• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.232-232
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• 2022

1차원 관망해석모형과 2차원 지표면범람 해석모형을 이용한 도시지역의 실시간 홍수예·경보시스템 구축은 모형의 모의에 많은 시간이 소요되므로 한계가 있다. 또한, 연구유역에서 시나리오 강우에 대해 침수를 유발시키는 한계강우량을 1-2차원 모형의 시행착오법을 적용한 반복적인 수행을 통해 산정하는 것은 비효율적인 방법이다. 따라서, 본 연구에서는 이에 대한 해결책으로 로지스틱 회귀를 이용하여 배수분구별 침수 발생기준 강우량을 산정하고자 한다. 침수 발생 한계강우량 산정을 배수분구 단위로 제시하기 위하여 로지스틱 회귀분석을 이용하였다. 풍수해저감종합계획(2015)과 침수흔적도를 이용하여 배수분구 별 침수이력에 대한 데이터베이스를 구축하고, 이를 1-2차원 수리해석을 통한 침수심과 함께 로지스틱 회귀모형에 학습하였다. 지속시간 1시간, 10mm 강우부터 500년 빈도의 Huff 3분위 시나리오 17개를 사용하여 확률강우량을 산정하였고, 이를 1-2차원 수리해석을 위한 입력자료로 사용하였다. EPA-SWMM을 통한 1차원 도시유출해석과 FLO-2D를 통한 2차원 침수해석에서 20cm 이상의 침수심이 발생하거나 지상관측자료, 침수흔적도 및 풍수해저감종합계획에서 실제 침수가 발생했을 경우를 1, 그렇지 않은 경우를 0으로 하여 데이터베이스를 구축하여 로지스틱 회귀모형에 학습시켜 침수 발생 한계강우량을 산정하였다. 로지스틱 회귀분석을 통해 서울시 지역의 배수분구별 한계강우량을 산정할 수 있으며, 지속적으로 관측되는 강우 및 침수 발생 유무 자료를 추가함으로써 산정된 침수 한계강우량을 상회하는 강우 사상이 나타났을 시에 침수 발생 유무를 확인하여 본 연구에서 제안한 방법에 대해 검증이 가능할 것으로 보인다.

• 한국공간정보시스템학회:학술대회논문집
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• 2000.06a
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• pp.189-201
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• 2000

접근성이란 특정 목적을 가진 통행자가 한 지점에서 다른 지점으로 얼마나 쉽게 갈 수 있는가 를 나타내는 척도를 말한다. 따라서 접근성은 주로 공간적인 거리나 시간이 가장 중요한 요인으로 작용하며 최근에는 공간적 거리보다는 접근시간이 더 중요한 접근성 척도로 사용되고 있다. 본 연구는 GIS공간분석기법과 접근성이론을 접목하여 도시시설의 적정후보지 평가방법을 정립한 후 현재 검토되고 있는 수도권 도심공항터미널 입지 후보지 중 어떤 후보지가 이용들의 총통행시간을 최소화하는 후보 지인가에 대해 평가해보았다. 평가 결과 다음과 같은 사실을 밝힐 수 있었다. 첫째, 수도권 전체로 볼 때 평균접근시간이 가장 양호한 후보지는 쌍문터미널(현 간이 도심공항터미널)이고, 2위는 현 삼성동 도심공항터미널과 강남고속터미널, 3위는 동서울터미널과 남서울터미널 순으로 나타났다. 둘째, 수도권전체 이용자들의 총통행시간을 최소로 하는 도심공항터미널 후보지는 접근성이 가장 양호한 쌍문동터미널이 아니라 현 서울역이 1위이고, 2위는 강남고속 터미널, 3위는 용산 역으로 나타났다. 셋째, 터미널 후보지간의 가중평균접근 시간은 도심인 서울시내에 입지한 후보지와 수도권 외곽에 입지 한 후보지간에 큰 차이가 없으나 총 이용자 접근시간은 서울시에 입지한 후보지보다 외곽의 후보지가 훨씬 높게 나타나 뚜렷한 차별성을 보이고 있다. 넷째, 최적후보지 1,2,3순위 모두 서울도심과 강남도심에 입지한 지역들로 나타나 교통의 접근성 보다는 아직 인구밀집도가 주요 도시시설의 입지결정에 주요한 결정요인 되는 것으로 나타났다.해석 시스템을 구축할 예정이다. 추후에는 하수도 관망해석 컴포넌트와 하수도 업무 컴포넌트와의 통합부분에 대한 연구가 진행되어야 할 것이다.7.0로 하고 표준(標準) EDTA 용액(溶液)을 소량(少量)넣고 8N-KOH로 pH $12{\sim}13$으로 하고 N-N 희석분말(稀釋粉末)을 지시약(指示藥) 으로써 표준(標準) EDTA 용액(溶液)으로 적정(滴定)하여 Ca 치(値)를 얻었다. Ca와 Mg의 합계결정치(合計決定値)와 Ca 적정치(滴定値) 차(差)로 Mg 치(値)를 얻었다. 음(陰) ion 구분(區分)으로부터 상법(常法)에 의하여 $MgNH_4PO_4$의 침전(沈澱)을 만들어서 HCl에 녹키고 일정량(一定量)의 표준(標準) EDTA 용액(溶液)을 넣어 pH 7.0로 한다음 완충액(緩衝液)으로 pH 10으로 하고 BT 지시약(指示藥)을 써서 표준(標準) Mg $SO_4$용액(溶液)으로 적정(滴定)하여 P 치(値)를 얻었다. 본법(本法)으로 Na-phytate를 분석(分析)한 결과(結果) Na-phytate의 분자식(分子式)을 $C_6H_6O_{24}P_6Mg_4CaNa_2{\cdot}5H_2O$라고 하였을 때의 이론치(理論値)에 비(比)하여 P가 98.9% Cark 97.1%, Mg가 99.1%이고 통계처리(統計處理)한 결과분석치(結果分析値)와 이론치(理論値)는 잘 일치(一致)된다. 그러나 종래법(從來法)에 의(依)한 분석치(分析値)는 이론치(理論値)에 비(比)하여 P가 92.40%, Cark 86.80

