• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.2
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• pp.1-15
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• 2007

This paper proposes a method for determining the number of storage rooms and designing the storage layout in warehouses for pyramid type stacks whose example are slacks for steel coils, paper rolls, and drums for oils. Formulas are derived for estimating the expected values and the variances of various handling times by cranes. From the derived formulas, the expected queuing time of road trucks is estimated. Base on the derived formulas, this study derives the cost function for determining the optimal numbers of rows, bays, and tiers of stacks and sizing cranes under the condition that the requirement for storage space is satisfied. Results of numerical analysis are provided.

• Water for future
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• v.29 no.4
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• pp.149-160
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• 1996

The parameters of the storage function model (SFM) are taken as constants, while they have different values every rainfall events and time of the runoff. Therefore, the results of the SFM show remarkably large errors in general. In this study, the modified sorage function model (MSFM), in which the time variant parameters are introduced, is proposed to improve the SFM which is a conceptual rainfall-runoff model. The fuzzy reasoning is applied as a real-time control method of the time-variant parameters of the proposed model. The applicability of the MSFM was examined in the Bochung river, a tributary of Geum river in Korea. The pattern of predicted outflow hydrograph and peak outflow by the MSFM with fuzzy control are much similar to the measured values in comparison with the results produced by the SFM.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.3
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• pp.38-48
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• 2001

A wetland is an ecosystem which is the most useful and highly-energetic transition area. This study has been carried out to develop the wetland function assessment methods and apply on the natural wetlands (Mul-young-ari wetland in Jeju-island and Bangdong wetland in Taejon Metropolitan city) using RAM (Rapid Assessment Method). The RAM is useful method for assessing the wetland functions in terms of general functions acquired by once or twice onsite surveying. Eight functions of 2-12 variables each are analyzed for assessing the wetland functions. The results are as follows : 1) The conservation values of two wetlands are "High". 2) In Mul-young-ari wetland, such functions as groundwater discharge, floral diversity and wildlife habitat, shoreline/stream bank protection are relatively high, but some functions such as flood/storm water storage, aesthetics and recreation are "Moderate" - "High". 3) In Bangdong wetland, such functions as floral diversity and wildlife habitat, groundwater discharge, flood/storm water storage, aesthetics and recreation are high, and another functions are "Moderate" - "High". The taxonomy of this study stems from assessing functions of inland wetlands using indices of RAM. So It is needed that consequent studies are to be performed with verifying the variables and indices.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.3
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• pp.3-13
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• 2005

The conceptual rainfall-runoff models are used to predict complex hydrological effects of a basin. However, to obtain reliable results, there are some difficulties and problems in choosing optimum model, calibrating, and verifying the chosen model suitable for hydrological characteristics of the basin. In this study, Genetic Algorithm and SCE-UA method as global optimization methods were applied to compare the each optimization technique and to analyze the application for the rainfall-runoff models. Modified TANK model that is used to calculate outflow for watershed management and reservoir operation etc. was optimized as a long term rainfall-runoff model. And storage-function model that is used to predict real-time flood using historical data was optimized as a short term rainfall-runoff model. The optimized models were applied to simulate runoff on Pyeongchang-river watershed and Bocheong-stream watershed in 2001 and 2002. In the historical data study, the Genetic Algorithm and the SCE-UA method showed consistently good results considering statistical values compared with observed data.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2245-2253
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• 2018

With the increase of electrical consumption and the unbalance of power demand and supply, power reserve rate is getting smaller and also the reliability of the power supply is getting deteriorated. Under this circumstance, the electrical energy storage (EES) System is considered as one of essential countermeasure for demand side management. This paper proposes efficient evaluation algorithms of multiple functions for EES systems, especially the secondary battery energy storage systems, in the case where they are interconnected with the power distribution systems. It is important to perform the economic evaluation for the new energy storage systems in a quantitative manner, because they are very costly right now. In this paper, the multiple functions of EES systems such as load levelling, effective utilization of power distribution systems and uninterruptible power supply are classified, and then the quantitative evaluation methods for their functions are proposed. From the case studies, it is verified that EES systems installed at distribution systems in a dispersed manner have multiple functions involved with direct and indirect benefits and also they can be expected to introduce to distribution systems with respects to economical point of view.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1219-1223
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• 2005

