. Results at various heights show no statistical difference in trend and size and data from wind lidar is found to be more accurate and have less error than data from offshore met-mast where error from structural shading effect is significant.

Analysis of Temperature Gradients in Greenhouse Equipped with Fan and Pad System by CFD Method (CFD 기법을 이용한 팬 앤 패드 냉방 온실의 온도경사 분석)

  • Nam Sang Woon;Giacomelli Gene A.;Kim Kee Sung;Sabeh Nadia
    • Journal of Bio-Environment Control
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    • v.14 no.2
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    • pp.76-82
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    • 2005
  • Evaporative cooling pad system is one of the main cooling methods in greenhouses and its efficiency is very high. However, it has some disadvantages such as greenhouse temperature distributions are not uniform and installation cost is expensive. In this study, a CFD simulation model f3r predicting the air temperature distribution in the fan and fad cooling greenhouse was developed. The model was calibrated and validated against experimental data and a good fit was obtained. The influence of different outside wind, fan and pad height, ventilation rate, shading, and greenhouse length, were then examined. In order to reduce the internal temperature gradients, it is desired that the prevail wind direction and the fan and pad heights are considered. The simulation indicates that high ventilation rates and shading contribute to reduce the temperature gradients in the fan and pad cooling greenhouse. In order to maintain the desired greenhouse temperature, the pad-to-fan distance should be restricted according to the design climate conditions, shading and ventilation rates. The developed CFD model can be a useful tool to evaluate and design the fan and pad systems in the greenhouses with various configurations.

Researches on the Case Study of Facade Greening in East Europe (동유럽의 건물벽면녹화에 관한 사례 연구)

  • Park, Yong-Jin
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.1
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    • pp.23-32
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    • 2008
  • In order to discern the development of technology in creating, properly managing, and characterizing the types used in facade greening, this article examines the instances of facade greening of Bulgaria, Greece and Turkey which is not only located in the latitude similar to South Korea's but also influenced by the both continental and oceanic climate. The study was carried out for 11 months from October 2002 to September 2003. The total 242 places were researched and they were 83 sites in Athens, 77 sites in Istanbul, and 82 sites in Sofia. Varieties, usage, configuration, foundation and characteristics of plants were studied. The goals of greening, and building's surface roughness and thickness, direction of the wall were also researched. The result of survey are as follows; 17 families and 33 species of climbing plants were found in Athens, Istanbul, and Sofia. Thickness of facade greening in the three cities is 46cm in Athens, 39cm in Istanbul, and 53cm in Sofia. The possible facade greening size per a climbing plant, Parthenocissus tricupidata takes up the largest portion of the wall in the three cities similarly followed by Vitis vinifera and Wistaria spp. By its diversity it can be assumed that these plants are most practical for large scale of facade greening and full covering. Evergreen climbing plants such as Hedera helix and Ficus niponica are useful plants for relatively large scale of facade greening area. In the facade greening types, the climbing type is the most dominant in the three cities and most of the climbing type was planted on the natural foundation but the hanging and combination types were planted on an artificial foundation located on the balcony or on the roof of the building. In the directions of the walls for facade greening, the west direction are most popular which is for the improvement of sun shading in summer season. In Sofia the apartments were most applied with facade greening but In Istanbul and Athens the residential buildings and the public buildings were adapted with facade greening actively as well as residential building. The purpose of lowering summer heat took up the highest portion followed by the purpose of ornamentation and maintaining privacy in all surveyed cities.