• 한국물환경학회지
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• 제26권5호
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• pp.841-849
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• 2010

Soil erosion is an natural phenomenon. However accelerated soil erosion has caused many environmental problems. To reduce soil loss from a watershed, many management practices have been proposed worldwide. To develop proper and efficient soil erosion best management practices, soil erosion rates should be estimated spatially and temporarily. The Universal Soil Loss Equation (USLE) and USLE-based soil erosion and sediment modelling systems have been developed and tested in many countries. The Sediment Assessment Tool for Effective Erosion Control (SATEEC) system has been developed and enhanced to provide ease-of-use interface to the USLE users. However many researchers and decision makers have requested to enhance the SATEEC system for simulation of soil erosion and sediment reflecting effects of single storm event. Thus, the SATEEC R factors were estimated based on 5 day antecedent rainfall data. The SATEEC 2.1 daily R factor was applied to the study watershed and it was found that the R2 and EI values (0.776 and 0.776 for calibration and 0.927 and 0.911 for validation) with the daily R were greater than those (0.721 and 0.720 for calibration and 0.906 and 0.881 for validation) with monthly R, which was available in the SATEEC 2.0 system. As shown in this study, the SATEEC with daily R can be used to estimate soil erosion and sediment yield at a watershed scale with higher accuracy. Thus the SATEEC with daily R can be efficiently used to develop site-specific soil erosion best management practices based on spatial and temporal analysis of soil erosion and sediment yield at a daily-time step, which was not possible with USLE-based soil erosion modeling system.

• 한국수자원학회논문집
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• 제55권8호
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• pp.613-621
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• 2022

전 세계적으로 기후변화를 겪고 있으며, 21세기 말 한반도에서 강우의 강도와 빈도가 증가할 것으로 전망하였다. 또한, 급격한 도시개발로 인해 불투수면적이 증가하여 도시 물순환 건전성이 왜곡되었다. 물순환 건전성 회복을 위해 빗물 관리기법 관련 연구가 다양하게 진행되어 빗물 관리기법의 효과는 검증되었지만 도시 물순환 건전성을 위해 적합한 설계 가이드라인이 없는 실정이다. 본 연구에서는 도시 빗물 관리기법의 설계 가이드라인 방법론을 제시하기 위해 부산관측소 10년 강우자료를 통해 60, 70, 80, 90 백분위수의 강우량 및 강우 지속시간별 시나리오를 설정하였다. 적절한 도시 빗물 관리를 위해 시나리오별로 그린인프라의 규모를 산정하였으며, SWMM 모형을 이용하여 장기 강우(10년)-유출량 모의를 통해 저감특성을 분석하였다. 그 결과 그린인프라 규모별 총 유출 저감량은 13.1~52.1%로 나타났다. 빗물 관리 목표량을 설정하기 위해 데이터를 정량적으로 분석한 결과 대상지역에서는 80~85 백분위수의 강우량으로 설정하는 것이 효과적으로 나타났다.

• Ecology and Resilient Infrastructure
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• 제6권1호
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• pp.12-22
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• 2019

본 연구에서는 팔당호 내 주요지점에서 수심별 연속 수리 및 수온 조사를 수행하여 팔당호의 시공간적 물순환 특성을 파악하고자 하였다. 이포보와 청평댐에서의 수온 및 방류 패턴의 차이로 인하여 팔당호 내 북한강 및 남한강 구간에서의 흐름 및 수온 변동특성이 상이하게 나타났다. 수직혼합기에는 북한강과 남한강 구간의 전 층에서 하류방향 흐름이 우세하게 나타났다. 성층형성기에 이포보 방류수의 수온이 청평댐 방류수의 수온보다 높았으며, 이로 인해 북한강 하류 구간에서 표층은 상대적으로 고온수가 위치하여 상류방향 흐름으로 배수 현상이 나타나고 수렴대가 형성되었다. 남한강 하류 구간은 중층과 저층에서 저온수가 분포하여 상류방향 흐름이 나타나고 표층과 혼합되기 어려운 이층류 구조를 나타내었다.

