• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.1
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• pp.83-92
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• 2001

In this paper, the monopulse channel receiver which can be matched between channels through a wide bandwidth has been proposed. The effects of the gain and phase imbalance between channels on the slope of monopulse error signal were analyzed. Also, the matching method between channels in a wide bandwidth was proposed, by which monopulse slope could be stabilized. Using the implemented monopulse radar system the monopulse slope was measured in the anechoic chamber which include the moving horn antenna and the target signal generator. The results show that the wide band matching method is useful and applicable to various channel receivers

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.381-383
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• 2006

본 논문에서는 5.8Ghz ISM대역 평행 결합선로 대역통과 여파기를 설계 제작하였다. 긴본적인 설계는 저역통과 여파기에서 대역통과 여파기로 변환한 후, 직 병렬 공진기를 이용한 설계와 J-인버터를 이용해 평행 결합선로 대역통과 여파기를 구현하였다. 2개의 공진 주파수를 실제로 구현하기 어렵기 때문에 하나의 공진기만을 사용하기 위해 인버터를 사용하였다. 또한 실제적인 마이크로스트립 라인의 layout크기를 결정하기 위해 우수 기수 모드 임피던스를 해석하고 근사식을 통해 스트립라인의 치수를 결정하였다. 이런 과정을 토대로 5.8GHz ISM밴드용 평행 결합선로 대역통과 여파기를 설계, 제작하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1203-1212
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• 2013

In this paper, an intra prediction hardware architecture is proposed to reduce computational complexity of intra prediction in HEVC decoder. The architecture uses shared operation units and common operation units and adopts a fast smoothing decision algorithm and a fast algorithm to generate coefficients of a filter. The shared operation unit shares adders processing common equations to remove the computational redundancy. The unit computes an average value in DC mode for reducing the number of execution cycles in DC mode. In order to reduce operation units, the common operation unit uses one operation unit generating predicted pixels and filtered pixels in all prediction modes. In order to reduce processing time and operators, the decision algorithm uses only bit-comparators and the fast algorithm uses LUT instead of multiplication operators. The proposed architecture using four shared operation units and eight common operation units which can reduce execution cycles of intra prediction. The architecture is synthesized using TSMC 0.13um CMOS technology. The gate count and the maximum operating frequency are 40.5k and 164MHz, respectively. As the result of measuring the performance of the proposed architecture using the extracted data from HM 7.1, the execution cycle of the architecture is about 93.7% less than the previous design.

• The Journal of the Acoustical Society of Korea
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• v.26 no.4
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• pp.173-181
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• 2007

In this paper, we propose a moving target localization algorithm using acoustic spectrograms. A time-versus-frequency spectrogram provide a information of trajectory of the moving target in underwater. For a source at sufficiently long range from a receiver, broadband striation patterns seen in spectrogram represents the mutual interference between modes which reflected by surface and bottom. The slope of the maximum intensity striation is influenced by waveguide invariant parameter ${\beta}$ and distance between target and sensor. When more than two sensors are applied to measure the moving ship-radited noise, the slope and frequency of the maximum intensity striation are depend on distance between target and receiver. We assumed two sensors to fixed point then form a circle of apollonios which set of all points whose distances from two fixed points are in a constant ratio. In case of three sensors are applied, two circle form an intersection point so coordinates of this point can be estimated as a position of target. To evaluates a performance of the proposed localization algorithm, simulation is performed using acoustic propagation program.