• 한국전자파학회논문지
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• 제7권4호
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• pp.346-352
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• 1996

초광대역 주파수 특성을 가지며, 제2층에 십자형 슬롯을 가지는 2층형 전파흡수체의 광대역 설계법을 제안하였다 이와같은 광대역 전파흡수체는 등가재료정수법을 적용한 이론 모델을 이용하여 설계할 수 있다. 제안한 모델을 바탕으로 30MHz~3,170MHz의 주파수 범위에서 우수한 반사감쇠 특성을 가지는 초광대역 전파흡수체를 설계하였다.

• Journal of Radiation Protection and Research
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• 제25권2호
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• pp.109-114
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• 2000

The SI unit of specific absorption rate (SAR) in W/kg in the electromagnetic (EM) field as non-ionizing radiation is exactly same as the SI unit of absorbed dose rate in Gy/s in the ionizing radiation field. The SI unit of both physical quantities can be expressed in $[m^{\cdot}s^{-3}]$. Where, the unit of absorbed dose, Gy stands for Gray. In EM biological interactions, the SAR equations are derived and the characteristics of EM field energy absorption in terms of the SAR are discussed and described on the mathematical basis.

• 조명전기설비학회논문지
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• 제19권5호
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• pp.68-73
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• 2005

본 논문은 선형유도전동기를 이용한 전자기펌프의 특성해석에 대하여 연구한 것이다. 전자기 펌프는 선형유도전 동기의 추진력에 의하여 용융 금속을 이송할 수 있다. 추진력을 높이기 위해 유전 알고리즘을 사용하여 최대 추력을 가지는 선형유도전동기를 설계 하고, 선형유도전동기를 이용한 전자기 펌프의 특성해석을 유동해석에 의하여 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1516-1517
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• 2007

This paper investigated the breakdown effect of the CMOS device by impact of high power electromagnetic wave. The experiments employed a waveguide to study the current characteristics of CMOS device broken by high power electromagnetic wave. The CMOS device were composed of a LED drive circuit for visual discernment. Also CMOS device broken by high power electromagnetic wave was observed by power current. The CMOS device were broke by high power electromagnetic wave at about 10 kV/m and when power current is 75 mA. Based on the result, CMOS devices should show plan to protect the CMOS devices by high power electromagnetic wave. And the database from this experiment should provide the basis for future investigation.

• ETRI Journal
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• 제40권4호
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• pp.546-553
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• 2018

Since the Gyeongju earthquakes in 2016, there have been increased research interests in the areas of seismic design, building collapse, and rescue radar applications in Korea. Ground penetrating radar (GPR) is a nondestructive electromagnetic method that is used for underground surveys. To properly design ground penetrating radar that detects buried victims precisely, it is important to study electromagnetic wave propagation channel characteristics in advance. This work presents an electromagnetic propagation environment analysis of a trapped victim for GPR applications. In this study, we develop a realistic collapse model composed of layered reinforced concrete and a victim positioned horizontally. In addition, the effects of rebars and the distance between the radar antenna and target are investigated. The numerical analysis presents the electromagnetic wave propagation characteristics, including amplitude loss and phase difference, in the 450-MHz and 1,500-MHz frequency band, and it shows the electric field distribution in the environment.

• 복식문화연구
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• 제30권4호
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• pp.579-593
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• 2022

This study examines the surface characteristics, electrical conductivity, electromagnetic wave blocking characteristics, infrared (IR) transmittance, stealth function, thermal characteristics, and moisture characteristics of IR thermal imaging cameras. Nylon film (NFi), nylon fabric (NFa), and 5 types of nylon mesh were selected as the base materials for aluminum sputtering, and aluminum sputtering was performed to study IR thermal imaging, color difference, temperature change, and so on, and the relationship with infrared transmittance was assessed. The electrical conductivity was measured and the aluminum-sputtered nylon film demonstrated 25.6kΩ of surface resistance and high electrical conductivity. In addition, the electromagnetic wave shielding characteristics of the sputtering-treated nylon film samples were noticeably increased as a result of aluminum sputtering treatment as measured by the electromagnetic wave blocking characteristics. When NFi and NFa samples with single-sided sputtering were placed on the human body (sputtering layer faced the outside air) and imaged using IR thermographic cameras, the sputtering layer displayed a color similar to the surroundings, showing a stealth effect. Moreover, the tighter the sample density, the better the stealth function. According to the L, a, b measurements, when the sputtering layer of NFi and NFa samples faced the outside air, the value of a was generally high, thereby demonstrating a concealing effect, and the △E value was also high at 124.2 and 93.9, revealing a significant difference between the treated and untreated samples. This research may be applicable to various fields, such as the military wear, conductive sensors, electromagnetic wave shielding film, and others.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.608-611
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• 2004

