• Journal of the Institute of Convergence Signal Processing
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• v.25 no.1
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• pp.1-6
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• 2024

The main function of intercept array sonar is to detect pulses radiated from enemy surface ships, submarines, and torpedoes. When a pulse is detected, it is a high risk situation for the own ship, so it is very important to find the target's location for the ship's maneuverability and survival. The target's location is calculated by finding the starting point of the pulse received form each sensor and calculating the time delay between sensors. In order to find starting point, the envelope of the signal is calculated and differential filtering is performed. However, since intercept array sonar has a high sampling frequency of the signal, the number of samples to be processed is large, so this process has a problem with a large computational amount. In this paper, we propose a pulse starting point calculation method using decimation for reducing computational amount. Simulations were performed while changing the decimation factor, and it was confirmed that computational amount was reduced. The proposed method is expected to be effective in real-time processing system and have advantages in resource utilization.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.9
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• pp.91-98
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• 1997

In this paper, a new pixel decimation algorithm for the estimation of motion vector is proposed. In traditional methods, the computational cost can be reduced since only part of the pixels are used for motion vector calculation. But these methods limits the accuracy ofmotion vector because of the same reason. We derive a selection criteria of subsampled pixels that can reduce the probablity of false motion vector detection based on stochastic point of view. By using this criteria, a new pixel decimation algorithm that can reduce the prediction error with similar computational cost is presented. The simulation results applied to standard images haveshown that the proposed algorithm has less mean absolute prediction error than conventional pixel decimation algorithm.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.135-138
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• 2002

본 논문은 반향경로의 순지연 시간 추정 및 보상을 이용한 네트워크 반향 제거기의 실시간 구현에 관한 연구이다. VoIP 게이트웨이와 연결된 복잡한 교환기망(PSTN)에서 발생되는 건 반향은 통화품질의 저하를 초래한다. 긴 순지연 시간을 포함하는 반향을 실시간 구현에 적합한 연산량으로 제거하기 위해, 간축 영역에서 반향 경로를 추정하여 순지연 시간을 추정후 보상하는 반향제거기를 구현하였다. 순지연 시간의 안정적인 추정을 위해 문턱치 보다 큰 유효 계수를 이용하여 순지연 시간을 추정하는 기법을 제안하였으며, 실시간 구현시 순간 최대 연산량을 줄이기 위해 추정된 반향 경로를 분할하여 순지연 시간을 추정하는 기법을 제안하였다. 제안된 시스템을 Texas Instruments사의 16비트 고정소수점 DSP TMS320C5409를 사용하여 구현하였고, 시뮬레이터를 통하여 성능을 검증하였다.

• Journal of Korea Multimedia Society
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• v.9 no.4
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• pp.443-450
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• 2006

In digital image communication systems, YUV 4:2:0 or YUV 4:2:2 images filtered and subsampled versions of YUV 4:4:4 images are utilized and these images recover their size by an interpolation filter. Low pass filters and interpolation filters in the image communication systems are generally utilized. Thus, to improve the image quality, efficient low pass filters and interpolation filters are still required. In this paper, we propose new and efficient low pass filters and interpolation filters and their design method. The low pass filters and interpolation filters used in the MPEG-2 system were developed independently. We utilize wavelet transforms to jointly design low pass filters and interpolation filters. Simulation results show that the proposed filters are superior to the filters used in MPEG-2 in terms of PSNR. In addition, the length of the proposed interpolation filters is shorter than that of the filters used in the MPEG 2 system.