• 제목/요약/키워드: electromagnetic waves

검색결과 558건 처리시간 0.034초

액체 질소중 교류방전 진전에 따른 방사전자파의 주파수 스펙트럼 특성 (The Characteristics of Frequency Spectrum of Radiated Electromagnetic Waves with AC Discharge Progress in Liquid Nitrogen)

  • 박광서;윤대희;이상훈;이현동;김충년;최병주;김기채;이광식
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권3호
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    • pp.123-129
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    • 2003
  • In this paper, a relationship between AC discharge progress and the radiated electromagnetic waves was investigated by measuring electromagnetic waves using a biconical antenna and a spectrum analyzer. The frequency spectrum of the radiated electromagnetic waves were measured at the atmospheric pressure in liquid nitrogen($LN_2$) during partial discharges progressed by AC high voltage in nonuniform electric field. Front the results of this study, a new method was introduced for measurement and analysis of the radiated electromagnetic waves with discharge progress in $LN_2$ Besides. according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress could be possible. It is considered that these results obtained from this investigation may be used as fundamental data for diagnosis and prediction of electric insulations about superconducting and cryogenic power equipments.

전자파 흡수 핸드폰용 캐릭터디자인 개발에 관한 연구 (Research about character design development for electromagnetic waves suction of hand phone)

  • 오성진
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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    • pp.849-852
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    • 2006
  • 본 연구에서는 전자파를 차단 및 흡수하는 물질을 개발하는 추세에 발맞추어 전자파를 흡수할 수 있는 물질을 이용하여 상품화 시키는 것에 초점을 두었다. 예컨대 휴대폰에서 전자파가 많이 발생하게 되는데 전자파를 흡수할 수 있는 물질을 이용하여 만든 캐릭터를 핸드폰 밧테리 부분에 부착 사용하여 전자파를 차단하고자 하는 것이다. 이때 차단하는 부위를 전자파 차단이란 본래 기능외에 캐릭터 개념을 도입하여 악세사리 겸용으로 부착하여 사용할 수 있는 캐릭터를 연구하고자 한다. 캐릭터디자인은 소비자설문조사를 실시하여 선호도가 가장 높은 것을 적용 반영하여 마무리하였다.

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Smart geophysical characterization of particulate materials in a laboratory

  • Kwon, Tae-Hyuk;Cho, Gye-Chun
    • Smart Structures and Systems
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    • 제1권2호
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    • pp.217-233
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    • 2005
  • Elastic and electromagnetic waves can be used to gather important information about particulate materials. To facilitate smart geophysical characterization of particulate materials, their fundamental properties are discussed and experimental procedures are presented for both elastic and electromagnetic waves. The first application is related to the characterization of particulate materials using shear waves, concentrating on changes in effective stress during consolidation, multi-phase phenomena with relation to capillarity, and microscale characteristics of particles. The second application involves electromagnetic waves, focusing on stratigraphy detection in layered soils, estimation of void ratio and its spatial distribution, and conduction in unsaturated soils. Experimental results suggest that shear waves allow studying particle contact phenomena and the evolution of interparticle forces, while electromagnetic waves give insight into the characteristics of the fluid phase and its spatial distribution.

전자파 차폐 임부복 개발을 위한 고령 산모의 임부복 착용 실태조사 (Actual Wearing State of Aged Pregnant Women for the Development of Electromagnetic Waves Shielding Maternity Wear)

