• Title/Summary/Keyword: 차폐 성능

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Effect of surface modification on adhesion of copper films on PET prepared by ECR-MOCVD (ECR 상온화학증착법에 의해 PET기판에 제조된 구리 박막의 표면전처리에 따른 접착력 특성)

  • Hyun, Jin;Byun, Dong-Jin;Lee, Jung-Gi
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.11a
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    • pp.210-210
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    • 2003
  • ECR(Electron Cyclotron Resonance)은 전자기장에 의한 회전주파수와 전원으로 가해지는 마이크로웨이브(microwave)의 주파수가 일치할 때 발생하는 공진(resonance)현상이다. ECR에 의해 형성된 고밀도, 고에너지의 플라즈마가 상온하에서도 표면에너지가 낮은 고분자수지상에 접착력과 내구성 및 성능이 우수한 금속박막을 형성시킬 수 있는 특징을 지니고 있다. [1] 이러한 고분자수지 표면에 제조되는 금속박막소재는 반도체산업을 비롯하여, 박막전지, 전자파 차폐 등의 다양한 용도로 개발되고 있다. 그러나, 고분자수지와 금속박막계면간의 접착성의 저하로 후처리 공정에서 외부의 응력을 받게되면 막이 쉽게 탈리되는 문제점이 대두되었고, 이에 대한 개선이 요구되고 있다. 따라서, 본 연구에서는 공업적으로 많이 사용되는 표면 전처리방법을 통하여 구리 박막의 접착력을 향상시키고자 하였다. 상온화학증착 방법에 의해 고분자수지표면에 구리금속박막을 제조하고 여러 가지 표준방법을 사용하여 고분자수지와 구리박막간의 접착특성을 조사하였다.

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Thermal Performance Evaluation of The Window Film Insulation for Building Energy Savings (건물에너지 절감을 위한 열차단 필름의 성능 평가)

  • Nam, Jung-Woo;Won, Jong-Seo
    • 한국태양에너지학회:학술대회논문집
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    • 2008.11a
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    • pp.75-80
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    • 2008
  • Recently, Energy savings in buildings has received much attention in response to the increased needs for global warming and better comforts of the occupants in apartment housing. This study proposes the method which uses the sun control window film to reduce the cooling load and heating load improving the thermal performance of the building and it improves an energy efficiency. The film which used in actual measurement has a low shading coefficient and a solar energy transmission. so we measured the surface temperature of the triple Low-e glazing system used and inside temperature according to the change of outside temperature and solar energy to study thermal performance evaluation. As a result, it was helpful to use window film insulation to reduce inside temperature in summer and to keep room warm in winter.

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Analysis of EMI Shielding Performance of Two Finite Image Planes Configuration (유한 이층 영상평면 구조에 의한 EMI 차폐성능 분석)

  • Kim, Jin-Suk;Yun, Jae-Hoon;Lee, Ae-Kyung;Kim, Nam
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.5A
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    • pp.682-687
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    • 2000
  • EMI problem is very important in a printed circuit board design. This paper deals with image plane as one of the most effective method to reduce EMI in PCB. The shielding performance of one and two layers of image planes of finite width and length is analyzed by the method of moments based on the triangular surface patch model. The current distributions were modeled as two simple line sources. It is demonstrated that proper triangulation should be made so as to take two basis functions in the boundary triangles of the surface.

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Evaluation of Electromagnetic Pulse Shielding Performance of Amorphous Metallic Fiber Reinforced Cement Composite (비정질 강섬유 보강 시멘트 복합체의 전자파 차폐성능 평가)

  • Lee, Sang-Kyu;Kim, Gyu-Yong;Hwang, Eui-Chul;Son, Min-Jae;Baek, Jae-Wook;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.50-51
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    • 2018
  • In this study, it evaluate the electromagnetic pulse shielding performance of amorphous metallic fiber reinforced cement composite with other steel fiber reinforced cement composite. Hooked-ended steel fiber, smooth steel fiber and amorphous metallic fiber were reinforced 2.0 vol.% in cement composites respectively. The electromagnetic pulse shielding performance was evaluated by MIL-STD-188-125-1. As a result, shielding performance of amorphous metallic fiber reinforced cement composite was higher than Hooked-ended and smooth steel fiber reinforced cement composites. In addition, the relationship between the electrical conductivity and the electromagnetic pulse shielding performance of the cement composite was confirmed.

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Effect of finite conductive image planes on PCB radiation (유한 도전성 영상 평면이 PCB 전자파 복사에 미치는 영향 분석)

  • Kim, Jin-Suk;Cho, Kwang-Yun;Kim, Nam
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.4
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    • pp.836-845
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    • 1998
  • In this ppaer, the confguration of multi-layers of the image planes surrounding the current trace of inite width has been considered, and the shielding performance of image planes is analyzed with the parameters of the width and conductivity of the planes, and the distance between the current trace and the planes. The induced current distributions on the image planes have bgeen calculated by solving a set of electric field integral equations by the method of moments. To cacluate the current distribution on the planes effectively, a new method for dividing integral intervals is proposed.

