• KIEE International Transactions on Power Engineering
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• v.4A no.1
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• pp.11-17
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• 2004

It becomes difficult and high in cost to construct new ducts and/or tunnels for power cables in domestic areas. This paper presents possible strategy of an HTS distribution cables for distributing electric power in local areas as niche marketing. Reflected were its important distinction such as system configuration, rationale, establishment of strategy and considerably high economical efficiency compared with present underground cables. In this paper, applicable important items by using HTS distribution cables in water pumping powerhouse and distribution substation as example objective regions were reviewed. Based on this, the following items on distribution HTS system are examined. (I)A review of constructing a model system to introduce high temperature superconducting distribution cables to objective areas is presented. (2)The strategy to capture HTS distribution cable in water pumping powerhouse and distribution substation as niche marketing regions were reviewed. (3)In concrete, system configuration, rationale, establishment of strategy and considerably high economical efficiency are reviewed between existing cable and HTS one.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.1
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• pp.1-12
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• 2012

The purpose of water distribution system is supplying water to users by maintaining appropriate pressure and water quality. For efficient monitoring of the water distribution system, determination of optimal locations for pressure monitoring is essential. In this study, entropy theory was applied to determine the optimal locations for pressure monitoring. The entropy which is defined as the amount of information was calculated from the pressure change due to the variation of demand reflected the abnormal conditions at nodes, and the emitter function (fire hydrant) was used to reproduce actual pressure change pattern in EPANET. The optimal combination of monitoring points for pressure detection was determined by selecting the nodes receiving maximum information from other nodes using genetic algorithm. The Ozger's and a real network were evaluated using the proposed model. From the results, it was found that the entropy theory can provide general guideline to select the locations of pressure sensors installation for optimal design and monitoring of the water distribution systems. During decision-making phase, optimal combination of monitoring points can be selected by comparing total amount of information at each point especially when there are some constraints of installation such as limitation of available budget.

• Water for future
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• v.29 no.3
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• pp.197-205
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• 1996

Flow carrying capacity of water distribution systems is getting reduced by deterioration of pipes in the systems. The objective of this study is to develop a managerial decision-making model for the rehabilitation of water distribution systems with a minimum cost. The decisions made by the model also satisfy the requirements for the discharge and pressure at demanding nodes in the system. The replacement cost, pipe break repair cost, and pumping cost are considered in the economic evaluation of the decision along with the break ratio and interest ratio to determine the optimal replacement time for each pipe. Then, the hydraulic integrity of the water distribution system is checked for the decision by a pipe network simulator, KYPIPE, if the discharge and pressure requirements, the decision made for the optimal replacement time is revised until the requirements are satisfied. The model is applied to an existing water distribution system, the Metropolita Water Supply Project (1st Phase). The result shows that the decisions for the replacement time determined by the economix analysis are accepted as optimal and the hydraulic integrity of the system is in good condition.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.85-93
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• 1996

This study is to make a comparison between the node method and the pipeline method for the analysis of the water distribution systems. For these purposes, the two methods were applied to a pipeline system in series, an artificial distribution network and a real distribution network. The results are as follows. 1. The difference between the results of the two methods was increased with the increase of the hydraulic gradient and the length between two adjacent nodes. 2. When all pipe lengths between two adjacent nodes were larger than 200~300m and have the steep hydraulic gradient, it was found that the results of the two methods showed high differences. 3. The difference between the results of the two methods were negligible in the case of the real distribution system in which only 12% whole pipelines were longer than 30m and the longest pipe length was 850m.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.3
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• pp.51-58
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• 1997

Determining sizes and the locations of reservoirs in the water distribution system(WDS) with multi-reservoirs is much difficult than that with single reservoir. The extended period simulation(EPS) models provide more comprehensive analysis of water distribution systems than the steady-state models can do. Therefore, EPS models should be applied to the WDS with multi-reservoirs. This study is to investigate the variations of required reservoir sizes and residual nodal pressures according to reservoir locations. In this study, EPS was applied to analyze an artificial and a real WDS under several water demand patterns. As a result, it was found that water demand patterns make no significant differences in the determining of the reservoir size, if they have similar peaking factors. And the variations of the peaking factor should be carefully checked in the design and the analysis of the WDS with multi-reservoirs, because the peaking factor itself will affect the minimum allowable sizes of reservoirs in those systems.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.136-139
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• 2003

