bluuebunny/crossref_metadata_2025_split huggingface dataset:
A solution for an infinite electrical network arising from various physical phenomena
Authors: Zemanian A. H. , Subramaniam Prasad 
Published: July 2007

AbstractA procedure for determining the currents and voltages in a square or cubic grounded grid, wherein the grounding conductances can differ in quite arbitrary ways, is presented. Such a semi‐infinite electrical network is of practical importance, for it arises naturally from the discretization of a number of physical phenomena. There are very few classes of infinite electrical networks for which computational methods of solution exist; the present work adds one more class to that brief list.
A classification of multiple‐source feedback filters
Authors: Bowron P. , Stephenson F. W. 
Published: July 2007

AbstractA family of two‐amplifier active‐RC filters having a single positive and/or negative‐feedback path is identified and evaluated. Four distinct categories emerge with respect to the input summing‐amplifier arrangement. These are embedded in buffered, differential and allpass‐pair networks to reveal many familiar and new configurations. the selectivity and sensitivity to gain‐bandwidth product are then presented in general expressions capable of describing the performance of all such circuits. Conditions for zero first‐order sensitivities and tuning flexibility are then developed.
A predistortion technique for RC‐active biquadratic filters
Authors: Goodman Ken , Zurada Jacek 
Published: July 2007

AbstractA general method of forcing the transfer function of a biquadratic active filter to have poles/zeros in the desired locations is presented. Examples of the required calculations are shown. an example predistortion of a Thomas‐Tow section has been performed, and the resulting predistorted natural frequency and selectivity are presented graphically for a wide range of q‐factors and amplifier gain‐bandwidth products. the technique has also been applied to the point‐by‐point predistortion of a digitally tuneable filter. the general predistortion method has been used to obtain estimates of frequency and selectivity errors in non‐predistorted filters. the expression for relative q errors agrees with previous high‐q approximations of this error.
A generator of a poisson stream and its engineering applications
Authors: Wulich D. 
Published: July 2007

AbstractA simple method of generating a Poisson stream is proposed. the method is based on the theorem which states that if a normal (Gaussian) and stationary process ‘upcrosses’ a ‘high’ threshold level, then the stream ‘upcrossings’ behave as a Poisson process. It is shown that it is sufficient to take a level equal to 3 xstandard deviation of the normal process (3σ) as the high level. the Poisson stream generator may be built from three blocks: a Gaussian noise generator, a lowpass filter and an ‘upcrossing’ detector. the intensity of the generated Poisson stream depends on the cutoff frequency of the lowpass filter and is proportional to it. Variation of intensity affects the variance of the normal process and, therefore, in a practical realization of the proposed generator, a circuit which automatically keeps the threshold level at 3σ must be added. Some engineering applications of the Poisson stream generator are given.
Analysis of wave switched‐capacitor filters
Authors: Pandel Jürgen , Dawei Huang 
Published: July 2007

AbstractFor a special class of switched‐capacitor filters, the wave SC filters, a very efficient analysis method will be given. It is based on a block partitioning technique, i.e. the whole wave SC network is divided into small subnetworks. Only small matrices have to be processed which saves computation time, so that even large wave SC filters can be analysed very fast and with high accuracy. It will also be shown that the methods can be extended for the analysis of other SC networks. Some numerical examples of different wave SC structures will be given.
A method of design for a class of 2‐D filters
Authors: Prasad K. P. , Unbehauen R. 
Published: July 2007

