• Title/Summary/Keyword: Radiation balance

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Heat Fluxes in the Marine Atmospheric Surface Layer around the Korean Peninsula based on Satellite Data (위성자료를 이용한 한반도 주변 해상 대기표층의 열속)

  • HONG, Gi-Man;KWON, Byung-Hyuk;KIM, Young-Seup
    • Journal of Fisheries and Marine Sciences Education
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    • v.17 no.2
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    • pp.209-217
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    • 2005
  • The energy balance of the surface layer of the water (the Yellow Sea, the East China Sea and the East Sea) was examined using satellite data. Variations of the net heat flux were similar to those of the latent heat flux which was more intensive than the sensible heat flux. The sensible heat flux was affected the difference between the sea surface temperature and the air temperature and was less important over the Yellow Sea. The maximum of the latent heat flux occurred in autumn when the air is drier and the wind is stronger. The shortwave radiation flux decreased with the latitude and depended on the cloudiness as the longwave radiation flux does. Annual variations of heat fluxes show that the latent heat flux was more intensive over the East China Sea than the East Sea and the Yellow Sea, while the spatial differences of the other heat fluxes were weak.

An Improved Estimation of Outgoing Longwave Radiation Based on Geostationary Satellite

  • Kim, Hyunji;Seo, Minji;Seong, Noh-hun;Lee, Kyeong-sang;Choi, Sungwon;Jin, Donghyun;Huh, Morang;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.35 no.1
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    • pp.195-201
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    • 2019
  • The Outgoing Longwave Radiation (OLR) is an important satellite-driven variable for understanding the Earth's energy budget balance. The geostationary OLR retrievals require angular and spectral integration using an empirical equation for irradiance flux-to-OLR from a regression analysis, which determines the accuracy of the narrowband satellite-based OLR. We selected homogeneous pixels which is satisfied less temporal-spatial variability of cloud, on three infrared channels (6.7, 10.8, $12.0{\mu}m$) of the first multipurpose geostationary satellite in Korea, namely the Communication, Ocean and Meteorological Satellite/Meteorological Imager (COMS/MI). Multiple regression analysis was performed to retrieve OLR with improved accuracy using selected parameters based on theoretical and physical significance. This algorithm yielded retrieval with higher accuracy than broadband-based OLR retrieval: RMSE of 10.54 to $3.81W\;m^{-2}$, and bias of -8.49 to $-0.07W\;m^{-2}$.

Design of a Nature-inspired Wideband Sprout-leaf Antenna (자연모사 기반 광대역 새싹 안테나 설계)

  • Woo, Dongsik;Bae, Sunghyun
    • Journal of IKEEE
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    • v.24 no.2
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    • pp.536-542
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    • 2020
  • This paper presents a nature-inspired wideband sprout-leaf shaped antenna with end-fire radiation pattern. A sprout-leaf shape angled-radiator was designed for wide beamwidth radiation patterns for motion detection sensors. An extended and truncated ground plane was used as a reflector for end-fire radiation patterns. To feed the balanced radiator, a broadband microstrip (MS) to coplanar stripline (CPS) balun was utilized with excellent amplitude and phase balance. The proposed antenna demonstrates wide frequency bandwidth from 8.5 to 14.5 GHz with wide beamwidth and the radiation efficiency of 90%. The measured gain is from 4 to 5 dBi and front-to-back ratio was 10 to 20 dB. It has been shown that the proposed antenna can be used for imaging sensors, phased array systems, and radars that require a wide bandwidth and a directional radiation pattern.

Estimation of Daytime Net Radiation above Corn Canopy (옥수수 군낙초관부(群落草冠部) 위에서의 주간순복사량(晝間純輻射量) 추정(推定))

  • Lee, Yang-Soo;Jeong, Young-Sang
    • Korean Journal of Soil Science and Fertilizer
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    • v.21 no.1
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    • pp.11-14
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    • 1988
  • Field study was conducted to evaluate the relationship between daytime net radiation (Drn) and global solar radiation (Rs) and to develop the empirical equation predicting daytime net radiation above corn canopy from observations of Rs and Ta (mean daily air temperature). The relationship between Drn and Rs under the cloudless day was Drn = 0.6659Rs and that under the cloudy (> 35% of possible sunshine) Drn = 0.729Rs. Thus, Drn/Rs Ratio under cloudless day was found to be lower than that under the cloudy day. Rs and Ta were used in the radiation balance equation to estimate Drn and the empirical model could be expressed as $Drn=[0.9Rs-(352-227{\times}10^{-10}{\times}Ta^4)]$ [1.11Rs/Rso - 0.05].

