• Title/Summary/Keyword: transmissivity

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Characteristic analysis of solar radiation and atmospheric transmissivity at Chupungryeong (추풍령의 일사량과 대기투과율의 특성 분석)

  • Park, Jin Ki;Kim, Bong Seop;Park, Jong Hwa
    • Korean Journal of Agricultural Science
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    • v.41 no.2
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    • pp.149-155
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    • 2014
  • The surface solar radiation is an important indicators for climate and agricultural research over the Earth system. For the climate and agricultural research, long-term meteorological data and accurate measured data are needed. The daily solar radiation from Jan. 2001 to Dec. 2010 have been employed in this study analyze atmospheric transmissivity for Chupungryeong. The corresponding daily value of atmospheric transmissivity is calculated for Chupungryeong meteorological data. In this paper, relationship analysis of daily solar radiation and atmospheric transmissivity is presented. It shows that atmospheric transmissivity over late December peaked in the 2000s, substantially decreased from the early-January, and changed little after that in summer. Reduction of solar radiation caused a reduction of more than 0.3 in atmospheric transmissivity during July to August. It was concluded that the atmospheric transmissivity could be very useful for evaluating solar radiation. Atmospheric transmissivity approach is suitable for daily-term simulation studies and useful for computing solar radiation.

Attenuation of the Atmospheric Aerosol Transmissivity due to Air Pollution (대기오염에 의한 대기투과도 감쇠에 대한 연구)

  • Kim, Yoo-Keun;Lee, Hwa-Woon;Lee, Yong-Seob
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.E
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    • pp.23-29
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    • 1995
  • Relationship between atmospheric aerosol transmissivity and air pollution was analyzed using observed data in a large industrial city, Pusan, Korea. The atmospheric aerosol transmissivity predicted by method of present study in Pusan was assessed by the method of Yamamoto et al.(1968) in order to set up an empirical model to predict the transmissivity using the various meteorological parameters and air pollution. As a result, good correlation between these tow method re observed. Thus, it is possible to conclude that the parameterization of air pollution suggested by this study is another method to give reliable estimate of atmospheric aerosol transmissivity and direct solar irradiance in Pusan.

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Determination of Aqnifer Characteristics from Specific Capacity Data of Wells in Cheju Island (제주도 지하수의 우물 비양수량자료를 이용한 대수층상수 결정방법)

  • 최병수
    • Journal of the Korean Society of Groundwater Environment
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    • v.6 no.4
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    • pp.180-187
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    • 1999
  • Transmissivity is often estimated from specific capacity data because of the expense of conducting standard aquifer test to obtain transmissivity and the relative availability of specific capacity data. Most often, analytic expression relating specific capacity to transmissivity derived by Theis (1963). Brown (1963). and Logan (1964) are used in this analysis. The analytic solution typically used to predict transmissivity from specific capacity in alluvial aquifers assuming influence radius and/or storage coefficient of the aquifers. But those do not agree well with the measured transmissivity in fractured rock aquifers and in heterogeneous aquifers. Razack-Huntely (199l). Huntely-Steffey (1992). and Mace (1997) proposed emphirical rotations between specific capacity and transmissivity in heterogeneous alluvial aquifers. fractured rock aquifers, and karst aquifers. This study focuses on comparison between transmissivity and specific capacity data in volcanic rock aquifers of Jeju Island. Emphirical relation between the log of transmissivity and the log of specific capacity suggests they no linearly related (correlation coefficient 0.951) and the width of $\pm$0.25 log cycles in transmissivity includes 96.6% of data.

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Estimation of Transmissivity Using Parameters of Groundwater Table Fluctuation Model (지하수위 변동 해석모델의 매개변수를 이용한 투수량계수 추정)

  • Kim, Nam-Won;Kim, Youn-Jung;Chung, Il-Moon
    • Journal of Environmental Science International
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    • v.24 no.4
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    • pp.461-470
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    • 2015
  • As hydrogeologic parameters such as hydraulic conductivity and specific yield are estimated by aquifer test, these are dependent on specific points at which field test was conducted. To overcome these site-specific limitations, a method of estimating transmissivity of aquifer using distribution features for parameters in Water table fluctuation model is newly suggested. Distribution features in reaction factor, specific yield and transmissivity having the function of pore space in aquifer are used to derive empirical equation for estimating transmissivity. From the result for applying the equation for 10 groundwater stations in Northeast Jeju Island, this equation is available for estimating transmissivity compared to the value estimated by existing equations. The estimated transmissivity ranged from 14.2 to $3,716.9m^2/day$, and its average was $821.8m^2/day$.

