• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.53-58
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• 2016

Because a progressive tax of home electricity rates is charged and a continuous rise of industrial electricity rates is expected in order to solve the global warming, the high oil prices and the serious power shortage problem, the efforts to apply the energy storage systems which can significantly improve the energy usage efficiency to the smart grid are trying newly. In this study, characteristics of the secondary battery which can be used as energy storage devices, the structure and operation principle of a lithium-ion battery, and the concept of energy storage systems are research and analyzed. In addition, in this paper, the base technologies which are required to apply to the energy storage system to electric power system are established by studying about installation location and application methodology of energy storage system to electric power system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.48-56
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• 2015

There is a wide variety of system and applications in the power system. However, they have compatibility issues because they use different data standard and communication method. With the introduction of the smart grid, power system has been grow and diversified. Therefore power system need to be compatible with each other and the interoperability between applications is increasingly important. Thus, the IEC established IEC61970 and CIM Standard data exchange model for interoperability and system integration. Server-Client system was constructed which using CIM HSDA(Part4), a standard communication model, presented in IEC 619710. Also, self-developed real-time voltage stability analysis application and contingency analysis application was used. CIM HSDA was used for data input and real-time analysis. Tolerance of result which is in the range of allowable derived by Perform real-time voltage stability and contingency analysis of Jeju power system, and then compare it's result with PSS/E result.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.1
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• pp.23-28
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• 2012

The market of domestic Power Plant Generator Protection and Control System (GPCS) is narrow and required the high reliability, and technology. So, it is still operated as turn-key. In recent years, digital relays has evolved into IED can perform the control and monitoring functions without central monitoring based on IEC61850 international standards communications, and attention for advancement of smart grid and ECMS has been increased in South Korea. The increasing attention on multi-function IED, DGPS(digital generator protection system), for internal fault protection of large generator results in starting a national project in South Korea, the IED prototype development for next-generation power units. The voltage restrained overcurrent relay have been used as back-up overcurrent protection for generators. In this paper, voltage restrained overcurrent relay is one of the back-up protective factors in generator protection IED was presented. For evaluation performance of the voltage restrained overcurrent relay, the data of ATPDraw5.7p4 modeling was used.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.628-632
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• 2012

우리나라의 최근 30년(1981-2010년)간 연 강수량은 1307.7mm로 세계 평균보다 크지만 좁은 국토면적과 높은 인구밀도로 1인당 수자원 강수량은 세계평균의 1/8에 지나지 않아 물 부족국가로 분류되고 있다. 기후 및 지형적 영향으로 매년 홍수와 가뭄이 반복되고 기상이변으로 더욱 심화되고 있는 실정이다. 최근 기후변화에 따른 저수지의 이 치수 능력을 강화하는 저수지 둑높이기 사업이 시행되고 있다. 이에 따라서 용수량이 증가함으로 치수 대책이 반드시 필요하다. 이를 위해서 반드시 체계적인 계측이 필요하고 수요 공급의 시스템적인 관리 체계가 필요하다. 본 연구에서는 저수지 유입량 및 공급량에 대한 정량적인 해석을 위해서 현재 용덕저수지에서 계측되고 있는 자료의 신뢰성 분석, 계측자료를 통해 유입량 및 공급량 분석, 이론에 의한 유입량 및 공급량 분석, 계측과 이론에 의한 무효 방류량 분석을 실시하였고, 저수지 계측 시스템의 방향을 제시하기 위해서 모의 및 계측결과의 비교를 통한 저수지 운영의 효율성 분석, 계측자료의 부족함과 이론식의 비현실성 파악, 무효방류량의 계측 필요성을 파악하였다. 이 결과를 바탕으로 Smart Water Grid의 개념을 도입하여 저수지 유역의 Proto Type을 제시하고 수자원의 효율적 운영을 위해 추가적인 계측 지점을 제안하였다. 또한 기존 시스템의 관측 및 분석 모듈을 분석하여 계측을 통한 통합적인 수자원 관리 시스템을 제시하였다.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.1-9
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• 2024

As the Internet of Things (IoT) continues to permeate every facet of modern life, the imperative to secure this vast and dynamic frontier becomes increasingly paramount. This presents a comprehensive exploration of the challenges and opportunities inherent in safeguarding the interconnected web of IoT devices. The research critically examines the limitations of current cybersecurity measures through an extensive review of diverse topics, including IoT network performance, smart grid security, and the escalating cyber threats against critical infrastructures. A meticulous analysis of research findings underscores the need for enhanced infrastructure and ongoing research to fortify the cybersecurity mechanisms surrounding IoT objects. We underline the imperative of relentless research efforts to parry the advancing threats and leverage the promise of nascent technologies. Our findings affirm the pivotal influence of robust cybersecurity measures in crafting a resiliently connected ecosystem. The paper underscores the importance of ongoing research to address evolving threats and harness the potential of emerging technologies, reaffirming the central role of cybersecurity in shaping a secure interconnected world. In conclusion, the study emphasizes the dynamic and ever-evolving nature of cybersecurity on the IoT frontier. It unveils a complex landscape of challenges, ranging from network performance intricacies to the security concerns of critical infrastructures.

