• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.365-367
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• 2013

해상감시레이더는 관제지역의 해상교통정보를 수집하는 해상교통관제시스템의 주요 센서로, 다양한 운동 특성을 갖는 선박의 안정적인 추적과 위치, 속도, 침로 등의 정확한 정보를 제공하는 것은 VTS 성능 개선 및 서비스 고도화에 매우 중요한 요소 기술이다. 본 논문에서는 해상교통관제시스템에서 다양한 기동 특성을 갖는 선박의 정확한 추적을 위하여 상호작용 다중필터(IMM) 추정기를 이용한 추적 알고리즘을 설계하고, 모의실험을 통하여 필터 뱅크의 구성에 따른 성능 비교 및 분석을 수행한다.

• 전기의세계
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• v.42 no.6
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• pp.38-45
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• 1993

앞으로 21세기 기술선도사업으로 고속성 및 병렬성의 장점을 지닌 퓨리에 광 신호처리 기술은 광통신 기술, 광소자 기술등과 병행하여 미래의 종합 정보통신 시스템에서 커다란 비중을 차지할 것으로 예상되며 특히, 자동감시, 로보트 비젼등 산업적 응용분야뿐만 아니라, 미사일 유도, 자동표적 인식 및 추적등의 분야에서 첨단기술로서 그 응용이 크게 기대되어 이에 대한 연구 개발이 활발히 진행되고 있다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.2
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• pp.179-188
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• 2015

Testing a radar system in real environment requires a lot of time and cost. Thus various target simulators are developed to evaluate the radar performance and its functions as well. In order to enhance the range resolution and the accuracy for tracking, recent radar system tends to use the wideband signal. In this paper, we summarize two target simulation methods - the direct sampling method with the digital memories and the beat frequency generation for the stretch processing - and suggest the condition to improve their performance for a wideband radar system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12B
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• pp.1244-1250
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• 2010

This paper presents a detection and ranging algorithm for a high-speed targets in the high PRF radar. We show, unlike the conventional methods, it firstly estimates Doppler frequency with a quasi-periodic pulse train prior to range processing. The estimated Doppler frequency can compensate the phase error enbeded in the received signal, which makes the signal integrated coherently in the range direction and localizes the target's signiture in low SNR. We present the derivation of the proposed algorithm and discuss how the system parameters such as the range/Doppler sampling condition, processing time and Doppler estimation error affect the performance of the proposed algorithm, which is verified by simulations.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.10
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• pp.1069-1076
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• 2014

This paper presents an efficient receive beam structure able to search and track the simultaneous bundle targets with the active electrically scanned array radar. One of the characteristic with the active phased array radar is to point toward wanted direction and to forming simultaneously the digital multi-beam. This paper proposes method to detect and track rapidly bundle targets coming to radar using the digital beam forming. The proposed the beam forming method in the paper is evaluated about the angle accuracy of targets via a computer simulation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.199-203
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• 2019

The penetration depth of a hypervelocity jet exceeding 4 km/s is described by the density ratio of the jet and the target. In the case of the same density, the difference in strength between the targets does not affect the penetration depth difference. This study focuses on the "strength irrelevance" of such a hypervelocity jet. For this purpose, the change of crater pressure caused by shaped charge jet(SCJ) was calculated by finite element analysis and the possibility of polymorphic phase transition of steel material was investigated. Hypervelocity jets were found to cause polymorphic phase transitions in the steel target craters, and the decrease in the fracture toughness of the target is predicted as the cause of the strength irrelevance.

• The Journal of the Acoustical Society of Korea
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• v.38 no.1
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• pp.120-127
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• 2019

Passive source depth discrimination has been studied for decades since the source depth can be used for discriminating whether the target is near the surface or submerged. In this thesis, an algorithm for source depth discrimination is proposed based on CIR (Channel Impulse Response) from target-radiated noise (or signal). In order to extract CIR without a known source signal, Ray-based blind deconvolution is used. Subsequently, intersections of CIR pattern, which is characterized by ray arrival time difference, is utilized for discriminating source depth. The proposed algorithm is demonstrated through numerical simulation in ocean waveguide, and verified via the experimental data.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.10 s.113
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• pp.913-919
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• 2006

This paper presents a technique for motion compensation of ISAR(Inverse SAR) images for a moving target. If a simple fourier transform is employed to obtain ISAR image for a moving target, the image is usually blurred. These images blurring problem can be solved with the time-frequency transform. In this paper, motion compensation algorithms of ISAR image such as STFT(Short Time Fourier Transform), GWT(Gabor Wavelet Transform) are described. In order to show the performances of each algorithm, we use scattering wave of the ideal point scatterers and simulated MIG-25 to obtain motion compensated ISAR image, and display the resolution of STFT and GWT ISAR image.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.5
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• pp.532-537
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• 2015

In this paper, we propose target range estimation method using ghost target in the submarine linear array sonar. Usually, when submarine detect target, they use passive sonar detection to avoid self-disclosure by active sonar transmission. But, originally, passive linear array sonar have limitation for target range estimation and additional processing is required to get target range information. For the case of near-field target, typical range estimation method is using multiple information by multipath effect in underwater environment. Acoustic signal generated from target are propagated along with numerous multipath in underwater environment. Since multipath target signals received in the linear array sonar have different conic angles each other, ghost target is appeared at the bearing different with real target bearing and sonar operator can find these information on the operation console. Under several assumption, this geometric properties can be analysed mathematically and we get the target range by derivation of this geometric equations using measured conic angles of real target and ghost target.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.7
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• pp.576-585
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• 2014

In this paper, we survey the Moving Target Indication(MTI) techniques for small UAVs. MTI consists of image alignment phase and frame differencing correction phase, and image alignment has two ways of parametric approach which is mainly focused in this paper and non-parametric approach. Since small UAVs are operated in the low altitude, the parallax is considerable and the epipolar geometry is applied to compensate the parallax. The related works and future works are presented.