• 제목/요약/키워드: Concentration Estimation

검색결과 944건 처리시간 0.026초

확률강우량을 이용한 AMC 조건에 따른 비점원 오염량의 변화 (Variation of Non-Point Source Pollution according to AMC Condition Using Probable Rainfall)

  • 안승섭
    • 한국농공학회지
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    • 제42권3호
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    • pp.76-88
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    • 2000
  • AGNPS model is applied in this study to analyze the changes of non-point source pollutant according to AMC condition using probable rainfall. Probable rainfall of H-dam area by Gumber's extreme value distribution is computed through frequency analysis for each return period. 35 coarse grids are subdivided into 134 find grids of finite differential network to analyze peak flow soil loss quantity and nutrients of study area and the modified CN estimation equation shows good result about rainfall events-peak flow relationship. And as the consequence of estimation of soil loss quantity for each rainfall event soil loss quantity shows 120%-170% of actual soil loss quantity Regression analysis for the observed and calculated values of flow T-P AMC has an important effect on nutrients concentration of outflow and it if found that the excessive fertilization under AMC III condition may cause eutrophication by nutrients because the range of increase of outflow concentration appears relatively high.

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자동차용 배기관 설계를 위한 유동 및 구조 해석 (CFD and Structural Analysis for Design of Automobile Exhaust Manifold)

  • 이광수
    • 한국산학기술학회논문지
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    • 제8권5호
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    • pp.984-990
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    • 2007
  • 본 연구에서는 자동차용 배기관에 대하여 유동, 열변형 및 내구해석 등 유동과 구조의 연계 해석을 수행하여, 배기관의 $O_2$ 농도의 유동분포, 고온의 배기가스에 의한 열적 거동 및 그 내구성능을 평가함으로써, 자동차 배기관의 최적설계를 위한 가이드로 활용하고자 한다.

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An Efficient Method Of The Suspended Sediment-Discharge Measurement Using Entropy Concept

  • Choo, Tai-Ho
    • Water Engineering Research
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    • 제1권2호
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    • pp.95-105
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    • 2000
  • A method is presented which enables easily the computation of the suspended sediment discharge as the mean sediment concentration and mean flow velocity. This method has significant advantages over the traditional method, which principally depend on a set of measured concentration data. The method is based on both a new sediment concentration and mean sediment concentration equations which have been derived from the entropy concept used in statistical mechanics and information theory: (1) The sediment concentration distribution equations derived, are capable of describing the variation of the concentration in the vertical direction. (2) The mean concentration equation derived, is capable of calculating easily the mean concentration by using only one measured concentration in open channel. The present study mainly addresses the following two subjects : (1) new sediment concentration and mean sediment concentration equations are derived from the entropy concept : (2) An efficient and useful method of suspended sediment-discharge measurements is developed which can facilitate the estimation of suspended sediment-discharge in open channel. Flume and laboratory data are used to carry out the research task outlined above. An efficient method for determining the suspended sediment-discharge in the open channel has been developed. The method presented also is efficient and applicable in estimating the sediment transport in rivers and the sediment deposit in the reservoirs, and can drastically reduce the time and cost of sediment measurements.

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A PRACTICAL THREE-DIMENSIONAL ESTIMATION TECHNIQUE FOR SPATIAL DISTRIBUTION OF GROUNDWATER CONTAMINANT CONCENTRATIONS

  • Richard Ewing;Kang, Sung-Kwon;Kim, Jeon-Gook;Thomas B.Stauffer
    • 대한수학회지
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    • 제38권3호
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    • pp.523-559
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    • 2001
  • To predict the fate of groundwater contaminants, accurate spatially continuous information is needed. Because most field sampling of groundwater contaminants are not conducted spatially continuous manner, a special estimation technique is required to interpolate/extrapolate concentration distributions at unmeasured locations. A practical three-dimensional estimations method for in situ groundwater contaminant concentrations is introduced. It consistas of two general steps: estimation of macroscopic transport process and kriging. Using field data and nonlinear optimization techniques, the macroscopic behavior of the contaminant plume is estimated. A spatial distribution of residuals is obtained by subtracting the macroscopic transport portion from field data, then kriging is applied to estimate residuals at unsampled locations. To reduce outlier effects on obtaining correlations between residual data which are needed for determining variougram models, the R(sub)p-estimator is introduced. The proposed estimation method is applied to a field data set.

