• Korea Trade Review
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• v.45 no.4
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• pp.125-136
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• 2020

Freight charges are one of the major clauses in the voyage charter. However, in case of unexpected delays at loading and discharging ports, the owner of the ship would not be willing to cover the various costs he should bear by paying the freight receives from the charterer. Therefore, the shipowner, whose time and the ship would be both considered to be an expense, would try to reduce the laytime as least as possible when signing the charter party and to receive compensation such as demurrage and damage for detention from the charterer, just waiting for the agreed laytime to pass. In this study, we review the differences between demurrage and damage for detention and examine the acknowledgeable circumstances through the actual cases. Since the shipowner and the charterer do not often agree on the damage for detention from the respective contract, it is necessary to examine each. Besides, the shipowner and the charterer must acquaint the damage for detention and specify in a contract, to compensate for the actual loss of the shipowner.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.343-350
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• 2004

For the last two decades, Seoul has always been affected by large floods. As climate change causes more frequent localized heavy rains exceeding the capacity of sewer or river to discharge water, flood damage is expected to increase. Under the situation, detention facilities for lacking capacity of sewers can control stormwater runoff to reduce flood damage in urbanized areas. In this study, in order to reduce flood damage in Cheonggyecheon areas, the capacity of detention facilities was decided to make up for the lacking capacity of main sewers in case of the rainfall in July, 2001 as large flood. The average amount of stormwater detained in eight Cheonggyecheon drainage areas is $235.09m^3/ha$. Location and size of stormwater detention facilities is designed to have effects in short term by targeting the reduction of flood damage. Schools and parks are suggested as optimal locations where detention facilities are constructed in drainage areas.

• Journal of Environmental Science International
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• v.17 no.6
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• pp.601-609
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• 2008

In this study for the development of area due to the increasing of industry, population and spreading of urbanization is rapidly increasing but about seventy percent of our nation's areas consists of the mountainous districts. In such case, when those areas have the heavy rains break, they are washed away by a fast-flowing stream of a valley and overflowed. Thus it could result on human life and property damage and also the widespread of flood damage in the downstream area. To decrease those damage, the construction of flood control reservoir is necessary. This research was aim to construct the flood runoff models of a mountainous small district and to determine the probability rainfall by analyzing precipitation. The study also examined the effects of location and size of flood control reservoir on flood reduction. The result showed that the construction of detention basin was an effective way to ensure the safety of flood control and multiple detention basin had superior result for reducing amount of runoff in the down stream area than the single detention basin.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.632-635
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• 2007

Detention pond has an important role in peak flow reduction to mitigate flood damage. Design of detention pond is accomplished through the preliminary stage, planning stage, and design stage in general. New development projects produce increased peak flow and flow amounts. In this case it is necessary to design the detention pond easily and simply. The simple procedure of detention pond design is proposed in this study. The relevant variables are peak flow ratio ($\alpha$) for the before and after development, and storage ratio which is ratio of storage volume to flow amounts. Simplified method for the detention pond design with runoff reduction is easily used for practical purposes.

• Water for future
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• v.28 no.6
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• pp.203-215
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• 1995

Operation models for storm water pumps in detention pond were developed in order to reduce the damage by inundation in urbanized area. The return periods (10, 20, 30 years) of rainfall were selected to estimate inflow discharge to detention ponds. Inflow hydrographs of detention ponds were derived by using the SWMM, and Petri net diagrams were selected to analyze the pump actions. Safety and efficiency of pumps and detention ponds were estimated by penalty index. In order to verify the models, the models were applied to three selected detention ponds in Seoul area. In numerical experimental results, the developed model 3 is more effective in inland flooding prevention than the existing one, and may be used to design and evaluate detention ponds with real time data of rainfall.

