• Title/Summary/Keyword: heat budget

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Estimation of Surplus Solar Energy in Greenhouse (II) (온실내 잉여 태양에너지 산정(II))

  • Suh, Won-Myung;Bae, Yong-Han;Ryou, Young-Sun;Lee, Sung-Hyoun;Kim, Hyeon-Tae;Km, Yong-Ju;Yoon, Yong-Cheol
    • Journal of Bio-Environment Control
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    • v.20 no.2
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    • pp.83-92
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    • 2011
  • This study is about an analysis of surplus solar energy by important greenhouse type using Typical Meteorological Year (TMY) data which was secured in order to provide basic data for designing an optimum thermal storage system to accumulate surplus solar energy generated in greenhouses during the daytime. The 07-auto-1 and 08-auto-1 types showed similar heat budget tendencies regardless of greenhouse types. In other words, the ratios of surplus solar energy were about 20.0~29.0% regardless of greenhouse type. About 54.0~225.0% and 53.0~218.0% of required heating energy will be able to be supplemented respectively according to the greenhouse types. The 07-mono-1 and 07-mono-3 types also showed similar heat budget tendencies regardless of greenhouse types. In other words, the ratios of surplus solar energy were about 20.0~26.0% and 21.0~27.0% respectively by greenhouse type. About 57.0~211.0% and 62.0~228.0% of required heating energy will be able to be supplemented by greenhouse type. Except for Daegwallyeong and Suwon area, other regions can cover heating energy only by surplus solar energy, according to the study.

Progess in Fabrication Technologies of Polycrystalline Silicon Thin Film Transistors at Low Temperatures

  • Sameshima, T.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.129-134
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    • 2004
  • The development of fabrication processes of polycrystalline-silicon-thin-film transistors (poly-Si TFTs) at low temperatures is reviewed. Rapid crystallization through laser-induced melt-regrowth has an advantage of formation of crystalline silicon films at a low thermal budget. Solid phase crystallization techniques have also been improved for low temperature processing. Passivation of $SiO_2$/Si interface and grain boundaries is important to achieve high carrier transport properties. Oxygen plasma and $H_2O$ vapor heat treatments are proposed for effective reduction of the density of defect states. TFTs with high performance is reported.

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Examination of Heat Budget Model for Urban Thermal Environment Evaluation (도심지의 열환경 평가를 위한 열수지 모델의 검증)

  • 김상백;염향희;권병혁;김연희;오성남
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.504-505
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    • 2003
  • 국지규모의 기상해석을 위한 기존의 방법은 중규모 모델로부터 down-nesting에 의한 방법으로 모델의 해상도를 향상시켜 기상장을 해석하는 것이 일반적이다(Clark and Farley, 1984). 그러나, 이 방법은 단지 물리적인 격자구조만을 향상시킨 것으로 근본적인 모델 내부 구조의 향상을 가져온 것은 아니다. 따라서, 다양한 토지 피복이 혼재해 있는 도심지를 대상으로 하는 고해상도의 국지기상 모델에 대하여 계산시간과 정확성을 고려한 효율적인 지표면 열수지 모델의 구축이 요구되고 있다. (중략)

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Design Study of a Korean Mars Mission

  • Lee, Eun-Seok;Chang, Keun-Shik;Park, Chul
    • International Journal of Aeronautical and Space Sciences
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    • v.5 no.2
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    • pp.54-61
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    • 2004
  • In this paper we carried out a design study for an unmanned Mars missionsuitable for Republic of Korea. The mission will use a KSLV series launch system,which is to place a one tonne payload into the LEO. We calculated the velocityincrements(AV) required for departure from Earth and insertion into the orbitaround Mars based on the mission opportunity data provided by NASA. Two typesof Mars modules - entry type and orbiter type - were considered in this studyWe calculated the mass of TPS(therma1 protection system) for the entry tvpe Marsmodule based on the heat transfer rate and heat load from the Mars atmosphere tothe surface of the TPS. The heat transfer rate and heat load were obtained throughan entry trajectory calculation. For the orbiter type Mars module, we calcuIated themass breakdown of the additional spacecraft which is to insert the Mars moduleinto the orbit around Mars. Other mass items were determined by proportioningfrom the existing Mars modules. This paper finally proposes the payload capacitiesfor each types of Mars modules.

