• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.755-758
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• 2007

For a stable water supply, it is necessary to consider the present unusual change in the weather, seasonal variation of water use, and the frequency and duration of low flow. Therefore, in this study, a theoretical background of specific probability distribution type and the reliability of frequency analysis for the time series of low flow data was investigated and programmed to support the operation of multipurpose dam.

• Journal of Korean Society of Rural Planning
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• v.18 no.3
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• pp.175-186
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• 2012

This is a study of a residential area for displaced villagers planned for residents of Gyodo Village who must evacuate their hometown because of flooding due to the Hantan River Dam Project. The study aims to construct a plan for a new residential area for the villagers focusing on reflecting the existing characteristics of their former village and on ensuring sustainability for the new village. Departing from previous practice of focusing on merely physical aspects when planning, the current study is significant in that it presents a new planning process and method for a sustainability-focused plan. While the study has many limitations such as objectivity in the process of deriving the sustainability indicators and the appropriateness of the indicator questions, it is hoped that future studies on sustainability will serve to make up for these limitations and problems.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.3 s.14
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• pp.61-72
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• 2004

In this research, multi reservoir operation methods for reservoirs in Han River are proposed based on the single dam operation models using fuzzy control techniques. The result of fuzzy controled single dam operation has shown that it can improve flood controllability at the downstream of dams. Among the many control rules of fuzzy operation, a rule that shows the most effective flood control rate at the downstream has been selected as Ike operation rule. The simulated results for 1990 and 1995 flood events are compared with historical ones. As the results, it is founded that suggested models can reduce the inundation of upstream and keep the water elevation lower at downstream, which make the proposed models as the effective methods in multi reservoir operation.

• Tunnel and Underground Space
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• v.22 no.4
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• pp.227-242
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• 2012

Youngju multipurpose dam is planned to minimizing the damage by flood and obtaining the water for industrial use in Nakdong river region. Faults in rock mass have strong influences on the behaviors of dam structure. Thus, it is very important to analyse for the characteristics of fault rocks in dam design. However, due to the limitation of geotechnical investigation in design stages, engineers have to carry out the additional geological survey including directional boring to find the distribution of faults and the engineering properties of faults for stability of dam. Especially, the selection of location of dam and type of dam considering fault zone must be analyzed through various experimental and numerical analysis. In this study, various geological survey and field tests were carried out to analyse the characteristics of the large fault zone through the complex dam is designed in foundation region. Also, the distribution of structural geology, the shape of faults and the mechanical properties of fault rock were studied for the reasonable design of the location and type of dam for long-term stability of the complex dam.

• Journal of Korea Water Resources Association
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• v.37 no.4
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• pp.273-281
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• 2004

Generally, reservoir storage is allocated according to planned purposes established before construction and operating policies are established through release control. The established reservoir allocation is hardly changed unless the special cases such as raising dam or changed purposes occur It Is, however, likely that public needs and objectives can be changed as time go on, the study for multipurpose reservoir storage reallocation is performed as an alternative to reflect these. In this study, flood control analysis is performed for several alternatives of reallocation for the Daechung multi-purpose reservoir in Geum river. As a result, it is confirmed that flood control capability is not decreased compared to single operation of Daechung reservoir for the same flood condition even if conservation level of Daechung multi-purpose reservoir is increased.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.10
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• pp.1532-1539
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• 2017

The floating photovoltaic system is a new concept in the renewable energy technology. That is similar to land based photovoltaic technology except floating system. So the system needs buoyant objects, mooring, ect, besides modules and supports, and that is able to withstand in water level changes and wind strength. Therefore the floating photovoltaic system is much different from land photovoltaic system. K-water (Korea Water Resources Corporation) has been operating two floating photovoltaic system that's capacity is 100 kW and 500 kW respectively since in summer 2011 for commercial generation, and have construction project for 2,000 kW in Boryeong multipurpose Dam and other areas. Furthermore K-water was developing a tracking-type floating photovoltaic system at Daecheong multipurpose Dam and developed and installed an ocean floating photovoltaic demonstration plant at Sihwa Lake in October 2013 for R&D. In this paper, we introduce that structure of floating photovoltaic system include buoyant structure, mooring system and auxiliary device. Especially the rope which is in part of mooring should be always maintain tension under any water level. Also we explain about structure design concept to wind load in an every loading condition and a kind of structure materials and PV structure types used in water environment. Especially ocean floating PV system is affected by tidal current and typhoon. So there are considering the elements in design. Finally we compare with floating and land photovoltaic on power amount. As a result of that we verified the floating photovoltaic system is more about 6.6~14.2 % efficiency than a general land photovoltaic system.