• Journal of Korea Water Resources Association
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• v.41 no.12
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• pp.1211-1218
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• 2008

This study is for design of the detention system distributed in a watershed by the Multi-Objective Genetic Algorithms(MOGAs). A new model is developed to determine optimal size and location of detention. The developed model has two primary interfaced components such as a rainfall runoff model to simulate water surface elevation(or flowrate) and MOGAs to get the optimal solution. The objective functions used in this model depend on the peak flow and storage of detention. With various constraints such as structural limitations, capacities of storage and operational targets. The developed model is applied at Gwanyang basin within Anyang watershed. The simulation results show the maximum outlet reduction is occurred at detention facilities located in upper reach of watershed in the peak discharge rates. It is also reviewed the simultaneous construction of an off-line detention and an on-line detention. The methodologies obtained from this study will be used to control the flood discharges and to reduce flood damage in urbanized watershed.

• Journal of Korea Water Resources Association
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• v.41 no.7
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• pp.693-700
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• 2008

Detention pond has an important role in peak flow reduction to mitigate flood damage. Design of detention pond is accomplished through the preliminary stage, and design stage in general. New development projects produce increased peak flow and flow amounts. In this case it is necessary to design the detention pond easily and simply. A simplified design method of the detention pond is suggested in this study. Used design variables are peak flow ratio(${\alpha}$) and storage ratio($S_r$). ${\alpha}$ is the peak flow ratio of before and after development of the basin. $S_r$ is a ratio of storage volume to total runoff volume. Applicability of the proposed method was also proved. The simple procedure of detention pond design is proposed in this study.

• Journal of Korea Water Resources Association
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• v.50 no.4
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• pp.223-232
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• 2017

The ability to defend against floods in urban areas was weakened, because the increase in the impervious rate of urban areas due to urbanization and industrialization and the increase in the localized torrential rainfall due to abnormal climate. In order to reduce flood damage in urban areas, various runoff reduction facilities such as detention ponds and infiltration facilities were installed. However, in the case of domestic metropolitan cities, it is difficult to secure land for the installation of storm water reduction facilities and secure the budget for improving the aged pipelines. Therefore, it is necessary to design a storage system (called the detention pond in trunk sewer) that linked the existing drainage system to improve the flood control capacity of the urban area and reduce the budget. In this study, to analyze the effect of reducing runoff amounts according to the volume of the detention pond in trunk sewer, three kinds of virtual watershed (longitudinal, middle, concentration shape) were assumed and the detention pond in trunk sewer was installed at an arbitrary location in the watershed. The volume of the detention pond in trunk sewer was set to 6 cases ($1,000m^3$, $3,000m^3$, $5,000m^3$, $10,000m^3$, $20,000m^3$, $30,000m^3$), and the installation location of the detention pond in trunk sewer was varied to 20%, 40%, 60%, and 80% of the detention pond upstream area to the total watershed area (DUAR). Also, using the results of this study, a graph of the relationship and relational equation between the volume of the detention pond in trunk sewer and the installation location is presented.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.3 s.14
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• pp.51-60
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• 2004

Urban flood damage has been caused by drainage deficiency. One of the methods to solve this problem is to construct detention basin and Pumping station and to pump out the water to the river. However, because of rapid urbanization, the capacity of drainage pipelines is sometimes not sufficient enough during the rainy season. Therefore, even though we have enough pumping stations, the inflow of surface water never reaches to the detention area, causing floods in urban area. This research is to find improvement of urban drainage system, estimating drainage pipeline risk. Also, eight models for a computer program were developed for practical use. The models were verified changing precipitation duration, intensity, design period, time distribution model, and etc. This verification was processed focusing that the model can regulate the water level in the detention basin and minimize the effect downstream. As a result Fuzzy models were found to be efficient to lower the water level in detention basin, and decreased about 8 cm in water level of downstream.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.129-130
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• 2023

This study proposes rainwater infiltration retention blocks as a solution to the flooding problems caused by recent climate change and developed a flood prediction simulation program to select the optimal site for installing rainwater infiltration retention blocks that can minimize damage from floods. By applying the existing 2D flood analysis model G2D and adding a reservoir function, the volume of water before and after installation can be determined through simulation results.