Showing papers by "Jeng-Shyang Pan published in 1999"
Journal Article•
17 citations
31 Aug 1999
TL;DR: Simulated annealing (SA) technique and a new parameter are introduced in the Tabu Search Approach (TSA) to improve the performance of the tabu search approach.
Abstract: Codeword Index Assignment (CIA) is a key issue to vector quantization (VQ). A new algorithm called Modified Tabu Search Algorithm (MTSA) is applied to codeword index assignment for noisy channels for the purpose of minimizing the distortion due to bit errors. Simulated annealing (SA) technique and a new parameter are introduced in the Tabu Search Approach (TSA) to improve the performance of the tabu search approach. Experimental tests show the modified tabu search algorithm is superior to the tabu search algorithm by evaluating the performance of channel distortion after the same number of iterations.
6 citations
TL;DR: An efficient approximate VQ codeword search algorithm is proposed, based on a modification of the Chebyshev metric, which finds that more than 36% and 5% multiplications can be saved for 8 and 1024 codewords, respectively.
Abstract: In this paper, an efficient approximate VQ codeword search algorithm is proposed. This algorithm is based on a modification of the Chebyshev metric (or Manhattan metric). Applying this new algorithm to VQ codeword search and comparing it with the minimax method, it is found that more than 36% and 5% multiplications can be saved for 8 and 1024 codewords, respectively. In terms of the total number of mathematical operations, a few mathematical operations can be saved without inducing any extra distortion. Experimental results confirm this new algorithm.
3 citations
Proceedings Article•
01 Jan 1999
TL;DR: A novel channel distortion measure is proposed by computing the expected chanel distortion using Belta distribution function and all codebook index assignment algorithms can be optimized based on this distortion measure.
Abstract: Vector quantization is very efficient for data compression of speech and image. The channel distortions are introduced due to channel noise. Assigning suitable indices to codevectors can reduce distortion due to an imperfect channel. Several codebook index assignment algorithms were proposed. Unfortunately, no algorithm is always better than the others for any bit error rate due to these algorithms are operated under the assumption of some fixed channel bit error rate which is not realistic. In this paper, a novel channel distortion measure is proposed by computing the expected chanel distortion using Belta distribution function. All codebook index assignment algorithms can be optimized based on this distortion measure. Besides, a fuzzy channel optimized vector quantization for codebook design and index assignment is also derived in this paper.
31 Aug 1999
TL;DR: An on-line, incremental credit assignment algorithm, which takes environmental reinforcement as input and assigns credit to individual rules according to environmental reinforcements is proposed.
Abstract: This article concerns the problem and solution of judging fuzzy rule bases according to environmental reinforcements. We propose an on-line, incremental credit assignment algorithm, which takes environmental reinforcement as input and assigns credit to individual rules. The proposed approach adopts a simple updating policy based on recency-weighted average, and demands only small amount of memory. We also contribute to the problem of delayed reinforcement. In the case of delayed reinforcement, the state preference function is constructed iteratively during the exploration phase.