AbstractThis paper discusses a method of designing quadrantally symmetric cascaded two‐dimensional (2‐D) digital recursive filters by subjecting a one variable approximating function to successive transformations. the needed approximation is done in the one variable domain rather than in the 2‐D domain, hence leading to a large reduction of computational labour. Using cepstral techniques each denominator polynomial is spectrally factorized into recursible non‐symmetric half plane components. A significant feature of the method is in decoupling the problems of approximation and stability. Consequently spectral factorization needs to be performed only once for each denominator polynomial. Effects of truncation on filter stability are minimized by ensuring rapid convergence of cepstra. the choice of an adequate DFT size in cepstral computations is shown to be an important consideration for many problems associated with spectral decomposition. Attempts are also made to stabilize the unstable transfer function using an existing 2‐D discrete Hilbert transform method. Considerable distortion in magnitude characteristics is shown to result on stabilization. Finally the method is illustrated by two examples.
Multifrequency approach to fault diagnosis
Authors: Swamy M. N. S. , Roytman L. M. , Plotkin E. 
Published: July 2007

AbstractThis paper deals with multiple‐fault diagnosis for linear analogue circuits. the proposed approach is based on multifrequency measurements of some voltage (transfer function) at the accessible output port and can be used for multiple‐fault location. It uses certain algebraic invariant properties of the transfer function with respect to the set of faulty elements. Computationally this approach reduces checking the problem of multiple‐fault diagnosis to one of the existence or non‐existence of a common solution of two systems of linear equations; this amounts to the finding of the rank of a matrix. These linear equations are derived via symbolic representation of the measured voltage (transfer function) accessible for measurements. A numerical example of the application of such an approach is given.
Interpolation with positive real functions of several variables
Authors: Gregor J. 
Published: July 2007

AbstractThe interpolation problem for n‐dimensional positive real functions is formulated in two different settings: with interpolation knots either contained on the distinguished boundary of the Cartesian product of open right half planes or in this n‐dimensional ‘open right half plane’. A complete solution of the first problem is given. Necessary conditions of existence of a solution of the second problem are proved and the well known Nevanlinna‐Pick algorithm is generalized so that construction of interpolating n‐dimensional positive real functions becomes possible at least in case when the interpolation knots are real vectors. Examples illustrate the suggested methods, show the complexity and significance of the problem and methods under discussion.Interpolation in special classes of functions has for some time been an important problem in mathematics. General schemes of solution in linear functional spaces with orthogonality are well known. For classes of functions which do not satisfy the axioms of a linear space special methods have been studied in detail, because they are closely connected to other important parts of mathematics such as approximation theory, numerical analysis and the theory of moments. Considerable efforts have been put into interpolation in the complex domain with functions analytic in the unit disc and with positive real functions. the significance of interpolation procedures in the class of one‐variable positive real functions in network theory, e.g. in broadband matching and approximation problems has been recognized in References 1‐3. an excellent survey paper has recently been devoted to these problems;4 in this paper some new ideas for the use of interpolation in system theory were outlined. the growing interest in multivariable network theory calls for generalizations of interpolation procedures to multivariable cases. Many of the one‐variable applications can easily be extended to the multivariable case and it is hoped that in passive network theory and in problems of n‐dimensional digital systems the solution of the interpolation problem will contribute to the difficult synthesis problems in the multivariable theory.In this paper conditions for the existence of multivariable positive real interpolating functions will be investigated and some procedures for the construction of such functions will be described.
A simplified design‐oriented analysis of switched‐capacitor active filters
Authors: Zhou Zhong‐Xuan 
Published: July 2007

AbstractThe method presented in this paper provides a simplified approach to obtain the z‐domain equivalent circuit of an SC active filter by one‐for‐one substitution of each basic SC element with its z‐domain equivalent admittance, if a specific terminal condition is met. Then, traditional circuit analysis techniques can be used to derive the z‐domain transfer function of the filter. This method makes the analysis and the design of the SC active filter simple and similar to the S‐domain method. Two application examples are given.
A generalized, complex adjoint approach to power network sensitivities
Authors: Bandler J. W. , El‐Kady M. A. 
Published: July 2007

