• Title/Summary/Keyword: Electric field interference

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Development of Monitoring System for Inspection of Polarization Optical Fiber (편광 유지형 광섬유의 검사 모니터링 시스템 개발)

  • Kim, Jae-Yoel;Lim, Jong-Han
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.5
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    • pp.145-150
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    • 2007
  • Optical communication according to request of technology of communications and optical fiber to be full filed faster communication and pass over transmission capacity limit per unit area, per unit hour appeared, and this optical fiber acts the biggest role to influence performance of optical communication network. Optical fiber(PMF Polarization Maintaining Fiber) is used, and is used by electric field measurement, self-discipline measurement, sensor(Sensor) Department by high definition measure such as thermometry and storehouse component that use because make broad sense status and polarized light information in passageway and union with storehouse integrated circuit etc. that use broad sense interference developing could transmit in state that keep transmitting broad sense plane of polarization is polarized light existence. Also, research is developed by optical fiber for Coherent communication recently.

The PZMN-BT-PT ceramics for Electrostrictive Actuator (전왜 액츄에이터용 PZMN-BT-PT계 세라믹스에 관한 연구)

  • 윤현상;윤광희;박용욱;최형욱;백동수;박창엽
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.4
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    • pp.620-626
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    • 1994
  • As the electrostrictive actuator for optic control, PZN-BT-PT ceramics were investigated for the influences of sintering conditions on the structural, electrostrictive properties and the optical properties of Fabry-perot Interferometer using eletrostrictive ceramics. The specimen SS15T, sintered 1hr at 1150$^{\circ}C$, is sutible for eletrostrictive actuator because its piezoelectric constants(dS131T) and strain(XS131T) at dc 10kV/cm had the higest value of 175${\times}$10S0-12TC/N, -255${\times}$10S0-6TΔl/l respectively. As the dc electric field increased, the interference effect of Fabry-Perot Interferometer was increased. The most intense interference fringe and the maximum power of 160${\mu}$W were observed at dc 6kV/cm. Thus it was considered that specimen SS15T could be used as the electrostrictive actuator for optic control.

Design of 3-D resonator for improvement of interference in ETCS (ETCS 신호 간섭 개선을 위한 3-D 공진기 설계)

  • Kim Ho-Yong;Lee Hong-Min
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.9 s.351
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    • pp.99-104
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    • 2006
  • In this paper, the conventional 2 dimensional metamaterial structure has degeneration of shielding characteristic in cross polarization effect. The proposed 3-D resonator is designed for reduction of cross polarization effect. The proposed 3-D resonator using LTCC consists of 2-D parallel resonators on X-axis, Y-axis and Z-axis. The 2-D parallel resonator consists of two plate and one via. When the co-polarization electric filed is excited, the resonance frequency of 3-D resonator is 5.024GHz. The stop bandwidth is 19MHz. When the cross-polarization electric field is excited, the resonance frequency of 3-D resonator is 4.825GHz. The stop bandwidth is 19MHz. The proposed 3-D resonator achieve reduction of cross-polarization effect. The concrete consists of proposed 3-D resonator and absorbtion materials. The concrete will be applied for reduction or interference signal of ETCS(Electric Toll collection system).

Development of a Superconducting Quantum Interference Device System for Biomagnetic Measurements (생체자기계측을 위한 초전도 양자간섭소자 시스템 개발)

  • Lee, Y.H.;Kwon, H.C.;Kim, J.M.;Park, Y.K.;Park, J.C.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.11
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    • pp.11-14
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    • 1996
  • Biomagnetic measurements provide superior spatial and temporal resolutions compared with the present electric measurements. We developed a SQUID system for biomagnetic applications. A magnetic field from the spontaneous ${\tau}$-rhythm activity and an auditory evoked magnetic field have been measured. And a measurement of magnetocardiogram and its field mapping have been done.

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Electrohydrodynamic Process Supplemented by Multiple-Nozzle and Auxiliary Electrodes for Fabricating PCL Nanofibers (멀티노즐/보조전극-Electrohydrodynamic 공정을 통한 PCL 나노파이버 제작)

  • Yoon, Hyeon;Kim, Geun-Hyung;Kim, Wan-Doo
    • Polymer(Korea)
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    • v.32 no.4
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    • pp.334-339
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    • 2008
  • Recently electro spinning is a widely used simple technique to prepared micro- to nanometer-sized fiber of various polymers. In general, a normal multiple-nozzle electro spinning system has been difficult to achieve high production-rate fabricating micro/nanofibers due to the interference of electric field between individual nozzles in the process. To reduce the interference effect of electric field between nozzles, we developed a multi-nozzle electrospinning system supplemented with auxiliary electrodes. Poly($\varepsilon$-carprolactone)(PCL), which has good mechanical property and biocompatibility, was electrospun by the multi-nozzle electro spinning system. Electrospinnability, product rate, and size uniformity of spun fibers for the system with and without auxiliary electrodes were characterized. As a result, the multi-nozzle electrospinning system supplemented with auxiliary electrodes provides excellently stable processability and showed high mass productivity of PCL-nanofibers relative to a normal multi-nozzle electro spinning system.

