• 제목/요약/키워드: Pollution method

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Pollution 오차를 이용한 요소생성에 관한 연구 (A mesh generation based on the pollution error)

  • 유형선;편수범
    • 한국철도학회논문집
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    • 제2권3호
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    • pp.46-53
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    • 1999
  • In this paper, made was a study on a mesh generation method based on the pollution error. This method is designed for the control of the pollution error in any patch of elements of interest. It is a well-known fact that the pollution error estimates are much more than the local one. When the pollution error is significant, nothing can be said about the reliability of any estimator based on local computations in the patch. Reliable a posteriori error estimation is possible by controlling the pollution error in the patch through proper design of the mesh outside the patch. This design is possible by equally distributing the pollution error indicators over the mesh outside the patch. The mesh generated from the conventional feedback pollution-adaptive mesh generation algorithm needs many iterations. Therefore, the solution time is significant. But the remeshing scheme in the proposed method was used here. It was shown that the pollution-adaptive mesh improves the E.I., simply denoted as Effectivity Index, on the patch of interest, and the pollution error reduces less than the local error.

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GIS based Non-Point Source Pollution Assessment

  • Sadeghi-Niaraki, Abolghasem;Kim, Kye-Hyun;Lee, Chol-Young
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.437-440
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    • 2008
  • In recent years, pollution load calculation has become a topic for research that resulted in the development of numerous GIS modeling methods. The existing pollution method for nonpoint source (NPS) can not be indentified and calculated the amount of the pollution precisely. This research shows that the association of typical pollutant concentrations with land uses in a watershed can provide a reasonably accurate characterization of nonpoint source pollution in the watershed using Expected Mean Concentrations (EMC). The GIS based pollution assessment method is performed for three pollutant constituents: BOD, TN, and TP. First, the runoff grid by means of the precipitation grid and runoff coefficient is estimated. Then, the NPS pollution loads are calculated by grid based method. Finally, the final outputs are evaluated by statistical technique. The results illustrate the merits of the approach. This model verified that GIS based method of estimating spatially distributed NPS pollution loads can lead to more accurate representation of the real world.

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Pollution error를 이용한 개선된 요소생성 알고리즘 (A Modified Mesh Generation Algorithm Using Pollution Error)

  • 유형선;장준환
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.34-42
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    • 2001
  • In this paper, we study on a modified mesh generation method based on the pollution error estimate. This method is designed for the control of the pollution error in any patch of elements of interest. It is a well-known fact that the pollution error estimates are much more than the local one. Reliable a posteriori error estimation is possible by controlling the pollution error in the patch through proper design of the mesh outside the patch. This design is possible by equally distributing the pollution error indicators over the mesh outside the patch. The conventional feedback pollution-adaptive mesh generation algorithm needs many iterations. Therefore, the solution time is significant. But we use the remeshing scheme in the proposed method. We will also show that the pollution error reduces less than the local error.

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부산연안역에서의 대기오염기상 예보시스템 개발에 관한 연구 -고농도 오존일의 예측을 중심으로- (A Study on Development of Air Pollution Weather Forecast System over Pusan Coastal Area - Centering around Forecast of Ozone Episode Day-)

  • 김유근;이화운
    • 한국환경과학회지
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    • 제5권4호
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    • pp.399-410
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    • 1996
  • Pusan is the largest coastal city with a population of about four mi18ion in Korea. Because of increased and confused traffic, photochemical air pollution become a major urban environmental problem recently. The photo-chemical air pollution weather forecasting method preciser than existing air pollution forecast method has been developed to forecast ozone episode days with meteorological conditions using the data measured at 7 air quality continuous monitoring stations from lune to September using 2 years (1994, 1995). The method developed in present study showed higher percentage correct and skill score than existing air pollution forecasting in KMA ( Korea Meteorological Administration).

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옥외 절연물의 전기적 특성 평가를 위한 오손주기시험법 (A Pollution Cycle Method to Evaluate the Electrical Properties of Outdoor Insulators)

  • 이원영;최남호;한상옥;박강식;최태식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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    • pp.6-9
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    • 2001
  • In this research, a experiment was performed to evaluate the electrical properties of outdoor insulator with the pollution cycle method. Cycle test methods such as DCM of STRI, IEC 61109 compared with pollution cycle method. Using dimatic properties of Korea peninsula, we could get the optimal condition for the pollution cycle method. As the factor, clean and saline fog, voltage, rainfall and drying was chosen. The applied voltage is 13,2 kV, the salinity of salt solution was changed from 0.1 wt% to 1.5 wt% and one cycle is about 4 hours. To ensure the reproducibility and reliability, experiments repeated 4 times. The leakage current was measured with Lab VIEW and the ESDD was measured with brushwiping method. This experiment could ensure superiority of pollution cycle method which developed through the result of this experiment and we could know the relationship between ESDD, leakage current and relative humidity.