AbstractA unified study of the class of adjoint network approaches to power system sensitivity analysis which exploits the Jacobian matrix of the load flow solution is presented. Generalized sensitivity expressions which are easily derived, compactly described and effectively used for calculating first‐order changes and gradients of functions of interest are obtained. These generalized sensitivity expressions are common to all modes of formulating the power flow equations, e.g. polar and Cartesian. the approach exploits a special complex notation and complex matrix manipulations to define the adjoint system and to derive the sensitivity formulae. the approach is applicable to both real and complex function sensitivities.
All‐pole biquadratic filter realization with the minimum ripple due to parameter variations
Authors: Tan M. Ali , Acar Cevdet 
Published: July 2007

AbstractIn this work, the minimization of the ripple in the relative change of the transfer function amplitude due to parameter variations is studied for the signal‐flow graph of the state equations realizing all‐pole second‐order transfer function. First the measure for the ripple is defined and then branch transmittances minimizing the measure are found. the results obtained in this study can be used in all‐pole active filter realizations with the minimum ripple measure.
Synthesis of passive networks containing periodically operated thyristors
Authors: Kropacz Witold S. , Mikolajuk Kazimierz , Tobola Andrzej 
Published: July 2007

AbstractThis paper gives a new approach to the designing of power electronic networks. A method for the determination of passive time‐varying networks is given when time functions of the excitation and response are given. These time functions are periodic. the period is divided into intervals. the network is linear and time‐invariant in each interval. A sequence of the linear time‐invariant networks is realized using switches. Switched windings of a multiport transformer are defined. Such elements enable one to realize the sequence of the linear time‐invariant networks. Conditions for the substitution switches for thyristors are formulated. A structure of a thyristor converter is presented as an example.
Design of switched‐capacitor elements with voltage inverter switches for the simulation of FDNR Reference Structures
Authors: Brückmann Diter 
Published: July 2007

AbstractA number of new elements for switched‐capacitor filters based on voltage inverter switches will be described. the new circuits simulate elements which are obtained from the normally used ones by FDNR transformation. They are insensitive to bottom plate parasitics and the influence of the to plate parasitics can be reduced. No matching is required between any capacitors in the SC circuit, so that the same low sensitivity to element variation holds as for the reference structure. These new elements allow realization of some further filter structures.
A generalized Chebyshev channelizing filter
Authors: Zabalwai Isam H. 
Published: July 2007

AbstractIn this paper some issues concerning the design and implementation of a satellite transponder's channelizing filter of degree 6 are discussed. In particular, the construction of the transmission coefficient, the synthesis procedure and the realization are discussed. the amplitude and the group delay responses of the filter are optimized simultaneously to meet prescribed requirements. the prototype filter has been synthesized as a cross‐coupled array. Explicit formulae for the element values in terms of the real and the imaginary parts of the poles of the transmission coefficient are derived. Single mode direct coupled cavity realization with positive and negative couplings has been developed. an experimental filter has been constructed, the measured responses are very close to the computed ones.
On discrete scattering Hurwitz polynomials
Authors: Fettweis Alfred , Basu Sankar 
Published: July 2007

AbstractDiscrete scattering Hurwitz polynomials play for discrete systems a similar role as scattering Hurwitz polynomials do for classical systems. A number of properties of discrete scattering Hurwitz polynomials are presented. These properties are obtained by deriving them from the corresponding properties of scattering Hurwitz polynomials. This is achieved by considering polynomials associated in a proper way to given polynomials and by examining the nature of the corresponding transformations.
Canonic forms of Brune and Darlington 2n‐ports
Authors: Belevitch V. 
Published: July 2007

AbstractThe Brune and Darlington syntheses for one‐ports have been extended to n‐ports by several authors. the synthesis algorithms are well established and are not discussed in this paper, which is essentially concerned with the minimal realizations (in the total number of elements, including ideal transformers) of the 2n‐ports occurring as building‐blocks in the synthesis. A unified view of that subject is presented, including many new results and a critical survey of the literature. an appendix dealing with the contragradient reduction of a pair of rectangular matrices is of independent algebraic interest.
On solving broadband matching design equations
Authors: Landau P. , Zeheb E. 
Published: July 2007