Airborne Remote Sensing of Evapotranspiration over Rice Paddy

  • Chen, Y.Y.;Liou, Yuei-An
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.351-353
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    • 2003
  • We present a retrieval scheme for the remote sensing of evapotranspiration (ET) over rice paddy. To perform the retrieval, high-resolution airborne imagery of multi-spectral visible and thermal infrared data, and ground-based meteorological measurements are utilized. Our ET retrieval scheme is based on the basic principal of surface energy budget, which is a result of balance in longwave and shortwave radiation, latent heat, sensible heat, and energy flux into the ground. To partition the latent and sensible heat fluxes of interest from the energy balance equation, three basic parameters are of most concern, including albedo, surface temperature, and normalized difference vegetation index (NDVI). The NDVI and albedo can be easily derived from the visible and near infrared spectral data, while the surface tem-perature can be determined through the analysis of the infrared data with the Stefan Boltzmann law. From the airborne imagery taken on 28 April 2003, we observe very good dry and wet pixels that can be easily corre-sponded to the radiation and evaporation controlled crite-ria, respectively, and, hence, for the further use in defin-ing the evaporative fraction needed to partition sensible and latent heat fluxes from the net energy flux. The de-rived ET is compared with the in situ measurements.

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The Analysis of Mesoscale Circulations Characteristics Caused by the Evaporation-Efficiency of Water Retention Pavement (보수성 도로 포장재의 증발효율 변화에 의한 중규모 순환장 특성 분석)

  • Kim, In-Su;Lee, Soon-Hwan;Kim, Hae-Dong;Suh, Young-Chan
    • Journal of the Korean earth science society
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    • v.30 no.6
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    • pp.709-720
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    • 2009
  • Field observation and numerical experiments were conducted to understand the impact of water retention pavement on the surface heat budget and on the regional circulation. The numerical model applied in this study is the atmospheric dynamic model Local Circulation Model (LCM) with two dimensional grid system, and a field observation was carried out under the clear sky and calm conditions of the weather on 19 July 2007. In the field observation, the maximum value of surface temperature on pavement covered with water retention material reached the $41.2^{\circ}C$ at 1430 LST and the values was lower for $16.1^{\circ}C$ than that of asphalt without the material. The Case BET03 assumed to be 0.3 for the surface evaporation efficiency was in good agreement with the observation and its sensible and latent heat fluxes were numerically estimated to be 229 and 227 $W/m^2$, respectively. Results of the numerical experiments demonstrated that the water retention pavement tends to induce the increase of latent heat flux associated with the lower surface temperature and mixing height during the daytime. Discontinuity of latent heat caused by the water retention pavement also tends to promote the development of mesoscale circulation called as land-land breeze or country breeze.

A Numerical Analysis of Regional Atmospheric Circulation with Large Scale Reclamation of Coastal Region (대규모 해안매립에 따른 기상장 변동의 수치해석)

  • 이성대
    • Journal of Ocean Engineering and Technology
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    • v.14 no.3
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    • pp.46-54
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    • 2000
  • Three dimensional numerical experiments that included the land-use transformation by the large scale reclamation were used to investigate the mesoscale air flow over the coastal regions. In this paper the surface temperature of the inland was determined through the surface heat budget consideration with inclusion of a layer of vegetation. The vertical diffusion coefficients of momentum, heat and specific humidity in the constant flux layer were taken from the Mellor and Yamada(1975). It has shown that the resulting model is able to reproduce the air circulation in coastal regions, and the simulated characteristics agree with the known properties of this circulation. A series of numerical experiments were then carried out to investigate the diurnal response of the air flow to various types of surface inhomogeneities.