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地域代表性과 汚染被害를 考慮한 大氣汚染 測定網 配置技法의 開發에 關한 硏究 (Development of an Air Pollution Monitoring Network Design Method Based on Regional Representativeness and Pollution Damage Impact)

  • 김태형;김정욱
    • 한국대기환경학회지
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    • 제3권1호
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    • pp.47-54
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    • 1987
  • A new method for designing air pollution monitoring newtork is presented in this study. In this method, the magnitudes and the correlation coefficients of predicted concentrations in each grid points are examined and the monitoring stations are assigned to those stations which cover the damage cost the most. This method was applied to the Ulsan-Onsan Industrial Complex. This method turned out to be much more efficient than the method of TM coordinates and the method of concentric circles prescribed in the Standard Methods for Pollution Measurement as well as the existing monitoring system established in the area. The 21 stations selected by the method of TM coordinates could cover only 64.4% of the damage cost in the area, the 16 stations by the method of concentric circles 72.1%, and the existing 21 stations 67.8%, while 11 stations were enough to cover 90% of the damage cost in the area with this method. It also was found that this method required only 24 stations to cover the entire area.

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Mathematical Modeling on AC Pollution Flashover Performance of Glass and Composite Insulator

  • Prakash, N.B.;Parvathavarthini, M.;Madavan, R.
    • Journal of Electrical Engineering and Technology
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    • 제10권4호
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    • pp.1796-1803
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    • 2015
  • While considering the current scenario, in this world power demand goes on increases day by day. Frequent power outages occur in high voltage transmission line due to the deprived performance of polluted insulators; this affects overall operation of power system and may indirectly impinge on the growth of production sector. Many researchers are keenly taking efforts to provide highly reliable and stable power to neediest. In this paper, A.C pollution flashover performance of disc type glass insulator and composite long rod insulators investigation under various artificial pollutions by varying Equivalent Salt Density Deposition (ESDD) levels. Here, we use different types of pollution methods like binding method, dipping method and spraying methods with different types of pollutants concentration. Based on dimensional analysis, four different Mathematical models have been developed to predict the A.C pollution Flashover Voltage (FOV) of insulators. Both the experimental and mathematically modeled results are compared; it's observed that mathematical model 3 yields better results.

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

  • Kim, Yoo-Keun;Lee, Hwa-Woon;Lee, Yong-Seob
    • Journal of Korean Society for Atmospheric Environment
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    • 제11권E호
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    • pp.23-29
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    • 1995
  • 산업 도시 부산에서 관측된 기상자료와 대기오염 자료를 이용해 대기오염과 대기투과도의 상호 관계를 연구하였다. 부산에서 대기오염에 의한 대기투과도를 예측하는데 경험적인 모델을 구축하기 위해 여러 기상 요소와 대기오염을 사용하였고, 이 결과를 Yamamoto et al.(1968)에 의한 대기투과도 계산 방법과 비교하였다. 그 결과, 두 방법에 의한 결과는 좋은 상관을 나타내었다. 따라서 본 연구에 의해 제시된 대기오염의 모수화는 부산에서 대기투과도와 직달일사량을 신뢰성 있게 예측하는 하나의 방법이라 생각된다. 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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도로조명의 빛공해 계산 및 규제안 제안 (Calculation and Regulation Proposal of Light Pollution from Road Lightings)

  • 조숙현;이민욱;최현석;김훈
    • 조명전기설비학회논문지
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    • 제25권12호
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    • pp.21-26
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    • 2011
  • This is a study to establish regulations against light pollution for lighting on roads. Many kinds of light pollution by luminaire on roads was calculated and analyzed by applying the classification method of luminaires(Cut-off classification of IDA-IESNA, BUG Rating Classification) and the calculation method of Upward Lighting Ratio of CIE among measures to prevent light pollution that international lighting organizations suggest. As a result of the analysis, it was found that the regulation by Cutoff of IESNA and ULR classification of CIE could be one for scattered light of light pollution compared to BUG classification but is not sufficient for the regulation of light tresspass or glare. BUG classification by each lighting zone was suggested as threshold value of the light pollution regulation considering domestic conditions.

빛공해 방지를 위한 관리기준 및 조명환경관리구역 설정 방안에 관한 연구 (A Study on the Control Standards and an Environmental Lighting Zone-Setting method for Making Light Pollution Management)

  • 김기태;오민석;김회서
    • 조명전기설비학회논문지
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    • 제25권12호
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    • pp.27-33
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    • 2011
  • This study aims to suggest some problems, which occur when environmental lighting zone is set by use-zone only, by comparing and analyzing the artificial illumination luminance. In addition, this study aims to review the control standards of light pollution and to suggest a practical environmental lighting zone-setting method. I checked out the standards of average surface luminance and luminance contrast as for light pollution management. In addition, I did some research on evaluation of light pollution on surroundings based on investigation of use-environment as for lighting environment setting method.