AbstractAlgorithms are presented which may be applied to:
Determining the real solution set in one variable plane, of a polynomial equation in many variables, where each variable other than the chosen one is confined to given intervals.
Determining the real solution set in one variable plane, of a system of polynomial equations and inequalities, where the number of variables is greater than the number of equations, and each variable other than the chosen one is confined to given intervals.
These algorithms are applied in certain cases of broadband matching design, which presented in the past some numerical difficulties. Illustrative examples are provided.
A very‐low‐frequency block‐digital oscillator
Authors: Acha José I. , Ayerbe Aranzau 
Published: July 2007

AbstractThe development of a block‐digital oscillator when the oscillating frequency fo is very low with respect to the sampling frequency fs is outlined. Explicit relations for the sensitivity to coefficient quantization, for scaling and for mean‐squared round‐off error analysis are derived. the principal conclusion is that both the sensitivity and the mean‐squared round‐off error remain constant and do not depend on the ration fs/fo. Finally, the block oscillator is compared with the scalar oscillator proposed in Reference 7; some numerical results are also included.
Designing non‐linear single OP‐AMP circuits: A cook‐book approach
Authors: Chua L. O. , Ayrom F. 
Published: July 2007

AbstractThe inherent saturation non‐linearity of the op amp is used to design circuits having a wide variety of useful non‐linear v‐i characteristics. These circuits are made of one op amp and 3 or 4 linear resistors which are passive under a rather mild assumption derived from the 3‐port paramountcy condition. Explicit design formulae are given for each prototype circuit and numerous examples are given and validated by actual measurements.
Design of digital filters with maximally flat passband and equiripple stopband magnitude
Authors: Saramäki Tapio 
Published: July 2007

AbstractThis paper introduces a general class of digital filters with maximally flat passband magnitude, equiripple stopband magnitude, and different order numerator and denominator. the classical Chebyschev type II (inverse Chebyschev) filters having equal numerator and denominator orders are considered as special members of this filter class. the filter types to be considered are lowpass, highpass and bandpass. the proposed filter class consists both of filters having all the zeros on the unit circle and of filters having some zeros off the unit circle to contribute to the passband shaping.An efficient iterative algorithm for the design of filters of the given type is presented. It is based on shaping the passband and stopband responses alternately until the difference between successive solutions is within given tolerance limits.Several comparisons show that in wideband applications filters with numerator order higher than denominator order present considerable advantages over equivalent Chebyschev type II designs, in terms of multiplication rate and/or frequency selectivity. In narrowband applications, in turn, filters with higher denominator order are shown to be the most effective.
On a class of SC resistors and its application to the synthesis of non‐linear driving‐point and transfer‐characteristic plots
Authors: Rodriguez‐Vazquez A. , Huertas J. L. , Chua L. O. 
Published: July 2007

AbstractThe use of switched‐capacitor components for designing non‐linear networks is discussed in this paper. We first introduce a new type of network component, the BESC resistor, and consider its application to the design of non‐linear transfer characteristic and driving point plots. Systematic methods for designing piecewise‐linear BESC resistors using switched capacitors are then given. Finally, experimental results showing the performance of the proposed circuits are included.
On the existence and uniqueness of stable quasi‐sinusoidal oscillations
Authors: Buonomo A. , di Bello C. , Greco O. 
Published: July 2007

AbstractConditions are established which ensure the existence and uniqueness of a stable oscillation in quasi‐sinusoidal electronic oscillators of any order. A method is presented whereby both the amplitude and frequency of the oscillation are computed and its stability verified.Examples are given which illustrate how this method can be employed in synthesizing oscillators.
Canonical structures of DC‐AC thyristor converters
Authors: Mikolajuk Kazimierz , Kropacz Witold S. 
Published: July 2007

