• Title/Summary/Keyword: 전자기장 측정 시스템

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EMF Measurement and Safety Assessment Method for Wireless Power Transfer System for Urban Railroad (도시철도용 무선 급집전 시스템 주변의 전자기장 측정 방법 및 안전성 평가 방법 연구)

  • Gimm, Yoon-Myoung;Kim, Jun-Hee;Ju, Young-Jun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.12
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    • pp.942-952
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    • 2018
  • A wireless power transfer (WPT) system for an urban railroad is currently under development in S. Korea. This system supplies power to railroad cars using 60 kHz magnetic fields. The electromagnetic fields (EMFs) generated by the WPT system should satisfy established safety requirements for exposure of the human body to these fields. However, EMF measurements and the safety assessment methods for fields generated by the WPT system have not yet been established. As such, a measurement and safety assessment method for EMF generated by a WPT system for an urban railroad is proposed in this report. The EMF generated by this WPT system on a test railroad was measured and compared to the reference level set by the human safety standard for EMF exposure.

복사 전자기장에 대한 전자파내성 측정시스템

  • 정연춘
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.5 no.2
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    • pp.67-78
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    • 1994
  • 1996년부터 유럽연합을 중심으로 전자파내성(Electromagnetic immunity; 흔히 군사규격에서는 전자파감응성(electromagnetic susceptibility)이라 함) 규제가 본격적으로 시작될 전망이다. 이러한 전자 파내성 규제는 우리가 과거 '80년대 초에 경험했던 전자파방출(electromagnetic emission; 흔히 electro- magnetic interference 라고도 표현한다) 규제에 비해 규제주파수가 대폭 확장됨(9KHz - 1GHz .rarw. 50/60 Hz - 40 GHz)은 물론, 규제항목도 크게 늘어나기(2개 항목 .rarw. 11개 항목)때문에 본격 규제가 시작되면 우리 산업체에 큰 피해를 초래할 것으로 우려된다. 특히 "복사 전자기장에 대한 전자파내성 요구사항"은 일부 전자파내성 측정항목을 포함하고 있던 안전규 격 등에서도 다루고 있지 않던 것으로서 우리에게는 매우 생소한 항목이다. 이 항목은 과거 미국의 군사 규격등에서 요구했던 항목인데, 앞으로 각국의 상용규격에도 대폭 추가될 것으로 보인다. 이러한 규제는 우리의 생활환경에서 결코 빼놓고 생각할 수 없는, 동시에 가장 큰 전자파장해원인 의도적 복사로서의 방 송신호 및 각종 무선통신 신호에 대해 전기, 전자기기가 전자파내성을 갖고, 성능저하나 오동작을 유발하 지 않아야 함을 요구하는 것이다. 이러한 항목의 평가를 위해서는 대형 시험환경(EMS chamber)과 표준 전자기장 발생장치(signal genera- tors + high power amplifiers), 그리고 오동작 모니터링 장치(monitorring equipments) 등이 필요하기 때 문에 평가시스템 구성에 막대한 비용이 소요된다. 따라서 시스템 구성에 매우 신중을 기해야 하며, 관련 국제표준화규격을 사전에 철저히 이해하여 관련 시험검사를 위한 투자계획을 수립하는 것이 바람직하다. 본 고에서는 복사 전자기장에 대한 대표적인 국제표준화규격을 소개하고, 나아가서 그러한 항목의 평가 시스템의 설계 및 구현에 대해서 설명할 것이다.