A Simulation Model for the Analysis of Direct and Diffuse Solar Radiation in Glasshouse - Effect of orientation on the transmissivity of direct solar radiation in single- span glasshouse - (유리온실내의 직달일사 또 산란일사 해석을 위한 시뮬레이션 모형 - 동방위가 단동 온실내의 직달일사 투과율에 미치는 영향 -)

  • 김용현;이석건
    • Journal of Bio-Environment Control
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    • v.6 no.3
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    • pp.176-182
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    • 1997
  • A simulation model for the analysis of the transmissivity of direct and diffuse solar radiation In glasshouse was developed. This model would be applicable to investigate the influences of time of year, orientation and slope of glasshouse, dimensions of the frames used, and latitude of the site on the transmissivity of direct and diffuse solar radiation in single-span or multispan glasshouse. The transmissivity of diffuse solar radiation was 60.4% for the single-span glass-house. It was independent of both orientation and time of year, During the winter season, the transmissivity of direct solar radiation was 67~69% for the E-W orientation single-span glasshouse, which was 14~16% higher than that for the S-N orientation. Oppositely the transmissivity of direct solar radiation for the S-N orientation was higher than that for the E-W orientation. during the autumn season. There was no influence of the latitude In the country on the transmissivity of direct solar radiation.

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Analysis of the Transmissivities of Direct and Diffuse Solar Radiation in Multispan Glasshouse (연동 유리온실내의 직달일사 및 산란일사 투과율 해석)

  • 김용현;이석건
    • Journal of Biosystems Engineering
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    • v.23 no.5
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    • pp.439-444
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    • 1998
  • Effects of the number of spans, orientation and latitude on the transmissivities of direct and diffuse solar radiation in multispan glasshouse were analyzed using a computer simulation model (Kim and Lee, 1997). The number of spans did not affect the transmissivity of diffuse solar radiation, ranging 60∼61%. The transmissivities of direct solar radiation were 55∼64% for E-W orientation and 47∼70% for N-S orientation in ten multispan glasshouse. There was no effect of the latitude on the transmissivity of direct solar radiation in domestic regions. Differences in the transmissivity of direct solar radiation between single-span and multispan glasshouse were significant for E-W orientation during winter season; however, those were relatively small for N-S orientation throughout the year. Transmissivity of direct solar radiation decreased with the increasing number of spans for E-W glasshouse, whereas those for N-S glasshouse was hardly affected by the number of spans.

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Effects of frame ratio and length on the transmissivity of solar radiation in glasshouse by a computer simulation (컴퓨터 시뮬레이션에 의한 유리온실내의 일사 투과율에 미치는 골조율 및 동길이의 영향)

  • 이석건;김용현
    • Journal of Bio-Environment Control
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    • v.8 no.3
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    • pp.202-208
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    • 1999
  • This study was conducted to investigate the effects of the frame ratio and greenhouse length on the transmissivities of direct and diffuse solar radiation in glasshouse using a computer simulation model developed by Kim and Lee(1997). Transmissivity of diffuse solar radiation slightly decreased as the frame ratio increased. There was no effect of number of spans on the transmissivity of diffuse solar radiation at the same frame ratio. In single or multispan glasshouse, transmissivity of direct solar radiation was 1.5-3.0% higher at the frame ratio of 11.3% than those at the frame ratio of 14.9%. Also the transmissivity of direct solar radiation was 1.5-3.0% lower at the frame ratio of 18.3% than those at the frame ratio of 14.9%. Effect of the increased or decreased frame ratio on the transmissivity of direct solar radiation was similar in I-W or S-N glasshouse. Since the high transmissivity of direct solar radiation exerted a beneficial influence upon the plant growth during winter season, the light and endurable structural members were needed to maximize the transmission of solar radiation in glasshouse. Transmissivity of direct solar radiation in I-W or S-N glasshouse did not vary with the length of 24.5m long or more.

