• 산업기술연구
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• 제34권
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• pp.71-78
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• 2014

Recently, using the electronic devices was increased with semiconductor developments. So, the EMI(Electromagnetic interference) problem become to important issue for coexistence with each electronic devices. The EMI is caused by switching operation from the power switches as the FET and the transistor in power conversion devices. In this paper, the hybrid EMI filter that composed with active components and passive components was described. The EMI filter is applied to the 160 watts LED driver experimentally verify the performance. The hybrid EMI filter is compared with non-filter, only passive filter and only active filter. The proposed EMI filter attenuated CM noise more than traditional passive filter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1956-1958
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• 2002

This paper reviews the calculation of induced voltage to a communication line from Power Transmission Line. Power lines, both overhead and underground, often run parallel to weak current lines, such as telecommunication, signal or data transmission systems or protection circuits. The coexistence of both systems in parallel over long lengths is accompanied by the possible induction of significant longitudinal voltage in the weak current line. In order to evaluate a precise induced voltage, this paper indicated problem about coefficient and numerical formula and present some induced voltage production technology standard application.

• 한국자기공명학회논문지
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• 제22권4호
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• pp.101-106
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• 2018

Magnetite is the oldest magnet material known to mankind. It is getting attention again from solid state physics researchers now a days because it is one of the most strongly correlated electron systems. Spin, charge, and orbital orders are interplaying with lattice and involved in the Verwey transition where magnetization, conductivity, and structure changes suddenly. The peculiar ordering states above and below the transition temperature mainly originate from the coexistence of $Fe^{2+}$ and $Fe^{3+}$ ions in the B site of the inverse spinel structure. In particular, the state of the charge and orbital order was the oldest and most intriguing problem. NMR has made significant contribution to the investigation of this question. A. Abragam stated that there is no doubt that NMR is a very powerful tool for the study of ferromagnetic and antiferromagnetic materials. In this mini-review, a short history of NMR investigation of magnetite is presented, providing a support to Abragam's claim.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권7호
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• pp.2496-2512
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• 2021

The requirements for powerful computing capability, high capacity, low latency and low energy consumption of emerging services, pose severe challenges to the fifth-generation (5G) network. As a promising paradigm, mobile edge networks can provide services in proximity to users by deploying computing components and cache at the edge, which can effectively decrease service delay. However, the coexistence of heterogeneous services and the sharing of limited resources lead to the competition between various services for multiple resources. This paper considers two typical heterogeneous services: computing services and content delivery services, in order to properly configure resources, it is crucial to develop an effective offloading and caching strategies. Considering the high energy consumption of 5G base stations, this paper considers the hybrid energy supply model of traditional power grid and green energy. Therefore, it is necessary to design a reasonable association mechanism which can allocate more service load to base stations rich in green energy to improve the utilization of green energy. This paper formed the joint optimization problem of computing offloading, caching and resource allocation for heterogeneous services with the objective of minimizing the on-grid power consumption under the constraints of limited resources and QoS guarantee. Since the joint optimization problem is a mixed integer nonlinear programming problem that is impossible to solve, this paper uses deep reinforcement learning method to learn the optimal strategy through a lot of training. Extensive simulation experiments show that compared with other schemes, the proposed scheme can allocate resources to heterogeneous service according to the green energy distribution which can effectively reduce the traditional energy consumption.

• 열처리공학회지
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• 제33권3호
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• pp.129-134
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• 2020

Due to excellent properties such as high specific strength and low density, application of magnesium alloys have been rapidly increased. However, magnesium alloy has a serious problem that is easily oxidized when exposed to high-temperature. For this reason, magnesium alloys have been generally used for SF6 gas such as protective cover gas in casting and melting, but it has been reported that this gas has a serious influence on global warming. Therefore, many researchers have been studied to improve the oxidation resistance of magnesium alloy. It was reported that addition of Be, Ca and CaO in magnesium alloy can improve the oxidation properties. In this study, the possibility of improving the oxidation resistance by adding CaO extracted from oyster shells was investigated. Oyster shells were completely decomposed into CaO and CO₂ by annealing. With the addition of CaO, a coexistence region of MgO + CaO was formed in the oxide layer and its thickness was also reduced.

• 한국통신학회논문지
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• 제39A권9호
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• pp.497-507
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• 2014

본 논문은 3GPP REL-12 에서 논의하는 반송파 집성(Carrier aggregation, CA) 기술의 표준 동향, 이를 지원하기 위한 단말요구 사항 정의, 그리고 이를 바탕으로 예측한 향후 기술 발전의 방향에 관한 것이다. 이는 REL-12에서 논의되는 상향 링크(Uplink, UL)에서의 2UL CA, 하향 링크(Downlink, DL)에서 3개의 반송파를 집성하는 3DL CA, TDD와 FDD를 결합하는 TDD-FDD CA 등이 포함되며, 또한 단말 RF 단에서 필요한 공존 이슈, 대역외 방사 이슈를 비롯한 여러 RF 요구사항을 분석 및 실험 결과들을 포함한다. 또한 CA 진화의 한 축인 비면허 대역과 LTE 운용 주파수 대역과의 반송파 집성기술인 LTE-U를 포함한 CA 진화 방향에 대해서도 기술한다.

