• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.8-12
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• 2022

Water loss is one of the typical but challenging problems in water management. To reduced water loss or increase water efficiency, the pilot projects were implemented in the TTD's irrigation area. Modern soil moisture technology and local level water user training were conducted together as a mean to achieve improved water efficiency. In terms of technology, soil moisture sensors and monitoring system were used to estimate crop water requirement to reduce unnecessary irrigation. This was found to save 16.47% of irrigated water and 25.20% of irrigation supply. Further improvement of water efficiency was gained by means of local level water user training in which stakeholders were engaged in the network of communications and co-planning. The lessons learnt from the TTD pilot project was translated into good water management practices at local level.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.220-220
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• 2011

관개배수를 수행하는 농업용 수리시설물은 소규모이고 개소수가 많아 효율적으로 관리하기가 어려우며, 넓은 지역에 분포하고 있어 시설 현황의 파악조차 쉽지 않다. 농업용 수리시설물은 점검자가 관리항목을 종이 조사표에 수기로 작성하여 시설상태를 점검하고 있기 때문에 자료의 누락 및 오류, 전산화를 위한 재입력 과정 등에 있어서 어려움이 발생할 수 있다. 이러한 시설물을 효과적으로 관리하기 위해서는 정보망을 구성하여 원격으로 관리하거나, 직접 시설물을 돌아보며 관리해야 한다. 전자의 경우에는 비용이 많이 들기 때문에 적은 수의 관리지점을 제어하는 데는 유리하나, 농업용 수리시설물과 같이 개체수가 많을 경우에는 적용이 어렵다는 단점이 있다. 본 연구에서는 농업용 수리시설 점검 및 관리의 편의성, 효율성을 제고하기 위하여 농업용 수리시설물에 대하여 점검표준코드를 설계하였으며, WSN (Wireless Sensor Network) 기반의 점검기술 (RFID 및 QR코드)을 개발, 현장 적용을 통하여 활용성을 평가하였다. WSN 기술을 바탕으로 빠르고 정확하게 시설물을 인식할 수 있으며, 식별한 시설물의 정보를 바탕으로 현장에서 시설물에 대한 적절한 대응이 가능하도록 설계하였다. 개발한 기술은 대한민국 이동 지구의 시설물을 관리하는 데 직접 이용함으로써 평가하였다. 본 연구는 기존 농업용 수리시설물 점검의 비효율성을 개선하고 시설물 안전 평가 및 현장 이력 관리 등 현장 업무 효율 향상을 통해 농업용 수리시설 관리 및 농업용수 관리에 기여하는 바가 클 것으로 기대된다.

• Journal of Korean Society on Water Environment
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• v.31 no.5
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• pp.491-506
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• 2015

Distributed models represent watersheds using a network of numerous, uniform calculation units to provide spatially detailed and consistent evaluations across the watershed. However, these models have a disadvantage in general requiring a high computing cost. Semi-distributed models, on the other hand, delineate watersheds using a simplified network of non-uniform calculation units requiring a much lower computing cost than distributed models. Employing a simplified network of non-uniform units, however, semi-distributed models cannot but have limitations in spatially-consistent simulations of hydrogeochemical processes and are often not favoured for such a task as identifying critical source areas within a watershed. Aiming to overcome these shortcomings of both groups of models, a hybrid watershed model STREAM (Spatio-Temporal River-basin Ecohydrology Analysis Model) was developed in this study. Like a distributed model, STREAM divides a watershed into square grid cells of a same size each of which may have a different set of hydrogeochemical parameters reflecting the spatial heterogeneity. Like many semi-distributed models, STREAM groups individual cells of similar hydrogeochemical properties into representative cells for which real computations of the model are carried out. With this hybrid structure, STREAM requires a relatively small computational cost although it still keeps the critical advantage of distributed models.

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.511-519
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• 2016

National Institute of Environmental Research (NIER) has developed the Korean Reach File (KRF) for scientific and systematic analysis of variables related to water quality, pollutant sources and aquatic ecosystems in consideration of steam reach networks. The KRF provides a new framework for data production, storage, management and analysis for water related variables in relation to spatial characteristics, connections, and topologies of stream reaches. However, the current version of KRF (ver.2) has limited applicability because its nodes include not only the stream points based on topological characteristics but also those based on water quality monitoring stations, which may undermine its generality. In this study, a new version of KRF (ver.3) was designed and established to overcome the weak point of version 2. The version 3 is a generalization of the old KRF graphic data and it integrates the attribute data while separating it from the graphic data to minimize additional work that is needed for data association and search. We tested the KRF (ver.3) on actual cases and convenience and adaptability for each application was verified. Further research should focus on developing a database link model and real-world applications that are targeted to process event data.

• Fire Science and Engineering
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• v.26 no.4
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• pp.10-17
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• 2012

This study classifies the fire suppression measures implemented by wooden temples into four types according to availability of the pump trucks (water tanks) at the fire sites. And this study outlines the strategies and methods based on each type of fire suppression measure. The results show that the fire suppression strategy applied in general buildings is also employed in temples where pump trucks (water tanks) and fire-fighting water are available. For temples where trucks and water are not available, the helicopter, water bag, fire suppression strategy focused on water supply link, automatic transmission system of a fire engine's level by using radio communication network, and water bladder are used. In addition, general four-wheel-drive vehicles equipped with fire fighting tools such as motor pump, hose, nozzle, and water bladder should be deployed in fire stations around the temples. A fire suppression strategy using A-type ladders is also required.

