• Journal of electromagnetic engineering and science
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• 제6권2호
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• pp.130-134
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• 2006

This paper presents the reduction characteristics of penetrated electromagnetic fields through a narrow slot in a planar conducting screen of infinite extent. When a plane wave is excited to the narrow slot, the aperture electric field is controlled by the parallel wire or parallel plate connected on the slot. The magnitude of penetrated electromagnetic fields through a narrow slot is controlled by electric field distributions on the slot. An integral equation for the aperture electric field on narrow slots is derived and solved by applying Galerkin's method of moments. The results show that the magnitude of the penetrated electromagnetic field can be effectively reduced by installing the parallel wire or parallel plate on the slot.

• 한국전자파학회논문지
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• 제14권9호
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• pp.950-954
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• 2003

본 논문에서는 내부 전자파원에 의해 여기된 공동의 내벽 한 면에 손실 유전체를 설치한 경우 공동 내부로 공급된 전력과 반사계수를 계산하였으며, 손실 유전체에 의해 공동 내부의 전자계가 저감되는 특성을 검토하고있다. 이론 해석으로는 내부 전자파원의 전류 분포 및 손실 유전체 경계면에서의 전계분포에 관한 연립 적분방정식을 유도하고 Galerkin의 모멘트법으로 해석하여 공동체 공급된 전력과 반사계수를 구하고 있다. 이론해석 결과, carbon을 함유한 발포 폴리스티렌을 손실 유전체로 사용하여 유전체의 두께와 carbon 함유량을 조절함으로써 공동 내부 전자파원으로부터의 전자파 방사를 저감시킬 수 있음을 보이고 있으며, 공급 전력의 실험치와도 비교하여 이론 해석의 타당성을 확인하고 있다.

• Journal of electromagnetic engineering and science
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• 제6권2호
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• pp.123-129
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• 2006

This paper presents a method of reducing penetration of penetrated electromagnetic fields through a narrow slot with parallel wire arrays in a planar conducting screen of infinite extent. An integral equation for the aperture electric field on the narrow slot is derived and solved by applying Galerkin's method of moments. When a plane wave is excited to the narrow slot, the aperture electric field is easily controlled by the parallel wire arrays connected on the slot and therefore the magnitude of the penetrated electric field is effectively reduced by loading the parallel wire arrays. The numerical results show that the magnitude of the penetrated electromagnetic field can be effectively reduced by installing the parallel wire arrays on the slot. The results of the calculated penetration electric fields are in good agreement with that of the measured results.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.433-436
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• 2005

This paper presents the reduction methods of penetrated electromagnetic fields through a narrow slot aperture in a planar conducting screen of infinite extent. When a plane wave is excited to the narrow slot, the aperture electric field is controlled by the resistive sheets loaded on the slot. The magnitude of penetrated electromagnetic fields through a narrow slot is controlled by electric field distributions on the slot aperture. The results show that the magnitude of the penetrated electromagnetic field can be effectively reduced by the resistive sheets on the slot aperture.

• 한국전자파학회논문지
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• 제14권8호
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• pp.884-890
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• 2003

본 논문은 휴대폰 전자파에 노출된 항부에서 SAR 값을 저감하기 위하여 전자파 흡수체를 단말기 표면에 부착하여 해석 및 측정하였다. 개발된 전자파 흡수체는 Mn-Zn계로 구성되었으며, 유전율은 7.30-j0.05 이고, 투자율은 2.20-j1.55이다 전자파 흡수체 부착에 의한 SAR 값은 비선형 FDTD 알고리즘을 적용하여 계산하였으며, 동작주파수 835 MHz에서 phantom 모델을 제작하여 SAR 값을 측정하였다. 그 결과, 전자파 흡수체 부착에 의한 SAR 값은 약 18 % 감소하였고, 안테나의 정재파비 및 패턴은 기존의 것과 거의 일치하였으며, 이득은 약 0.3 dB 감소하였다. 그러나 휴대폰의 수신감도는 전반적으로 약 1 dB 향상되었다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.214-217
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• 2007

This paper presents a reduction method of penetrated electromagnetic fields through a narrow slot with resistive sheet in a planar conducting screen of infinite extent. When a plane wave is excited to the narrow slot, the aperture electric field is controlled by the parallel plates connected on the slot. The magnitude of penetrated electromagnetic fields through the narrow slot is controlled by the electric field distribution on the slot. The results show that the magnitude of the penetrated electromagnetic field can be effectively reduced by installing the resistive plates on the slot.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 학술대회 논문집
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• pp.107-110
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• 2005

This paper presents the reduction methods of penetrated electromagnetic fields through a narrow slot aperture in a planar conducting screen of infinite extent. When a plane wave is excited to the narrow slot, the aperture electric field is controlled by the resistive sheets loading on the slot. The magnitude of the penetrated electromagnetic fields through a narrow slot is controlled by electric field distributions on the slot aperture. The results show that the magnitude of the penetrated electromagnetic field can be effectively reduced by the resistive sheets on the slot aperture.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.281-283
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• 2006

This paper presents the reduction methods of penetrated electromagnetic fields through a narrow slot aperture in a planar conducting screen of infinite extent. When a plane wave is excited to the narrow slot, the aperture electric field is controlled by the resistive sheets loading on the slot. The magnitude of the penetrated electromagnetic fields through a narrow slot is controlled by electric field distributions on the slot aperture. The results show that the magnitude of the penetrated electromagnetic field can be effectively reduced by the resistive sheets on the slot aperture.

• Journal of Magnetics
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• 제17권1호
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• pp.68-71
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• 2012

Acute injuries to skeletal muscles can lead to significant pain and disability. Muscle pain results in muscle weakness and range of motion (ROM) decreases. Pulsed electromagnetic fields (PEMF) promote tissue repair, healing rates and reduce musculoskeletal pain. The results of many previous studies suggest that PEMF can contribute to chronic pain reduction, particularly in musculoskeletal injurys. However, we do not have enough information of its effects compared to a placebo. The principal objective of this study was to investigate differences in acute pain induced by the direct destruction of muscle tissue (extensor digitorum) with varying times of the application of PEMF, measured through the expression of c-fos on the spinal cord. Significant reduction of pain was found in groups exposed to PEMF and the group exposed to PEMF immediately after muscle injury showed the most significant differences. In conclusion, PEMF may be a useful strategy in reducing acute pain in muscle injury.

• 전기학회논문지
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• 제57권11호
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• pp.2027-2034
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• 2008

There are concerns on possible health effects from exposure to electromagnetic fields. One reflection of this concerns is the considerable controversy, delay, and cost increases involved in the construction of power lines and facilities. To cope with such challenges, in this paper we investigated magnetic fields reduction techniques such as general compaction, in' span compaction, cruciform, vertical, 3 way splits phase, and 4way splits phase. As results, we found general compaction and 4 way splits phase could reduce magnetic fields up to 90%, while cruciform, vertical, and 3 way splits phase gave lower reduction rates of 30% because these configurations were similar to a current type of low reactance arrangement. We also knew 1 spacer in span compaction was appropriate in Korea in view of effectiveness and economy.