Jacques Neirynck

Autonomous cellular neural networks: a unified paradigm for pattern formation and active wave propagation

This tutorial paper proposes a subclass of cellular neural networks (CNN) having no inputs (i.e., autonomous) as a universal active substrate or medium for modeling and generating many pattern formation and nonlinear wave phenomena from numerous disciplines, including biology, chemistry, ecology, engineering, and physics. Each CNN is defined mathematically by its cell dynamics (e.g., state equations) and synaptic law, which specifies each cells interaction with its neighbors. We focus on reaction-diffusion CNNs having a linear synaptic law that approximates a spatial Laplacian operator. Such a synaptic law can be realized by one or more layers of linear resistor couplings. An autonomous CNN made of third-order universal cells and coupled to each other by only one layer of linear resistors provides a unified active medium for generating trigger (autowave) waves, target (concentric) waves, spiral waves, and scroll waves. When a second layer of linear resistors is added to couple a second capacitor voltage in each cell to its neighboring cells, the resulting CNN can be used to generate various turing patterns. >

A new method for solving broadband matching problems

Keywords: Non-Linear Signal Processing Reference LANOS-CONF-1993-012 Record created on 2004-12-03, modified on 2016-08-08

New broadband‐matching circuit

Keywords: Non-Linear Signal Processing Reference LANOS-ARTICLE-1994-001 Record created on 2004-12-03, modified on 2017-05-12

Simplified impedance broadband matching by the image parameter method: The RC case

Reference LANOS-ARTICLE-1995-005View record in Web of Science Record created on 2004-12-03, modified on 2017-05-12

General formulas for the ideal flat gain in the case of double broadband matching

The objective of this article is the determination of the optimal flat gain level in the case of double broadband matching, through the use of the integral relations. It is shown how these integral relations can be established by using Cauchys integrals in a way similar to Fanos [1950] and Fielders [1961] methods, but also involving the polynomial formalism.<<ETX>>

A simplified real frequency computation method for broadband matching

The authors present a new method for computing the component values of LC ladder equalizers for broadband matching purposes. The method is inspired by the theory of recursive identification and results in a very compact algorithm. The load has to be known only at a small number of frequencies. Starting from an assumed topology for the equalizer with small random values for the components, the equalizer components are iteratively built to satisfy asymptotically a least mean-square criterion. The method is based on the theory of recursive approximation. The key parameter which must be calculated is the transducer power gain sensitivity with respect to the components of the equalizer. As the vector of sensitivities can be found with ease using two networks the recursive method turns out to be very simple. This is an advantage compared with the great complexity of other known methods, notably Carlins real frequency technique and the Yarman and Fettweis parametric technique.<<ETX>>

Application de Prolog à la détermination exhaustive des cellules biquadratiques à facteurs de qualité infinis

AnalyseCet article propose une nouvelle méthode de recherche pour des cellules biquadratiques qui s’appuie sur l’utilisation du langage Prolog qui permet de créer un programme débrouillant le grand nombre de cas possibles. L’article décrit seize cellules optimales extraites d’un ensemble de plus de deux millions de cellules. Ces seize cellules répondent à un ensemble de conditions réalistes mais hétérogènes, qui rendent très difficile l’approche algébrique.AbstractThis paper proposes here a new method for seeking biquadratic cells. The language Prolog is used to create a programe which searches the large number of possible cases. This article describes sixteen optimal cells which have been selected from a set of more than two million cells. These sixteen cells comply with a set of realistic but dissimilar requirements, which would make an algebraic approach very difficult.

Double broadband matching of a lowpass generator and a lowpass load by equal minima gain functions

By using the polynomial formalism, the gain-bandwidth restrictions will be established in the case of the double broadband matching of an RL generator impedance and an RLC load. By using an automatic procedure based on the Gauss-Newton algorithm, the optimal equal minima gain function will be determined and compared to the Chebyshev and real frequency solutions. It will be shown how the equal minima method can be extended.<<ETX>>

Design Methods for the Classical Filter

The paper describes the central concept of a classical filter which is defined by the following features: a lossless 2-port between resistive terminations; individually tunable attenuation poles; as many attenuation zeroes as feasible. This set of three conditions has an unexpected side result: the unsensitivity of the filter to variations of its components up to the first order. This explains a posteriori why it was possible to build, during fifty years, filters out of coils and condensers which were relatively imprecise, subject to aging and temperature effects. The concept of the classical filter emerged when the designers tried to depart from this solution. The first attempts to build RC active filters were total failures till the designers learned to simulate the classical filter. Hence this concept has an interest in its own right and it transcends the border between lumped and distributed circuits.