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Evidence Based Approach of Wheel Balance Cancer Therapy: A Review (수레바퀴 암 치료법에 대한 근거중심적 연구)

  • Zheng, Hongmei;Yoon, Jeungwon;Yoo, Hwa-Seung;Cho, Chong-Kwan
    • Journal of Korean Traditional Oncology
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    • v.17 no.2
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    • pp.1-16
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    • 2012
  • Background : Integrative cancer treatment is a holistic approach embracing body, mind, and spirit incorporating conventional treatments of surgery, chemotherapy, radiation and personalized complementary treatments. Wheel Balance Therapy (WBT) of East-West Cancer Center(EWCC), Dunsan Oriental Hospital of Daejeon University was developed to balance out all factors involved in cancer care based on the traditional theories of oriental medicine. Objective : This work aims to analytically review literatures on WBT and its related components. Methods : Literatures published from January 1st, 1990 to April 30th, 2011 were reviewed focusing on 4 main components of WBT; herbal medicine, immune activation, anti-cancer diet, and breathing/meditation. Data were retrieved from medical search engines and electronic data bases including Pubmed, Research Information sharing Service (RISS), Korean-studies Information Service System (KISS), China National Knowledge Infrastructure (CNKI), and Korea's National Digital Library (KNDL). Results : In this review, EWCC's most commonly prescribed formulas are explored. The composition of the formulas, their use in clinical settings as well as the background studies and other therapeutic efficacies are explained. Information on incorporating anti-cancer dietary support and breathing and meditation techniques, other therapies practiced as part of the center's integrative cancer care are also covered. Conclusion : WBT based on holistic theories of oriental medicine embracing body, mind, and spirit is expected to further contribute in promotion of cancer patients' quality of life and prolonged survival time.

Soil Surface Energy Balance and Soil Temperature in Potato Field Mulched with Recycled-Paper and Black Plastic Film (감자밭의 재생종이 및 흑색 플라스틱 필름 멀칭에 따른 지표면 에너지 수지와 토양온도의 변화)

  • 최일선;이변우
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.3
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    • pp.229-235
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    • 2001
  • The thermal and photometric properties of mulching materials modify the radiation and energy balance on the mulched soil surface and thereby change the soil temperature. The soil surface energy balances and soil temperatures under the mulching treatments of non-mulched control, recycled paper (RPM), and black polyethylene film (BPFM) were compared before and after the establishment of potato canopy. On August 30 in 1998 when potato was not emerged yet and solar radiation was 17.9 MJ $m^{-2}$${day}^{-1}$ , the net radiation of the soil surface was estimated as 10.(1, 2. 4, and 1.3 MJ $m^{-2}$${day}^{-1}$ under the control, BPFM, and RPM, respectively. The sensible and latent heat loss from the soil surface was 9.65 MJ $m^{-2}$${day}^{-1}$ in the control, most of the net radiation being lost through evaporation and convection, whereas it amounted only to 1.39 MJ $m^{-2}$${day}^{-1}$ in BPFM and 1.36 MJ $m^{-2}$${day}^{-1}$ in RPM. Therefore, the soil heat fluxes were 0.36 1.02, and 0.06 MJ m$^{-2}$ day$^{-1}$ under the control, BPFM and RPM, respectively. On September 27 when potato canopy was fully developed, the soil surface net radiation in the control was sharply decreased as compared to that of Aug. 30, whereas the net radiation of the mulched soil surfaces showed little changes. The soil heat flux was -0.01, 0.95, and 0.12 MJ $m^{-2}$${day}^{-1}$ at the soil surface under the control, BPFM and RPM, respectively. As the mulching treatments brought about such alteration of energy partitioning into the soil, the highest soil temperature was recorded in BPFM and the lowest in RMP without regard to potato canopy development. However, the soil temperature differences among the treatments become smaller when potato canopy were fully developed.

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Radiation Flux Impact in High Density Residential Areas - A Case Study from Jungnang area, Seoul - (고밀도 주거지역에서의 복사플럭스 영향 연구 - 서울시 중랑구 지역을 대상으로 -)

  • YI, Chae-Yeon;KWON, Hyuk-Gi;Lindberg, Fredrik
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.4
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    • pp.26-49
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    • 2018
  • The purpose of this study was to verify the reliability of the solar radiation model and discuss its applicability to the urban area of Seoul for summer heat stress mitigation. We extended the study area closer to the city scale and enhanced the spatial resolution sufficiently to determine pedestrian-level urban radiance. The domain was a $4km^2$ residential area with high-rise building sites. Radiance modelling (SOLWEIG) was performed with LiDAR (Light Detection and Ranging)-based detailed geomorphological land cover shape. The radiance model was evaluated using surface energy balance (SEB) observations. The model showed the highest accuracy on a clear day in summer. When the mean radiation temperature (MRT) was simulated, the highest value was for a low-rise building area and road surface with a low shadow effect. On the other hand, for high-rise buildings and vegetated areas, the effect of shadows was large and showed a relatively low value of mean radiation temperature. The method proposed in this study exhibits high reliability for the management of heat stress in urban areas at pedestrian height. It is applicable for many urban micro-climate management functions related to natural and artificial urban settings; for example, when a new urban infrastructure is planned.