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Performance Evaluation of Low Frequency Magnetic Field Shielding by Eddy-Current (와전류에 의한 저주파 자기장 차폐 성능 평가)

  • Choi, Hak-Yun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.9
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    • pp.124-128
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    • 2010
  • In this paper, the shielding effectiveness of aluminum shielded room with using eddy-current is calculated and measured after fabricated. The size and thickness of shielded room are decided as $2.4{\times}2.4{\times}2.4[m^3]$ and 12[mm] after AC shielding characteristics by eddy-current of conductive materials is analyzed. To verify the shielding effectiveness, a rectangular helmholtz coil is fabricated to generate magnetic field of 1.37[${\mu}T$] and measured magnetic field inside shielding room for 0.01~10[Hz]. According to calculations and measurements, AC Shielding effectiveness by eddy-current in aluminum is very small for 0.01~2[Hz] and 5 times to 11 times for 5~10[Hz].

추진기관에 사용되는 내열 복합재료

  • Jeong, Bal
    • Defense and Technology
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    • no.9 s.163
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    • pp.46-50
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    • 1992
  • 고온, 고압의 추진제 연소가스로부터 노즐 구조물을 보호하기 위해 사용되는 열 차폐용 삭마성 내열재료(ablative material)의 종류와 재료선정을 위한 시험방법, 설계 및 제작기법, 성능평가 기준 등에 관한 연구동향을 검토하고 본 연구팀의 연구결과를 제시하였습니다 고체추진제 연소 환경하에서의 노즐 보호재료로서는 고분자계 삭마성 내열재가 주로 사용되는데, 이 ablative material에는 여러 종류가 있으나 높은 heat flux와 빠른 mass flow에 대한 내열을 위해서는 페놀, 폴리이미드 등 열경화성 수지인 charring material이 모재로 주로 사용되며 강도향상을 위해서 탄소, 실리카, 석면, 유리등의 강화섬유가 보강재로 사용됩니다 현재는 모재로서 고분자계 수지외에도 세라믹과 같은 무기재료, 금속재료등과 강화섬유를 조합하여 내열성과 강도가 향상된 재료를 개발하는 연구도 진행되고 있습니다

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Analysis of Electromagnetic Shielding Performance for a BiMODAL Tram using an Electromagnetic Concentration Index (전자파의 집중도를 이용한 바이모달 트램의 전자파 차폐 성능 분석)

  • Choi, Nak-Sun;Jeung, Gi-Woo;Kim, Nam-Kyung;Song, Myung-Kon;Lee, Kang-Won;Mok, Jai-Kyun;Kim, Dong-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.7
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    • pp.1378-1384
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    • 2011
  • In this paper, the electromagnetic shielding performance of a BiMODAL Tram is investigated by means of an electromagnetic analysis tool, called HFSS. For the purposed of doing this, first, three-dimensional finite element modeling for the tram including electronic devices and engine room is carried out. Then, for quantitatively assessing the electromagnetic shielding performance of the tram's body, concentration indexes for electric field magnitude and time-average stored electric energy are introduced. From numerical results, it is inferred that the tram's body can protect the electronic devices and engine room against external electromagnetic waves from 30 MHz to 100 MHz.

Efficient Message Relaying Scheme for Heterogeneous Platoons (혼성플래툰을 위한 효율적 메시지 중계 기법)

  • Jeong, Dong Geun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.2
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    • pp.172-174
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    • 2016
  • In heterogeneous platoons, consisting of various size of vehicles, the signal from/to a small-size vehicle may be blocked by adjacent large-size ones. In this case, some vehicles in between the source and the destination should relay the messages. We design an efficient message relaying scheme for these platoons and evaluate its performance, taking the linear topology of platoons into account.

A Study on the Inverter Arc Welder with High Power Factor Using Single-Chip Microprocessor (싱글칩 마이크로프로세서를 이용한 고역율 인버터 아크 용접기에 관한 연구)

  • 채영민;이승요;신우석;목형수;최규하
    • The Transactions of the Korean Institute of Power Electronics
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    • v.2 no.4
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    • pp.56-64
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    • 1997
  • 최근 용접분야에서는 용접성능을 향상시키기 위하여 인버터회로를 용접기에 적용한 인버터 용접기에 관한 연구가 활발히 진행되고 있다,. 그러나 범용의 인버터 용접기의 경우 다이오드 정류기를 사용함에 저차의 전류고조파가 발생하고 시스템 역율을 저하시킨다. 따라서 본 논문에서는 인버터 아크 용접기의 역율개선을 위한 PWM 컨버터에 관하여 연구하여 입력전류의 저차 고조파를 저감하였고 전원전압과 동상으로 전원전류를 제어함에 의한 단위 역율형 인버터 용접기의 특성을 해석하였다. 또한 본 논문에서는 에너지 절약, 용접 특성, 역율, 사용율, 크기 및 부피 등의 관점에서 인버터 아크용접기의 응용연구 및 실험적 분석을 수행하였고 용접기 시스템에서 발생하는 전기적 노이즈를 억제하고 전력용 반도체 소자를 보호할 목적으로 새로운 노이즈 차폐변압기를 채택하였다. 이상의 전체시스템은 싱글칩 마이크로 프로세서를 이용한 디지털 제어기로 구현함으로서 제어기의 유연성과 기능의 다양화를 추구하였다.

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