• Journal of the Korean Magnetics Society
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• v.22 no.2
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• pp.66-72
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• 2012

The findings of ferromagnetic superconductor have attracted much attention not only for fundamental research to investigate how the antagonistic properties of ferromagnetism and superconductivity coexist peacefully but also for potential technological applications. Firstly, in order to help for understanding the ferromagnetic superconductor, I have explained the orbital and paramagnetic pair-breaking effects of magnetic field, which breaks the superconducting Cooper pairs. In addition to such effects of magnetic field, the singlet Cooper pairs become unstable upon going through the ferromagnetic materials by the proximity effect. The proximity effect occurs at the interface of thin films composing of superconductor and ferromagnet and leads to have very short penetration depth of Cooper pairs. However, a type of odd-frequency triplet in comparison with the singlet could be very stable and has a longer effective depth. It needs to be explored for the innovative spintronic devices. Finally, various ferromagnetic superconductors coexist and the lower-dimensional materials under the Quantum confinement effect have been introduced.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.7
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• pp.599-611
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• 2016

This paper proposes a cognitive engine platform that enables dynamic spectrum access(DSA) based on a spectrum sharing system for the military tactical network environment. The current military tactical wireless communication system is increasing need to secure a supplementary wireless spectrum to ensure that multiple wireless networks for different weapon systems co-exist, so that tactical wireless communication between the same or different systems can be operated effectively. This paper examined policy development and research activities engaged by the U.S. and European countries on wireless spectrum sharing to secure more spectrum. It also introduces the current status of cognitive engine development, which is the core technology of tactical wireless communication for DSA. In addition, based on the investigation performed into the latest trends, we propose a platform structure for a cognitive engine based on a spectrum sharing method where more frequencies can be added for tactical radio communication, so that DSA can be realized, and wireless networks of different weapon systems can co-exist.

• Resources Recycling
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• v.8 no.5
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• pp.44-50
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• 1999

The sbdy iwestlgaled ihc propa-ties of Lhe dust\ulcorner rrom fe~~oallomya ~~ufacturTeh. e chemical composition, cornpasitlon material, p d c l e sire md shapes of the bulk dust, sired dust and magnetically separated durl were mvesligaled. As the re\ulcornerulL, we suppose that the dust from &gh Carbon Fenama~~gunesMc anuiact~vingP rocess is not sufiicient as solulce material of Mn because of ale low Mn canlenl (13.5%) and complicaled composition mate~ial. The dust from Bug F!lter or AOD Proccss is mi~inlym ade up of 0.2-2 pm Mn30, (Hausmam~iu)p iutlde in spherical shape and thc Mn content is 63.190.The dust from Cooler of AOD Process is inninly made up of coarse Ca(O1-Or)zM. n,FeyO,, SiO, and fine Mn30d.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.481-486
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• 2022

The recent rapid growth of the IoT(Internet of Things) is leading to the spread of low-power wireless technology. A major challenge in designing IoT wireless networks is to achieve coexistence between different wireless technologies that share the 2.4 [GHz] ISM (Industrial Scientific Medical) frequency band. Therefore, there is a need for research on improving the reliability of wireless networks and coexisting operation between wireless networks. In particular, it is necessary to study an interference model and performance for mutual service coexistence in a BLE (Bluetooth Low Energy) wireless network environment, which is expected to be widely used as a connection medium between devices in various industrial fields. In this paper, the co-channel interference model with the IEEE 802.15.4 system is established focusing on the physical layer of the BLE system widely used in residential and industrial wireless applications, and the performance of the BLE wireless communication system is analyzed in the co-channel interference environment. As a result of the analysis, as the distance between the interference source and the BLE system increases in an environment where noise and co-channel interference exist, the amount of co-channel interference decreases and the error rate performance of the BLE system improves.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.51-51
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• 2003

생체친화재료란 생체내에 사용하거나 혹은 생체외에서 보조재료로 사용되는 것을 총칭하고, 인체와 직접 또는 간접적으로 접촉하여 사용되는 것이 특징이며 그 때문에 사용상 안전을 확보하기 위하여 생체에 대한 무해성 내지 생체적합성이 요구된다. 생체적합성이란 각각 고유의 기능을 가진 생체와 인공재료가 그 계면에서 서로 기능을 해치는 상호 반응을 일으키지 않고 공존하며 사용목적을 달성하는 것을 말한다. 생체친화재료로서는 재료의 종류에 따라서 인공관절의 고밀도 폴리에틸렌제, 인공힘줄이나 혈액 펌프등의 폴리우레탄 등 고분자재료, 생체기능을 대행하는 구조재료로서 스테인레스강, CO-Cr 합금, 타이타늄 및 그 합금, 탄탈륨 등 금속재료, 정형외과나 치과 등 굵은 조직대체용 재료로서의 세라믹재료로 구분되고 있다.

