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18
Conditional Independence in Directed Cyclic Graphical Models for Feedback
, 1994
"... Conditional independence in directed cyclic graphical models representing feedback or mixtures ..."
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Cited by 6 (1 self)
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Conditional independence in directed cyclic graphical models representing feedback or mixtures
Error Recovery Properties and Soft Decoding of QuasiArithmetic Codes
, 2008
"... This paper first introduces a new set of aggregated state models for softinput decoding of quasi arithmetic (QA) codes with a termination constraint. The decoding complexity with these models is linear with the sequence length. The aggregation parameter controls the tradeoff between decoding perfor ..."
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Cited by 4 (0 self)
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This paper first introduces a new set of aggregated state models for softinput decoding of quasi arithmetic (QA) codes with a termination constraint. The decoding complexity with these models is linear with the sequence length. The aggregation parameter controls the tradeoff between decoding performance and complexity. It is shown that closetooptimal decoding performance can be obtained with low values of the aggregation parameter, that is, with a complexity which is significantly reduced with respect to optimal QA bit/symbol models. The choice of the aggregation parameter depends on the synchronization recovery properties of the QA codes. This paper thus describes a method to estimate the probability mass function (PMF) of the gain/loss of symbols following a single bit error (i.e., of the difference between the number of encoded and decoded symbols). The entropy of the gain/loss turns out to be the average amount of information conveyed by a length constraint on both the optimal and aggregated state models. This quantity allows us to choose the value of the aggregation parameter that will lead to closetooptimal decoding performance. It is shown that the optimum position for the length constraint is not the last time instant of the decoding process. This observation leads to the introduction of a new technique for robust decoding of QA codes with redundancy which turns out to outperform techniques based on the concept of forbidden symbol.
A SignalFlowGraph Approach to Online Gradient Calculation
 Neural Computation
, 2000
"... A large class of nonlinear dynamic adaptive systems such as dynamic recurrent neural networks can be effectively represented by signal flow graphs (SFGs). By this method, complex systems are described as a general connection of many simple components, each of them implementing a simple oneinput, on ..."
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Cited by 3 (1 self)
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A large class of nonlinear dynamic adaptive systems such as dynamic recurrent neural networks can be effectively represented by signal flow graphs (SFGs). By this method, complex systems are described as a general connection of many simple components, each of them implementing a simple oneinput, oneoutput transformation, as in an electrical circuit. Even if graph representations are popular in the neural network community, they are often used for qualitative description rather than for rigorous representation and computational purposes. In this article, a method for both online and batchbackward gradient computation of a system output or cost function with respect to system parameters is derived by the SFG representation theory and its known properties. The system can be any causal, in general nonlinear and timevariant, dynamic system represented by an SFG, in particular any feedforward, timedelay, or recurrent neural network. In this work, we use discretetime notation, but the same theory holds for the continuoustime case. The gradient is obtained in a straightforward way by the analysis of two SFGs, the original one and its adjoint (obtained from the first by simple transformations), without the complex chain rule expansions of derivatives usually employed. This method can be used for sensitivity analysis and for learning both offline and online. Online learning is particularly important since it is required by many real applications, such as digital signal processing, system identification and control, channel equalization, and predistortion. 1
Using the Fourier transform to compute the weight distribution of a binary linear block code
 IEEE Communications Letters, Volume
"... ..."
The serially coupled multiple ring resonator filters and Vernier effect
"... The general characteristics of serially coupled multiple ring resonator (SMRR) filters are analyzed. In this case, the ring resonators of the SMRR have identical perimeters and the coupling coefficients distribution provides passband characteristics with steeper rolloff, flatter top and greater sto ..."
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The general characteristics of serially coupled multiple ring resonator (SMRR) filters are analyzed. In this case, the ring resonators of the SMRR have identical perimeters and the coupling coefficients distribution provides passband characteristics with steeper rolloff, flatter top and greater stopband rejection than a single ring resonator. In addition, we have also designed and simulated a nonsymmetric Vernier type of SMRR filters for improving a wide free spectral range (FSR) with different ring radii. To expand the FSR of the SMRR, Vernier filters are determined by the least common multiple of the FSR of individual ring resonators. The improvement in suppression of interstitial resonances is also investigated. A novel derivation of the optical transfer functions in Zdomain of SMRR filters is expressed employing a graphical approach to ring resonators with unequal perimeters that can be represented in signal flow graph diagrams.
Slow light generation using microring resonators for optical buffer application
 Opt. Eng
"... Slow light generation using microring resonators for optical buffer application ..."
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Slow light generation using microring resonators for optical buffer application
A New Hybrid Acquisition Scheme for CDMA Systems Employing Short Concatenated Codes
, 1997
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doi:10.1155/2008/752840 Research Article Error Recovery Properties and Soft Decoding of QuasiArithmetic Codes
, 2007
"... This paper first introduces a new set of aggregated state models for softinput decoding of quasi arithmetic (QA) codes with a termination constraint. The decoding complexity with these models is linear with the sequence length. The aggregation parameter controls the tradeoff between decoding perfor ..."
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This paper first introduces a new set of aggregated state models for softinput decoding of quasi arithmetic (QA) codes with a termination constraint. The decoding complexity with these models is linear with the sequence length. The aggregation parameter controls the tradeoff between decoding performance and complexity. It is shown that closetooptimal decoding performance can be obtained with low values of the aggregation parameter, that is, with a complexity which is significantly reduced with respect to optimal QA bit/symbol models. The choice of the aggregation parameter depends on the synchronization recovery properties of the QA codes. This paper thus describes a method to estimate the probability mass function (PMF) of the gain/loss of symbols following a single bit error (i.e., of the difference between the number of encoded and decoded symbols). The entropy of the gain/loss turns out to be the average amount of information conveyed by a length constraint on both the optimal and aggregated state models. This quantity allows us to choose the value of the aggregation parameter that will lead to closetooptimal decoding performance. It is shown that the optimum position for the length constraint is not the last time instant of the decoding process. This observation leads to the introduction of a new technique for robust decoding of QA codes with redundancy which turns out to outperform techniques based on the concept of forbidden symbol. Copyright © 2008 Simon Malinowski et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1.
HighOrder Inductorless Elliptic Filter with Reduced Number of Capacitors Using Signal Flow Graphs
"... Abstract—In this paper a method of realizing seventhorder elliptic filter using signalflow graphs is presented. The elliptic filter having a minimum number of capacitors is compared with the filter having a higher number of capacitors. The version with minimum number of capacitors provides area sa ..."
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Abstract—In this paper a method of realizing seventhorder elliptic filter using signalflow graphs is presented. The elliptic filter having a minimum number of capacitors is compared with the filter having a higher number of capacitors. The version with minimum number of capacitors provides area savings in IC form. Both filters (i.e. filter with minimum and one with higher number of capacitors) have a low sensitivity to component tolerances in the pass band according to Orchard’s theorem. The seventhorder elliptic filter has three parallel capacitors forming three parallel tanks, and therefore has three finite elliptic transferfunction zeros. The realizations of one and two parallel capacitors have already been presented elsewhere. The sfg derivations necessary to realize seventhorder filter having additional resistive network is presented, which is very complicated in the case of three zeros. Transfer function magnitudes are simulated using the PSpice program. Monte Carlo runs confirm the low sensitivity to component tolerances of both circuit types.