• 제목/요약/키워드: Water-based

검색결과 16,109건 처리시간 0.041초

Climatic Water Balance Analysis using NOAA/AVHRR Satellite Images

  • KWON Hyung J.;KIM Seong J.;SHIN Sha C.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.7-9
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    • 2004
  • The purpose of this study was to analyze the climatic water balance of the Korean peninsula using meteorological data and the evapotranspiration (ET) derived from NOAA/AVHRR. Quantifying water balance components is important to understand the basic hydrology. In this study, a simple method to estimate the ET was proposed based on a regression approach between NDVI and Morton's actual ET using NOAA/AVHRR data. The Morton's actual ET for land surface conditions was evaluated using a daily meteorological data from 77 weather stations, and the monthly averaged Morton's ETs for each land cover was compared with the monthly NDVIs during the year 2001. According to the climatic water balance analysis, water deficit and surplus distributed maps were created from spatial rainfall, soil moisture, and actual and potential ETs map. The results clearly showed that the temporal and spatial characteristics of dryness and wetness may be detected and mapped based on the wetness index.

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급속여과공정에서 여과수질 저하원인 및 개선방안 (Cause of Filtrate Deterioration and Its Improvement in Rapid Filtration)

  • 김진근;이송희;김재원
    • 상하수도학회지
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    • 제24권3호
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    • pp.333-339
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    • 2010
  • Particle removal is an important step taken at water treatment plants (WTPs) for the safety of tap water due to its proportionality to the pathogen inactivation. Government promulgated a treatment technique for the optimization of filtration including continuous turbidity monitoring using on-line turbidimeters. Based on the turbidity measurements of 460 filters at 31 WTPs operated by K-water, the evaluation of filtration performance and the investigation of major causes related to particle breakthrough were explored. 98.1 % of the filters had an effluent turbidity measurement which was less than 0.1 NTU, but turbidity breakthrough of more than 0.3 NTU was noticed occasionally which is in violation of AWWA 5-Star guidelines. It was shown that the optimization of coagulation, filter-to-waste, the observance of optimal filtration velocity and backwashing process based on filtrate turbidity were crucial for the improvement of filtrate.

Effect of Surface Finishing Materials on the Moisture Conditions in Concrete: Vapor and Water Permeability of Finishing Materials Under Changing Environmental Conditions

  • Ryu, Dong-Woo
    • International Journal of Concrete Structures and Materials
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    • 제2권2호
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    • pp.83-90
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    • 2008
  • Permeability to vapor and water among other performances required for finishing materials is dealt with in this study. The relative moisture content of concrete coated/covered with a finishing material was experimentally investigated while changing the environmental conditions including temperature, relative humidity, and rainfall. An organic paint (water-based urethane), organic synthetic resin emulsion-type film coating (film coating E), and inorganic porcelain tiles were selected as the finishing materials. When compared from the aspect of vapor and water permeability, the vapor permeability and water permeability of water-based urethane were high and low, respectively; those of film coating E were high and high, respectively; and those of porcelain tiles were low and low, respectively. This means that the moisture state of concrete structures is governed not only by the environmental conditions but also by the performance of finishing materials. It is therefore of paramount importance to appropriately select a finishing material to address the specific deteriorative factors involved in the concrete structure to be finished.

불량 매립지에서의 지하수 오염특성과 환경오염 방지방안 (Characteristics of Groundwater Contamination in Uncontrolled Landfill and Pollution Control Measures)

  • 구자중;윤석표
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1993년도 지반.환경 매립에 관한 학술발표회 논문집
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    • pp.28-44
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    • 1993
  • Remediation actions in uncontrolled landfill site should be conducted after the investigation of contamination status and potential health risk or damage. Based on the above, proper control measures should be established and operated. Also continuous monitoring should be followed. In this study, the status of ground water contamination around Nanji Landfill Site was investigated. Monitoring wells were installed around the landfill and ground water was sampled once a month and analyzed. Water quality of each monitoring well was different depending on the horizontal and vertical distance from the landfill, and the seasonal leachate characteristics were not significantly changed because percolating water stayed long time in the deep waste layer. It was predicted that major multivalent cations were mainly precipitated as metal carbonate form, and chemical mass balances (CMBs) could be applied for the apportionment of leachate contamination to ground water quality of surrounding areas of Nanji Landfill. Parameters required to estimate pollutant flux to the receptor near landfill were listed and discussion to get these parameters was made. Finally, based on the above data, control measures of ground water contamination were suggested and discussed.

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Application of Grid-based Kinematic Wave Storm Runoff Model

  • Kim, Seong-Joon;Kim, Sun-Joo;Chae, Hyo-Seok
    • 한국수자원학회논문집
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    • 제33권S1호
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    • pp.20-27
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    • 2000
  • The grid-based KIneMatic wave STOrm Runoff Model(Kim, 1998; Kim, et al., 1998) which predicts temporal variation and spatial distribution of saturated overland flow, subsurface flow and stream flow was evaluated at two watersheds. this model adopts the single overland flowpath algorithm and simulates surface and/or subsurface water depth at each cell by using water balance of hydrologic components. the model programmed by C-language uses ASCII-formatted map data supported by the irregular gridded map of the GRASS (Geographic Resources Analysis Support System) GIS and generates the spatial distribution maps of discharge, flow depth and soil moisture of the watershed.