• Cross-Cultural Studies
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• v.48
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• pp.361-389
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• 2017

This essay examines 'precarity politics' by Judith Butler, a well-known gender theorist and queer philosopher, in Notes Towards a Performative Theory of Assembly (2015) focused on concepts as unchosen cohabitation of Hannah Arendt and unwilled proximity of Emmanuel Levinas. Butler's precarity politics is the condition of our dispossessed political beings with fundamental vulnerability and interdependency that cannot choose with whom we will live on this Earth. Butler's political ethics is twofold: on one hand, she examines significance of 'action'' the most significant vita activa in the public area, and 'plurality'' the condition-not only the necessary condition but the possible condition-for a political life suggested by Hannah Arendt in Human Condition; on the other hand, Butler reflects upon global precarity based on a diasporic precarious life in the social world towards freedom and equality. Unchosen cohabitation of plural humans on Earth, and global pervasion of precarity, that indicates "politically induced condition in which certain populations suffer from failing social and economic networks of support and become differentially exposed to injury, violence, and death," so called "differential distribution of precariousness," are practical possibilities of ethical and equal cohabitation of different ethnic groups in the social world. Ethical obligations or ethical demand to respond to others' suffering in distance and proximity originated from precarity politics, mentioned in Precarious Life, Parting Ways, and Frames of War, could be non-foundational joint of plural people living together globally. We should presume the 'reversibility' of distance and proximity in others' suffering, based on responsiveness and responsibility of others, if we want to stay attuned to the pain of others we never chose to live together. That is the significance of Butler's 'precarity politics' with 'ethical obligation' to accept 'unchosen plurality' of living population on Earth, and 'reversibility between of distance and proximity,' in her 'new plural and embodied body politics' or 'new corporeal ontology', through human primary vulnerability, fundamental interdependency, being exposed and responsive to suffering of others.

• Journal of KIISE:Information Networking
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• v.35 no.1
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• pp.11-20
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• 2008

An inevitable trend in the next generation wireless network environments is coexistence of different wireless access networks in a complementary, manner. In addition, mobile devices equipped with multiple air interfaces simultaneously executing diverse applications have been emerging, In such network environment, It is required that a solution for mobile users to seamlessly roam between different access networks as well as to satisfy QoS requirements of each application by efficiently utilizing coexisting various wireless access networks. In this paper, therefore, we propose a mobility management platform based on per-application end-to-end mobility management and cross-layer handover controls. Four core functional modules composing the proposed platform for end user devices are defined: Monitoring Agents, Profile Database, Decision Engine, and IP Agent. We show through simulations that the presented platform provides an improved QoS as it selectively utilizes the best available networks.

• Korean journal of communication and information
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• v.24
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• pp.37-67
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• 2004

