9,774 research outputs found

    Self-checking on-line testable static RAM

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    This is a fault-tolerant random access memory for use in fault-tolerant computers. It comprises a plurality of memory chips each comprising a plurality of on-line testable and correctable memory cells disposed in rows and columns for holding individually addressable binary bits and provision for error detection incorporated into each memory cell for outputting an error signal whenever a transient error occurs therein. In one embodiment, each of the memory cells comprises a pair of static memory sub-cells for simultaneously receiving and holding a common binary data bit written to the memory cell and the error detection provision comprises comparator logic for continuously sensing and comparing the contents of the memory sub-cells to one another and for outputting the error signal whenever the contents do not match. In another embodiment, each of the memory cells comprises a static memory sub-cell and a dynamic memory sub-cell for simultaneously receiving and holding a common binary data bit written to the memory cell and the error detection provision comprises comparator logic for continuously sensing and comparing the contents of the static memory sub-cell to the dynamic memory sub-cell and for outputting the error signal whenever the contents do not match. Capability for correction of errors is also included

    Phase Diagram Of The Biham-Middleton-Levine Traffic Model In Three Dimensions

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    We study numerically the behavior of the Biham-Middleton-Levine traffic model in three dimensions. Our extensive numerical simulations show that the phase diagram for this model in three dimensions is markedly different from that in one and two dimensions. In addition to the full speed moving as well as the completely jamming phases, whose respective average asymptotic car speeds equal one and zero, we observe an extensive region of car densities ρ\rho with a low but non-zero average asymptotic car speed. The transition from this extensive low average asymptotic car speed region to the completely jamming region is at least second order. We argue that this low speed region is a result of the formation of a spatially-limited-extended percolating cluster. Thus, this low speed phase is present in n>3n > 3 dimensional Biham-Middleton-Levine model as well.Comment: Minor clarifications, 1 figure adde

    Fourier Series Formalization in ACL2(r)

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    We formalize some basic properties of Fourier series in the logic of ACL2(r), which is a variant of ACL2 that supports reasoning about the real and complex numbers by way of non-standard analysis. More specifically, we extend a framework for formally evaluating definite integrals of real-valued, continuous functions using the Second Fundamental Theorem of Calculus. Our extended framework is also applied to functions containing free arguments. Using this framework, we are able to prove the orthogonality relationships between trigonometric functions, which are the essential properties in Fourier series analysis. The sum rule for definite integrals of indexed sums is also formalized by applying the extended framework along with the First Fundamental Theorem of Calculus and the sum rule for differentiation. The Fourier coefficient formulas of periodic functions are then formalized from the orthogonality relations and the sum rule for integration. Consequently, the uniqueness of Fourier sums is a straightforward corollary. We also present our formalization of the sum rule for definite integrals of infinite series in ACL2(r). Part of this task is to prove the Dini Uniform Convergence Theorem and the continuity of a limit function under certain conditions. A key technique in our proofs of these theorems is to apply the overspill principle from non-standard analysis.Comment: In Proceedings ACL2 2015, arXiv:1509.0552

    Diversity and biosynthetic potential of culturable microbes associated with toxic marine animals

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    Tetrodotoxin (TTX) is a neurotoxin that has been reported from taxonomically diverse organisms across 14 different phyla. The biogenic origin of tetrodotoxin is still disputed, however, TTX biosynthesis by host-associated bacteria has been reported. An investigation into the culturable microbial populations from the TTX-associated blue-ringed octopus Hapalochlaena sp. and sea slug Pleurobranchaea maculata revealed a surprisingly high microbial diversity. Although TTX was not detected among the cultured isolates, PCR screening identifiedsome natural product biosynthesis genes putatively involved in its assembly. This study is the first to report on the microbial diversity of culturable communities from H. maculosa and P. maculata and common natural product biosynthesis genes from their microbiota. We also reassess the production of TTX reported from three bacterial strains isolated from the TTX-containing gastropod Nassarius semiplicatus

    Relation Between Quantum Speed Limits And Metrics On U(n)

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    Recently, Chau [Quant. Inform. & Comp. 11, 721 (2011)] found a family of metrics and pseudo-metrics on nn-dimensional unitary operators that can be interpreted as the minimum resources (given by certain tight quantum speed limit bounds) needed to transform one unitary operator to another. This result is closely related to the weighted 1\ell^1-norm on Rn{\mathbb R}^n. Here we generalize this finding by showing that every weighted p\ell^p-norm on Rn{\mathbb R}^n with 1\le p \le \limitingp induces a metric and a pseudo-metric on nn-dimensional unitary operators with quantum information-theoretic meanings related to certain tight quantum speed limit bounds. Besides, we investigate how far the correspondence between the existence of metrics and pseudo-metrics of this type and the quantum speed limits can go.Comment: minor amendments, 6 pages, to appear in J.Phys.

    Quantum Convolutional Error Correcting Codes

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    I report two general methods to construct quantum convolutional codes for NN-state quantum systems. Using these general methods, I construct a quantum convolutional code of rate 1/4, which can correct one quantum error for every eight consecutive quantum registers.Comment: Minor revisions and clarifications. To appear in Phys. Rev.

    Numerical study on the correlation between CP violation in neutrino oscillations and baryogenesis

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    We numerically study the correlation between CP violation in the neutrino oscillations and baryogenesis in the seesaw model. In this study we get the heavy Majorana neutrino masses and lepton number asymmetries from their decays by fitting the data of neutrino oscillations and by working on some hypothesis of the Dirac-Yukawa term for neutrinos.Comment: 3 pages, 2 figures, Latex, presented at KEKTC5(Nov. 2001), to be published in Nucl. Phys. Proc. Supp

    Beamforming in Two-Way Fixed Gain Amplify-and-Forward Relay Systems with CCI

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    We analyze the outage performance of a two-way fixed gain amplify-and-forward (AF) relay system with beamforming, arbitrary antenna correlation, and co-channel interference (CCI). Assuming CCI at the relay, we derive the exact individual user outage probability in closed-form. Additionally, while neglecting CCI, we also investigate the system outage probability of the considered network, which is declared if any of the two users is in transmission outage. Our results indicate that in this system, the position of the relay plays an important role in determining the user as well as the system outage probability via such parameters as signal-to-noise imbalance, antenna configuration, spatial correlation, and CCI power. To render further insights into the effect of antenna correlation and CCI on the diversity and array gains, an asymptotic expression which tightly converges to exact results is also derived.Comment: Accepted for presentation on IEEE International Conference on Communications (ICC 2012), Ottawa, Canada, June 201
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