In this paper, a set of efficient decoding algorithms based on a Speaker Independent Mandarin Connected Digit Speech Recognition System is proposed. By simplifying the computation of observation probabilities and adop...
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ISBN:
(纸本)9628576623
In this paper, a set of efficient decoding algorithms based on a Speaker Independent Mandarin Connected Digit Speech Recognition System is proposed. By simplifying the computation of observation probabilities and adopting improved beam search pruning algorithm combined with duration information, the average decoding time is reduced froth 0.92 second to 0.11 second per digit string while the recognition rate of unknown-length string is only decreased from 94.3% to 94.0%.
We look at graphical descriptions of block, codes known as trellises, which illustrate connections between algebra and graph theory, and can be used to develop powerful decoding algorithms. Trellises for linear block ...
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We look at graphical descriptions of block, codes known as trellises, which illustrate connections between algebra and graph theory, and can be used to develop powerful decoding algorithms. Trellises for linear block codes are known to grow exponentially with the code parameters and hence decoding on such objects is often infeasible. Of considerable interest to coding theorists therefore, are more compact descriptions called tail-biting trellises which in some cases can be much smaller than any ordinary trellis for the same code. We derive some interesting properties of tail-biting trellises and present an optimal maximum-likelihood decoding algorithm that performs rather well in terms of decoding complexity even at low signal-to-noise ratios.
We consider the problem of list decoding from erasures. We establish lower and upper bounds on the rate of a (binary linear) code that can be list decoded with list size L when up to a fraction p of its symbols are ad...
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We consider the problem of list decoding from erasures. We establish lower and upper bounds on the rate of a (binary linear) code that can be list decoded with list size L when up to a fraction p of its symbols are adversarially erased. Such bounds already exist in the literature, albeit under the label of generalized Hamming weights, and we make their connection to list decoding from erasures explicit. Our bounds show that in the limit of large L, the rate of such a code approaches the "capacity" (1 - p) of the erasure channel. Such nicely list decodable codes are then used as inner codes in a suitable concatenation scheme to give a uniformly constructive family of asymptotically good binary linear codes of rate Omega(epsilon(2)/log(1/epsilon)) that can be efficiently list-decoded using lists of size O(1/epsilon) when an adversarially chosen (1 - epsilon) fraction of symbols are erased, for arbitrary epsilon > 0. This improves previous results in this vein, which achieved a rate of Omega(epsilon(3) log(1/epsilon)).
Recent advances in cortically controlled brain-machine interfaces (BMIs) have demonstrated that goal-directed movement of external devices is possible in real-time using multi-electrode recordings from cortex. A numbe...
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ISBN:
(纸本)0780377893
Recent advances in cortically controlled brain-machine interfaces (BMIs) have demonstrated that goal-directed movement of external devices is possible in real-time using multi-electrode recordings from cortex. A number of challenges are currently being confronted to further advance BMI research to the next level. These include choosing the optimal decoding algorithm for the type of control to be performed, localizing the optimal cortical site for reliable control, and focusing on the most suitable electrophysiological signal for practical use in a BMI. We present results that attempt to address these challenges based on multi-electrode recording from multiple motor cortical areas in behaving monkeys.
We investigate a class of Lee metric alternant codes with symbols in Z(p)(n), establishing a lower bound on the minimum Lee distance where certain restrictions are placed on the code parameters. Corresponding to this ...
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We investigate a class of Lee metric alternant codes with symbols in Z(p)(n), establishing a lower bound on the minimum Lee distance where certain restrictions are placed on the code parameters. Corresponding to this bound, we have devised a decoding algorithm which is implemented over a finite field. The algorithm proceeds by finding a Grobner basis of the module M of solutions to a key equation. We obtain a necessary characterization of the solution module by solving iteratively a linear sequence over a Galois ring and show that the particular solution sought by the decoder is minimal in M. The required solution can then be found in an appropriate Grobner basis of M.
A new probabilistic algorithm for decoding one received word from a set of many given received words, into a codeword such that the Hamming distance between the received word and the codeword is at most t, is proposed...
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A new probabilistic algorithm for decoding one received word from a set of many given received words, into a codeword such that the Hamming distance between the received word and the codeword is at most t, is proposed. The new algorithm is applicable to several cryptographic problems, such as the Stern identification scheme, the McEliece public-key cryptosystem, and in correlation attacks on stream ciphers. When applicable, it runs significantly faster than previous algorithms used for attacks on these cryptosystems.
A new probabilistic algorithm for decoding one received word from a set of many given received words, into a codeword such that the Hamming distance between the received word and the codeword is at most t, is proposed...
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ISBN:
(纸本)0780350006
A new probabilistic algorithm for decoding one received word from a set of many given received words, into a codeword such that the Hamming distance between the received word and the codeword is at most t, is proposed. The new algorithm is applicable to several cryptographic problems, such as the Stern identification scheme, the McEliece public-key cryptosystem, and in correlation attacks on stream ciphers. When applicable, it runs significantly faster than previous algorithms used for attacks on these cryptosystems.
In this correspondence, we present a method for decoding an arbitrary linear code over a Galois ring R by a process of lifting decoding algorithms for a family of linear codes over a finite field K: forming an alpha -...
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In this correspondence, we present a method for decoding an arbitrary linear code over a Galois ring R by a process of lifting decoding algorithms for a family of linear codes over a finite field K: forming an alpha -element chain, where K: is the quotient field of a and a has characteristic p(alpha). As a new result, this method also works for linear codes over R which are nonfree R-modules.
Given an error-correcting code over strings of length n and an arbitrary input string also of length n, the List decoding problem is that of finding all codewords within a specified Ramming distance from the input str...
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Given an error-correcting code over strings of length n and an arbitrary input string also of length n, the List decoding problem is that of finding all codewords within a specified Ramming distance from the input string. me present an improved list decoding algorithm for decoding Reed-Solomon codes, The list decoding problem for Reed-Solomon codes reduces to the following "curve-fitting" problem over a field F: Given n points {(x(i).y(i))}(i=1)(n), x(i) ,y(i) is an element of F, and a degree parameter L and error parameter e, find all univariate polynomials p of degree at most I;such that y(i) = p(x(i)) for all but at most e values of i is an element of {1, ..., n}, We give an algorithm that solves this problem for e < n - root kn, which improves over the previous best result [27], for every choice of k and n, Of particular interest is the ease of k/n > 1/3, where the result yields the first asymptotic improvement in four decades [21], The algorithm generalizes to solve the list decoding problem for other algebraic codes, specifically alternant codes (a class of codes including BCH codes) and algebraic-geometry codes. In both cases, we obtain a list decoding algorithm that corrects up to n - root n(n - d') errors, where n is the block length and d' is the designed distance of the code. The improvement for the case of algebraic-geometry codes extends the methods of [24] and improves upon their bound for every choice of n and d'. We also present some other consequences of our algorithm including a solution to a weighted curve-fitting problem, which may be of use in soft-decision decoding algorithms for Reed-Solomon codes.
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