본 연구는 인터넷 이용수준이 전통적 미디어의 이용수준에 미치는 영향과 수용지들의 미디어 소비 패턴에 대해 살펴보았다. 미디어 대체이론, 이용과 충족이론, 미디어 레퍼토리 연구를 바탕으로 인터넷 이용이 전통적 미디어의 이용에 미치는 영향을 중심으로 개인들의 정보와 오락 미디어 레퍼토리, 인터넷 레퍼토리에 영향을 미치는 사회적, 심리/태도적 변인과 인구통계학적 특징 등도 검토하였다. 이를 위해 전국에 있는 18세 이상 성인들을 대상으로 성별, 나이별, 지역별 층화표집방법을 이용해 표본을 추출하고 500개의 유효 서베이 설문지를 수집하였다. 데이터의 분석결과, 인터넷 이용정도가 다른 매체에 미치는 영향은 각 미디어별로 세 가지 다른 양상을-상호보완적 영향, 대체 치환의 영향, 그리고 영향을 받지 않음-보였으나 대체로 인터넷은 다른 미디어의 대체 미디어라기보다는 보완적인 매체로 현재 이용되고 있음이 나타났다. 또, 전반적인 미디어 이용시간 측면에서는 인터넷을 많이 이용하는 응답자일수록 오락과 정보 미디어 레퍼토리 크기가 더 컸던 것으로 나타나, 현재까지는 인터넷이 다른 미디어와 상호 보완하는 양상, 피들러(Fidler)의 미디어 변형이론 가운데 공존 공진화 현상을 보여주었다. 응답자들은 평균 2.01개와 2.25개의 오락과 정보 미디어 레퍼토리를 가졌으며 텔레비전, 신문, 인터넷을 두 미디어 레퍼토리의 3대 주요 미디어로 꼽았다. 또한 인터넷 레퍼토리와 사회적, 태도적 변인들간의 상관관계는 최근의 이용 충족이론과 미디어 레퍼토리 연구에서 나타났던 결과들과 일치해 사회적, 심리 태도적 요인들이(친밀도, 접근성, 유용성, 여가시간) 미디어 레퍼토리의 크기에도 영향을 미친다는 사실이 검증되었다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.16 no.1
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• pp.79-89
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• 2005

Objectives : To acquire an improved understanding of oppositional defiant disorder, we evaluated the characteristics of children who have the symptoms of ODD in community sample. Methods : 1200 children from an elementary school in Bucheon (an urban community near Seoul) were recruited by randomized sampling method. By Disruptive Behavior Disorder Scale according to DSM-III-R & DSM-IV, we evaluated the symptoms of ODD and selected subjects with ODD. Psychiatric comorbidity, character trait were compared in subjects with ODD and comparison group. Also we examined the association between prenatal/perinatal risk factors, family functions and the symptoms of ODD. Data were analyzed by appropriate statistical method using SPSS 11.5 window version. Result : Children with oppositional defiant disorder were revealed to have significantly higher rates of psychiatric comorbidity and significantly greater family dysfunction compared to comparison group. Among the prenatal/perinatal risk factors, severe emotional stress during pregnancy, postpartum depression, medication during pregnancy were revealed as risk factors of ODD. In character inventory, ODD group were evaluated to have high score in novelty seeking, harm avoidance, but low in reward dependency. Conclusion : These results support that 1) prenatal/perinatal and psycho-social risk factors could be a important role in the progression of ODD, and 2) children with ODD have diverse comorbid psychiatric symptoms.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1472-1476
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• 2008

남북 공유하천은 크게 임진강과 북한강으로 대별된다. 이중 임진강은 2000년을 기점으로 상호 협력방안이 모색되고 있다. 그러나 북한강수계에서는 북한이 유역변경을 위해 대댐을 건설하여 운영중에 있는 등 남북관계에 있어서 협력과 갈등이 공존하고 있는 상황이다. 국제공유하천에 있어 수자원 개발과 이용은 협력과 공평성에 기초하여야 한다. 그러나 갈등은 모든 국제하천이 가지고 있는 공통의 문제로 해결을 위한 대안마련에 많은 노력이 필요하다. 그럼에도 국 내외의 사례에서 볼 수 있듯이 예방적 조치들이 미약한 것이 현실이다. 남 북한 공유하천에서도 수자원 이용과 관련된 문제점은 계속되고 있다. 특히, 북한강 수계의 경우 상류유역을 점하고 있는 북한이 임남댐을 건설해 유역변경 수력발전을 함으로서 하류를 점하고 있는 남한지역에서는 하천관리 및 용수공급 등 지장을 받고 있다. 얼마 전에는 댐의 안정성 문제가 제기되어 국가안보 차원에서 문제를 다루어야 할 정도로 중대 사안이 되었다. 임진강 유역에서는 수해방지를 위한 남 북한간 협력체제의 토대가 마련되어 가고 있지만 황강댐의 유역변경 이 구체화될 경우 문제는 더욱 복잡해진다. 본 연구에서는 국제공유하천의 갈등해소 이론을 바탕으로 보다 현실적인 접근방법을 대안으로 제시하고자 하였다.