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Analysis of Direct and Diffuse Radiation in Plastic Greenhouse (플라스틱 하우스의 직달(直達) 및 산란(散亂) 일사량(日射量) 해석(解析))

  • Koh, Hak-Kyun;Kim, Moon-Ki;Kim, Yong-Hyeon
    • Solar Energy
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    • v.9 no.3
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    • pp.13-24
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    • 1989
  • Direct and diffuse components of solar radiation were measured inside and outside a single-span plastic greenhouse. To analyze the direct solar radiation inside the plastic greenhouse, the cross-section of the greenhouse was assumed to be circular. Then the direct solar radiation transmitted into the greenhouse was calculated theoretically, and compared with the experimental measurements. The results are summarized as follows: (1) The transmissivities of total solar radiation were about 65% on cloudy days and 50% on clear days. For cloudy days, the transmissivity of the total solar radiation was regarded as the transmissivity of sky diffuse radiation. (2) The ratio of the inside effective scattered component of direct solar radiation to the diffuse radiation was 60-65%. (3) It appeared that the seasonal variation of the transmissivity of total solar radiation was adversely affected by the transmissivity of direct solar radiation and the effective scattered coefficient. But the effect of the transmissivity of direct solar radiation was dominant factor. (4) Computer simulation showed that the inside direct solar radiation was decreased as the floor of the plastic greenhouse was higher. (5) The predicted value of the inside direct solar radiation was 3.3% to 29.0% higher than the measured value.

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Manufacture Technology Development of Paper Mending Tape for Conservation of Archive Document (종이 기록물 보수용 안전 테이프 시제품 제조 기술 연구)

  • Shin, Joung-Soon;Yoo, Sun-Kyun
    • Journal of the Korean Graphic Arts Communication Society
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    • v.29 no.3
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    • pp.41-53
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    • 2011
  • For manufacturing the tape for repairing archival documents, we tested ten carrier candidates for selecting best material. The tensile strength, transmissivity, stability of deterioration, and processability were determined. Physical-chemical characteristics and stability of deterioration was best to the Hanji. Tensile strength and transmissivity was best in tracing paper, but was low in oil paper, white sketch paper, lyon coat paper. Synthetic carrier to tensile strength showed higher than paper carrier and to the transmissivity showed 2-8 times higher than paper carriers. The tracing paper to the transmissivity was 10 times higher than others. To determine characteristic of conservation to the selected carriers, stability of deterioration was examined at conditions of $90^{\circ}C$ for 15 days. Oil paper and white sketch paper turned strongly yellowish. Cellulopane, Felt, and Cpp film showed stable stability of deterioration, but deformation like wrinkles. PET film and Syntheletic film showed excellent conservation characteristics without any change of exterior. Test of adhesive uniform between carriers and adhesive processability was performed. PET film > Syntheletic film > Tracing Paper in order were determined. Ununiformal adhesive characteristics appeared to Hangi. Accordingly, we thought that Hanji as carrier material might be unsuitable because of low adhesive processability.

Hydraulic Properties of Duksan Hot-spring Area (덕산온천 지역의 수리적 성질)

  • 함세영;조병욱;성익환
    • The Journal of Engineering Geology
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    • v.9 no.2
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    • pp.101-118
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    • 1999
  • The pumping test analysis on 28 pumping test data in Duksan hot-spring area was performed using the fractal model, the leaky fractal model, and the steady-state dual-porosity fractal model. The fractional flow dimension 1.9 or 2.0 was determined in the central put of the hot spring and the fractional flow dimension 1.5-1.7 in the marginal area. For the flow dimension 2.0, the correlation between the transmissivity and the productivity index by the aquifer loss was much better than that between the transmissivity and the specific yield by the total drawdown. On the other hand, for the flow dimension 1.9, the correlation between the generalized transmissivity and the productivity index was very similar to that between the generalized transmissivity and the specific yield.

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