• 한국농공학회논문집
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• 제62권6호
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• pp.1-9
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• 2020

Reservoir storage and water level information is essential for accurate drought monitoring and prediction. In particular, the agricultural drought has increased the risk of agricultural water shortages due to regional bias in reservoirs and water supply facilities, which are major water supply facilities for agricultural water. Therefore, it is important to evaluate the available water capacity of the reservoir, and it is necessary to determine the water surface area and water capacity. Remote sensing provides images of temporal water storage and level variations, and a combination of both measurement techniques can indicate a change in water volume. In areas of ungauged water volume, satellite remote sensing image acts as a powerful tool to measure changes in surface water level. The purpose of this study is to estimate of reservoir storage and level variations using satellite remote sensing image combined with hydrological statistical data and the Normalized Difference Water Index (NDWI). Water surface areas were estimated using the Sentinel-2 satellite images in Seosan, Chungcheongnam-do from 2016 to 2018. The remote sensing-based reservoir storage estimation algorithm from this study is general and transferable to applications for lakes and reservoirs. The data set can be used for improving the representation of water resources management for incorporating lakes into weather forecasting models and climate models, and hydrologic processes.

• 농업과학연구
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• 제50권4호
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• pp.903-916
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• 2023

This study aims to establish basic data for efficient management of rural water by analyzing regional irrigation facilities and benefitted areas in the statistical yearbook of land and water development for agriculture at the watershed level. For 511 domestic rural water use areas, water storage facilities (reservoirs, pumping & drainage stations, intake weirs, infiltration galleries, and tube wells) are spatially distributed, and the benefitted areas provided at the city/county level are divided by water use area to provide agricultural water supply facilities. The characteristics of rural water district areas such as benefitted area, were analyzed by basin. The average area of Korea's 511 rural water districts is 19,638 ha. The average benefitted area by rural water district is 1,270 ha, with the Geum River basin at 2,220 ha and the Yeongsan River basin at 1,868 ha, which is larger than the overall average. The Han River basin at 807 ha, the Nakdong River basin at 1,121 ha, and the Seomjing River basin at 938 ha are smaller than the overall average. The results of this basic analysis are expected to be used to set the direction of various supply and demand management projects that take into account the rational and scientific use and distribution of rural water and the characteristics of water use areas by presenting a quantitative definition of Korea's agricultural water districts.

• 한국항해항만학회지
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• 제33권10호
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• pp.709-713
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• 2009

근해의 수질오염은 수산양식 산업에 큰 영향을 미친다. 이러한 문제점을 해결하기 위하여 근해에서 외해로 양식장이 이동하고 있다. 외해 양식장의 구축을 위해서는 자동먹이 공급장치 및 원격 관리 시스템이 필요하다. 본 논문은 해상의 양식장에서의 자동 먹이 공급 시스템에 관하여 설명하고자 한다. 어류는 수온 및 어체 중량에 따라 먹이를 먹는 양이 변화하며, 해상 양식장의 경우 육상에 비하여 온도 변화가 크게 일어난다. 본 논문은 수온 및 어체 중량에 따라 먹이량을 계산하고 자동으로 먹이를 공급하는 시스템을 연구하였으며 모형 실험을 통하여 먹이 공급 장치의 성능을 검증하였다.

• 미생물학회지
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• 제49권4호
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• pp.313-320
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• 2013

정수처리 시설에서 급 배수관으로 많이 사용되는 스테인리스관과 동관에 형성되는 생물막의 특성에 대해 16주 동안 조사하였다. 생물막 반응기는 실제 배급수관의 구조와 유사하게 설계하였으며, 정수처리장으로 유입되는 상수원수와 약품혼화 응집수, 침전수, 여과수, 처리수를 사용하였다. 평균 종속영양세균수는 $1.6{\times}10^4CFU/ml$, $5.8{\times}10^3CFU/ml$, $1.8{\times}10^3CFU/ml$, $1.3{\times}10^2CFU/ml$, 1 CFU/ml로 각 처리 과정을 거치면서 감소하였다. 스테인리스관과 동관에 형성된 생물막 세균수는 원수, 응집수, 침전수에서 2주만에 $2.9{\times}10^3CFU/cm^2$ 이상으로 증가하였고, 동관보다 스테인리스관에서 생물막 세균수가 높게 검출되었다. 여과수(평균 잔류염소 0.44 mg/L)에서는 두 관 재질에 따른 생물막 세균수의 명확한 차이는 없었으며, 5주 이후부터 두 관재질 모두 $18CFU/cm^2$ 이하의 생물막 세균이 검출되었다. 정수(평균 잔류염소 0.88 mg/L)에서는 두 관 재질 모두 생물막 세균이 검출되지 않았다. DGGE 분석결과, 원수, 응집수, 침전수에서 스테인리스관은 Sphingomonadaceae가 우점이였고, 동관에서는 Bradyrhizobiaceae와 함께 Sphingomonadaceae도 우점이였다. 여과수의경우, 5주차 이후 스테인리스관과 동관에 형성된 생물막에서 Propionibacterium sp., Sphingomonas sp., Escherichia sp. 등과 유사한 16S rRNA 유전자 서열을 가지는 밴드들이 검출되었다. 종 풍부도 및 다양성은 동관에 비해 스테인리스관이 더 높게 나타났다.