Evaluation of Water Retentive Pavement as Mitigation Strategy for Urban Heat Island Using Computational Fluid Dynamics

  • Cortes, Aiza;Shimadera, Hikari;Matsuo, Tomohito;Kondo, Akira
    • Asian Journal of Atmospheric Environment
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    • v.10 no.4
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    • pp.179-189
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    • 2016
  • Here we evaluated the effect of using water retentive pavement or WRP made from fly ash as material for main street in a real city block. We coupled computational fluid dynamics and pavement transport (CFD-PT) model to examine energy balance in the building canopies and ground surface. Two cases of 24 h unsteady analysis were simulated: case 1 where asphalt was used as the pavement material of all ground surfaces and case 2 where WRP was used as main street material. We aim to (1) predict diurnal variation in air temperature, wind speed, ground surface temperature and water content; and (2) compare ground surface energy fluxes. Using the coupled CFD-PT model it was proven that WRP as pavement material for main street can cause a decrease in ground surface temperature. The most significant decrease occurred at 1200 JST when solar radiation was most intense, surface temperature decreased by $13.8^{\circ}C$. This surface temperature decrease also led to cooling of air temperature at 1.5 m above street surface. During this time, air temperature in case 2 decreased by $0.28^{\circ}C$. As the radiation weakens from 1600 JST to 2000 JST, evaporative cooling had also been minimal. Shadow effect, higher albedo and lower thermal conductivity of WRP also contributed to surface temperature decrease. The cooling of ground surface eventually led to air temperature decrease. The degree of air temperature decrease was proportional to the surface temperature decrease. In terms of energy balance, WRP caused a maximum increase in latent heat flux by up to $255W/m^2$ and a decrease in sensible heat flux by up to $465W/m^2$.

Fundamental Rights Reflected by the Legislation Regarding Radiation and Nuclear Power (방사선 및 원자력 관련 법제가 반영하는 기본권)

  • Han, Eun Ok;Lee, Jae Seong;Cho, Hong Jea
    • Journal of Radiation Protection and Research
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    • v.41 no.1
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    • pp.15-29
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    • 2016
  • Research background: Despite the visible growth in radiation usage and nuclear power development, the analysis of their relationship with fundamental rights, a subject of public concern regarding issues including the right to health, environmental rights, safety rights, the right to know, the right to development, and the right to life, is currently non-existent. Methods: By examining various fundamental rights in the context of positive laws regarding radiation and nuclear power in an idealistic perspective that guarantees the maximum degree of rights, this paper aims to propose legislative supplements that will lead to improvements in quality of life. Result and discussion: In the South Korean Constitution, radiation and nuclear power is a subject incorporating several rights, including at least 12 clauses that are directly related to fundamental rights; these constitutional rights are manifested in the various clauses of the 14 positive laws regarding radiation and nuclear power. The question on the relative importance of each fundamental right as reflected in these positive laws- whether the right to life should be prioritized or considered equal in weight to the right to health, environmental rights, the right to know, and safety rights- requires careful deliberation and is difficult to humanly resolve in the short term. Conclusion: Making policy that expands the usage of radiation and nuclear power while simultaneously preventing their associated risks is an important task for the Republic of Korea, and a proper value judgment is necessary to find a balance in its associated rights.

Analysis of Heat Loss with Mirror Array and Receiver Shapes on the Dish Solar Collector (반사경 배치 및 흡수기 형상에 따른 접시형 태양열 집열기의 열손실 해석)

  • Seo, Joo-Hyun;Ma, Dae-Sung;Kim, Yong;Kang, Yong-Heack;Seo, Tae-Beom
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.1
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    • pp.35-41
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    • 2008
  • The radiative heat loss from a receiver of a dish solar collector is numerically investigated. The dish solar collector considered in this paper consists of a receiver and multi-faceted mirrors. In order to investigate the performance comparison of dish solar collectors, six different mirror arrays and four different receivers are considered. A parabolic- shaped perfect mirror of which diameter is 1.40 m is considered as the reference for the mirror arrays. The other mirror arrays which consist of twelve identical parabolic-shaped mirror facets of which diameter are 0.405 m are suggested for comparison. Their reflecting areas, which are 1.545 $m^{2}$, are the same. Four different receiver shapes are a conical, a dome, a cylindrical, and a unicorn type. The radiative properties of the mirror surfaces and the receiver surfaces may vary the thermal performance of the dish solar collector so that various surface properties are considered. In order to calculate the radiative heat loss in the receiver, two kinds of methods are used. The Net Radiation Method that is based on the radiation heat balance on the surface is used to calculate the radiation heat transfer rate from the inside surface of the receiver to the environment. The Monte-Carlo Method that is the statistical approach is adopted to predict the radiation heat transfer rate from the reflector to the receiver. The collector efficiency is defined as the results of the optical efficiency and the receiver efficiency. Based on the calculation, the unicorn type has the best performance in receiver shapes and the STAR has the best performance in mirror arrays except the perfect mirror.