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NOAA/AVHRR 위성영상을 이용한 기후학적 물수지 분석 (Climatic Water Balance Analysis Using NOAA/AVHRR Satellite Images)

  • 권형중;신사철;김성준
    • 한국농공학회논문집
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    • 제47권1호
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    • pp.3-9
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    • 2005
  • The purpose of this study was to analyze the climatic water balance of the Korean peninsula using meteorological data and the evapotranspiration (ET) derived from NOAA/AVHRR, Quantifying water balance components is important to understand the basic hydrology, In this study, a simple method to estimate actual ET was proposed based on a regression approach between NDVI and Morton's actual ET using NOAA/AVHRR data, The Mortons actual ET for land surface conditions was evaluated using a daily meteorological data from 77 weather stations, and the monthly averaged Morton's ETs for each land cover was compared with the monthly NDVIs during the year 2001. According to the climatic water balance analysis, water deficit and surplus distributed maps were created from spatial rainfall, soil moisture, and actual and potential ETs map, The results clearly showed that the temporal and spatial characteristics of dryness and wetness may be detected and mapped based on the wetness index.

Application of Grid-based Kinematic Wave Storm Runoff Model

  • Kim, Seong-Joon;Kim, Sun-Joo;Chae, Hyo-Seok
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2000년도 학술발표회 논문집
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    • pp.20-27
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    • 2000
  • The grid-based KlneMatic wave STOrm Runoff Modei (Kim, 1998; Kim, et al., 1998) which predicts temporal variation and spatial distribution of saturated overland flow, subsurface flow and stream flow was evaluated at two watersheds. This model adopts the single overland flowpath algorithm and simulates surface and/or subsurface water depth at each cell by using water balance of hydrologic components. The model programed by C-language uses ASCII-formatted map data supported by the irregular gridded map of the GRASS (Geographic Resources Analysis Support System) GIS and generates the spatial distribution maps of discharge, flow depth and soil moisture of the watershed.

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EXPERIMENT AND SIMULATION OF A WIND-DRIVEN REVERSE OSMOSIS DESALINATION SYSTEM

  • Park, Sang-Jin;Clark C.K. Liu
    • Water Engineering Research
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    • 제4권1호
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    • pp.1-17
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    • 2003
  • A mathematical model was developed to simulate the performance of a prototype wind-powered reverse osmosis desalination system. The model consists of two sub-models operated in a series. The first sub-model is the wind-energy conversion sub-model, which has wind energy and feed water as its input and pressurized feed water as its output. The second sub-model is a reverse osmosis (RO) process sub-model, with pressurized feed water as its input and the flow and salinity of the product water or permeate as its output. Model coefficients were determined based on field experiments of a prototype wind powered RO desalination system of the University of Hawaii, from June to December 2001. The mathematical model developed by this study predicts the performance of wind-powered RO desalination systems under different design conditions. The system optimization is achieved using a linear programming approach. Based on the results of system optimization, a design guide is prepared, which can be used by both manufacturer and end-user of the wind-driven reverse osmosis system.

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파키스탄 파트린드댐의 저수지 퇴사관리를 위한 배사효과 분석 (Analysis of Sediment Flushing Effect for Reservoir Sedimentation Management of the Patrind Dam in Pakistan)

  • 노준우;박진혁;허영택;김상호
    • 한국물환경학회지
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    • 제29권6호
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    • pp.799-807
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    • 2013
  • Reservoir sedimentation is one of the major concerns for sustainable reservoir operation. Since sediment concentration of the rivers in the Himalayan Mountain is very high, a proper sediment management scheme is necessary. This paper presents long-term reservoir sedimentation and sediment flushing based on the gate operation. Focused on the reservoir to be constructed for the Patrind hydropower project in Pakistan, 4 different flushing scenarios were proposed in this study to prevent successive sedimentation. By extending flushing period and by increasing the flushing discharge for 2 times, the flushing rate increases up to 53.2% and 43.6% in proportion to flushing period and discharge, respectively. Based on the simulation presented in this paper, it is expected to establish efficient sediment management plan to increase hydro power generation and sediment flushing simultaneously.

A TabNet - Based System for Water Quality Prediction in Aquaculture

  • Nguyen, Trong–Nghia;Kim, Soo Hyung;Do, Nhu-Tai;Hong, Thai-Thi Ngoc;Yang, Hyung Jeong;Lee, Guee Sang
    • 스마트미디어저널
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    • 제11권2호
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    • pp.39-52
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    • 2022
  • In the context of the evolution of automation and intelligence, deep learning and machine learning algorithms have been widely applied in aquaculture in recent years, providing new opportunities for the digital realization of aquaculture. Especially, water quality management deserves attention thanks to its importance to food organisms. In this study, we proposed an end-to-end deep learning-based TabNet model for water quality prediction. From major indexes of water quality assessment, we applied novel deep learning techniques and machine learning algorithms in innovative fish aquaculture to predict the number of water cells counting. Furthermore, the application of deep learning in aquaculture is outlined, and the obtained results are analyzed. The experiment on in-house data showed an optimistic impact on the application of artificial intelligence in aquaculture, helping to reduce costs and time and increase efficiency in the farming process.