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Effects of EAS Systems on Pacemakers and ICDs Malfunction (도난방지 시스템의 전자기장이 인공심장 박동기 등의 오동작에 미치는 영향)

  • Shim, Young-Woo;Kim, Jong-Jeong;Yang, Dong-In;Lee, Moon-Hyung;Kim, Deok-Won
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.46 no.6
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    • pp.44-49
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    • 2009
  • EAS (electronic article surveillance) systems have increased rapidly for article surveillance. In this paper, the strength of the EMF (electromagnetic fields) of EAS systems were measured. Pacemaker and ICD were investigated for inappropriate response resulting from EM (electromagnetic) EAS systems. The strength of EMF and the response of pacemaker and ICD were measured in the inner left side, outer right sides and the center of gates of the 6.3 kHz and 14.25 kHz EAS systems at a height of 130cm. As the result, EMF of the EAS system using 14.25 kHz was stronger than that of 6.3 kHz. AU interferences were observed only for 14.25 kHz, and the noisy ECG was found in three static positions on the pacemaker. The ICD resulted in noise reversion and VF (ventricular fibrillation) both static and moving positions by the EMP of 14.25 kHz EAS system. Therefore, it is necessary to post a message warning radiation of EMF from every EAS systems and possible risk of pacemakers and ICDs.

Standard Field Generation Using a Micro-TEM Cell and Its Measurement Uncertainty Evaluation (Micro-TEM Cell을 사용한 표준 전자기장의 발생 및 측정불확도 평가)

  • Kang, Jin-Seob;Kim, Jeong-Hwan;Kang, Ung-Taek;Kang, No-Weon;Kang, Tae-Weon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.1
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    • pp.91-99
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    • 2009
  • In this paper, a standard field generation method using a micro-TEM ceil is described and its measurement uncertainty is evaluated. The standard field generation system consists of an auto-leveling signal source, a micro-TEM cell operating up to 1.2 GHz, and a power measuring Instrument using a thermistor mount. Measurement results of a field strength key comparison (CCEM.RF-K20) for the field strength of 20 V/m at frequencies between 10 MHz and 1 GHz are presented for validating the standard field generation method.

Characteristics and Measurement Method of the Underwater Electromagnetic Signature Emitted from a Naval Ship (함정 발생 수중 전자기장 신호의 특성 및 측정 기법)

  • Yang, Chang-Seob;Chung, Hyun-Ju;Shin, Seung-Je
    • Journal of the Korea Institute of Military Science and Technology
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    • v.9 no.2 s.25
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    • pp.11-19
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    • 2006
  • The underwater electromagnetic signatures of a naval ship are mainly generated from three sources which are the permanent and induced magnetic field in the ship's hull and other ferrous components, the cathodic current electromagnetic field established by the Impressed Current Cathodic Protection(ICCP) system or the Sacrificial Anode and the stray electromagnetic fields generated by onboard equipment. These signatures can be minimized by certain design methods or installation of signature reduction equipment. In this paper, we represented the characteristic of the underwater electromagnetic signature and the signature reduction techniques for a naval ship. Also, we measured the electromagnetic field changes emitted from the real ship using the Electric and Magnetic field Measurement System(EMMS). We found that the underwater electromagnetic signature for a naval ship can be used as input or trigger signal in a surveillance system and an influence mine.

A small ocean bottom electromagnetometer and ocean bottom electrometer system with an arm-folding mechanism (Technical Report) (팔-접힘 구조를 가지는 소규모 OBEM과 OBE시스템 (기술보고서))

  • Kasaya, Takafumi;Goto, Tada-nori
    • Geophysics and Geophysical Exploration
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    • v.12 no.1
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    • pp.41-48
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    • 2009
  • Natural magnetic fields are attenuated by electrically conductive water. For that reason, marine magnetotelluric surveys have collected data at long periods (1000-100 000 s). The mantle structure has been the main target of seafloor magnetotelluric measurements. To ascertain crustal structure, however, electromagnetic data at shorter periods are important, e.g. in investigations of megathrust earthquake zones, or in natural resource surveys. To investigate of the former, for example, electromagnetic data for periods of less than 1000 s are necessary. Because no suitable ocean bottom electromagnetometer (OBEM) has been available, we have developed a small OBEM and ocean bottom electrometer (OBE) system with a high sample rate, which has an arm-folding mechanism to facilitate assembly and recovering operations. For magnetic observation, we used a fluxgate sensor. Field observations were undertaken to evaluate the field performance of our instruments. All instruments were recovered and their electromagnetic data were obtained. Results of the first experiment show that our system functioned well throughout operations and observations. Results of other field experiments off Tottori support the claim that the electromagnetic data obtained using the new OBEM and OBE system are of sufficient quality for the survey target. These results suggest that this device removes all instrumental obstacles to measurement of electromagnetic fields on the seafloor.