• KDI Journal of Economic Policy
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• 제33권4호
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• pp.119-142
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• 2011

본 연구는 풍수해보험사업이 도입 취지와는 달리 여러 문제점을 내포하고 있다는 문제의식하에 풍수해보험에 대한 개념적이고 이론적인 분석을 시도하였다. 우선 현재와 같이 재난지원금과 풍수해보험이 공존하는 상황은 풍수해보험 활성화에 장애로 작용할 것이므로, 풍수해보험을 확대하기 위해서는 재난지원금의 점차적 축소를 고려할 필요가 있다. 또한 풍수해보험의 기본취지 중 하나가 자율적 방재노력을 제고하는 것이나, 풍수해보험은 보험에 따른 도덕적 해이로 인해 오히려 그러한 노력을 저해할 가능성이 높다. 끝으로 현재의 손해방지비용 지원은 그 효과가 불확실하므로 보다 심도 있는 분석이 필요하다.

• 한국환경교육학회지:환경교육
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• 제25권1호
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• pp.77-88
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• 2012

The purpose of this study was to analyze characteristics of environmental awareness and environmental worldviews on environmental UCCs which made by 27 pre-service biology teachers, and relationship between environmental awareness and environmental worldviews of them. Environmental worldviews were divided into planetary management worldview, stewardship worldview and environmental wisdom worldview. As for theme fo environmental UCCs, most of pre-service teachers chose themes such as environmental destruction, environmental protection, environmental conservation and coexistence with human and environment. Themes of environmental UCCs were somewhat different between females and males. Female pre-service teachers preferred UCC themes related to human's daily life as a consumer but males preferred to environmental protection. Many pre-service teachers referred that major cause of environmental problem was development of environment. Most of them had envionmental wisdom worldview, and tried to use fear appeal to express ways of solving of environmental problems and envieonmnetal worldviews. After making environmental UCCs, more pre-service teachers had envionmental wisdom worldview. This result implies that it is necessary to develop pre-service educational programs realted to environmental worldview formation.

• 예술인문사회 융합 멀티미디어 논문지
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• 제8권9호
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• pp.133-141
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• 2018

In Europe side, Most of North Korean refugee lives in New Malden, Kingstone resident with South Korean and international student near London, United Kingdom (UK).The reason why dispersed around in Europe is can be issue in societies with secure problem and temporary protection status have to be accept for change the concept in international law and refugee law. their ethnicity is organized by North Korean defectors, South Korean, Korean-Chinese in the area of New Malden and Kingstone.it means small unification is going to foundation on abroad. also their solidarity of diasporic integration development would ahead. and have to organise of Coexistence between U.K and thier ethnicity. for Humanitarian way for vulnerable. But Europe is not the most welcoming place for North Koreans at the moment. The European Alliance for Human Rights in North Korea, an advocacy group, reported in 2015 that many European countries had rejected the vast majority of North Korean asylum cases. Partly this is to do with how governments view North Korean defectors: the UK "considers North Koreans as South Korean citizens, thus excluding them from refugee status".

• 한국인터넷방송통신학회논문지
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• 제15권5호
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• pp.225-236
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• 2015

소셜 네트워크 서비스는 과거 주로 오프라인 상에서만 가능한 것으로 여겨졌던 인적 네트워크 형성을 온라인 및 모바일 상에서도 가능하게 해 줌으로써 많은 인기를 끌고 있다. 그러나 최근 다른 기능을 가진 다양한 SNS들이 많이 등장함에 따라 이용자들은 하나의 SNS 이용만을 고집하기보다 필요에 따라 두 가지 이상의 SNS에 동시에 가입하는 실정이며, 최근 불거진 프라이버시 침해 논란으로 인해 SNS를 이용하면서도 동시에 자신이 주로 쓰는 SNS를 떠날 것인지 고민하는 이중적인 태도를 보여주고 있다. 본 연구에서는 이러한 현상에 주목하여 사람들이 왜 이용하는 SNS를 바꾸는지를 파악하고자 하였다. 이를 위해 2 요인 이론을 도입하여 SNS 이용에 대한 만족하면서도 동시에 불만을 느끼는 이용자들의 심리를 파악하고자 하였고 유의미한 결과를 얻었다.