• Journal of Aerospace System Engineering
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• v.17 no.5
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• pp.42-57
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• 2023

In this paper, to increase the research capability of flight missions and maintenance in operating military aircraft, we studied the requirements for additional mounting of flight video and data recorders and safety verification methods. The verification process of the recorder equipment itself, structural safety in the aircraft system, power and electrical safety, electromagnetic compatibility, and impact of airworthiness are described in accordance with military standards and operating environment requirements. In addition, through ground/flight tests, the results of functional operation suitable for the influence and demand of interference between the flight video and data recorder and other systems are also presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.500-506
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• 2015

In this paper, we designed and fabricated the EM wave absorber consisted of Sendust for suppressing EM wave noise PCB in ISM (Industrial, Scientific and Medical) band of 2.4 GHz. We fabricated several samples with different composition ratios of some kinds of Sendust to CPE (Chlorinated Ploy-ethylene) as a binder, and it was confirmed that the optimum composition ratio of absorbing materials was Flaked Sendust : CPE = 72.5 : 27.5 wt.%.. The absorbing abilities were simulated by changing the thickness and the measured material constants of EM wave absorber. The measured absorption abilities were analyzed and compared with the simulated ones. As a result, the simulated results agree well with the measured ones, and the developed EM wave absorber with extremely thin thickness of 0.6 mm has absorption ability of 5.4 dB at 2.4 GHz is excellent one. The thin type EM wave absorber can be applied for suppressing and absorbing electromagnetic noises from information and communication equipments.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2004.01a
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• pp.1-226
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• 2004

I. Title APMC'03(2003 Asia Pacific Microwave Conference) II. Objecuve $\bigcirc$Investigation of new trend in the field of microwave engineering $\bigcirc$Establishment of R＆D track for wireless and high speed communication III. Scope of investigation $\bigcirc$R＆D trend in various microwave engineering areas-Solid state Devices and circuits-Electromagnetic Field Theory-EMI＆EMC-Phased ＆ Active Array Antennas-Scattering ＆ Propagation $\bigcirc$Discussions with various technical topics-New research ＆ development topics-Establishment of wireless ＆ high speed communications IV. Results During the conference, very active academic exchange were possible between Korean and foreign microwave engineering scholars. It was also possible to introduce the level and activities of Korean microwave engineering researches to foreign countries. Also, it was good opportunity to contact foreign scholars and researchers for valuable academic discussion using technical paper presentations and inquiries.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.2
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• pp.58-67
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• 1995

The paper describes the variation of magnetic fields caused by the operation of induction motors. The measuring system consists of the self-integrating magnetic field sensor, amplifier, and active integrator. From the calibration experiments, the frequency bandwidth of the magnetic field measuring system ranges from 20[Hz] to 300[kHz] and sensitivity is 0.234(mV/$\mu\textrm{T}$]. The magnetic fields generated under steady state and starting operations of duction motor are recorded by the proposed measuring system, and the fast Fourier transformation(FFT) of the measured data is performed to analyze the harmonic components. A single pulsed magnetic field is strongly caused by direct starting the induction motor, and its peak value is greater than 5 times as compared with the steady state value. The long transient duration and high intensity originates from the large inductance and dynamic characteristic of the induction motor, During the steady state operation of induction motor, subharmonics of magnetic field components, which depend on the pole number of induction motor, are observed. The lower order power-line harmonics can be inferred from the voltage flicker and current ripple which are derived from the torque fluctuation of induction motor. In the case of the induction motor drived by inverter, the harmonics of magnetic field are much more than those caused by direct starting method and are found generally to increase with decreasing the driving frequency.