• 한국태양에너지학회 논문집
• /
• 제27권4호
• /
• pp.11-17
• /
• 2007

The purpose of this study is to check whether the plate temperature could be lower than the surrounding air by using the radiant cooling during the day time in summer at Seoul. Without an insolation shield as this experiment was performed, a few cases were found. The temperatures of the black painted plate are lower than those of the aluminium film coated plate if the following condition exist; no or small insolation over the plate, the wind velocity less than around 2 m/s, and clear sky However if there are insolation over the plate, the temperatures of the aluminium coated plate are lower than the black painted plate. Also, as the wind velocity increases, the plate temperature decreases faster. The temperature response of the small system is much faster than the large system.

• 대한건축학회논문집:계획계
• /
• 제35권2호
• /
• pp.83-92
• /
• 2019

This study set out to analyze James Turrell's Skyspace works by applying the object relations theory, compare them with several modern architectural works with a sky window based on the analysis results, and check common and differentiating features between them. The findings were as follows: first, Turrell's Skyspace works shed new light on the images of the sky by projecting inner light to the outside; second, sky windows in architecture make the self-representation of inner space clear through the introjection of light; third, 'Hill of the Buddha' reflects the most general aspect of the object relations theory as the nature of projection found in Turrell's Skyspace is added to it; and finally, Turrell installed event-like spaces and steps in 'Roden Crater' to apply the introjection of others that was deficient in Skyspace.

• 설비공학논문집
• /
• 제22권11호
• /
• pp.788-797
• /
• 2010

This study examines the influence of fluctuating daylight illuminance on daylight dimming control systems. Field measurements were performed for a full-scale mocked-up model under various daylight conditions in winter. Fluctuating ranges for a partially-shielded photosensor were great when the variation of sky ratio was great. When solar altitude was lower the illuminance and fluctuating range of illuminance were great due to the influence of direct components of daylight and the interrefelction between surfaces in rear area of space. It implies that daylight dimming system would not function effectively, unless the desktop illuminance by daylight is enough. Fluctuation ranges of photosensor illuminance were lower than 50 lx under clear sky conditions, but they were greater than 100 lx under partly-cloudy sky conditions. It means that the fluctuation range of electric light output of lighting fixture would greater under the partly-cloudy conditions and cause potential visual annoyance to occupants. Outdoor vertical illuminance reaching the windows would be an effective factor that can be used to predict the fluctuation of photosensor signals for effective controls of daylight dimming system.

• 한국농림기상학회지
• /
• 제17권4호
• /
• pp.281-289
• /
• 2015

일조시간 및 일사량은 작물생육에 중요한 기상요소이지만 기상청 동네예보 항목에 없기 때문에 3시간 간격 '하늘상태'를 활용하여 일조시간 및 수평면 일사량을 추정하는 방법을 고안하였다. 기상청 동네예보의 3시간 간격 '하늘상태' 자료를 수집하고 전국 22개 일사관측 기상대의 동시간대 실측 운량과 비교하여 '하늘상태'의 4단계 격자값 '맑음(1)', '구름조금(2)', '구름많음(3)', '흐림(4)'을 0부터 10까지의 운량으로 변환하였다. 22개 일사관측 기상대의 일 평균운량 0인 날에 대하여 일조율을 비교하여 관측여건이 가장 좋은 3개 지점을 선정하였다. 선정된 지점의 3년치 운량과 일조시간 실측자료로부터 운량-일조시간 추정식을 도출하였으며, 이 식에 의해 추정된 일조시간값으로 Angstrom-Prescott 모형을 구동하여 수평면 일사량을 산출하였다. '하늘상태' 기반으로 추정된 일조시간 및 일사량을 3 지점에서 2년간 실측자료와 비교한 결과 RMSE 기준 일조시간 추정오차는 1.5~1.7 시간, 일사량 추정오차는 $2.5{\sim}3.0MJ\;m^{-2}\;day^{-1}$ 이었다.