• 상하수도학회지
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• 제35권3호
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• pp.237-246
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• 2021

The ILI, developed by the IWA (International Water Association), has been used in many countries as an indicator of water leakage. In Korea, the revenue water has been used as a performance indicator for waterworks although there is an opinion to replace it with the ILI. Hence, it has been necessary to investigate whether the ILI can replace the revenue water in Korea. The four main operating indicators (i.e., water service population, profit-loss ratio, fiscal self-reliance, and aged pipe rate) of 162 Korean waterworks were compared with the ILI with the linear regression method. Local water authorities with more than 1 million water service population, with more than 60% profit-loss ratio, more than 40% and less than 60% fiscal self-reliance, and more than 20% aged pipe rate showed meaningful correlation between the four parameters and the ILI. In the remaining cases, their correlations were little or weak. This means that using the ILI may not be an efficient method to represent the performance of the water supply system in Korea because of the lack of UARL (Unavoidable Annual Real Losses) data accuracy. To use the ILI in Korea, it will be required to carry out an additional research to accumulate reliable CARL (Current Annual Real Losses) and UARL data in the future.

• 한국지진공학회논문집
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• 제20권4호
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• pp.201-209
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• 2016

Damages of large embankment dams by recent strong earthquakes in the world highlight the importance of seismic security of dams. Some of recent dam construction projects for water storage and hydropower are located in highly seismic zone, hence the seismic performance evaluation is an important issue. While state-of-the-art numerical analysis technology is generally utilized in practice for seismic performance evaluation of large dams, physical modeling is also carried out where new construction technology is involved or numerical analysis technology cannot simulate the behavior appropriately. Geotechnical centrifuge modeling is widely adopted in earthquake engineering to simulate the seismic behavior of large earth structures, but sometimes it can't be applied for large embankment dams due to various limitations. This study proposes a dynamic centrifuge testing method for large embankment dams and evaluated its applicability. Scaling relations for a case which model scale and g-level are different could be derived considering the stress conditions and predominant period of the structure, which is equivalent to previously suggested scaling relations. The scaling principles and testing method could be verified by modified modeling of models using a model at different acceleration levels. Finally, its applicability was examined by centrifuge tests for an embankment dam in Korea.

• 한국전자통신학회논문지
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• 제12권5호
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• pp.737-746
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• 2017

2017년 통합보안(IS, Integrated Security), 융합 보안(CS, Convergence Security) 등과 같은 새로운 보안시장의 변화 속에서 운영과 관리 차원의 다양한 보안 패러다임이 제시되고 있다. 이러한 솔루션과 기술은 현존하는 네트워크 인프라의 변경과 유동적인 다차원적인 변화를 이끌어 내기보다는 보안성을 높이는 1차원적인 방어에 모든 보안 역량이 집중되어짐으로써 예상치 못한 침해와 장애를 지속적으로 내제하고 있는 네트워크 인프라를 유지해 오고 있다. 따라서 WB(Water-Bubble)이라는 새로운 아이디어를 네트워크 인프라에 접목하고 실험과 구현 기반의 분석을 진행함으로써 유사패턴 공격과 집중화 트래픽 공격을 방어할 수 있는 탄력적 네트워크 구간을 제안하고 개발할 수 있는 기회이기도 한다. 또한 본 논문에서 제안하는 WB 기반의 강한 보안성을 갖는 탄력적 네트워크 구간에 관한 연구기법은 공격의 최종 목적지로 예상되는 네트워크 영역을 울림형태의 탄력적 영역변화를 갖는 네트워크 구간(구역)으로 유동성과 비예측성, 상호 접점비율에 따른 비 영역 확장성 등의 3대 주요 제한 및 보안 기준을 바탕으로 네트워크 구간 보안성 확보를 위한 연구 자료를 제공하고자 한다.