• Membrane and Water Treatment
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• v.10 no.1
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• pp.1-11
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• 2019

The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) predicted that recent extreme hydrological events would affect water quality and aggravate various forms of water pollution. To analyze changes in water quality due to future climate change, input data (precipitation, average temperature, relative humidity, average wind speed and sunlight) were established using the Representative Concentration Pathways (RCP) 8.5 climate change scenario suggested by the AR5 and calculated the future runoff for each target period (Reference:1989-2015; I: 2016-2040; II: 2041-2070; and III: 2071-2099) using the semi-distributed land use-based runoff processes (SLURP) model. Meteorological factors that affect water quality (precipitation, temperature and runoff) were inputted into the multiple linear regression analysis (MLRA) and artificial neural network (ANN) models to analyze water quality data, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), total nitrogen (T-N) and total phosphorus (T-P). Future water quality prediction of the Anseongcheon River basin shows that DO at Gongdo station in the river will drop by 35% in autumn by the end of the $21^{st}$ century and that BOD, COD and SS will increase by 36%, 20% and 42%, respectively. Analysis revealed that the oxygen demand at Dongyeongyo station will decrease by 17% in summer and BOD, COD and SS will increase by 30%, 12% and 17%, respectively. This study suggests that there is a need to continuously monitor the water quality of the Anseongcheon River basin for long-term management. A more reliable prediction of future water quality will be achieved if various social scenarios and climate data are taken into consideration.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.6
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• pp.1-13
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• 2023

Irrigation return flow plays an important role in river flow forecasting, basin water supply planning, and determining irrigation water use. Therefore, accurate calculation of irrigation return flow rate is essential for the rational use and management of water resources. In this study, EPA-SWMM (Environmental Protection Agency-Storm Water Management Model) modeling was used to analyze the irrigation return flow and return flow rate of each intake work using irrigation canal network. As a result of the EPA-SWMM, we tried to estimate the quick return flow and delayed return flow using the water supply, paddy field, drainage, infiltration, precipitation, and evapotranspiration. We selected 9 districts, including pumping stations and weirs, to reflect various characteristics of irrigation water, focusing on the four major rivers (Hangang, Geumgang, Nakdonggang, Yeongsangang, and Seomjingang). We analyzed the irrigation period from May 1, 2021 to September 10, 2021. As a result of estimating the irrigation return flow rate, it varied from approximately 44 to 56%. In the case of the Gokseong Guseong area with the highest return flow rate, it was estimated that the quick return flow was 4,677 10³ m³ and the delayed return flow was 1,473 10³ m³ , with a quick return flow rate of 42.6% and a delayed return flow rate of 13.4%.

• IE interfaces
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• v.20 no.4
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• pp.427-437
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• 2007

As increasing the Internet traffic, many researches on access network are reported for end-to-end highspeed broadband network, where E-PON (Ethernet-Passive Optical Network) is one of reasonable candidates for the network with respect to cost and bandwidth utilization. For the high-speed access network, E-PON needs an efficient bandwidth allocation method. This paper describes a WFBA (Water-Filling Bandwidth Allocation) algorithm for the efficient bandwidth allocation with various simulation test. Based upon the simulation test, we suggest several ways to improve performance of E-PON.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.3
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• pp.59-66
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• 1997

Although it produces well-treated water in water treatment plant, water quality at the tap can be changed depending on the state of pipes. It is because water quality deteriorates as plant water passes through pipeline networks. Therefore, the improvement of not only water treatment technology but also O & M of water pipelines is required to supply good water to consumers. The purpose of the study was to obtain the basic data of control technology for water quality in pipes through investigating water quality in distribution system. We selected 11 sampling sites and investigated water quality from plant to endpoint of distribution system. we also simulated decreasing tendency of free chlorine through pipeline network. As the result of water quality test, all parameters were below allowable levels, but some parameters had the possibility of being over levels. So there must be more work to set up proper countermeasure for violable parameters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4145-4164
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• 2016

Energy harvesting is an increasingly attractive source of power for cellular networks, and can be a promising solution for green networks. In this paper, we consider a cellular network with power beacons powering multiple mobile terminals with microwave power transfer in energy beamforming. In this network, the power beacons are powered by grid and renewable energy jointly. We adopt a dual-level control architecture, in which controllers collect information for a core controller, and the core controller has a real-time global view of the network. By implementing the water filling optimized power allocation strategy, the core controller optimizes the energy allocation among mobile terminals within the same cluster. In the proposed green energy cooperation paradigm, power beacons dynamically share their renewable energy by locally injecting/drawing renewable energy into/from other power beacons via the core controller. Then, we propose a new water filling optimized green energy cooperation management strategy, which jointly exploits water filling optimized power allocation strategy and green energy cooperation in cellular networks. Finally, we validate our works by simulations and show that the proposed water filling optimized green energy cooperation management strategy can achieve about 10% gains of MT's average rate and about 20% reduction of on-grid energy consumption.