• Journal of Korea Water Resources Association
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• v.42 no.9
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• pp.759-771
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• 2009

The electricity cost of pumping system accounts for a large part of the total operating cost for long distance water supply networks. This study presents a method based on dynamic programming for establishing an joint optimal operation of pumps and storages system on a hourly basis. Analysis is taken of the relative efficiencies of the available pumps, the structure of the electricity tariff, the consumer-demand pattern, and the storage characteristics and operational constraints of the pipe. The possible system objectives and constraints are described. An application of the method to the existing Yangju Water Supply System consisted of two pump station and 5 storage pools under the condition of expanding pumping facility in the part of the Capital Area Water Supply System is presented, showing that considerable electricity cost savings are remarkable. The approach was found to be implementable in real system operation and large-scale water supply system design in respect of minimizing life-cycle total cost.

• Journal of Korea Water Resources Association
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• v.57 no.4
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• pp.301-310
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• 2024

The spatial and temporal non-uniform distribution of precipitation makes water management difficult. Due to climate change, nonuniform distribution of precipitation is worsening, and droughts and floods are occurring frequently. Additionally, the intensity of droughts and floods is intensifying, making existing water management systems difficult. From June 2022 to June 2023, most of the water storage rates of major dams in the Yeongsan river and Seomjin river basin were below 30%. In the case of Juam dam, which is the most dependent on water use in the basin, the water storage rate fell to 20.3%, the lowest ever. Pyeongnim dam recorded the lowest water storage rate of 27.3% on May 4, 2023. Due to a lack of precipitation starting in the spring of 2022, Pyeongnim dam was placed at a drought concern level on June 19, 2022, and entered the severe drought level on August 21. Pyeongrim dam and Suyangje(dam) have different operating institutions. Nevertheless, the low water level was not reached at Pyeongnim dam through organic linkage operation in a drought situation. Pyeongnim dam was able to stably supply water to 63,000 people in three counties. In order to maximize the use of limited water resources, we must review ways to move water smoothly between basins and water sources, and prepare for water shortages caused by climate change by establishing a consumer-centered water supply system.

• Water for future
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• v.30 no.1
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• pp.45-49
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• 1997

• Water for future
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• v.19 no.1
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• pp.16-20
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• 1986

• Water for future
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• v.21 no.1
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• pp.25-30
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• 1988

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.69-70
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• 2008

Automatic control systems(AVR, Governor, Synchronizer) installed $1970{\sim}1980$ in K-water were considered to be rehabilitated around 2000. Moreover, Korea Power Exchange market system was changed from PPA (Power Purchase Agreement) to a bidding system. Therefore, depending on the power quality, the power provider could achieve additional profits. It is the excitation system and governor that have the functions of enhancing power necessities. During the 20 to 30 years of generator operation, there were many major and minor problems. Examples are SCR burnout (Andong: Excitation system), hunting (Imha: governor), field circuit breaker failure (Chungju 1st: excitation system), the rise of leakage current (Chungju 2nd: excitation system), power supply burnout (Chungju 2nd: governor). These are the typical examples of malfunction which hindered the generator operation and, consequently, diminished the profit of power business. In order to satisfy the needs of the power market and prevent malfunctions mentioned above, the rehabilitation of AVRs and governors were executed. A new system was made to have the flexibility of ancillary service (GF, AGC, etc.), PSS function. With user friendly HMI software, it is more convenient for the operator to fulfill suitable maintenance. It was possible to connect SCADA system by opening protocol of AVR, governor for the efficiency of operation and maintenance.

• Proceedings of the KIEE Conference
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• 2005.05b
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• pp.7-9
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• 2005

The rotating machine diagnosis technology is very important techniques to secure reliability of facility operation and life extension of operation to rotating machines that are exposed in danger of the insulation deterioration. The rotating machine diagnosis technology road map minimizes economic losses according to the unpredictable accidents of the rotating machine diagnosis technology. As technology is secured, it strengthen the competitiveness and the diagnosis technology road maps will be realizing the technique independence and applying industrial sites

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2495-2497
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• 2005

The satellite communication equipment, which has been installed and operated for the flood forecast and warning system at KOWACO, needs the review of the transmission Power control for keeping the stable operation of the satellite communication equipments. In this study, made the sample hardware for the transmission power control at Mini-Hubs and remote sites, and developed the control algorithm for stable operation of the transmission power controller.

• Journal of Korea Water Resources Association
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• v.55 no.7
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• pp.531-543
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• 2022

Integrated water resources management (IWRM) has focused on efficient response to various water related disasters by climate change. In particular, more flexible usage of conventional water resources infrastructures is expected to provide an eco-friendly water management. Multi-purpose dams and water supply dams are well known as water management facilities for securing and supplying water in drought season. Recently, based on the report '2021 multi-purpose use of hydropower dams in Han river', contribution of hydropower dams on water resources management is becoming more significant beyond the traditional role of hydropower generation. In drought conditions, the dams control water supply depending on the pre-defined drought stages. In the case of multi-purpose dams, an operation standard during drought has been already prepared and applied; however, for the hydropower dams, specific standards are not fully prepared yet in South Korea. In this study, a method for calculation of standard water storage and discharge reduction of hydropower dams according to drought stage is newly proposed reflecting the characteristics of hydropower dams. The proposed method was applied to the hydropower dams in Han river, where six hydropower dams are located. A case study of the historical droughts occurred in 2014-2017 demonstrated that the proposed hydropower dam operation rule could improve the water supply stability under severe drought conditions compared to the conventional operations. In the future, the role of hydropower dams for water resources management is expected to become more important, and this study can be widely used for water supply planning such as drought response using hydropower dams.

• Journal of Korea Water Resources Association
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• v.34 no.6
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• pp.617-625
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• 2001

Peace dam constructed against the water attack had stopped in the first step, linked with Hwacheon dam through bypass tunnels and had an effect of flood surcharging in its pocket on Hwacheon dam downstream. To study the utility of Peace dam, the flood control effects of Peace dam and the restricted water level (RWL) in Hwacheon dam were reviewed and identified with operating Hwacheon dam system. Analysing the results the ideas of expanding the usability of the water resources in Hwacheon dam system were suggested. To do that, the criteria and the model of reservoir operation were established frist and the optimization of the operation have done. Based on the results the performance of the optimization was evaluated as an reference coefficient with relative value of the registered data to the optimized. And examining several alternatives for the RWL in Hwacheon reservoir operation made more feasible RWL suggested. And its economic benefit was also reckoned.