  • 김영임;이정란
    • 한국의류산업학회지
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    • 제21권5호
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    • pp.618-626
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    • 2019
  • This study conducted basic studies to develop electromagnetic wave shielding maternity wear. We investigated electromagnetic wave shielding fabrics and products as well as surveyed actual wearing states for pregnant women aged 35 to 44 and women who gave birth within the past one year. Available electromagnetic wave blocking products for pregnant women were blankets, aprons, maternity belts, and underwear. These only cover the abdomen and it was hard to find out electromagnetic waves shielding maternity wear, which can enhance functionality and complement the body shapes of pregnant women. The aged mother responded pregnancy delay was mostly attributable to late marriage, career, financial difficulty and health problems. Major health threats to babies were high stress levels during pregnancy, followed by electromagnetic waves from electronic devices. They prioritized physical activity, design, functionality and safety when wearing maternity wear. When purchasing maternity wear, they emphasized design, price, materials and size. The most preferred clothing was one-piece dress; consequently, only 11.1% of them were satisfied with the quality of maternity wear with complaints mostly about design and price. A total of 63% of respondents tried to protect themselves from electromagnetic waves. Most aged mothers showed a positive intention on purchasing electromagnetic waves blocking maternity wear for babies with concerns dealing with safety of materials, prices, ease of laundry, and body complementing design.

전자파 고노출 직업군의 근무환경 조사 및 시판 전자기파 차폐소재를 이용한 철도 근무복의 차폐성능 연구 (A Comparative Study of the Shielding Performance of Uniforms using Electromagnetic Wave Shielding Materials Currently on the Market for Workers at Korea Railroad Corporation)

  • 정희정;최혜선;김은경
    • 복식
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    • 제60권6호
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    • pp.23-36
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    • 2010
  • This study set out to develop clothes made of electromagnetic wave shielding materials. Among the various worker groups exposed to electromagnetic waves for long hours, railroad workers were chosen for the study. After selecting the locations they worked, the investigator measured electromagnetic wave on the field. To examine the effects of electromagnetic wave shielding materials, I applied a lining made of electromagnetic wave shielding materials to the existing work clothes. The first experimental clothes had the silver fabric for the lining in the current working clothes, the second experimental clothes had the copper- and nickel-plate polyester placed between the outer and the lining to prevent the corrosive material from contacting the skin, and the third experimental clothes had the silver fabric for the lining and the copper- and nickel-plate polyester between the outer and the lining. The results indicate that even if a fabric is evaluated to shield electromagnetic waves after tests, it cannot completely shield electromagnetic waves emitting from everyday appliances of 60Hz. Therefore, there should be ongoing development and research efforts on fabrics that can shield electromagnetic waves to a certain degree in order to develop working clothes to alleviate fatigue for those who are constantly exposed to electromagnetic waves, relieve their anxiety, offer them psychological stability and thus help them increase job efficiency.

전자파의 측정과 패턴인식 기법에 의한 부분방전 신호 검출 (The Detection of Partial Discharge Signal by the Measurement of an Electromagnetic Wave and Pattern Recognition Technique)

  • 김영노;김재철;서인철;전영재;김광화
    • 대한전기학회논문지:전력기술부문A
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    • 제51권6호
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    • pp.276-283
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    • 2002
  • This Paper Presents the method for detecting a partial discharge(PD) using an electromagnetic wave measured by an antenna. The various electromagnetic waves are measured in the laboratory and wavelet transform, which is provides a direct quantitative measure of spectral content in the time-frequency domain, are applied for identifying the property of electromagnetic waves. Also, the statistical method and self-organizing feature map(SOFM) are applied for the pattern recognition of electromagnetic waves. The proposed method is shown to be useful for detecting electromagnetic waves emitted for PD in test data.

구급차량 내 전자파 방출에 관한 조사 (Research on the emission of electromagnetic waves in ambulance)

