• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.73-79
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• 2001

In this paper, shielding effectiveness(SE) of the shielding material of electromagnetic(EM) waves was investigated with actual experiments. The materials used in this study were made up of sputtering, film and powder of conductive materials - Cr, Al, Ag and Cu etc. Also, the polyester film was used as a base material. The experiment was carried out by using a shielding evaluator(Shielding box) TR17302 with an ADVANTEST spectrum analyzer, model R3361C. It was found from the experimental results that silver, copper, aluminum and chromium were good candidates as a shielding material against the EM waves with increasing the SE as the composite was laminated. The characteristics of the SE against the EM waves depended on a mode of preparation of specimen. The effects of density of particles on the SE were studied when the sputtering. The SE strongly depended on the electric resistance by density of sputtering and painting particles. SE increased as the density of particles was increasing.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.244-249
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• 2004

In this paper, shielding effectiveness(SE) of the shielding paint of electromagnetic(EM) waves was investigated with actual experiments. The shielding paint used in this study were made of powder of conductive materials - Ag, Cu, Al, Sn, Ni. Cr, Graphite and Charcoal etc. with a solubility in oil and water. Also, the paper was used as a base sheet. The experiment was carried out by using a shielding evaluator(Shielding box) TR17302 with an ADVANTEST spectrum analyzer, model R3361C. It was found from the experimental results that silver, copper, nickel were good candidates as a shielding material against the EM waves with increasing the SE as the composite was laminated. The characteristics of the SE against the EM waves depended on a mode of preparation of specimen. The effects of density of particles on the SE were studied about the EM shielding paint. The SE strongly depended on the electric resistance by density of painting particles. SE increased as the density of particles was increasing.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.413-416
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• 2001

In high frequency range, RF circuit design without considering shielding effect can cause several significant changes due to increase in parasitic capacitance and inductance between RF signal lines and shielding box. In this paper, bandpass filter has been made to measure the shielding effect and its s-parameter has been measured by Vector Network Analyzer (VNA). Equivalent circuit model including the shielding effect has been constructed with the lumped elements extracted from the 3D electromagnetic simulator, Maxwell SI. Then, the validity of the model is verified using microwave circuit simulator, ADS (Advanced Design System).

• IEIE Transactions on Smart Processing and Computing
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• 제5권1호
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• pp.63-69
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• 2016

This paper presents methods to improve the effectiveness of electromagnetic shielding. The slit appears in an enclosure's surface to ventilate. Slits may also appear due to power supply lines or to serve as a communication link between electronic circuits inside and outside the box. We simulated electromagnetic radiation in different conditions in order to propose a method to improve the effectiveness of electromagnetic shielding to ensure electromagnetic compatibility using CST software (Computer Simulation Technology).

• 대한기계학회논문집A
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• 제23권6호
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• pp.1048-1054
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• 1999

It is important to study the shielding effectiveness(SE) of reinforcing material of plastic composite materials against the electromagnetic(EM) waves. In this paper, SE of the shielding material of EM waves was investigated with actual experiments. The materials used in this study were made up of film, fiber and powder of conductive materials - Cu, Al, CF etc. Also, The resin film was used as matrix. The experiment was carried out by using a shielding evaluator(Shielding box) TR17302 with an ADVANTEST spectrum analyzer, model R3361C. It was found from the experimental results that copper, aluminum and carbon fiber were good candidates as a shielding material against the EM waves with increasing the SE as the composite was laminated. The characteristics of the SE against the EM waves depended on a mode of preparation of specimen. The effects of interval of wires on the SE were studied when the orientation and the space of Cu wires were changed. The SE strongly depended on the. orientation and the space of the Cu wire. SE decreased as the space of the Cu wires was increasing.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권4호
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• pp.166-171
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• 2005

Shielding methods on ELF(Extremely Low Frequency) magnetic fields may include the use of induced currents, modification of magnetic field flux patterns using high permeability and/or high conductivity materials, and others. The magnetic shielding properties of enclosures can be utilized to reduce the magnetic field of current carrying conductors. In this paper, to get a more practical understanding of shielding phenomena, we have investigated the magnetic field reduction by means of 3 dimensional numerical analysis and experiments. We found copper could reduce flux density more then permalloy in both cases of box shield and cylindrical shield. Iron under l0$\mu$T of 1 phase could reduce flux density about $20\%$ more than silicon steel, but both of them under 50$\mu$T has a similar reduction rate of $10\%$. The 3 phase horizontal model gave the highest reduction rate and the 1mm thickness iron under 10$\mu$T of 3 phase lines did lowest.

