In this paper we translate in terms of coding theory constraints that are used in designing DNA codes for use in DNA computing or as bar-codes in chemical libraries. We propose new constructions for DNA codes satisfyi...
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In this paper we translate in terms of coding theory constraints that are used in designing DNA codes for use in DNA computing or as bar-codes in chemical libraries. We propose new constructions for DNA codes satisfying either a reverse-complement constraint, a GC-content constraint, or both, that are derived from additive and linear codes over four-letter alphabets. We focus in particular on codes over GF(4), and we construct new DNA codes that are in many cases better (sometimes far better) than previously known codes. We provide updated tables up to length 20 that include these codes as well as new codes constructed using a combination of lexicographic techniques and stochastic search. (c) 2004 Elsevier B.V. All rights reserved.
Multiple emerging technologies in nanometer scale, including Quantum computing, requires circuit design with fan-out restriction and impose logical reversibility as a prerequisite to achieve asymptotically zero power ...
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Multiple emerging technologies in nanometer scale, including Quantum computing, requires circuit design with fan-out restriction and impose logical reversibility as a prerequisite to achieve asymptotically zero power consumption. This has prompted researchers to explore efficient design of important classes of Boolean functions with limited fan-out and using reversible logic gates as building blocks. Symmetric Boolean functions, a key subclass of Boolean functions, is studied well from the perspective of circuit complexity theory, with some promising recent results. Efficient reversible logic synthesis of symmetric Boolean functions also has been developed. On the other hand, in 1963, Arnold and Harrison proposed an algorithm that symmetrizes any Boolean function by adding an exponential number of additional input variables. The recent efficient implementation and synthesis studies, when put in combination with the Arnold-Harrison algorithm, represents an interesting possibility that one may first symmetrize an arbitrary Boolean function and then proceed towards synthesis. In this paper, we look into this possibility and present a general impossibility result. The core contribution of our work is to explain the Arnold-Harrison algorithm with the help of coding theory. Based on this framework, we show that there exists a large subclass of Boolean functions, for which a linear number of additional input variables suffice when symmetrization is attempted. As a result, indeed, for such classes of non-symmetric Boolean functions, the synthesis approach via symmetrization yields improved results.
This note presents some new information on how the minimum distance of the generalized toric code corresponding to a fixed set of integer lattice points S subset of R-2 varies with the base field. The main results sho...
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This note presents some new information on how the minimum distance of the generalized toric code corresponding to a fixed set of integer lattice points S subset of R-2 varies with the base field. The main results show that in some cases, over sufficiently large fields, the minimum distance of the code corresponding to a set S will be the same as that of the code corresponding to the convex hull conv(S). In an example, we will also discuss a [49,12,28] generalized toric code over F-8, better than any previously known code according to M. Grassl's online tables, as of December 2012. (C) 2013 Elsevier Inc. All rights reserved.
We apply automata theory and Karp's minimum mean weight cycle algorithm to minimum density problems in coding theory. Using this method, we find the new upper bound 53/126 approximate to 0:4206 for the minimum den...
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We apply automata theory and Karp's minimum mean weight cycle algorithm to minimum density problems in coding theory. Using this method, we find the new upper bound 53/126 approximate to 0:4206 for the minimum density of an identifying code on the infinite hexagonal grid, down from the previous record of 3/7 approximate to 0:4286
We consider the problem of source compression under three different scenarios in the one-shot (nonasymptotic) regime. To be specific, we prove one-shot achievability and converse bounds on the coding rates for distrib...
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We consider the problem of source compression under three different scenarios in the one-shot (nonasymptotic) regime. To be specific, we prove one-shot achievability and converse bounds on the coding rates for distributed source coding, source coding with coded side information available at the decoder, and source coding under maximum distortion criterion. The one-shot bounds obtained are in terms of smooth max R,nyi entropy and smooth max R,nyi divergence. Our results are powerful enough to yield the results that are known for these problems in the asymptotic regime both in the i.i.d. (independent and identically distributed) and non-i.i.d. settings.
In this paper we propose memory protection architectures based on nonlinear single-error-correcting, double-error-detecting (SEC-DED) codes. Linear SEC-DED codes widely used for design of reliable memories cannot dete...