This study was accomplished to confirm the possibility of supplying stream minimum flow from detention storage which was determined to reduce peak flows of flood within developing planned district. The results analyzed was summarized as follows; Firstly, Sin-gil district situated in Ansan city was selected, of which watershed area has $0.56km^2$. And detention storage was determined to $5,370m^3$ from analyzing flood volume by the SCS unit hydrograph method. Secondly, using Visual Basic ver 6.0, a detention storage water balance model was developed, in which simulation was based on conditioning storage inflow and outflow according to streamflow volume or rate state. And streamflow was simulated using the DAWAST model. Thirdly, detention operation scenarios were consisted of the combinations with inflow referencing streamflow of 5mm/day, 10mm/day and outflow referencing streamflow of 1mm/day, 2mm/day. The developed detention storage water balance model was operated to simulate daily water storages of detention sized on flood by scenarios. Stream minimum flows were able to be supplied during 209 days to 237 days per a year, total volume of stream minimum flows supplied for this period was analyzed to reach 27 to $55\% of yearly streamflow volume. If inflow criteria of streamflows to detention was considered to be established on a theoretical condition, it is expected to supply stream minimum flows of 20 to $30\% of yearly streamflow from stream to detention. Also to maximize function of supplying urban stream minimum flow from detention storages, sewage waters within developing planned district have to be treated and entered to detention inflow together with streamflows to enrich function of detention planned to reduce flood volumes.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.3
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• pp.1-16
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• 2022

The purpose of this study is to quantitatively evaluate the amount of carbon storage for trees in forest ecosystem to support the foundation for carbon neutrality implementation in Korea National Park. It targeted 22 national parks designated and managed as national parks in Korea, and conducted research on forest trees in the terrestrial ecosystem among various natural and ecological carbon sink. The survey and analysis method followed the IPCC guidelines and the National Greenhouse Gas Inventory in Korea. The amount of tree carbon storage in the forest ecosystem of Korea National Park was confirmed to be about 218,505 thousand CO₂-ton and the amount of carbon storage per unit area was 570.8 CO₂-ton per hectare. Compared to 299.7 CO₂-ton per hectare, the average carbon storage per unit area of the entire Korean forest, it was found that about twice as much carbon was stored when assuming the same area. In other words, it means that the tree carbon storage function of the national park is about twice as high as that of the average tree carbon storage function of entire Korean forest. It has great implications in Korea National Park not only provides biodiversity promotion and exploration services as a national protected area, but also performs excellent functions as a carbon sink.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.2
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• pp.227-236
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• 2007

This paper proposes a method for designing stacking warehouses of pyramid type which can be found in storage rooms for steel coils, paper rolls, and drums for oils. Formulas were derived for estimating the expected travel time of cranes and the expected time for rehandling activities. Based on the derived formulas, this study derives the cost function for determining the optimal numbers of rows, bays, tiers of stacks under the condition that the requirement for storage space is satisfied. Numerical examples were given.

• KIISE Transactions on Computing Practices
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• v.23 no.8
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• pp.473-480
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• 2017

In recent years, semiconductor-based storage devices such as flash memory (SSDs) have been developed to high performance. In addition, a trend has been observed of optimally utilizing resources such as the central processing unit (CPU) and memory of the internal controller in the storage device according to the needs of the application. This concept is called In-Storage Processing (ISP). In a storage device equipped with the ISP function, it is possible to process part of the operation executed on the host system, thus reducing the load on the host. Moreover, since the data is processed in the storage device, the data transferred to the host are reduced. In this paper, we propose a method to optimize graph query processing by utilizing these ISP functions, and show that the optimized graph processing method improves the performance of the graph 500 benchmark by up to 20%.

• Journal of Korea Water Resources Association
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• v.41 no.7
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• pp.737-746
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• 2008

The purpose of developing a rainfall-runoff and reservoir model is to provide an analysis tool for hydrological engineers in order to forecast discharge of rivers and to accomplish reservoir operations easily and accurately. In this study, based on the short-term rainfall-runoff storage function model which has gained popularity for real time flood forecast in practical water management affairs, a long-term runoff model was developed for the improvement of the calculation method of effective rainfall and percolation at the infiltration area. Annual discharge was simulated for three dam watersheds(Andong, Hapcheon, Milyang) in Nakdong River basin to analyze the accuracy of the developed model and compare it to SSARR model, which is used as the long-term runoff model in current practical water management affairs. As the result of the comparison of hydrographs, SSARR model showed relatively better results. However, it is possible for the developed model to simulate reliable long-term runoff using relatively little available data and is useful for hydrological engineers in practical affairs.