• 한국수자원학회논문집
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• 제55권1호
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• pp.59-70
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• 2022

상수도관망은 대표적인 사회기반시설로 수원에서 수용가에게 물을 공급하는 과정에서 병원성 미생물을 소독하기 위해 염소를 주입한다. 안전한 물의 공급을 위해 잔류염소 농도 기준(0.1-4.0 mg/L)을 유지하도록 규정하고 있으나, 사용자의 사용 패턴, 수령, 상수도관망의 형식 및 특징은 수리학적(i.e., 절점의 압력, 관로의 유속) 및 수질적(i.e., 잔류염소 농도) 특징에 영향을 미친다. 따라서, 본 연구에서는 Multi-objective Harmony Search (MOHS)를 사용하여 수질-수리 인자를 고려한 상수도관망 최적 설계 기법을 개발하였다. 설계인자로는 설계비용과 시스템 탄력성을 고려하였으며, 절점의 압력과 잔류염소 농도를 제약조건으로 적용하였다. 도출된 최적설계안은 상수도관망의 형식 및 특징에 따라 분석하였다. 이러한 최적설계안은 경제적인 측면과 수질 측면의 안전성을 충족할 수 있으며, 사용자의 사용성을 증가시킬 수 있다.

• 한국농공학회논문집
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• 제49권3호
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• pp.11-20
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• 2007

Estimation of crop consumptive use is a key term of agricultural water resource systems design and operation. The 10-year return period drought has special aspects as a reference period in design process of irrigation systems in terms of agricultural water demand analysis so that crop evapotranspiration (ETc) about the return period also has to be analyzed to assist understanding of crop water requirement of paddy rice. In this study, The ETc of 10-year return period drought was computed using frequency analysis by 54 meteorological stations. To find an optimal probability distribution, 8 types of probability distribution function were tested by three the goodness of fit tests including ${\chi}^2$(Chi-Square), K-S (Kolmogorov-Smirnov) and PPCC (Probability Plot Correlation Coefficient). Optimal probability distribution function was selected the 2-parameter Log-Normal (LN2) distribution function among 8 distribution functions. Using the two selected distribution functions, the ETc of 10-year return period drought was estimated for 54 meteorological stations and compared with prior study results suggested by other researchers.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.304-305
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• 2005

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1110-1111
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• 2005

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1338-1339
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• 2011

Recently the wind turbine generating systems are increasing world widely. This type of systems will change the nation's energy environment which largely depends on the fossil fuels. It will also bring new problems to the power industry and the customers. The expected problem is the voltage and frequency stability of the power distribution network, when a wind turbine generating system is connected to the line. It becomes necessary and important to evaluate their impact on the electrical network stability. This paper shows the electrical data measurement and analysis of a inductive wind turbine generator affecting the power quality problem of the distribution line.

• 지구물리
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• 제7권1호
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• pp.51-60
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• 2004

시간이 경과함에 따라 상수도 관망시설은 부식 혹은 파손 등의 이유에 의하여 통수능의 저하 및 통수 불가능의 위험에 처할 수 있다 이에 따라 계속적인 관리의 적용을 위해서는 각 관망의 교체 시기 및 개선 방안에 대한 연구가 필요하며 이의 효율적인 방안으로서 최적화 기법 혹은 의사결정 지원 시스템 등의 구성이 요청된다 그러나 현재의 연구 동향들로서는 수리특성의 변화만을 관망 교체의 주 고려 대상으로 인식하고 공업 경영학적 계획을 고려하고 있지 못하다 본 연구에서는 이들 두 가지 개념으로서의 관망 개량 프로그램을 제시하였으며 대전광역시에 대하여 기초적으로 적용하여 보았다

• 상하수도학회지
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• 제29권4호
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• pp.519-531
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• 2015

It has been widely accepted that the pressure management of water distribution systems using pressure reducing valves(PRVs) would be an effective method for controlling leakages. A pressure reducing valve (PRV) regulates outlet pressure regardless of fluctuating flow and varying inlet pressure, thereby reducing leakage and mitigating the stress on the water distribution system. However, the operation of a PRV is vulnerable to its mechanical condition and hydraulic operability. In this research, the effect of PRVs installed in water distribution system are evaluated in terms of hydraulic pressure reduction and mechanical performance by analyzing measured pressure data with statistical approach. A statistical approach using the moving average filter and frequency analysis based on fourier transform is presented to detect abnormally operated PRVs that have been densely installed in water distribution system. The result shows that the proposed approach can be a good performance evaluation method by simply measuring pressures for the PRVs.

• Environmental Engineering Research
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• 제11권2호
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• pp.99-105
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• 2006

A digital ultrasonic image construction system was developed for the nondestructive detection of cracks in water distribution pipes. The system consists of PC based ultrasonic testing system and a scanning device. The PC based ultrasonic system has an ultrasonic pulse/receive board for the generation and reception of ultrasonic signals, an analogue to digital conversion board for the digitization of the received ultrasonic signals, and transducers for the ultrasonic sensors. Using this system, the digitized ultrasonic signals were properly constructed in accordance with the position information obtained by scanning device that moves an ultrasonic transducer along the outer surface of pipes. In the construction of the ultrasonic signals, signal processing concepts, such as spatial average and array concept, were considered to enhance the resolution of ultrasonic images of pipe wall. Using the developed system, crack detection experiments were performed in both laboratory and field, which shows promise for crack detection in the water distribution system.

• 상하수도학회지
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• 제11권3호
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• pp.96-104
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• 1997

In-pipe formation of THM in water distribution systems was simulated by using the continuously and easily measurable parameters such as water temperature, residual chlorine and soluble organic compounds. The concentration of miscellaneous organics which could be the precuror of THM, was measured and represented as the absorbance of ultraviolet at wave length 260 nm. As the results, the developed equation in this study showed a more reliability on the change of THM than the normally regressed equation. In addition, the simulation was successfully fitted in the actual water treatment and distribution systems. Of the THM components, dibromochloromethane was the main cause dropping the overall reliability in the simulation.

• 상하수도학회지
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• 제23권1호
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• pp.77-87
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• 2009

In existing systems, the best method inhibiting corrosion control in water distribution systems is to reduce water corrosiveness. Water corrosion can be decreased by controlling water quality through simple water treatment in treatment plants. On this research, we study the characteristics of tab water qualities in domestic areas, assessment of corrosive water quality and the method of water quality monitoring. This review presents the method of water quality monitoring which is the most applicable. Monitoring for corrosion control in waterworks system is the most proper method; It can prevent serious accidents economically and reduce civil appeals. Surely we should assess corrosive water quality in tab water, and introduce water treatment methods to control corrosive water quality before monitoring for corrosion. According to a lot of researches, it has been proved that simple water treatments can reduce the pipe corrosion. In this review we should indicate that we do not control of the corrosive water quality due to domestic conditions, we should monitor the water quality basically. Therefore, we recognize how the existing water quality can cause problems on pipeline corrosion, how to deal with it. Then it will be possible to apply water quality monitoring for corrosion control in water distribution system. Monitoring for corrosion control can be expressed by LI index, it is already known in literatures. This review presents more simple method than existing methods than existing ones we expect to apply these methods to SCADA in the future.