• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.162-162
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• 2019

Water Distribution Network (WDN) is a critical infrastructure to be maintained ensuring proper water supply to wide-spread consumers. The WDN consists of pipes, valves, pumps and tanks, and these elements interact each other to provide adequate system performance. If elements fail by internal or external interruptions, it may result in adverse impact to water service with different degree depending on the failed element. To determine an appropriate maintenance priority, the critical elements need to be identified and mapped in the network. In order to identify and prioritize the critical elements in WDN, an element-based simulation approach is proposed, in which all the elements composing the WDN are reviewed one at a time. The element-based criticality is measured using several resilience indexes that are newly developed in this study. The proposed resilience indexes are used to quantify the impacts of element failure to water service degradation. Here, three resilience indexes are developed, such as User Demand Severity, Economic Value Loss and Water Age Degradation, each of which intends to measure different aspects of consequences, such as social, economic, and water quality, respectively. For demonstration, the proposed approach is applied to a benchmark water network to identify and prioritize the critical elements.

• 상하수도학회지
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• 제30권5호
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• pp.561-569
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• 2016

In this paper a concept of the paradigm shift in the operations of Water and Wastewater systems regarding the production and usage of water was introduced. Based on this concept the interrelationships between the water quality in the upper basin of NakDong River relative to Busan and the degree of satisfaction of the customers on the water supply service in Busan were modeled using the System Dynamics modeling methodology. SamRangJin basin area was determined as the upper basin of Busan after analyzing the relationships between the water quality of MoolGeum water intake point and water quality data of various mid- and upper water intake points along NakDong River. The amount of contaminants generated in SamRangJin basin was modeled using the Gross Regional Domestic Product in the area and the treated amount was calculated using the efficiency of wastewater treatment and the degree of improvement of environmental condition per investment. The water quality at MoolGeum water intake point was modeled to take the effects of the remaining amount of contaminants after treatment and the non-point source contaminants in SamRangJin basin. Using the developed System Dynamics model the effects of the investment for the improvement of environmental condition in SamRangJin basin were compared to the case of alternate water source development for Busan in terms of the degree of satisfaction of the customers on the water supply service in Busan.

• 한국농공학회논문집
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• 제51권5호
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• pp.101-106
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• 2009

The previous study developed the Filter-Disinfection-Adsorption (FDA) system to provide clean irrigation water for greenhouse cultivation as well as convenience water to farmers. In this study, the field examination was undertaken to assess performance of the FDA system. The field application was made in the suburb of Daegu, one of the large city in Korea. The study area located near by down-stream of Gum-Ho river is suffering low irrigation water quality problems with no water supply service facilities. Four water quality parameters including Suspended Solid (SS), Biological Oxygen Demand (BOD), coliform, and turbidity were selected to test the purification performance of FDA system. Also in order to improve the system, this study investigated the defects of using the FDA system through field monitoring. As results, it was found that this system can be used to supply good quality of irrigation water for greenhouse cultivation and also provide convenience water to farmers in the field areas of no water supply services.

• 상하수도학회지
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• 제32권4호
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• pp.309-315
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• 2018

Currently, the commercialization of the $5^{th}$ Generation (5G) service is becoming more prevalent in domestic communication network technology. This has reduced communication delay time and enabled large-capacity data transmission and video streaming services in real-time. In order to keep pace with these developments, K-water has introduced a smart process control system in water purification plants to monitor the status of the water purification process. However, since wireless networks are based on the public Long Term Evolution (LTE) network, communication delay time remains high, and high-resolution video services are limited. This is because communication networks still have a closed structure due to expense and security issues. Therefore, with 5G in its current form, it is very difficult to accommodate future services without improving the infrastructure of its communication networks. In recognition of these problems, this study implemented the authentication and management function of wireless networks on a wired network management system in the K-water Bansong water purification plant. The results confirmed that wired Local Area Network (LAN) services give a higher security performance than an expensive commercial wireless LAN system. This was achieved by using an Internet Protocol (IP) address management system of wired networks and the packet filtering function of the Layer2 (L2) switch. This study also confirmed that it is possible to create a wireless LAN service that is 3.7 times faster than the existing LTE communication network.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2007년도 학술발표회 논문집
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• pp.366-372
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• 2007

본 연구에서는 기 구축된 수도GIS 활용의 활성화 및 정보제공 기반의 체계성을 확보하여 수도관리 업무의 수행에 있어 과학화 달성을 위한 유비쿼터스 기반의 수도관리 방안을 수립하고자 하였다. 이를 위해 기구축된 수도GIS 추진현황 및 GIS DB를 분석하여 최신 IT기술 적용방안을 검토하고, 최신 기술 동향 분석을 통하여 수도GIS의 활용성 극대화를 위한 위치기반서비스(LBS; Location Based Service) 기술을 선정하여 업무전용 모바일 단말기 개발 및 LBS 시스템 설계 구축하였다. 또한, 실시간 수도관리 기술 확보를 위하여 유비쿼터스 기술 및 시스템 활용에 대한 분석을 통해 수도관리 업무의 체계적인 도입을 위한 기술을 검토하여 이를 활용할 수 있는 방안을 제시하였다.

• 한국농공학회논문집
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• 제59권5호
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• pp.61-72
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• 2017

The purpose of this study is to establish an integrated management system for the efficient management of rural water, to improve current problems, and to lay the foundations for active use of rural water information. We proposed a plan for informatization with a focus on establishing a database that can be used to provide customized services to users by applying advanced IT technology and to strengthen the management system of cities and counties with poor information. Data linkage and integration, user service development and integration system, application of IT technology, advanced decision support for rural water management, strengthening of city and county management system And the details of the implementation of the key project were presented.