• Ocean Science Journal
• /
• 제41권4호
• /
• pp.235-244
• /
• 2006

Determining 'photosynthetically active radiation' (PAR) is a key part of calculating phytoplankton productivity in a biogeochemical model. We explore the daily and seasonal variability in the ratio of PAR irradiance to total irradiance that occurred at Ieodo Ocean Research Station (IORS) in the East China Sea under clear-sky conditions in 2004 using a simple radiative transfer model (RTM). Meteorological data observed at IORS and aerosol optical properties derived from Aerosol Robotic Network observations at Gosan are used for the RTM. Preliminary results suggest that the use of simple PAR irradiance-ratio values is appropriate in calculating phytoplankton productivity as follows: an average of $0.44\;({\pm}0.01)$ in January to an average of $0.48\;({\pm}0.01)$ in July, with average daily variabilities over these periods of about $0.016\;({\pm}0.008)$ and $0.025\;({\pm}0.008)$, respectively. The model experiments demonstrate that variations in the major controlling input parameters (i.e. solar zenith angle, precipitable water vapor and aerosol optical thickness) cause PAR irradiance ratio variation at daily and seasonal timescales. Further, increases (>0.012) in the PAR irradiance ratio just below the sea-surface are positively correlated with high solar zenith angles and strong wind stresses relative to those just above the sea-surface.

• 한국대기환경학회지
• /
• 제22권2호
• /
• pp.223-233
• /
• 2006

We analyzed the monthly and seasonal mean of the daily Erythemal Ultraviolet-B (EUV-B, $280{\sim}320nm$) irradiance operating in Pohang, Anmyeon, Gosan, Mokpo and Kangnung with UV-Biometer (Solar Light Co., Model No. 501) at clear-sky noon during the period from 1999 to 2004. Also, we investigated the seasonal and regional characteristics for the UV index over the Korean Peninsula. The daily maximum occurred near solar southing time and the highest monthly accumulated EUV-B irradiance appeared in July and August at each regional observatory. The monthly mean value of the clear-sky EUV-B irradiance in Pohang, Anmyeon, Gosan, Mokpo and Kangnung showed 196.6, 161.8, 221.9, $171.5mWm^{-2}\;and\;179.7mWm^{-2}$ near noon in July respectively. The annual mean value of the daily accumulated EUV-B irradiance in Pohang, Anmyeon, Gosan, Mokpo and Kangnung were 1.8, 2.1, 2.2, $1.8kJm^{-2}\;and\;1.5kJm^{-2}$ respectively. The UV Index (UVI) showed above UVI 7(High) more than 90 days during one year over the Korean Peninsula.

• ETRI Journal
• /
• 제31권2호
• /
• pp.182-192
• /
• 2009

Rain attenuation and intercell interference are two crucial factors in the performance of broadband wireless access networks such as local multipoint distribution systems (LMDS) operating at frequencies above 20 GHz. Power control can enhance the performance of downlink CDMA-based LMDS systems by reducing intercell interference under clear sky conditions; however, it may damage system performance under rainy conditions. To ensure robust operation under both clear sky and rainy conditions, we propose a novel power-control scheme which applies an adaptive neuro-fuzzy inference system (ANFIS) for downlink CDMA-based LMDS systems. In the proposed system, the rain rate and the number of users are two inputs of the fuzzy inference system, and output is defined as channel quality, which is applied in the power control scheme to adjust the power control region. Moreover, ITU-R P.530 is employed to estimate the rain attenuation. The influence of the rain rate and the number of users on the distance-based power control (DBPC) scheme is included in the simulation model as the training database. Simulation results indicate that the proposed scheme improves the throughput of the DBPC scheme.

• 천문학논총
• /
• 제30권2호
• /
• pp.593-594
• /
• 2015

We present our analysis results for an updated orbital ephemeris for the dipping low mass X-ray binary 4U 1624-49, using the light curve collected by the All Sky Monitor (ASM) on board the Rossi X-ray Timing Explorer (RXTE) and the Monitor of All-Sky X-ray Image (MAXI). To make clear dip profiles, the light curve from the ASM and the MAXI were divided into ten 500d segments and four 400d segments for ASM and MAXI light curves, respectively, and folded with the linear ephemeris proposed by Smale et al. (2001). The phases of dip centers were determined by the method adopted from Hu et al. (2008). The phase drift was then fitted with a linear function. We obtained an updated orbital period of 0.869896(1) d and a phase zero epoch of JD 2450088.6618(57). No clear orbital period derivative is detected with a 2-sigma upper limit of $1.4{\times}10^{-6}(yr)^{-1}$ from a quadratic curve fitting of the dip phase evolution.