• Journal of Korea Water Resources Association
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• v.53 no.11
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• pp.1015-1024
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• 2020

Recently, water pollution accidents have continued to occur in pipelines such as red water Incheon and Seoul. In order to recognize this water quality problem, it is necessary to install a water quality sensor in an appropriate location and measure it in advance to detect or block the water supply to the water faucet of the shelter. However, there are limitations, such as maintenance costs, to installing multiple water meters in all pipelines. Therefore, this study proposed a methodology for determining and prioritizing the installation location of flow-based water quality sensor for the recognition of water quality problems in pipelines. We applied the proposed procedure to the pipe break scenario. The results of the determination of the location of the water quality sensor were presented by applying it to the pipe network that actually operates the emergency pipe in Korea. The result of the decision showed that in the event of abnormal situation caused by the destruction of individual pipes, the flow rate of the pipes around the aqueduct and the tank may change rapidly, resulting in water quality accidents caused by turbidity. In the future, it is expected that the water quality monitoring point selection method, such as establishing an external pipe operation plan for pipe cleaning, will utilize the procedure for determining the location of the water quality sensor according to the velocity.

• Journal of Korea Water Resources Association
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• v.55 no.spc1
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• pp.1261-1270
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• 2022

The purpose of this study is to collect and analyze information related to water leaks that cannot be easily accessed, and utilized by using the news search results that people can easily access. We applied a web crawling technique for extracting big data news on water leakage accidents in the water supply system and presented an algorithm in a procedural way to obtain accurate leak accident news. In addition, a data analysis technique suitable for water leakage accident information analysis was developed so that additional information such as the date and time of occurrence, cause of occurrence, location of occurrence, damaged facilities, damage effect. The primary goal of value extraction through big data-based leak analysis proposed in this study is to extract a meaningful value through comparison with the existing waterworks statistical results. In addition, the proposed method can be used to effectively respond to consumers or determine the service level of water supply networks. In other words, the presentation of such analysis results suggests the need to inform the public of information such as accidents a little more, and can be used in conjunction to prepare a radio wave and response system that can quickly respond in case of an accident.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1249-1256
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• 2005

This study was performed to investigate the efficiency of the corrosion prevention in the simulated distribution system using CCPP(Calcium Carbonate Precipitation Potential) as the anti-corrosive index by adjusting pH, total dissolved solids, alkalinity and calcium hardness in the water treatment pilot process. The materials of the simulated distribution system(SDS) were equiped with same materials of real field water distribution system. CCPP concentrations controlled by $Ca(OH)_2$, $CO_2$ gas and $Na_2CO_3$ in the simulated distribution system and uncontrolled by the chemicals in the general water distribution system were average 0.61 mg/L and -7.77 mg/L. The concentrations of heavy metals like Fe, Zn, Cu ions in effluent water of the simulated distribution system controlled with water quality were decreased rather than the general water distribution system uncontrolled with water quality. In simulated distribution system(SDS), corrosion prevention film formed by CCPP control was observed that scale was come into forming six months later and it was formed into density as time goes on. We were analyzed XRD(X-ray diffraction) for investigating component of crystal compounds and structure for galvanized steel pipe(15 mm). Finding on analysis, scale was compounded to $Zn_4CO_3(OH)_6{\cdot}H_2O$ (Zinc Carbonate Hydroxide Hydrate) after ten months late, and it was compounded on $CaCO_3$(Calcium Carbonate) and $ZnCO_3$(Smithsonite) after nineteen months later.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.67-78
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• 2006

