In this paper, we introduce new codeword sets based on order complexity (OC) which measures uncertainty of the order having each permutation string. The proposed codeword sets are generated by two procedures: Indexing...
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ISBN:
(纸本)9781424445936
In this paper, we introduce new codeword sets based on order complexity (OC) which measures uncertainty of the order having each permutation string. The proposed codeword sets are generated by two procedures: Indexing and B-transform. Indexing is that a smaller positive integer is mapped to a permutation string whose OC is lower. B-transform plays role of generating a binary string from the permutation string on reflecting the OC, that is, low OC is represented by short binary strings and high OC is represented by long binary strings. The sets of these binary strings are our proposed codeword sets (B-codes). The B-codes are the uniquely decipherable complete variablelength codeword sets and have shorter codeword length than most other variablelength codes for values of 4 or more for the finite integers.
Consider a decision maker who is responsible to dynamically collect observations so as to enhance his information in a speedy manner about an underlying phenomena of interest while accounting for the cost of data coll...
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ISBN:
(纸本)9781457705953
Consider a decision maker who is responsible to dynamically collect observations so as to enhance his information in a speedy manner about an underlying phenomena of interest while accounting for the cost of data collection. Due to the sequential nature of the problem, the decision maker relies on his current information state to adaptively (re-) evaluate the tradeoff between the cost of various sensing actions and the precision of their outcomes. In this paper, using results in dynamic programming, a lower bound for the optimal total cost is established. Moreover, an upper bound is obtained using a heuristic policy for dynamic selection of actions. Using the obtained bounds, the closed loop (feedback) gain is shown to be at least logarithmic in the penalty associated with wrong declarations. Furthermore, it is shown that the proposed heuristic achieves asymptotic optimality in many practically relevant problems such as variable-length coding with feedback and noisy dynamic search.
Cascaded binary hypothesis testing is studied in this paper with two decision centers at the relay and the receiver. All terminals have their own observations, where we assume that the observations at the transmitter,...
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ISBN:
(纸本)9781665403122
Cascaded binary hypothesis testing is studied in this paper with two decision centers at the relay and the receiver. All terminals have their own observations, where we assume that the observations at the transmitter, the relay, and the receiver form a Markov chain in this order. The communication occurs over two hops, from the transmitter to the relay, and from the relay to the receiver. Expected rate constraints are imposed on both communication links. In this work, we characterize the optimal type-II error exponents at the two decision centers under constraints on the allowed type-I error probabilities. Our recent work characterized the optimal type-II error exponents in the special case when the two decision centers have same type-I error constraints and provided an achievability scheme for the general setup. To obtain the exact characterization for the general case, in this paper we provide a new converse proof as well as a new matching achievability scheme. Our results indicate that under unequal type-I error constraints at the relay and the receiver, a tradeoff arises between the maximum type-II error probabilities at these two terminals. Previous results showed that such a tradeoff does not exist under equal type-I error constraints or under general type-I error constraints when a maximum rate constraint is imposed on the communication links.
In this paper, we propose an improved coeff_token variable-length decoding (VLD) method in the CAVLC decoder. The number of memory accesses is one of the significant issues in the applications such as DMB and videopho...
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ISBN:
(纸本)9781424417650
In this paper, we propose an improved coeff_token variable-length decoding (VLD) method in the CAVLC decoder. The number of memory accesses is one of the significant issues in the applications such as DMB and videophone services, where the low-power consumption and high-speed operation are required. In order to cut down the heavy memory accesses, a new fast VLD method is developed through the careful examination of the codewords in variable-length code tables (VLCTs). The simulation results show that the proposed method achieves an approximately 60% memory access saving without video-quality degradation, compared to the existing fast coeff-token VLD method.
Test data compression/decompression schemes for testing SoCs can reduce test application cost. A drawback of the previous schemes, however is that a decompressor must be embedded in an SoC under test. In this paper we...
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ISBN:
(纸本)9780769528908
Test data compression/decompression schemes for testing SoCs can reduce test application cost. A drawback of the previous schemes, however is that a decompressor must be embedded in an SoC under test. In this paper we target the testing of SoCs with multimedia cores and introduce a scheme of test compression/decompression with the decoding function in the multimedia cores. This scheme can utilize the decoder and encoder in a multimedia core for compressing and decompressing test data, and consequently it requires slight hardware overhead. As an example of the proposed scheme, we focus on a lossless variable-length coding (VLC) in the JPEG algorithm, and propose a test compression/decompression method using the VLC decoder We also propose a test generation method for this scheme. Experimental results show that the test compression with the VLC can achieve high compression ratio and the proposed test generation method can increase the compression ratio.
In this paper, we propose an embedded satellite image compression method using Weighted ZeroBlock coding (WZBC) and optimal sorting. In order to reduce average codeword length, Set Partition Embedded block (SPECK) and...
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In this paper, we propose an embedded satellite image compression method using Weighted ZeroBlock coding (WZBC) and optimal sorting. In order to reduce average codeword length, Set Partition Embedded block (SPECK) and Embedded ZeroBlock Coder (EZBC) both encode significant block-sets with fixed-length bits, while WZBC assigns different-length bits to encode block-sets which contain different numbers of significant sub-blocks. In view of the context correlation among coefficients/blocks, WZBC employs a weight context to optimize the scanning order of the significance testing and the rate-distortion performance. Experimental results show that the proposed WZBC in binary coding mode provides excellent coding performance compared with those of SPECK and Set Partitioning In Hierarchical Trees (SPIHT) which use arithmetic coding, and can even closely approach that of JPEG2000. When arithmetic coding is extensively used, the proposed method has clear advantages.
In this paper, a new improvement of Lempel-Ziv-Welch (LZW) compression method is presented. The original LZW method is widely used in real-time application since it provides with fast compression and acceptable compre...
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In this paper, a new improvement of Lempel-Ziv-Welch (LZW) compression method is presented. The original LZW method is widely used in real-time application since it provides with fast compression and acceptable compression rate. Some techniques to improve its compression rate have been proposed. A multiple dictionary approach and the least-recently-used (LRU) deletion heuristic are adopted in the implementation of our new LZW method. In addition, a simple variable-length coding technique is applied to further improve the compression rate in our method. The experimental results show that our method achieves better compression rate than the original LZW method without significant degrading its speed.
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