• 한국물환경학회지
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• 제26권3호
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• pp.413-419
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• 2010

A silica mine monitoring was conducted from March to December in 2008 to measure rainfall, runoff amounts and pollution loads. A total of 13 rainfall-runoff events were measured and analyzed with respect to runoff ratio, pollutant concentration and load, and initial flush. Over rainfall-runoff events, 95% confidence range of SS concentration was 942.5~2,056.2 mg/L. Other measured water quality indices also showed relatively large variation. This wide concentration variation was thought to be caused by the bare working ground of the mine that was used to store, process and transport the mined silica. Total pollution load of the 13 rainfall-runoff events was SS 17,901 kg/ha, $COD_{Cr}$ 160.9 kg/ha, $COD_{Mn}$ 111.24 kg/ha, BOD 79.6 kg/ha, T-N 13.8 kg/ha, T-P 3.5 kg/ha, and TOC 39.3 kg/ha. Initial flush was not well observed except SS. Very high SS concentration and load was occurred when rainfall was large. Therefore, it was recommended to manage the bare ground not to discharge excessive pollutants during wet days by covering the ground or constructing runoff treatment systems such as a sediment basin.

• 한국지반환경공학회 논문집
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• 제19권9호
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• pp.29-36
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• 2018

국내 외에서는 사면붕괴를 사전에 예방할 수 있는 모니터링 및 자동계측기에 관한 다수의 연구가 수행되어져 오고 있으나, 이러한 연구들은 다소 복잡한 구조로 이루어져 있고, 계측시스템의 대부분은 사면표층에 설치되어 있으며, 사면파괴 전 붕괴징후를 사전에 감지하고 경보를 울려주는 계측시스템에 관한 연구는 미진한 실정이다. 본 연구에서는 강우 조건에서의 사면 붕괴 메카니즘을 파악하기 위하여 사면 붕괴 실험을 수행하고 지중 변위와 체적 함수비 계측을 통해 사면 모델의 붕괴 초기에 발생되는 함수비와 변위 거동 특성을 분석하였다. 본 연구를 통해 고찰된 내용은 지방자치단체에서 집중호우로 인해 급경사지 붕괴위험지역 등 사면붕괴나 산사태가 예측될 때 사전에 주민을 대피시키는 사면붕괴 예 경보시스템 구축 시 기초자료로 활용될 수 있을 것으로 기대된다.

• 한국농공학회논문집
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• 제57권1호
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• pp.111-118
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• 2015

This research aims to utilize lapilli from the Mt. Baekdusan as environmently-friendly construction material. First of all, the neutralizing method for fabricating lapilli-cement-mixed bioblock was examined. And then, by use of the neuralized bioblock with microorganism for water purification, the growth inhibition effect against the pathogenic coliform bacillus was evaluated. The result regarding growth inhibition effect on pathogenic coliform bacillus indicates that the pretreatment condition, which is a concurrent procession with aqueous solution of 10% di-ammonium Phosphate after water curing, led to pH degraded below 10 which was the target value. Therefore it was concluded that the method was effective on bio-block neutralization. The microorganisms purifying water and di-ammonium phosphate were detected through the examination for microorganism existence on the bioblock, therefore it was concluded that the bioblock composed of lapilli and cement is able to be utilized in various structures as an environment friendly construction material.

• 상하수도학회지
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• 제33권2호
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• pp.141-150
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• 2019

Total organic carbon(TOC) was introduced as the water quality index of the rivers and lakes in 2013. This paper evaluated factors affecting effluent TOC concentrations and treated and discharged loads of existing publicly owned treatment works(POTWs). For selected POTWs with greater treatment capacity than $500m^3/day$, factorial analysis was used to consider effects of kinds of biological treatment processes, inflow of other types of wastewater(industrial, livestock, landfill leachate wastewater, etc.) with domestic wastewater, sewer separation rate, and effluent discharging zones in which different effluent criteria applied. As a result, those factors did not show significant effect on effluent TOC concentration of POTWs in effluent discharging zone I and II. However, In effluent discharging zone III and IV, kinds of biological treatment processes, the inclusion of other waste in influent of domestic wastewater, and the sewer separation rate were significant factors. The treated TOC load in POTWs was also not affected significantly by the variables set in this study. On the other hand, those three factors influenced significantly on the TOC load discharged to water bodies. The sum of factorial effects and the contribution rate of three factors to the discharged TOC load was 60.23 and 41%, 59.57 and 41%, and 42.04 and 18%, respectively.