Analysis of Electromagnetic Shielding Performance for a BiMODAL Tram using an Electromagnetic Concentration Index (전자파의 집중도를 이용한 바이모달 트램의 전자파 차폐 성능 분석)

  • Choi, Nak-Sun;Jeung, Gi-Woo;Kim, Nam-Kyung;Song, Myung-Kon;Lee, Kang-Won;Mok, Jai-Kyun;Kim, Dong-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.7
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    • pp.1378-1384
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    • 2011
  • In this paper, the electromagnetic shielding performance of a BiMODAL Tram is investigated by means of an electromagnetic analysis tool, called HFSS. For the purposed of doing this, first, three-dimensional finite element modeling for the tram including electronic devices and engine room is carried out. Then, for quantitatively assessing the electromagnetic shielding performance of the tram's body, concentration indexes for electric field magnitude and time-average stored electric energy are introduced. From numerical results, it is inferred that the tram's body can protect the electronic devices and engine room against external electromagnetic waves from 30 MHz to 100 MHz.

Auto-Tracking Camera Gimbal for Power Line Inspection Drone and its Field Tests on 154 kV Transmission Lines (송전선로 자동추적 카메라 짐벌 및 154 kV 송전선로 현장시험)

  • Kim, Seok-Tae;Park, Joon-Young;Lee, Jae-Kyung;Ham, Ji-Wan
    • KEPCO Journal on Electric Power and Energy
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    • v.5 no.3
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    • pp.149-156
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    • 2019
  • In the field of maintenance of power transmission lines, drones have been used for their patrol and inspection by KEPCO since 2017. This drone technology was originally developed by KEPCO Research Institute, and now workers from four regional offices of KEPCO have directly applied this technology to the drone patrol and inspection tasks. In the drone inspection system, a drone with an optical zooming camera and a thermal camera can fly automatically along the transmission lines by the ground control system developed by KEPCO Research Institute, but its camera gimbal has been remotely controlled by a field worker. Especially the drone patrol and inspection has been mainly applied for the transmission lines in the inaccessible areas such as regions with river-crossings, sea-crossings and mountains. There are often communication disruptions between the drone and its remote controller in such extreme fields of mountain areas with many barriers. This problem may cause the camera gimbal be out of control, even though the inspection drone flies along the flight path well. In addition, interference with the reception of real-time transmitted videos makes the field worker unable to operate it. To solve these problems, we have developed the auto-tracking camera gimbal system with deep learning method. The camera gimbal can track the transmission line automatically, even when the transmitted video on a remote controller is intermittently unavailable. To show the effectiveness of our camera gimbal system, its field test results will be presented in this paper.

Measurement of Screening Effect by Metal Pipe on Induced Voltage to Communication Cable from Electric Railway (전기철도에서의 통신선 유도전압에 대한 금속관 차폐효과 측정)

  • Seol, Il-Hwan;Choi, Kyu-Hyoung;Lee, Sang-Mu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2355-2362
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    • 2014
  • Electric railway induces interference voltage on wayside communication cable which brings about communication errors, malfunction of devices, and safety problem. The magnitude of the induced voltage depends on the electromagnetic field coupling which is affected by metallic installations such as rail and track structures. This paper provides an experimental analysis of the screening effect of metallic pipe on the inductive voltage caused on communication cable. The measurements at a high-speed rail site show that the screening effect of metallic pipe is about 20% when the separation distance between the pipe and communication cable is 1~2 m. The screening effects is less than 1% and can be neglected when the separation distance is more than 4 m. These results are useful to evaluate the screening effects of the metallic installations such as water pipe, gas pipe, and reinforcing bar.

The Development of System for Measuring Ion Generated from HVDC Overhead Transmission Line (초고압 직류 가공 송전선로에서 발생되는 이온 계측시스템 개발)

  • Ju, Mun-No;Yang, Kwang-Ho;Lee, Dong-Il;Shin, Koo-Yong;Lim, Jae-Seop
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.11
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    • pp.2035-2040
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    • 2008
  • The electrical discharge of high voltage direct current(HVDC) overhead transmission line generate audible noise, radio noise, electric field, ion current and induced voltage on the ground. These items are major factors to design environmentally friendly configuration of DC transmission line. Therefore, HVDC transmission lines must be designed to keep all these corona effects within acceptable levels. Several techniques have been used to assess interference caused by ions on HVDC overhead transmission line. In this study, to assess the ion characteristic of DC line, the ion current density and induced voltage caused by ion flow were measured by plate electrodes manufactured from a metal flat board and charged bodies, respectively. The charged body has two types of cylinder and cylindrical plate. From the results of calibration experiments, the sensitivity of flat electrode and charged body can be obtained. At present, the developed system is used to investigate the ion generation characteristics of Kochang DC ${\pm}500kV$ test line.

Field Test of Mitigation Methods for Stray Currents from DC Electric Railroad(1) Stray Current Drainage System (직류전기철도 전식대책 실증실험(1) 누설전류 배류시스템)

  • Ha, Yoon-Cheol;Bae, Jeong-Hyo;Ha, Tae-Hyun;Lee, Hyun-Goo;Kim, Dae-Kyeong;Choi, Jeong-Hee
    • Proceedings of the KIEE Conference
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    • 2007.10c
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    • pp.220-222
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    • 2007
  • With the wide spread of direct current (DC) electric railroads in Korea, the stray currents or leakage currents from negative return rails become a pending problem to the safety of nearby underground infrastructures. The most widely used mitigation method for this interference is the stray current drainage method, which connects the underground metallic structures to the rails with diodes (polarized drainage) or thyristor (forced drainage). Although this method inherently possesses some drawbacks, its cost effectiveness and efficiency to protect the interfered structures has been the main reason for the wide adoption. In this paper, we show the field test results for the application of stray current drainage system to a city gas pipeline paralleling a depot area of a metropolitan rapid transit system. The process for optimal positioning is briefly illustrated. The effectiveness of constant voltage, constant current, and constant potential drainage schemes was also described.

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