• Journal of Soil and Groundwater Environment
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• v.28 no.5
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• pp.1-11
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• 2023

The phenomenon of sediment resuspension in rivers and lakes causes contaminants (heavy metals and nutrients) accumulated in the sediment to leach into the overlying water. As a result, it can lead to changes in toxic effects and eutrophication in the aquatic ecosystem. In this regard, it is important to quantitatively determine the amount of contaminants leached during sediment resuspension. In this study, methods for assessing the amount of released contaminants and the types of contaminants potentially released due to sediment resuspension were studied and summarized. Methods for assessing leaching can be divided into three groups based on the principle of causing resuspension: (i) the oscillating grid chamber method, (ii) the mechanical stirrer method, and (iii) the shaker method. It was confirmed that the types of contaminants that can potentially be released include heavy metals bound to sulfides, as well as exchangeable and labile forms of heavy metals and nutrients. To effectively manage stable aquatic ecosystems in the future, a simplified leaching test method is needed to assess in advance the risks (i.e., changes in toxic effects and eutrophication) that sediment resuspension may pose to aquatic ecosystems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.1
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• pp.24-31
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• 2012

This study is designed to predict the overall electric power load, to apply the method of time sharing and to reduce simultaneous load factor of electric power when authorized by user entering demand plans and using schedules into the user's interface for a certain period of time. This is about smart grid, which reduces electric power load through simultaneous load factor of electric power reduction system supervision agent. Also, this study has the following characteristics. First, it is the user interface which enables authorized users to enter and send/receive such data as demand plan and using schedule for a certain period of time. Second, it is the database server, which collects, classifies, analyzes, saves and manages demand forecast data for a certain period of time. Third, is the simultaneous load factor of electric power control agent, which controls usage of electric power by getting control signal, which is intended to reduce the simultaneous load factor of electric power by the use of the time sharing control system, form the user interface, which also integrate and compare the data which were gained from the interface and the demand forecast data of the certain period of time.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.235-235
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• 2009

본 연구는 친환경 신새생 에너지를 이용한 전력 시스템을 개발함으로써 전력 IT인 Smart Grid 기술 활용과 더불어 예기치 못한 정전으로부터 중요한 전자 장비를 보호하는 UPS 기능을 갖는 친환경 3.0kW급 하이브리드 연료전지 UPS 시스템을 개발하는 것이다. 이를 위하여 시뮬레이션 기법을 이용하여 소형 경량화에 따른 구성 부품 배치 합리화 및 발생열 최적화 설계를 도출하였으며, 연료전지용 장수명 밀폐형 Ni-MH전지, 고효율 전력변환기, 하이브리드 PMS의 설계 및 제작과 개발된 3kW급 하이브리드 연료전지 UPS 시스템 기능 및 성능 평가를 공인 기관에서 검증받았다. 본 연구를 통하여 개발된 연료전지용 장수명 100Ah급 밀폐형 Ni-MH전지는 밀폐화와 더불어 장수명화 및 저온 방전 특성이 우수한 뿐만 아니라 KS규격을 모두 만족하였으며, 내구성도 DOD100%에서 1,093cycle의 결과를 얻을 수 있었다. 또한, 전지 설계 및 제작 기술뿐만 아니라 양산화 관련 기술들이 개발되어 향후 고용량, 고출력, 장수명의 축전지가 필요로 하는 분야에 적용될 수 있는 기반이 마련되었다. 또한 고효율 전력 변환기 및 연료전지과 축전지를 조절하는 PMS을 탑재한 소형 경량화 된 친환경 IT제품의 이미지를 구현하였다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.388-396
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• 2016

Through the correspondence works with international electrotechnical vocabulary(IEV) in the smart grid field and power information technology field, we analyzed cases for discussion of terms and definitions in the IEV and then proposed an advanced procedure and computing system for standardization of International Electronical Committee(IEC) terminologies. The standardization procedure consists of processes for existing terminology, new terminology and correspondent terminology which have different structures. An example of the standardization work of correspondent terminology is given. The standardization computing system are based on the process for terminology extraction, terminology verification and terminology management which could provide the Wikipedia type terminology search function. In order to prevent that there exist multiple terminologies in IEV, the database search system is needed to be developed. We proposed the 'IEV_Term_Search' program which is the database search system. Terminology standardization of different technical committees(TC) and completion of the IEV to promote cooperation between TC 1 and the TCs must be followed by revision and standardization using the standardization computing system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.3
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• pp.365-370
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• 2013

Generally, photovoltaic modules consist of glass, EVA, Solar Cell, back sheet and ribbon. But EVA, solar cell, ribbon affect electric output with temperature. EVA is a change in the transmittance of light from the sun. In addition, the solar cell output is decreased with temperature and the ribbon increases resistance. Transmittance and reflectance of glass and EVA were measured. In this paper, the characteristics of the components of PV module as EVA and Glass, ribbon were studied by variable temperature. effects on material properties investigated. As a result, glass is independent in temperature variation. EVA was the reduction 1~4% in transmittance. Solar cell decrease 0.469[%/$^{\circ}C$] in electric output by temperature variation. Other factors was controlled in solar cell..