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In this paper we propose memory protection architectures based on nonlinear single-error-correcting, double-error-detecting (SEC-DED) codes. Linear SEC-DED codes widely used for design of reliable memories cannot detect and can miscorrect lots of errors with large Hamming weights. This may be a serious disadvantage for many modern technologies when error distributions are hard to estimate and multi-bit errors are highly probable. The proposed protection architectures have fewer undetectable errors and fewer errors that are miscorrected by all codewords than architectures based on linear codes with the same dimension at the cost of a small increase in the latency penalty, the area overhead and the power consumption. The nonlinear SEC-DED codes are generalized from the existing perfect nonlinear codes (Vasil'ev codes, Probl Kibern 8:375-378, 1962;Phelps codes, SIAM J Algebr Discrete Methods 4:398-403, 1983;and the codes based on one switching constructions, Etzion and Vardy, IEEE Trans Inf theory 40:754-763, 1994). We present the error correcting algorithms, investigate and compare the error detection and correction capabilities of the proposed nonlinear SEC-DED codes to linear extended Hamming codes and show that replacing linear extended Hamming codes by the proposed nonlinear SEC-DED codes results in a drastic improvement in the reliability of the memory systems in the case of repeating errors or high multi-bit error rate. The proposed approach can be applied to RAM, ROM, FLASH and disk memories.
A group of subroutines, designed to extend the application range of the fuel performance code DIONISIO to high burn up, has recently been included in the code. The new calculation tools, which are tuned for UO2 fuels ...
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A group of subroutines, designed to extend the application range of the fuel performance code DIONISIO to high burn up, has recently been included in the code. The new calculation tools, which are tuned for UO2 fuels in LWR conditions, predict the radial distribution of power density, burnup, and concentration of diverse nuclides within the pellet. The balance equations of all the isotopes involved in the fission process are solved in a simplified manner, and the one-group effective cross sections of all of them are obtained as functions of the radial position in the pellet, burnup, and enrichment in U-235. In this work, the subroutines are described and the results of the simulations performed with DIONISIO are presented. The good agreement with the data provided in the FUMEX II/III NEA data bank can be easily recognized. (c) 2012 Elsevier B.V. All rights reserved.
The non-linear filtering is a commonly used time-domain technique for narrowband interference (NBI) suppression in the direct-sequence spread spectrum (DSSS) communication systems. In this study, the authors analyse h...
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The non-linear filtering is a commonly used time-domain technique for narrowband interference (NBI) suppression in the direct-sequence spread spectrum (DSSS) communication systems. In this study, the authors analyse how the decision feedback error of the spread spectrum (SS) signal influences the performance of the NBI prediction. A partial-code-aided scheme is proposed, which despreads partial chips in a spreading sequence and reconstructs the rest part by spreading the bit decision. This method utilises partial spreading gain to improve the decision accuracy of the SS signals while keeping similar time consumption and implementation complexity with the traditional scheme. It has been verified by simulation that with different NBI models and under different channel conditions, the proposed non-linear filtering method always outperforms the traditional one with chip-wise decision feedback.
FPT3 was the last of the five in-pile integral experiments in the Phebus FP programme, whose overall purpose was to investigate fuel rod degradation and behaviour of fission products (FPs) released via the primary coo...
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FPT3 was the last of the five in-pile integral experiments in the Phebus FP programme, whose overall purpose was to investigate fuel rod degradation and behaviour of fission products (FPs) released via the primary coolant circuit into the containment building. The results contribute to validation of models and computer codes used to calculate the source term for a severe accident with core meltdown in light water reactors. Unlike the previous tests, FPT3 used B4C as absorber material in the pre-irradiated (24.5 GWd/tU) fuel bundle, while featuring a steam-poor period as in FPT2, which used Ag/In/Cd absorber. The main FPT3 containment results are summarised: the source term of FPs, fuel and structural materials from the experimental circuit into the containment;the composition, morphology and deposition processes of aerosols in the containment atmosphere;the specific behaviour of the radiologically significant FP iodine;and finally the performance of passive autocatalytic recombiner (PAR) coupons exposed to the containment atmosphere just after the transient. The major elements contributing to the aerosol mass in the containment are the volatile FPs Cs and Mo, the control rod material B, the cladding material Sn, and the instrumentation materials Re and W (specific to Phebus tests). The fractional compositions, leaving aside the control rod materials, were very similar in FPT2 and FPT3. After reactor shutdown, homogenisation of the aerosol size in the containment led to only one aerosol population, similar to the previous tests. Long-term aerosol deposition in the containment was dominated by gravitational settling and diffusiophoresis, but significant deposits were also measured on the vertical wall, consisting of multi-component aerosols, again comparable with FPT2. A significant result of FPT3 was that iodine is mainly in gaseous form in the atmosphere up to containment isolation;the rest in aerosol form. Another important result was the fast decrease of the iodin
In this paper, a coding-theory construction of Cartesian authentication codes is presented. The construction is a generalization of some known constructions. Within the framework of this generic construction, several ...
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In this paper, a coding-theory construction of Cartesian authentication codes is presented. The construction is a generalization of some known constructions. Within the framework of this generic construction, several classes of authentication codes using certain classes of error-correcting codes are described. The authentication codes presented in this paper are better than known ones with comparable parameters. It is demonstrated that the construction is related to certain combinatorial designs, such as difference matrices and generalized Hadamard matrices.
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