• Ecology and Resilient Infrastructure
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• v.9 no.3
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• pp.131-140
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• 2022

The magnitude and frequency of extreme floods are increasing owing to the effects of climate change. Therefore, multipurpose flood management techniques incorporating nature-based solutions have been introduced to mitigate the limitations of flood management and river design methods relying on existing observation data. Nature-based solutions to prepare for such extreme flooding events include ways to retreat the embankment, expand the floodplain, and reduce flood damage. To apply these technologies, adopting appropriate location selection methods based on various evaluation factors, such as flood damage reduction effects, sustainable ecological environments, river connectivity, and physical channel structure enhancements, should be prioritized. Therefore, in this study, the optimal location for implementing the multipurpose floodplain construction project was determined by selecting the location of the floodplain expansion with objectivity in the river waterfront area upstream of Daecheong Dam to downstream of Yongdam Dam. Through the final location determination, the Dongdaeje and Jeogokje sections were included in the optimal location considering both flood damage reduction and water environment improvement.

• Water for future
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• v.29 no.2
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• pp.209-219
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• 1996

The existing gate operation rule of Paldang hydroelectric plant has been used since the construction of the dam in 1973 except partial modification due to the construction of Chungju multipurpose dam in 1985. The water level near the downstream of Paldang dam has been lowered about 3 m because of the channel maintenance of Han River development project. Thus, the discharge estimation formula based on the submerged orifice type spillway has to be re-evaluated by considering various patterns of the gate operation rules and lowered channel bed. In this study, three types of gate openings were tested to select the proper gate operation rules through the hydraulic model test for various discharges and opening heights. Also, the numerical analysis has been performed to simulate the flow patterns of downstream. As a result, the gate operation rule, which opens 5 gates each time from the left side, was selected as the proper gate operation rule of Paldang dam.

• Journal of Environmental Science International
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• v.19 no.2
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• pp.149-155
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• 2010

Rainfalls would increase the discharges or stages of tributary channels in natural watersheds, which in turn augment the magnitude of main stream stages. Rising of water surface elevation in main streams can affect and damage the human activities because of the possibilities of the breakdown or overflow of the embankment. Therefore it is necessary to establish the structural or non-structural alternatives for the sake of prevention or treatment of those disasters. Many mathematical models to analyze the flood flows in natural watercourses have been proposed as the non-structural alternatives so far. In this study one of the such models, FLDWAV developed by NWS(National weather Service), is applied to the downstream reach of Nakdong river. Model calibration is performed on various Manning's roughness coefficients at the gauging stations. The simulation results are compared well with hydrological estimations of flood discharges considering the effects of multipurpose dams upstream of control points.

• Journal of Korea Water Resources Association
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• v.33 no.6
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• pp.745-755
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• 2000

The dam operation system of KOWACO for flood control doesn't have capability to account for the downstream hydrologic conditions and any feasible index to decide the pre-release from the forecasted rainfall and inflow. In this study, a dam operation model for flood control was developed to account for the flood flow condition of its downstream to give users the dam release schedules. Application test of EV ROM to Keum River showed that EV ROM is superior to the Rigid ROM and Technical ROM which are currently used by KOWACO. EV ROM developed in this study provides a release schedule accounting for the cumulative lateral flow hydrograph at the downstream control points where the discharge does not depend only on the dam operation. but also on lateral inflow from the tributaries. In order to reduce the peak discharge at the control points, it suggests the preliminary release during the early rising phase of the predicted hydrograph, holding the flood flow inside the dam during a peak phase, and afterward resuming the release. Three case studies of flood control by the operation of Daechung Multipurpose Dam in Geum River Basin show that the EV ROM is superior to the Rigid ROM and Technical ROM. This must be due to its nature to account for the downstream flow condition as well as the inflow and water level of the dam. It was also conceived that further case studies of EV ROM and more accurate rainfall prediction would improve the dam operation for flood control.ontrol.