Local governments began to construct geographic information system to improve government productivity and performance. In support, central government organized a national commission for GIS. The master plan by NGIS has been the base for local government to participate in the construction of GIS at the local level in the under ground facilities management including water and sewers. The challenge faced by sewer facility managers includes controlling 'data accuracy'. The input for sewer data handling for efficient performance in local government requires accurate data. However data manipulation to get the 'good quality' data can be burdensome. Thus, the aim of this research is to provide the appropriate tool to guarantee the high quality of digital data in sewer facility management. It is helpful to pass the data examination by government as well as to insure confidence of decision and data analysis works in local government. In this research, error types of sewer data were classified and pointed the limitation of traditional examination methods. Thus this research suggested more improved method for finding and correcting errors in data input using sewer volume analysis and prediction model as immigrating sewer facility management work to Geographic Information System.

• Journal of Korea Water Resources Association
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• v.49 no.12
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• pp.981-993
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• 2016

This study explains the GIS database of flood inundation area developed for Samsung-1 Drainage Sector, Seoul, Korea. The XP-SWMM dual drainage model was developed for the study area, and the time series observed at the watershed outlet was used to obtain the watershed time of concentration and to calibrate the XP-SWMM model. The rainfall scenario was developed by dividing the 40 minute watershed time of concentration into two 20-minute time steps and then applying the gradually increasing 5 mm/hr interval rainfall intensity to each of the time step up to 200 mm/hr, which is the probable maximum precipitation of the study area. The developed rainfall scenarios was used as the input of the XP-SWMM model to obtain the database of the flood inundation area. The analysis on the developed GIS database revealed that: (1) For the same increment of the rainfall, the increase of the flooded area can be different, and this was caused by topographic characteristics and spatial formation of pipe network of the study area; (2) For the same flooded area, the spatial extent can be significantly different depending on the temporal distribution of rainfall; and (3) For the same amount of the design rainfall, the flood inundation area and the extent can be significantly different depending on the temporal distribution of rainfall.

• Journal of Korea Water Resources Association
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• v.55 no.spc1
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• pp.1235-1249
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• 2022

This study applied the web crawling technique for extracting big data news on water quality accidents in the water supply system and presented the algorithm in a procedural way to obtain accurate water quality accident news. In addition, in the case of a large-scale water quality accident, development patterns such as accident recognition, accident spread, accident response, and accident resolution appear according to the occurrence of an accident. That is, the analysis of the development of water quality accidents through key keywords and sentiment analysis for each stage was carried out in detail based on case studies, and the meanings were analyzed and derived. The proposed methodology was applied to the larval accident period of Incheon Metropolitan City in 2020 and analyzed. As a result, in a situation where the disclosure of information that directly affects consumers, such as water quality accidents, is restricted, the tone of news articles and media reports about water quality accidents with long-term damage in the event of an accident and the degree of consumer pride clearly change over time. could check This suggests the need to prepare consumer-centered policies to increase consumer positivity, although rapid restoration of facilities is very important for the development of water quality accidents from the supplier's point of view.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.4
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• pp.421-431
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• 2023

Sewer deterioration models can offer important information on prediction of future condition of the asset to decision makers in their implementing sewer pipe networks management program. In this study, Markov chain model was used to estimate sewer deterioration trend based on the historical structural condition assessment data obtained by CCTV inspection. The data used in this study were limited to Hume pipe with diameter of 450 mm and 600 mm in three sub-catchment areas in city A, which were collected by CCTV inspection projects performed in 1998-1999 and 2010-2011. As a result, it was found that sewers in sub-catchment area EM have deteriorated faster than those in other two sub-catchments. Various main defects were to generate in 29% of 450 mm sewers and 38% of 600 mm in 35 years after the installation, while serious failure in 62% of 450 mm sewers and 74% of 600 mm in 100 years after the installation in sub-catchment area EM. In sub-catchment area SN, main defects were to generate in 26% of 450 mm sewers and 35% of 600 mm in 35 years after the installation, while in sub-catchment area HK main defects were to generate in 27% of 450 mm sewers and 37% of 600 mm in 35 years after the installation. Larger sewer pipes of 600 mm were found to deteriorate faster than smaller sewer pipes of 450 mm by about 12 years. Assuming that the percentage of main defects generation could be set as 40% to estimate the life expectancy of the sewers, it was estimated as 60 years in sub-catchment area SN, 42 years in sub-catchment area EM, 59 years in sub-catchment area HK for 450 mm sewer pipes, respectively. For 600 mm sewer pipes, on the other hand, it was estimated as 43 years, 34 years, 39 years in sub-catchment areas SN, EM, and HK, respectively.