This study is to observe the occurrence of heterotrophic bacteria in terms of free chlorine residuals in two different water distribution system which belongs to both K and Y water treatment plant of S city of Korea. The data analyzing in distribution systems (DS) shows that the free chlorine residuals decrease from 0.10 to 0.56 mgmg/L for K, and 0.51 to 0.78 mg/L for Y. The decay of free chlorine is clearly higher in both March and August than those of in January. The HPC in DS are ranged from 0 to 40 CFU/mL for K, 0 to 270 CFU/mL for Y, on R2A medium. In particular, its level is relatively high at consumers ground storage tanks, taps and point-of-end area of Y. The predominant genera is studied in distribution systems are Acinetobacter, Sphingomonas (branch of Pseudomonas), Micrococcus, Bacillus, Staphylococcus. The diversity of heterotrophic bacteria increase in the end-point area. Most of them are either encapsulated cells or cocci of gram-positve. In conclusion, the point-of-end area in distribution systems shows the longer flow distance from water treatment plants, the greater diversity and higher level of heterotrophic bacteria due to the significant decay of free chlorine residuals.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.6
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• pp.89-100
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• 2021

The conservation of stream habitats has been gaining more public attention and fish habitat suitability index (HSI) is an important measure for ecological stream habitat assessment. The fish habitat preference is affected not only by physical stream conditions but also by water quality of which HSI was not available due to the lack of field data. The purpose of this study is to estimate the HSI of Zacco platypus for water quality parameters of water temperature, dissolved oxygen (DO), and biochemical oxygen demand (BOD) using the water environment monitoring data provided by the Ministry of Environment (ME). Fish population data merged with water quality were constructed by spatio-temporal matching of nationwide water quality monitoring data with bio-monitoring data of the ME. Two types of the HSI were calculated by the Instream Flow and Aquatic Systems Group (IFASG) method and probability distribution (Weibull) fitting for the four major river basins. Both the HSIs by the IFASG and Weibull fitting appeared to represent the overall distribution and magnitude of fish population and this can be used in stream fish habitat evaluation considering water quality.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.6
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• pp.617-623
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• 2015

In this study, determination methods of monitoring location in water distribution system were suggested and applied to real test bed. Small block of Gwangtan water distribution system is consisted of 582 pipes, 564 junctions, 1 reservoir, and 1 pump station. Small block of Ho Chi Minh water distribution system is consisted of 162 pipes, 148 junctions, and 1 reservoir. Two small block water distribution systems were analyzed by pressure contribution analysis method to determine the optimum monitoring locations. The pressure change was estimated at each junctions by the additional demand at a junction. From the results, the optimum monitoring location can be determined by rank of pressure contribution index at each junctions due to demand change at a junction.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.20 no.2
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• pp.125-133
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• 1991

This paper presents some design guidelines for using cold air/water distribution to cool commercial and industrial buildings. Cold air /water distribution systems provide primary air/water for space conditioning at nominal temperature between $3^{\circ}C$ and $10^{\circ}C$ ($4{\sim}5^{\circ}C$ might be recommendable for better selection). By using lower temperature primary air/water equipment could be downsized, means lower first costs, and often reduce annual energy costs up to 50% less than that of the conventional ($13^{\circ}C$) system. This concept takes full advantages of the $2{\sim}4^{\circ}C$ chilled water (brine) available with ice storate systems.

• Journal of Environmental Health Sciences
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• v.32 no.4 s.91
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• pp.282-291
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• 2006

This study investigated the inactivation of the total coliform, an indicator organism in chlorine and chlorine in order to control microbial regrowth for water distribution systems and select an appropriate disinfection strategy for drinking water systems. The disinfection effects of chlorine and chlorine dioxide with regard to the dosage of disinfectant, contact time and DOC was investigated experimentally. In spite of the consistency of chlorine residuals at approximately 0.2 mg/l, bacteria regrowth was detected in the distribution system and it was confirmed by the scanning electron microscope results. The influence of organic carbon change on the killing effect of chlorine dioxide was strong.