Study for generation of standard EM field using 8 ports-variable wave impedance generator (8단자 가변 임피던스 전자파 발생 장치를 이용한 표준 복사 전자기장 조성 연구)

  • 윤재훈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.3
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    • pp.771-783
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    • 1996
  • A desing technique of 8 ports variable wave impedance generator (8P-VWIG) is described. The design technique employs not only a numerical algorithm to find the structure with arbitrary characteristic impedance, but also a numerical solution to analyze the uniform elementrognentic fields established inside the generator. The 8P-VWIG so obtained is shown to have good performance with the VSWR of less than 1.4 at any frequency of interest below which higher order mode begin to propagate. The measured first resonant frequency is 152.1 MHz. The 8P-VWIG is designed based on the concept of an expanded multi-transmission line(8 channel). It is especially useful for the electronmagnetic interference(EMI) and electronmagnetic susceptibility(EMS) testing since it maximizes usable test crosssectional area, and its is easy change the polarization, vertical or horizontal, of field.

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Assessment and Analysis of Human EMF Exposure to UHF RFID System (UHF 대역 RFID 시스템에서 전자기장의 인체노출량 측정 및 분석)

  • Byun, Jin-Kyu;Yun, Jae-Hun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.1
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    • pp.132-140
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    • 2009
  • For human exposure assessment of UHF RFID system, electric field distribution of commercial 900[MHz] RFID antenna was measured and analyzed. Also, SAR(Specific Absorption Rate) of RFID antenna was calculated by simulation, and compared with basic restrictions in EMF guidelines. For EMF exposure assessment according to EN and IEC standards, the reader was tested for the normal operation, and electric field from RFID antenna was measured at various distances and angles. For electric field measurement, narrow band isotropic electric field probe was used, and the measurements were made at 0.3, 0.5, 1.0 and 1.5[m] for every 15[$^{\circ}$] angle from the antenna. Also, the rationale for measurement distance in EN and IEC standards is analyzed from the measurement results.

Development of Pains Therapy System Using Focused Variable Electromagnet (비침습 집중형 전자기장을 이용한 통증치료기 개발)

  • Cho, Dong-Guk;Lee, Gyoun-Jung;Kim, Soo-Byung;Kwon, Sun-Min;Shin, Tae-Min;Lee, Kyoung-Joung;Lee, Yong-Heum
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.6
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    • pp.1157-1166
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    • 2009
  • The effect of acupuncture that occurs at Meridians, can not be defined by western science. But we can find out the electrical effects when acupuncturing by measuring the charges meridians electric potential. So instead of using a needle to acupuncture, we used a electromagnet to give the same effect. We stimulated the meridians, with a electromagnet. Then we observed the pattern of the meridians potential, that occurred at ST-39 and ST-37. After doing clinical experiments with the acupuncture stimulation and the electromagnet stimulation. We found out the acupuncture stimulation and the electromagnet stimulations electric waves were similar. From this result, we knew it was possible to give similar effects to acupuncture stimulation by using electromagnets.

Analysis and Estimation of Long Distance Dredged Soil Transport Technology (준설토 장거리 이송기술 분석 및 평가)

  • Kim, Eunsung;Jeong, Soon Yong;Kim, Yu Seung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2891-2898
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    • 2015
  • The new developed long distance transport technology uses the effect of electro-magnetic energy. But it's difficult to estimate the new technology. We monitored the velocity profile and pressure drops in pipes and estimated the technology quantitatively from data analysis. Laboratory test and field test gave us that the effects of electro-magnetic energy changed the flow properties and increased the velocity, especially at the slip layer. When transporting the dredged soil, electro-magnetic field generation reduces the frictional resistances at the slip layer, increases the velocity of flow. Furthermore, it would be possible to transport the dredged materials up to 15km long with one pump station.