• 항공우주기술
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• 제7권1호
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• pp.68-75
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• 2008

우주방사선환경은 위성의 운용궤도와 임무 기간 및 시기에 따라 달라지고 시뮬레이션을 통 해 예측이 가능하다. 총 이온화 조사량(TID)의 경우 dose-depth 곡선으로 차폐두께에 따른 조사량을 알 수 있다. 그러나 이는 차폐두께에 따른 조사량의 정보만 보여주므로 실제 차폐 구조물의 형상에 따른 부품수준에서의 총 이온화 조사량을 예측하기 위해서는 구조물의 형태를 고려한 유효 방사선 차폐두께의 상세 분석이 필요하다. 이를 위해 다양한 구조형상을 3차원 좌표로 입력하여 모델링이 가능하게 하고 여기에 임의 지점에서 방사되는 ray를 이용하여 구조체의 전 방향에 대한 유효 차폐두께분포를 계산하는 프로그램을 개발하였다. 이 분포결과를 위성의 우주임무환경에서 예측되는 dose-depth 곡선 데이터와 결합하여 최종적으로 위성내부의 임의지점에서 예측되는 총 이온화 조사량을 계산함으로써 3차원 구조형상을 고려한 상세 분석이 가능하도록 하였다. 이를 이용하여 위성의 전자박스구조를 모델링하여 부품수준의 임의지점에서 예측되는 총 이온화 조사량을 분석하였다.

• 한국전자파학회논문지
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• 제8권3호
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• pp.254-263
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• 1997

通信 및 電子훌業의 發達에 따라, 電磁波放射에 對한 밟素鐵維彈化樹(CFRTP)의 電磁波 避廠效果(SE)를 冊究하는 것은 重要하다. 本R究에서는 밟素熾維(CF)의 避빼옷效果를 電波8홉室內에서, 驗的으로 測定하였다. 使用한 樹服는 PC, PP, PEl, PMMA 및 PA이다. 實嚴은 分光分析器에 의해 鋼避蘇箱子와 모노폴안테나를 使用해 修行하였다. 훌훌結果로부터 CF는 良好한 電磁波適嚴材의 한 候補임을 알 수 있었다. SE는 CF의 積層의 增加에 따라 增加하였다. 徵小한 揚傷의 增加는 CF의 平面密度, 透過두께 및 反射角의 增加로 인해 SE를 增加 시켰다. SE에 미치는 다른 特性들은 母材樹服, 안테나問의 距離 및 노이즈의 周波數에 따라 달랐다.

• Journal of Astronomy and Space Sciences
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• 제18권2호
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• pp.153-162
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• 2001

본 논문에서는 아리랑 2호가 운용될 궤도의 우주방사능 환경 및 total ionizing dose(TID) 영향에 대하여 분석하였다. 포획된 양자의 경우 SAA(South Atlantic Anomaly) 지역에 집중되어 있음을 알 수 있었으며, TID에 영향을 미치는 우주 방사능은 포획된 양자 및 전자와 태양양자임을 알 수 있었다. 저 에너지 입자는 알루미늄 차단 구조물을 이용하여 방사능 영향을 효과적으로 차단할 수 있음을 알 수 있었으나, 고 에너지 입자의 경우 구조물의 두께를 증가하여도 방사능 영향을 효과적으로 차단할 수 없음을 알 수 있었다. 아리랑 2호의 임무수명기간 동안 전자부품에 계속적으로 피폭되는 전체 방사량을 알루미늄 차단두께의 함수로 나타내었으며, 이 값들은 아리랑 2호의 전자부품의 선택기준 및 위성체 또는 구성품의 구조물 두께를 설정할 수 있는 기준으로 제시하였다.

• 천문학회보
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• 제39권2호
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• pp.45.1-45.1
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• 2014

structure of matters of Lambda cold dark matter (CDM) cosmology on detailed numerical simulations. To accomplish our research goal, we have added the following baryonic physics on the existing cosmological hydrodynamic code, Gadget-2: 1) radiative heating and cooling, 2) reionization of the Universe and UV shielding, 3) star formation, 4) energy and metallicity feedback by supernova. In addition, we included cluster formation to distinguish clustered star formation inside the very high density gas clumps from the field star formation. Our simulations cover a cubic box of a side length 4Mpc/h with 130 million particles. The mass of each particles is $3.4{\times}104Msun$, thus the GCs can be resolved with more than hundreds particles. We discuss various properties of the GCs such as mass function, specific frequency, baryon-to-dark matter ratio, metallicity, spatial distribution, and orbit eccentricity distribution as functions of redshift. We also discuss how the formation and evolution of the GCs are affected by UV shielding.