• Proceedings of the Korea Multimedia Society Conference
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• 1998.04a
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• pp.95-99
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• 1998

본 논문에서는 웨이브렛 변환을 이용한 영상 부호화에서 입력 영상의 통계적 성질에 관계없이 부호화 결과에 범용성을 갖는 새로운 벡터 양자화기 설계법을 제안한다. 제안하는 벡터 양자화기에서는 대표벡터를 생성하기 위한 학습계열로 난수에 영상의 상관과 에지성분을 첨가한 모사 영상을 사용한다. 제안한 방식에 의해 설계된 벡터양자화기와 코드북 생성에 이용하는 학습계열에 부호화 대상이 되는 영상과 같은 실제의 영상을 사용한 종래방식으로 설계된 벡터양자화기와 부호화 성능을 비교하여 종래방식의 문제점을 명확하게 밝힌다.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.1
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• pp.161-169
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• 1996

This paper presents a new search region prediction method using vector quantization for the motion estimation. We find motion vectors using the full search BMA from two successive frame images first. Then the motion vectors are used for training a codebook. The trained codebook is the predicted search region. We used the unsupervised neural network for VQ encoding and codebook design. A major advantage of formulating VQ as neural networks is that the large number of adaptive training algorithm that are used for neural networks can be applied to VQ. The proposed method reduces the computation and reduce the bits required to represent the motion vectors because of the smaller search points. The computer simulation results show the increased PSNR as compared with the other block matching algorithms.

• The Journal of the Acoustical Society of Korea
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• v.30 no.1
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• pp.1-8
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• 2011

This paper presents a method for improving the performance of ISF coefficients quantizer through compensating the defect of the split structure vector quantization using the ordering property of ISF coefficients. And design the ISF coefficients quantizer for wideband speech codec using proposed method. The wideband speech codec uses split structure vector quantizer which could not use the correlation between ISF coefficients fully to reduce complexity and the size of codebook. The proposed algorithm uses the ordering property of ISF coefficients to overcome the defect. Using the ordering property, the codebook redundancy could be figured out. The codebook redundancy is replaced by the adaptive-extended codebook to improve the performance of the quantizer through using the ordering property, ISF coefficient prediction and interpolation of existing codebook. As a result, the proposed algorithm shows that the adaptive-extended codebook algorithm could get about 2 bit gains in comparison with the existing split structure ISF quantizer of AMR-WB (G.722.2) in the points of spectral distortion.

• Journal of Ocean Engineering and Technology
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• v.22 no.4
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• pp.90-96
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• 2008

In general, the swing motions of a crane are controlled and suppressed by controlling the trolley motion. In many of our previous studies, we suggested a new type of anti-sway control system for a crane. In this proposed control system, a small auxiliary mass (moving-mass) is installed on the spreader and moving this auxiliary mass controls tire swing motion. The actuator reaction against the auxiliary mass applies inertial control forces to the container in order to reduce the swing motion in the desired manner. However, measuring systems based on a laser sensor or other means are not veryuseful in real-worldapplications. So, in this paper, animage sensor is used to measure the motions of the spreader and the measured data are fed back to the controller in real time. The applied image processing technique is a kind of robust template matching method called Vector Code Correlation (VCC), which was devised to consider real environmental conditions. The H $\infty$ based control technique is applied to suppress the swing motion of the crane. Experimental results showed that the proposed measurement and control system based on an image sensor is useful and robust to disturbances.