• 상하수도학회지
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• 제29권3호
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• pp.305-317
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• 2015

The function failure of present major facilities is likely to lead to failure of related systems and/or whole facilities, increasing the necessity for protection of infrastructures, main structures, and major industrial facilities. In addition, safe and efficient management for urban infrastructure (waterworks and sewerage facilities, electricity, telecommunications, roads, etc) installed in the basement or on large cities grounds at various public areas is required. Recently in response to this demand, efforts for vitalizing asset management are being made such as enacting related laws and developing asset management system in the U.S., Australia, Europe and other advanced countries with the concept for a new maintenance. In our county, identifying maintenance system problems such as aging and rapid increasing of existing infrastructures and decision-making about updating maintenance is required for systematic and organizational maintenance. In this study, by comparing and observing the LOS(Level of Service) of each countries' waterworks and risk-based LOS, we suggest the direction of future urban water infrastructure management systems for more effective management.

• 한국농공학회논문집
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• 제51권5호
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• pp.95-100
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• 2009

The water purification systems have been hardly used for agricultural purpose due to their complicated compositions and high costs for farmers, while only simple filtrations have been applied to irrigation systems in order to prevent the system from clogging problems. This study therefore developed a clean water supplying system, the Filter-Disinfection-Adsorption (FDA) system, especially for greenhouse cultivation of where low quality of water is available. This system has also been produced for providing convenience water to farmers in the areas of no water supply service systems for the purpose of washing their bodies or agricultural machineries after farm work. The FDA system consists of three stages of purification processes with an integral module, including disk and teflon filtrations and Ultraviolet (UV) sterilization processes. Indoor experiments were undertaken with a trial product of the FDA system to test its performance. The operation test of the process was performed as well as the condition check of each item including UV module, filters, control panel, pump, valves, etc. The results shows good performance of each test with no critical problems. The initial and maintenance costs were also analysed with other purification systems. From the comparisons, the FDA system found to be very economical and easy to use.

• 대한원격탐사학회지
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• 제33권6_2호
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• pp.1119-1137
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• 2017

본 연구는 서울과 경기도 지역 도시숲의 수자원 공급 생태계서비스와 기후완화 생태계서비스를 평가하였다. 생태계서비스를 자연기능기반 서비스, 산림의 자연기능과 인구분포를 고려한 생태계서비스, 산림의 자연기능과 수혜자 분포를 고려한 생태계서비스의 세 가지 서비스로 구분하여 평가하고, 이후 기후변화가 생태계서비스에 미치는 영향을 평가하였다. 평가 결과, 토지피복과 토양 등 자연조건을 반영한 도시림의 수자원 공급서비스의 경우, 경기도가 서울보다 높은 서비스를 제공하는 것으로 나타났으며, 지역별 인구분포를 추가적으로 반영한 서비스 평가에서는 인구가 많은 곳에서 서비스가 높게 나타나는 양상을 보였다. 그러나 도시림의 수자원 수혜자 분포를 추가로 반영한 수자원 공급 생태계서비스 평가 결과는 인구분포를 반영한 서비스 평가 결과와 공간적으로 다르게 나타났다. 같은 수원함양 기능을 가진 지역이라도 인구분포나 물 사용 수혜자의 분포가 많은 지역일수록 높은 서비스 결과가 나타났다. 또한 기후변화가 수자원 공급 생태계에 서비스에 미치는 영향을 평가한 결과, 기후변화에 따른 수자원 공급 서비스는 평균적으로 26%정도 줄어들어 전반적인 수자원 공급 생태계서비스가 낮아지는 경향을 보였다. 기후완화부문의 경우, 산림으로부터 가까운 거리에 있을수록 높은 온도저감 효과가 나타나 산림주변지역에서 높은 기후완화서비스가 나타났으며, 기후 완화 서비스의 수혜자 인구를 고려한 생태계서비스 평가에서는 수혜인구의 밀도가 높은 서울 도심지역에서 높은 서비스가 나타났다. 기후변화에 따른 산림 생장량 변화를 반영하여 산림의 기후완화 생태계서비스의 변화를 평가한 결과, 평균적으로 약 33%의 서비스 감소가 나타났다. 본 연구의 결과는 도시림을 관리하기 위해서 산림청에서 제시하고 있는 공급기능기반의 6가지(자연환경보전, 산지재해방지, 목재생산, 산림휴양, 생활환경보전, 수원함양) 기능구분 외에 서비스를 수혜하는 수요자 기반의 기능 및 서비스가 평가의 필요성을 제시한다. 이는 기존의 산림의 공급기능기반의 평가에서 간과할 수 있는, 자연기능은 낮지만 수혜를 받는 시민들이 많아 높은 서비스 가치를 갖는 산림을 재평가하고 올바른 관리 계획을 수립하는데 기여할 수 있을 것으로 판단된다.

• Journal of Electrical Engineering and Technology
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• 제12권5호
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• pp.1916-1924
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• 2017

Fossil oil, as the main energy of transportation, is destined to be exhausted. The electrification of transportation is a sustainable solution to the energy crisis, since electric power could be acquired from the inexhaustible sun, wind and water. Among all the problems that hinder the development of Electric Vehicle (EV) industry, charging issue might be the most prominent one. In this paper, the service process of a charging station with Battery Energy Storage System (BESS) is analyzed by means of $Cram{\acute{e}}r$ - Lundberg model which has been intensively utilized in ruin theory. The service quality is proposed in two dimensions: the service efficiency and the service reliability. The arrival rate and State of Charge (SOC) upon arrival are derived from 2009 National Household Travel Survey (NHTS). The simulations are performed to show how the service quality is determined by the system parameters such as the number of servers, the service rate, the initial capacity, the charge rate and the maximum waiting time. At last, the economic analysis of the system is conducted and the best combination of the system parameters are given.