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Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on

Issue 3 • Date March 1994

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Displaying Results 1 - 9 of 9
  • Comments on "Artificial neural networks for four-coloring map problems and K-colorability problems"

    Publication Year: 1994 , Page(s): 248 - 249
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (194 KB)  

    The paper (see ibid., vol 38 p 326-33, 1991) gives a proof that the binary Hopfield neural network using the McCulloch-Pitts binary neuron model converges to the local minimum. In this correspondence the authors present a counter example to the proof and then point out the error in the proof.<> View full abstract»

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  • Balanced decompositions of sparse systems for multilevel parallel processing

    Publication Year: 1994 , Page(s): 220 - 233
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1012 KB)  

    The objective of this paper is to present a recursive algorithm for permuting sparse matrices into the bordered block diagonal form. An outstanding feature of this algorithm is the resulting balance between the border size and the size of the diagonal blocks, which gives rise to an efficient multilevel scheme for parallel matrix factorization. This scheme is characterized by good load balancing and low interprocessor communications. In addition, it is specifically designed to minimize fill in within the factored matrix in order to preserve the original sparsity. Applications to power transmission systems are presented, together with a discussion of relevant parallelization and sparsity issues View full abstract»

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  • Digital implementation of a nonlinear delayed-feedback system

    Publication Year: 1994 , Page(s): 238 - 242
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (360 KB)  

    A digital electronic system which implements a certain class of nonlinear delayed feedback models and reproduces the nonlinear oscillation phenomena in real time was designed and constructed. The purpose of the system is two-fold: to act as a simulator and to act as a prototype design for a functional digital device using complicated nonlinear oscillations. The system has an architecture which simulates the signal flow in a nonlinear delayed feedback system with fixed-point arithmetic. We describe the design principles aimed at maintaining the simplicity of the circuit structure and the variety of dynamics generated. Quantization effects are discussed. In particular, it is shown how spurious quantization effects peculiar to digital systems can be estimated and avoided View full abstract»

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  • On the properties of Gram matrix

    Publication Year: 1994 , Page(s): 234 - 237
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (256 KB)  

    The Gram matrix of the system is very useful in system identification model-reduction applications. The computation of this matrix involves evaluation of scalar product of repeated integrals and can be computed in the frequency domain. In this paper new properties of the Gram matrix are presented. Based on these properties new techniques for the computation of the Gram matrix and the characteristic equation of the system are presented. The new techniques presented are shown to be elegant and easier to use than the existing techniques View full abstract»

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  • Influence of the line characterization on the transient analysis of nonlinearly loaded lossy transmission lines

    Publication Year: 1994 , Page(s): 197 - 209
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1096 KB)  

    The analysis of nonlinearly terminated lossy transmission lines is addressed in this paper with a modified version of a method belonging to the class of mixed techniques, which characterize the line in the frequency domain and solve the nonlinear problem in the time domain via a convolution operation. This formulation is based on voltage wave variables defined in the load sections. The physical meaning of such quantities helps to explain the transient scattering process in the line and allows us to discover the importance (so far often overlooked) of the reference impedance used to define the scattering parameters. The complexity of the transient impulse responses, the efficiency of the algorithms, and the precision of the results are shown to be substantially conditioned by the choice of the reference impedance. The optimum value of the reference impedance depends on the amount of line losses. We show that a low-loss line can be effectively described if its characteristic impedance or the characteristic impedance of the associated LC line is chosen as the reference impedance. Based on the physical interpretation of our formulation, we are able to validate the numerical results, and to demonstrate that, despite claimed differences or improvements, the formulations of several mixed methods are fundamentally equivalent View full abstract»

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  • Common-mode feedback circuit with differential-difference amplifier

    Publication Year: 1994 , Page(s): 243 - 246
    Cited by:  Papers (11)  |  Patents (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (296 KB)  

    A common-mode feedback circuit suitable for fully balanced analog MOS structure realization is discussed. A novel scheme of differential-difference amplifier, the concept of which can be employed in CMFB system, is proposed. A transconductance amplifier is shown as an application example. SPICE simulation is used to verify the theory View full abstract»

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  • A limited disproof to the conjecture of evaluating the matrix polynomial I+A+A2+···+AN-1

    Publication Year: 1994 , Page(s): 247 - 248
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (144 KB)  

    The problem of evaluating matrix polynomial I+A+A2+···+AN-1, has been considered. The proposed algorithms require at most 3·[log2 N] and 2·[log2 N]-1 matrix multiplications, respectively. If the binary representation of N is (itit-1···i1i 0)2, then the number of the matrix multiplication for the evaluation of this polynomial is at least 2·[log2 N]-2+it-1. In the present communication the authors prove that for many values of N there exists an algorithm requiring a fewer number of matrix multiplications, thus disproving Lei-Nakamura's conjecture View full abstract»

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  • Stability analysis of an autonulling AC bridge for use with silicon-based sensors

    Publication Year: 1994 , Page(s): 210 - 219
    Cited by:  Papers (3)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (804 KB)  

    A novel circuit incorporating integral feedback to automatically null an AC bridge is analyzed and discussed. Stability of the feedback scheme is examined by linearizing the system near the critical point (null) of the bridge using a standard perturbation method. Solutions of the nonlinear coupled differential equations that describe the operation of the autonulling AC bridge were obtained by numerical integration. A prototype was constructed using integrated circuits and discrete components to measure the transient response; test results of the circuit from transient impedance changes are compared to the time-dependent numerical solutions View full abstract»

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  • On an integral equation approach to the steady-state problem in nonlinear circuits

    Publication Year: 1994 , Page(s): 246 - 247
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (180 KB)  

    Recently [see ibid., vol. 39, p.744-5, 1992] an efficient method for computing the steady-state response in nonlinear circuits was proposed. Additional background information has come to the attention of the authors regarding the general framework of the described research. They wish to point out that Sandberg [see ibid., vol. CAS-31, no. 8, p. 689-701, 1984] has also used the "integral equation" description to study nonlinear systems View full abstract»

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