• Journal of the Institute of Convergence Signal Processing
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• v.4 no.1
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• pp.36-40
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• 2003

A number of embedded wavelet image coding methods have been Proposed since the introduction of EZW(Embedded Zerotree Wavelet) algorithm. A common characteristic of these methods is that they use fundamental ideas found in the EZW algorithm. Especially, one of these methods is the SPIHT(Set Partitioning in Hierarchy Trees) algorithm, which became very popular since it was able to achieve equal or better performance than EZW without having to use an arithmetic encoder. The SPIHT algorithm is computationally very simple, but even so it provides excellent numerical and visual results. But the evaluation of its time complexity is no more than the relative result of experimental comparisons and the strict time complexity analysis wasn't taken until now. In this paper, we analyze strictly the processing time complexity of SPIHT algorithm and prove that the time complexity for one bit-plane processing is O( nlog $_2$n) in worst case.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.2
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• pp.197-206
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• 2000

A hybrid control structure for vision-based soccer robot system is considered. The structure is om-posed of four levels such as the role action behavior and execution levels. The control structure which is a combination of hierarchical and behavioral structures can efficiently meet the behavior and design specifications of a soccer robot system Among the four levels only the design of the action level is proposed in the paper and is experimentally evaluated. Design hypothesis and evaluation method are presented to improve the reliability and accomplishment of the robot system. Due to the essential element of soccer robot system design a systematic design procedure of the action level is proposed With the proposed structure and algorithm of the action level the excellent result was shown at the MiroSot'98 held in France.