AbstractRealizability conditions of periodic waveforms in passive switched circuits are presented. Formulae for an identification of state matrices in switched circuits are derived. As input data, time functions of excitation and response are chosen. Six general transformer structures of 1‐port thyristor converters have been obtained as a result of the synthesis method. The synthesis methods presented can be applied to create new thyristor and transistor arrangements, particularly thyristor compensators.
Canonic coupling of oscillators in a ring
Authors: Radparvar K. , Kaplan B. Z. 
Published: July 2007

AbstractThe paper deals with the phenomenon of coupling of several sinusoidal oscillators. The oscillators are arranged in a ring, and each oscillator affects its next neighbour in the ring. The coupling is unilateral and its main effect is due to variations in phase differences between neighbouring oscillators. The simple approach to the treatment of the behaviour of the coupling and the relative simplicity of the models of oscillators participating in the system enable an analytical solution of the problem to be found without a need to resort to complicated approximate methods. The results are supported by computer simulations. Several modes of dynamic behaviour of the system are identified. The number of possible modes increases with the number of oscillators in the ring. The paper concludes by demonstrating that the present results possess a potential of being useful in analysing some technological and natural systems.
Large change sensitivity analysis in linear systems using generalized householder formulae
Authors: Bandler J. W. , Zhang Q. J. 
Published: July 2007

AbstractThis paper investigates multiparameter large change sensitivity problems in linear systems by a set of generalized Householder formulae. The newly developed rectangular formulae can accommodate large, small and zero parameter changes directly by avoiding a critical matrix inversion as compared to the traditional square formulae. Possible determination of a minimum order reduced system, whose solution procedure constitutes the major work in large change evaluation is discussed. Applications to linear systems are considered for the original and adjoint systems w.r.t. single as well as multiple input‐output cases. This approach makes it possible to use large change analysis algorithms even if many parameters are changed.
Synthesis of recursive digital filters by state feedback of non‐recursive cascaded lattice filters
Authors: Feng Z. , Unbehauen R. 
Published: July 2007

AbstractA general method to realize any digital transfer function is presented. The method is understood as a two‐stage process. First, a non‐recursive system having the same transfer zeros as the given transfer function is synthesized in the form of a special cascaded lattice structure. Then the poles of the non‐recursive system, which occur exclusively at the origin, are shifted by extending this system through state feedback so that the shifted poles coincide with the poles of the specified transfer function while the transfer zeros remain unchanged.1 Compared with the well‐known cascaded lattice structures proposed by Mitra et al.2 the resulting filters exhibit advantages in the realization of the adders. Furthermore, it is pointed out how the cascaded lattice structure2 can be derived from the structure introduced here by applying a state transformation.
One‐dimensional orthogonal search—a method for a segment approximation to acceptability regions
Authors: Ogrodzki Jan 
Published: July 2007

AbstractAs is well known, computer‐aided design methods that make use of specific properties of the networks being solved are much more efficient than general approaches suitable for very large classes of problems. In this paper an approach to acceptability regions, grounded on the bilinear theorem convenient for linear networks, is studied. Thanks to the bilinearity, exact analytical solutions on first‐order linear manifolds in the parameter space, i.e. when only one parameter is being changed at time, are available. This so‐called one‐dimensional orthogonal search (ODOS) has been applied to a segment approximation of acceptability regions. This approach lead; to spectacular results concerning shapes of acceptability regions, applicable in fundamental design problems.
Fault diagnosis of non‐linear systems: Graphical approach to detectability, distinguishability and diagnosis algorithm
Authors: Maeda Hajime , Ohta Yoshito , Kodama Shinzo , Takeda Shoichi 
Published: July 2007

AbstractThis paper discusses the problem of fault diagnosis for non‐linear systems described by a set of non‐linear algebraic equations. Necessary and sufficient conditions for fault detectability and fault distinguishability are given as analytic conditions, as well as graphical conditions. These conditions are then used to derive an algorithm for fault diagnosis. The technique is illustrated by an example.