As the use of various electronic equipments has been increased recently according to industrialization and information network establishment, concern about electromagnetic wave exposed environment has also been increased. Therefore, this study aims to verify electromagnetic wave absorbing effects of inorganic paint that is made of carbon, electro-conductive materials with regard to its physical characteristics, its electromagnetic wave absorbing rate through a mock-up test for proving its effects in the indoor condition. The results are as follows: The results of running tests on electromagnetic wave absorbing inorganic paints for checking their requirements as painting material such as adherence degree, resistance to fine crack, resistance to washing, alkali-resistance, discoloration-resistance, etc. show that inorganic paints have the physical characteristics meeting the requirements for painting materials. In addition, it shows that the electromagnetic wave absorbing effect, in line with the number of paintings and the thickness of paintings, secures $75\~89\%$ of efficiency. And the mock-up test shows that the electromagnetic wave absorbing effect inside building is directly proportional to the distance from the source of electromagnetic wave such as electronic equipments.

• 한국정밀공학회지
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• 제27권7호
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• pp.71-78
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• 2010

The objective of this research is to investigate the influence of material characteristic and design on to the electromagnetic interference (EMI) shielding characteristics. Basalt glass fiber reinforced composite specimens with stainless fiber conductive filler were manufactured to perform the electromagnetic interference shielding effectiveness(SE) experiments. In order to reflection and absorb the specimen in electromagnetic fields, flanged coaxial transmission line sample holder was fabricated according to ASTM D 4935-89. Electromagnetic shielding effectiveness(EMSE) was measured quantitatively to examine the electromagnetic shielding characteristics of designed specimens. The result of EMI shielding experiments showed that maximum EMSE value of sandwich type specimens with GSG(basalt glass fiber/stainless fiber/basalt glass fiber) and SGS(stainless fiber/basalt glass fiber/stainless fiber) were 65dB and 80dB at a frequency of 1,500MHz, respectively.

• 한국정밀공학회지
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• 제22권10호
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• pp.121-128
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• 2005

The research on electromagnetic shielding has been advanced for military applications as well as for commercial products. Utilizing the reflective properties and absorptive properties of shielding material, the replied signal measured at the rear surface or at the signal source can be minimized. The shielding effect was obtained from materials having special absorptive properties and structural characteristics such as stacking sequence. Recently researchers studied the electromagnetic properties of nano size particles. In this research {glass fiber}/{epoxy}/{nano particle} composites(GFR-Nano composites) was fabricated using various nano particles, and their properties in electromagnetic shielding were compared. For the visual observation of the nano composite materials, SEM(Scanning Electron Microscope) and TEM(Transmission Electron Microscope) were used. For the measurement of electromagnetic shielding, HP8719ES S-parameter Vector Network Analyser System was used on the frequency range of 8 GHz${\~}$12GHz. Among the nano particles, carbon black and Multi-Walled Carbon Nano-Tube (MWCNT) revealed outstanding electromagnetic shielding. Although silver nano particles (flake and powder) were expected to have effective electromagnetic shielding due to their excellent electric conductivities, test results showed little shielding characteristics.

• 한국전자파학회논문지
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• 제12권2호
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• pp.227-233
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• 2001

본 논문에서는 전자파 장해 및 복사내성 측정의 대용 시험시설로서 활용될 수 있는 전자파 잔향실의 전자기장 특성에 관하여 연구되었다. 전자파 잔향실 내부에서의 필드 균일성을 확보하기 위하여, Shroeder 방식의 Quadratic Residue 확산기(diffuser)를 설계한 후, 확산기의 방향에 따른 3가지 배열 형태로 잔향실 내부에 적용하여, 필두 분포를 해석하였다. FDTD(Finite-Difference Time-Domin) 수치해석 방식을 이용하여 잔향실 내부의 필드 특성을 연구한 결과 확산기를 부착한 3가지 형태 모두 최대 변화범위 $\pm$3 dB 이내의 필드 균일도를 나타내었으며, type 3, 대칭형 구조의 확산기 형태가 효율이 가장 우수하다는 결과를 나타내었다.