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가능최대강수량 및 홍수량 산정에 대한 개선방안 연구 (A Study on the Improvement of Probability Maximum Precipitation and Probability Maximum Flood Estimation)

  • 전시영;문영일;안재현;김종석
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2006년도 학술발표회 논문집
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    • pp.1762-1766
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    • 2006
  • In order to protect properties and human lives from disasters such as heavy rainfall, rational Probability Maximum Flood(PMF) estimation procedures for existing dam basins are recently required. This study analyzes the Probable Maximum Flood(PMF) as a part of a counterplan for disaster preventions of hydraulic structures such as dams, according to recent unfavorable weather conditions. In this study, an improvement method of parameter estimation was proposed, being estimated as an appropriate method for application to the unit hydrograph, the time of concentration and storage constant corresponding to the discharge of flood were considered differently when estimating PMF in Hoengseong dam basin.

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반도체식 가스센서와 퍼지 ART를 이용한 혼합가스의 농도 추정 (Concentration estimation of gas mixtures using a tin oxide gas sensor and fuzzy ART)

  • 이정헌;조정환;전기준
    • 전자공학회논문지SC
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    • 제43권4호
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    • pp.21-29
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    • 2006
  • 본 논문에서는 혼합가스의 종류를 구분하고 농도를 추정하기 위하여 퍼지 ARTMAP 신경회로망과 퍼지 ART 신경회로망을 각각 사용하였다. 온도변환 구동방식의 반도체식 가스센서를 이용하여 $NH_3,\;H_2S$, 그리고 그들의 혼합가스에 대해서 데이터를 획득하였고, 데이터들을 제안한 패턴인식방법의 입력으로 사용하기 위해서 전 처리 과정을 통해 데이터들의 차원을 줄여주었다. 실험을 통해서 본 논문에서 사용한 방법이 이전의 다른 방법들과 비교하여 학습시간을 줄이면서 좀더 안정된 농도 추정 성능을 보여줌을 확인하였다.

Sidewalk Gaseous Pollutants Estimation Through UAV Video-based Model

  • Omar, Wael;Lee, Impyeong
    • 대한원격탐사학회지
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    • 제38권1호
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    • pp.1-20
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    • 2022
  • As unmanned aerial vehicle (UAV) technology grew in popularity over the years, it was introduced for air quality monitoring. This can easily be used to estimate the sidewalk emission concentration by calculating road traffic emission factors of different vehicle types. These calculations require a simulation of the spread of pollutants from one or more sources given for estimation. For this purpose, a Gaussian plume dispersion model was developed based on the US EPA Motor Vehicle Emissions Simulator (MOVES), which provides an accurate estimate of fuel consumption and pollutant emissions from vehicles under a wide range of user-defined conditions. This paper describes a methodology for estimating emission concentration on the sidewalk emitted by different types of vehicles. This line source considers vehicle parameters, wind speed and direction, and pollutant concentration using a UAV equipped with a monocular camera. All were sampled over an hourly interval. In this article, the YOLOv5 deep learning model is developed, vehicle tracking is used through Deep SORT (Simple Online and Realtime Tracking), vehicle localization using a homography transformation matrix to locate each vehicle and calculate the parameters of speed and acceleration, and ultimately a Gaussian plume dispersion model was developed to estimate the CO, NOx concentrations at a sidewalk point. The results demonstrate that these estimated pollutants values are good to give a fast and reasonable indication for any near road receptor point using a cheap UAV without installing air monitoring stations along the road.