• 대한한의학원전학회지
• /
• 제11권1호
• /
• pp.224-307
• /
• 1998

The above study is based upon the Theory of Five Woon(Reasons) and Six Qi(Climates), namely Five dynamic Yin and Yang, the principle of five-six combination, the rules of ten periodically changing Woon and twelve periodically changing Qi, and its reference to the main chapters of the theory by several experts. After careful, comprehensive research and study, the followings are concluded. 1. The Theory of Five Woon and Six Qi controls all of the physical phenomena of the universe, yet it originates from Essence of the Sky that is replete and in constant motion within the abysmal expanse of the universe. So it is natural to claim that it is the Essence of the universe that is the source of the variety of phenomena in nature. 2. There is order of dynamics in the Essence and it is Yin Yang Five Movement and expressed by Five Woon and Six Qi. Therefore the Five Woon and Six Qi, which is the climatic changes of nature, is the basis and condition for all of the natural, physical occurrences including the organic phenomena of human beings. 3. Since the Sky embodied the number Five, and the Earth the number Six, Qi of the Sky itself is consequently Five Woon and Qi of the Earth itself is Six Qi. 4. In Sixty Repetition Intervals (Yuk Sip Kap Ja), the Sky took the number Six, designating the six times repetition of the ten Intervals of the Sky and the Earth chose the number Five, symbolizing five times recurrence of the twelve Intervals of the Earth. Though the number for the Sky is Five and the number for the Earth is Six, the two combine and interact in order for the Sky to exploit the number Six and for the Earth to use the number Five. This interplay implies the relationship of operation and principle of Yin in Yang and Yang in Yin. 5. There seems to be clear and intimate association between five dynamics, five bearings and five Qi' in nature and five organs, five stamina, and five emotions in physiological activities of human beings. Such an correlation apparently demonstrates the idea of climatic changes of the universe in balance among human beings, the Sky, and the Earth. 6. Because nature is of an endlessly dynamic organism itself, to have changes must mear there being movements. Thus the climatic changes in nature are the subsequent consummation of the interaction in mutual balance and unbalance of the rise and fall of the Five Woon and Six Qi. 7. The interpretation, by Chang Ji Chong of "Yin and Yang of the Sky are for birth and growth and Yin and Yang of the Earth for demise and interment" as an explanation that the first half is mainly for life and the second half for death, appears to be correct by his view that there is balance and harmony between the long and short and the strong and weak. 8. In addition to Three Yang and Three Yin, as attributes of the Intervals of the Sky and the twelve Intervals of the Earth, Five Woon and Six Qi are utilized in the annual observation of the perpetual changes of climates.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.20-25
• /
• 1998

Solar irradiation controls the exchange of heat energy between atmosphere and land or ocean, and becomes an important factors to the radiance flux at the surface and the biosphere. In order to estimate solar irradiance and earth albedo In Korea peninsula during 1996, GMS date and paramaterization model was combinationally used. In clear sky, the paramaterization model was used to estimate solar iradiance. Also in cloudy sky, the earth albedo was used to calculate the Interceptive effect of solar irradiance. The hourly solar irradiance [the hourly earth albedo] showed generally very low values with <1.00 MJ/m$^2$hr [high values with >0.65] on the middle part (36.00-36.50$^{\circ}$S) and the Southeastern part (near 34.50$^{\circ}$S) in Korea peninsula, respectively. Satellite estimates (GMS data) with pyramometer measurements (in-situ data) were compared for 21 observed stations. Totally, correlation coefficient showed high values with 0.85. In the monthly variation, correlation coefficient of the spring and summer with rms=about 0.42 MJ/m$^2$hr was better than the autumn and winter with rms >0.5 MJ/m$^2$hr. Generally monthly variations of correlation coefficient between satellite estimetes and pyranometer measurements showed r=0.936 in clear sky during 1 year except only May, June, July and August.