• Title/Summary/Keyword: Electromagnetic waves

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

  • 박광서;윤대희;이상훈;이현동;김충년;최병주;김기채;이광식
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.3
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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.

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

  • Oh, Sung-Jin
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.849-852
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    • 2006
  • In this research electromagnetic waves in interception and that do so that keep in step in trend that develop material that draw water by sucking and material that can absorb electromagnetic waves use and do goods anger focus. Character that electromagnetic waves use and make material that can absorb electromagnetic waves to be happened much in portable phone for instance using sticking on hand phone bar Terry part electromagnetic waves intercept wish to. Wish to study character that can conglutinate by evil worldly affairs reason combined us introducing character concept beside function originally electromagnetic waves interception and use region that intercept this time. Because character application process executes question investigation, design preference degree reflects the highest thing and arranged to conclusion.

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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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    • v.1 no.2
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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.

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

  • Kim, Young-im;Lee, Jeong-Ran
    • Fashion & Textile Research Journal
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    • v.21 no.5
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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.

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

  • Jung, Hee-Jung;Choi, Hei-Sun;Kim, Eun-Kyong
    • Journal of the Korean Society of Costume
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    • v.60 no.6
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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.

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

  • Kim, Yeong-No;Kim, Jae-Cheol;Seo, In-Cheol;Jeon, Yeong-Jae;Kim, Gwang-Hwa
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.6
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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.

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

  • Yun, Jong-Geun
    • The Korean Journal of Emergency Medical Services
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    • v.23 no.1
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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
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.10
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    • pp.231-240
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    • 2020
  • Countries around the world have already taken direct and indirect measures to warn of the harmful effects of mobile phone electromagnetic waves. On the other hand, in the Republic of Korea the installation of Wi-Fi has been expandedwithout restrictions by location, and there is a widespread atmosphere of protesting human rights violations even if young students cannot use mobile phones, ignoring problems caused by the use of mobile phones. Human brain cells are increasingly exposed to electromagnetic waves of mobile phones as the penetration rate of smartphones grows.In order to solve the long-lasting question of whether electromagnetic waves from mobile phones will harm the human body, many studies are being conducted in various countries around the world, andthe recently published findingshave warned of the potential for harm. The labeling of electromagnetic waves alone is not sufficient to raise awareness about the dangers of electromagnetic waves. It is necessary that the Republic of Korea organize and operate a national electromagnetic wave research center in line with its status as an IT powerhouse, along with the revision of the Radio Wave Act, which directly warns the public about the hazards of mobile phone electromagnetic waves and can directly impose obligations on the mobile phone industry.

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

  • Seo, Yong-beom;Kang, Hyun-il
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.65 no.1
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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.

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 (유해 전자파의 인체적 영향과 유.무기 복합 전도성 코팅제에 의한 전자파 차단 특성에 관한 연구)

  • You, Hee-Ok;Yoon, Jeong-Phil;Kang, Byung-Bok;Lim, Jung-Ryul;Cha, In-Su
    • Proceedings of the KIEE Conference
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    • 2001.10a
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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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