• 한국농공학회논문집
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• 제63권2호
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• pp.85-96
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• 2021

Irrigation return flow is defined as the excess of irrigation water that is not evapotranspirated by direct surface drainage, and which returns to an aquifer. It is important to quantitatively estimate the irrigation return flow of the water cycle in an agricultural watershed. However, the previous studies on irrigation return flow rates are limitations in quantifying the return flow rate by region. Therefore, simulating irrigation return flow by accounting for various water loss rates derived from agricultural practices is necessary while the hydrologic and hydraulic modeling of cultivated canal-irrigated watersheds. In this study, the irrigation return flow rate of agricultural water, especially for the entire agricultural watershed, was estimated using the SWMM (Storm Water Management Model) module from 2010 to 2019 for the Madun reservoir located in Anseong, Gyeonggi-do. The results of SWMM simulation and water balance analysis estimated irrigation return flow rate. The estimated average annual irrigation return flow ratio during the period from 2010 to 2019 was approximately 55.3% of the annual irrigation amounts of which 35.9% was rapid return flow and 19.4% was delayed return flow. Based on these results, the hydrologic and hydraulic modeling approach can provide a valuable approach for estimating the irrigation return flow under different hydrological and water management conditions.

• 한국안전학회지
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• 제30권5호
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• pp.29-36
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• 2015

Common utility tunnel is essential to the daily lives of people underground utilities (electricity, gas and supply facilities such as water, communication facilities, sewer facilities, etc.) to improve the appearance by co-acceptance and disaster prevention, important for the conservation of the city's population was concentrated road construction the city-based facilities. There is recognition of the importance of the various supply treatment facilities in common utility tunnel as infrastructure to accommodate joint according to the city expanded, the demand for infrastructure. In this paper, a cost-benefit analysis using a one-time occurrence, without simply relying on cost or current cost, project manager for the city-dimensional feasibility study conducted, the user level of the maintenance costs and user costs, including social costs items from various angles can be investigated and proposed a mechanism of economic feasibility common utility tunnel. Evaluation of the proposed technique is cost-benefit and cost caused by installing common utility tunnel the existing pipeline area - was investigated by the benefit analysis, extended and repeated common utility tunnel installation depends much affected by the excavation, so users of reducing the number of repeat excavation convenience can be seen that this occurs.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 추계 학술발표회
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• pp.191-201
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• 2006

The flood control ability improvement project on existing dams is the project for prevention of disasters from excessive flood due to climate changes and thus protects lives and property damages by increasing safety of dams. The collapse of dam brings unimaginable disasters, so the project needs to be swiftly conducted by Government's funding. This paper introduces tile examples of the flood control ability improvement projects of multi-purpose and water supply dams, which is conducted in the way of structural measures among 26 dams operated by Kwater.

• International Journal of Safety
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• 제8권2호
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• pp.9-14
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• 2009

This paper describes analysis of risk voltage for grounding electrode where earth leakage current is injected. To assess risk voltage of grounding electrode, the grounding simulator and CDEGS program were used to obtain measured data and theoretical results of this study. The grounding simulator was composed of a hemispherical water tank, AC power supply, a movable potentiometer, and test grounding electrodes. The shapes of grounding electrode model was ground rod. The potential rise was measured by grounding simulator, and the touch and step voltages were computed by CDEGS program. As a consequence, the potential rise of ground rod abruptly decreases with increasing the distance from the grounding electrode to the point to be tested. The touch voltage above the ground rod was low, but the step voltage was high. The measured results were compared with the computer calculated data and were known in good agreement.

• Nuclear Engineering and Technology
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• 제41권8호
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• pp.1005-1014
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• 2009

The Dual Unit Optimizer 2000 MWe (DUO2000) is put forward as a new design concept for large power nuclear plants to cope with economic and safety challenges facing the $21^{st}$ century green and sustainable energy industry. DUO2000 is home to two nuclear steam supply systems (NSSSs) of the Optimized Power Reactor 1000 MWe (OPR1000)-like pressurized water reactor (PWR) in single containment so as to double the capacity of the plant. The idea behind DUO may as well be extended to combining any number of NSSSs of PWRs or pressurized heavy water reactors (PHWRs), or even boiling water reactors (BWRs). Once proven in water reactors, the technology may even be expanded to gas cooled, liquid metal cooled, and molten salt cooled reactors. With its in-vessel retention external reactor vessel cooling (IVR-ERVC) as severe accident management strategy, DUO can not only put the single most querulous PWR safety issue to an end, but also pave the way to very promising large power capacity while dispensing with the huge redesigning cost for Generation III+ nuclear systems. Five prototypes are presented for the DUO2000, and their respective advantages and drawbacks are considered. The strengths include, but are not necessarily limited to, reducing the cost of construction by decreasing the number of containment buildings from two to one, minimizing the cost of NSSS and control systems by sharing between the dual units, and lessening the maintenance cost by uniting the NSSS, just to name the few. The latent threats are discussed as well.

• 한국안전학회지
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• 제26권4호
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• pp.34-40
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• 2011

This paper is purposed to develop an leakage current detecting system(LCDS) which can prevent electrical fires on breaker capacity expansion as well as ruptures of XL(Extra long) pipelines and power failure by operation of ELB(Earth leakage breaker) at auto water machine in winter. In order to develop LCDS, this paper studied field state investigation, field state experiment, development of leakage alarm system and verification experiments. Field states investigation at livestock companies(10 companies) in cheong-won location to deduce the problems of auto water machine is analyzed. The field state experiment is conducted at B livestock company in cheong won location. The field state experiment method is measured with leakage current when ELB tripped by environment factor(fine, cloudy, and rainy day). The LCDS is developed as MCU(Micro Control Unit) part applied leakage current values at B livestock company. Verification experiments for the leakage current detecting system were conducted by two methods of current supply and field test. Results show that LCDS suggested in this paper are valuable and usable in auto water machine based on environment factor, which will prevent severe damage to human beings and properties and reduce the electrical fires in livestock.