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Numerical Analysis of Meso-Scale Circulation with Inclusion of a Layer of Vegetation over Ulsan Area (식생의 영향을 고려한 울산지역의 중규모 지역기상장에 관한 연구)

  • Lee, Seong-Dae
    • Journal of Korea Water Resources Association
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    • v.30 no.2
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    • pp.119-129
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    • 1997
  • A three-dimensional numerical model for the simulation of meso-scale local circulation is developed and it is applied to the land and sea breezes which take place around Ulsan. The surface temperature and moisture on the land are determined by means of the surface heat budget with a layer of vegetation considered. The vertical diffusion coefficients of momentum, heat and specific humidity at the surface layer are obtained by the lever-2 model of the turbulence closure proposed by Yamada (1982). This model proved to be effective in simulating the structure of the land and sea breezes around Ulsan.

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Radiative Role of Clouds on the Earth Surface Energy Balance (지표 에너지 수지에 미치는 구름의 복사 역할)

  • Hong, Sung-Chul;Chung, Ii-Ung;Kim, Hyung-Jin;Lee, Jae-Bum;Oh, Sung-Nam
    • Journal of Environmental Science International
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    • v.16 no.3
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    • pp.261-267
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    • 2007
  • In this study, the Slab Ocean Model (SOM) is coupled with an Atmospheric General Circulation Model (AGCM) which developed in University of Kangnung based on the land surface model of Biosphere-Atmosphere Transfer Scheme (BATS). The purposes of this study are to understand radiative role of clouds considering of the atmospheric feedback, and to compare the Clouds Radiative Forcing (CRF) come from the analyses using the clear-cloud sky method and CGCM. The new CGCM was integrated by using two sets of the clouds with radiative role (EXP-A) and without radiative role (EXP-B). Clouds in this two cases show the negative effect $-26.0\;Wm^{-2}$ of difference of radiation budget at top of atmosphere (TOA). The annual global means radiation budget of this simulation at TOA is larger than the estimations ($-17.0 Wm^{-2}$) came from Earth Radiation Budget Experiment (ERBE). The work showed the surface negative effect with $-18.6 Wm^{-2}$ in the two different simulations of CRF. Otherwise, sensible heat flux in the simulation shows a great contribution with positive forcing of $+24.4 Wm^{-2}$. It is found that cooling effect to the surface temperature due to radiative role of clouds is about $7.5^{\circ}C$. From this study it could make an accurate of the different CRF estimation considering either feedback of EXP-B or not EXP-A under clear-sky and cloud-sky conditions respectively at TOA. This result clearly shows its difference of CRF $-11.1 Wm^{-2}$.

Development of a Method for Measuring Social Interest Index on Disaster Using News Data (뉴스 데이터를 활용한 재난에 대한 사회적 관심 측정방법 개발)

  • Eun Hye Shin;Do Woo Kim;Jae Hak Chung;Seong Rok Chang
    • Journal of the Korean Society of Safety
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    • v.38 no.5
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    • pp.27-35
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    • 2023
  • Social interest in disasters is a significant factor in shaping disaster management policies, enabling the enhancement of disaster safety management and prevention activities according to the specific needs of society. However, in the past, there were limits to measuring which disasters society was particularly interested in. Hence, in this study, a method of measuring social interest using news data was devised. Specifically, we classifed news reports into natural and social disasters, creating a comprehensive Social Interest Index (SII) on disasters covering from 2011 to 2021. Additionally, we quantitatively compared the SII with budgets allocated to disaster-related efforts. Our primary findings are as follows: First, our methodology not only distinguishes natural disasters from social disasters but also identifies emerging areas of societal concern. Second, in recent years (2014-2021), social disasters gained more attention than natural disasters. Third, the disaster safety budget accounted for approximately 3.5% of Korea's total budget, closely paralleling the SII we measured. However, exceptions were noted in cases such as heavy snow, cold waves, and heat waves, where the SII remained high, but the disaster safety budget was relatively low, indicating potential outliers. The findings of this research are projected to contribute to the improvement of national disaster management policies by providing a quantitative measure of social interest in disaster, enabling more informed and effective policy decisions.