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

Issue 1 • Date Jan. 1992

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Displaying Results 1 - 12 of 12
  • Comment, with reply, on "Vertex implications of stability for a class of delay-differential interval system" by K.D. Kim and N.K. Bose

    Page(s): 68 - 70
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (234 KB)  

    The commenters disagree with the claim by K.D. Kim and N.K. Bose (see ibid., vol.37, no.7, p.969-972, 1990) that for an important special case of delay-differential systems when the characteristic equation is describable by certain quasi-polynomials, the vertex implication for stability does hold. The commenters show that this claim is not true. What may be true is that the vertex implication holds for the very limited case of systems which are known as stable independent of delay. The authors' reply is included.<> View full abstract»

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  • Low-sensitivity SC simulation of reactance E-type zero producing section

    Page(s): 59 - 63
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (316 KB)  

    A method for the switched-capacitor implementations of D and E-type zero producing reactance sections of the distributed prototype reference network is described. The main feature of this approach is its complete insensitivity with respect to bottom plate parasitics and low sensitivity as far as top plate parasitics are concerned. Apart from its simplicity, demonstrated by having the capacitance ratios directly related to the element values of the prototype reference network, it has the advantage of yielding low C max/Cmin. An illustrative example is given View full abstract»

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  • Theoretical analysis of a coherent phase synchronous oscillator

    Page(s): 11 - 18
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (536 KB)  

    The synchronous oscillator (SO) is a network capable of recovering signals down to -100 dBm. Its output amplitude is independent of the input amplitude and is constant. Without an input signal, the SO free runs at a frequency ω0, determined by the L- C-C tank parameters. The coherent phase synchronous oscillator (CPSO) is a modification of the SO and retains the SO properties of high noise rejection and fast acquisition time. Advantages of the CPSO are a coherent signal acquisition and a much wider tracking bandwidth. An analysis of the SO and CPSO is performed to explain the coherent signal processing that occurs in the CPSO. Such an analysis also sheds light on the design and calibration of the CPSO View full abstract»

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  • A polynomial time algorithm for the computation of the iteration-period bound in recursive data flow graphs

    Page(s): 49 - 52
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (324 KB)  

    Rate-optimal scheduling of iterative data-flow graphs requires the computation of the iteration period bound. According to the formal definition, the total computational delay in each directed loop in the graph has to be calculated in order to determine that bound. As the number of loops cannot be expressed as a polynomial function of the number of modes in the graph, this definition cannot be the basis of an efficient algorithm. A polynomial-time algorithm for the computation of the iteration period bound based on longest path matrices and their multiplications is presented View full abstract»

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  • A simple configuration for realizing voltage-controlled impedances

    Page(s): 52 - 59
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (508 KB)  

    A simple configuration is proposed that incorporates an effective cancellation of the nonlinearity of the VDS-i D characteristics of the FET to produce a voltage-controlled resistance (VCR) with linear range considerably more extended than other conventional FET-based VCRs. The configuration is shown to be simpler than op-amp-JFET based VCRs yet is more versatile than the previously known circuits. It makes possible the realization of VCC and VCL elements from the same configuration, which cannot be realized from the earlier circuits. CMOS versions of the proposed schemes of the VCC and VCL are suggested View full abstract»

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  • A new method for solving the polynomial generalized Bezout identity

    Page(s): 63 - 65
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    Several formulas for finding the polynomial generalized Bezout identity solutions are derived. To obtain the elements, one need only construct a controller-form realization, determine a real number, solve a pole-assignment problem, and perform some algebraic manipulations. The results allow one to compute the generalized Bezout identity elements with existing software packages View full abstract»

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  • Approximations for nonlinear functions

    Page(s): 65 - 67
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    Results concerning the uniform approximation of nonlinear functionals on compact sets are discussed. The results are of interest in connection with neural network-like classifiers for continuous-time signals and approximations for the input-output maps of dynamic systems. It is shown that function-space feedforward neural networks with one input layer of bounded linear functionals and one hidden nonlinear layer each are universal approximators of real continuous functionals on compact subsets of a normed linear space View full abstract»

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  • Conjugate gradient techniques for adaptive filtering

    Page(s): 1 - 10
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (720 KB)  

    The application of the conjugate gradient technique for the solution of the adaptive filtering problem is discussed. An algorithm that does not require a line search or a knowledge of the Hessian is developed based on the conjugate gradient method. The choice of the gradient average window in the algorithm is shown to provide a trade-off between computational complexity and convergence performance. The method is capable of providing convergence comparable to recursive least squares (RLS) schemes at a computational complexity that is intermediate between the least mean square (LMS) and the RLS methods and does not suffer from any known instability problems View full abstract»

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  • Analytical transient response of CMOS inverters

    Page(s): 42 - 45
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    A general formula relating the waveform at the output of a CMOS inverter to the waveform at its input is derived. The formula is applied to three cases: a step input, a ramp input, and an exponential input. A one-dimensional function dependence of the inverter propagation delay and output slew rate on circuit parameters is derived and an inverter macromodel for timing analysis is suggested and experimentally verified View full abstract»

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  • The undirected de Bruijn graph: fault tolerance and routing algorithms

    Page(s): 45 - 48
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (372 KB)  

    The undirected version of the de Bruijn graph, also called the shift-and-replace graph, has N=kn vertices, maximum degree k, and minimum degree k-2. A.H. Esfahanian and S.L. Hakimi (1985) have shown that this graph has diameter n=logkN, connectivity 2k-2, and has an increase in diameter of at most logkn+4 in the presence of up to 2k-3 fault vertices. The author tightens this bound significantly. It is shown that the increase in the diameter of this graph is at most logklog φn+6+logk5, where φ is the golden ratio. The methods used draw upon the theory of string overlaps and the theory of finite automata View full abstract»

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  • A model reduction method for a class of 2-D systems

    Page(s): 28 - 41
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    A decomposition-aggregation scheme for reduction of dimensionality for a class of 2-D systems is introduced. This method, which is based upon the extension of the singular perturbation method in two dimensions, is used to decompose the original 2-D system into two reduced-order 2-D subsystems. These reduced order subsystems are shown to effectively capture the dynamical behavior of the original full-order system. Two numerical examples are provided that indicate the effectiveness of this method when used in image modeling applications View full abstract»

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  • Device modeling by radial basis functions

    Page(s): 19 - 27
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    An alternative modeling technique that works directly from data and provides a straightforward and relatively automatic method of interpolating smoothly from measurements is presented. Since the results are nonexplicit (that is, the models are algorithmic rather than analytic), the approach is likely to be most appropriate in situations where it is difficult to derive an explicit functional form analogous to the Ebers-Moll equation for bipolar transistors. A good example is in the modeling of submicron devices in VLSI circuits, where the relevant device physics are currently poorly understood View full abstract»

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