  • 윤종근
    • 한국응급구조학회지
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    • 제23권1호
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    • pp.61-69
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    • 2019
  • Purpose: The study aims to provide basic data to enhance the health of paramedics responsible for patient transport and treatment by analyzing the exposure level of paramedics to electromagnetic waves generated by electric devices used in ambulances. Methods: The study measured electromagnetic waves in ambulances in N region from July to December 2018. ME3030B produced by German Gigahertz Solutions was used to measure these waves and the maximum value was selected by moving it slowly in various directions. Each measurement part was selected and the mean value was calculated by repeatedly measuring at 10-minute intervals three times in total: $1^{st}$, $2^{nd}$, and $3^{rd}$ phase. Results: Among the electrical devices installed in the patient room of the ambulance measured at distances of 1 cm or 30 cm, results showed a high level of electric waves at the inverter ($26.25{\pm}39V/m$) and high level of electromagnetic waves ($564.00{\pm}31.75nT$) at the ozone sterilizer. According to measurements toward the front near the driver's seat, results indicated high levels of electric waves ($3.67{\pm}1.15V/m$) and electromagnetic waves ($450.00{\pm}19.52nT$) at the black box hard drive. Conclusion: Electromagnetic waves within the ambulance were stable and not beyond the range that might impact human health. However, in the case of the black box hard drive ($3.67{\pm}1.15V/m$, $450.00{\pm}19.52nT$) located under the passenger seat, it may have a direct effect on the human body and, thus it is necessary to move it to a storage area further away from the paramedics to minimized the impact.

Study on the Improvement of Laws Related to the Electromagnetic Wave of Mobile Phones

  • Park, Jong-Ryeol;Noe, Sang-Ouk
    • 한국컴퓨터정보학회논문지
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    • 제25권10호
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    • pp.231-240
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    • 2020
  • 이미 세계 여러나라는 핸드폰 전자파의 위험성을 경고하며 조치를 실시하여왔다. 반면 우리나라는 휴대폰 사용으로 인한 문제보다 학생들조차 핸드폰을 사용하지 못하게 하면 인권침해라고 항의하는 분위기이다. 인간의 뇌세포도 핸드폰 전자파에 더 많이 노출되고 있어 인체의 유해가능성에 대해 세계 여러나라에서 연구하고 있으며 최근의 연구한 발표결과들은 강력히 경고하고 있다. 현재 국내의 전자파 등급표시로는 국민에게 경각심을 불러일으키기에는 너무나 부족하다. IT 강국이라는 명성에 발맞추어 국립 전자파연구센터를 조직·운영하고 일반대중에게 핸드폰 전자파의 유해성을 경고하고 업계에 직접적인 의무를 부과할 수 있는 전파법제의 개정이 필요하다고 생각된다.

자기부상체 적용을 위한 전자파 흡수체의 특성 분석 (Analysis of Electromagnetic Wave Absorbers for Applying Magnetic Levitation)

  • 서용범;강현일
    • 전기학회논문지P
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    • 제65권1호
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    • pp.13-17
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    • 2016
  • EMC (Electro Magnetic Compatibility) of the electrical railway must be ensured for safety of passenger. Maglev trains has not friction between the wheels and the rails because levitation by an permanent magnets, electromagnets and superconducting magnets etc. So, it is advantageous to maintain a high speed without noise and vibrations. In this paper, we investigated that the magnetic field of the before and after installation electromagnetic waves absorber in order to analyze the effects of electromagnetic waves. The theoretical analysis of the electromagnetic wave absorber was simulated using finite element method. The magnetic field properties of electromagnetic waves absorber were measured by EMI (Electro Magnetic Interference) test receiver.

유해 전자파의 인체적 영향과 유.무기 복합 전도성 코팅제에 의한 전자파 차단 특성에 관한 연구 (Related to research some pollutants electromagnetic wave's impact of the human body and electromagnetic wave's a specific interception by the conductibility coating with organic.inorganic composition matter)

  • 유희옥;윤정필;강병복;임중열;차인수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.254-257
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    • 2001
  • This paper is managing about problem and EMI by electromagnetic waves occurrence of electrical appliances and harmfulness of EMS and standard. Specially, because this paper certifies a mouse and electromagnetic waves interception effect of electricity market place which possess electromagnetic waves interception facility, there is effect that contribute in health life that do to secure safe going to sleep condition from electromagnetic waves of electricity market place that is security of computer working environment of safe state through electromagnetic waves interception and essential electric appliance of home life.

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