• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.112-114
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• 2008

AC 전동기용 다이나모 시스템은 동력흡수방식을 중심으로 제작되어 많이 사용되고 있으나, 속응성 및 내구성등이 열악하여 유지 보수등에 다소 어려움을 겪고 있어 소형 전동기를 중심으로 유도전동기를 이용한 다이나모 시스템에 관한 연구가 증가하고 있는 추세이다. 현재 소형 AC 전동기를 이용한 다이나모 시스템에 관한 연구가 진행되어 있으나 수십 kW급 전동기의 운전에만 제한되어 있다. 본 논문에서는 200kW급 AC 다이나모미터의 설계 및 제어에 대하여 서술한다. 기존 데이터 취득방식의 단점을 보완한 초고속 통신모듈을 내장한 데이터 송수신 시스템을 이용하여 AC 다이나모미터의 특성을 개선하였다. 실험을 통하여 본 논문에서 제안한 시스템의 설계 및 제어를 검증한다.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.97-103
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• 2014

Signal processing technique of linear frequency modulation-frequency shift keying (LFM-FSK) waveform has been introduced for rear view radars of an automobile. LFM-FSK waveform consists of two sequential stepped frequency waveforms with some frequency offset, and thus, can be used to generate inverse synthetic aperture radar (ISAR) images of rear view target of an automobile. However, ISAR images can often be blurred due to inter-pulse phase errors. To resolve this problem, one-dimensional (1-D) entropies of high resolution range profiles (HRRP) are minimized with the help of particle swarm optimization (PSO). The searching space used in PSO is adaptively adjusted by the use of information on the target's velocity obtained from LFM-FSK waveforms. Simulation results show that the proposed method can generate well-focused ISAR images.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.7
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• pp.560-570
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• 2017

Recently, well-known SAR imaging algorithms have been developed to form the focused SAR images for stationary targets. In general, the conventional methods exploit the range variation only defined by the motion of radar platform and SAR geometry. However, for SAR imaging of ground moving targets, the motion of the targets induces an additional range shift, yielding the blurred SAR images. To overcome the problem, in this paper we propose an effective motion compensation algorithm operated under a multi-channel SAR, named along-track interferometry(ATI) and phase unwrapping to directly estimate the motion parameters of the targets. In simulations, 50 Monte-Carlo simulation results show the effectiveness of the algorithm in the presence of noise.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.9
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• pp.740-748
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• 2017

In this paper, we compared performance of conventional inverse synthetic aperture radar(ISAR) imaging methods for maritime target with real data measured by X-band radar. Following conventional approaches were used for performance comparisons: 1) range instantaneous Doppler(RID) method, 2) range Doppler(RD) processing with phase adjustment, and 3) RD processing with prominent point processing(PPP). It is noteworthy that the comparison results have significance of providing basic concept to establish ISAR imaging frame work for maritime targets.