A collection of functions addressing various modelling problems for nonlinear control systems has been developed in Mathematica environment. The mathematical apparatus behind the programs is based on the theory of non-commutative skew polynomial rings. The functions described in paper allow to find the state-space realization of the set of input-output equations, reduce the system equations, co...

In this paper the structural controllability of a class of a nonlinear system is investigated. The transfer function (matrix) of nonlinear systems is obtained by putting the nonlinear system model on non-commutative ring. Conditions of structural controllability of nonlinear systems are presented according to the criterion of linear systems structural controllability in frequency domain. An exa...

conclusions this study highlights the close link between the role of the phrenic nerve and pulmonary function, such that the use of this nerve as a transfer donor leads to spirometric impairments. results all patients regained biceps power to m3 strength or above. none of our patients experienced pulmonary problems or respiratory complaints, but a significant reduction of spirometric parameters...

In this article, a special type of orthogonalization is obtained to construct a multiple input transfer function model. By using this technique, construction of a transfer function model is divided to sequential construction of transfer function models with less input time series. Furthermore, based on real and simulated time series we provide an instruction to adequately perform the stages of ...

This paper introduces a new class oj simple nonlinear PID-type controllers comprised of a sector-bounded nonlinear gain in cascade with a linear fixed-gain P, PD, PI, or PID controller. Three simple nonlinear gains are proposed: the sigmoidal function, the hyperbolic function, and the piecewise-linear function. The systems to be controlled are assumed to be modeled or approximated by second-ord...

A method for the analysis of transmission electron microscopy diffractograms for determination of the phase contrast transfer function (PCTF) is presented. This is accomplished by pattern recognition methods together with a nonlinear regression method using apriori knowledge about diffractogram shapes and results in an automatic computation of defocus and astigmatism parameters. Other applicati...

The Multivariable Continuous-time Generalised Predictive Controller (CGPC) is recast in a state-space form and shown to include Gen-eralised Minimum Variance (GMV) and an new algorithm, Predictive GMV (PGMV) as special cases. Comparisons are drawn with the exact linearisation methods of nonlinear control and it is noted that the state-space approach extends readily to the nonlinear case. The re...

A, k, q are known constants. Equation (1) is of the type which arises in problems of heat flow when there is an internal generation of heat within the medium; if the heat is due to a chemical reaction proceeding at each point at a rate depending upon the local temperature, the rate of heat generation is often defined by an equation such as (2). The presence of the non-linear term q(Ow/at) in (1...

In this paper we examine the stability of an irrigation canal system. The system considered is a single reach of an irrigation canal which is derived from Saint-Venant’s equations. It is modelled as a system of nonlinear partial differential equations which is then linearized. The linearized system consists of hyperbolic partial differential equations. Both the control and observation operators...

The notion of realization for single-input single-output nonlinear systems is studied based on a new notion of input/output equivalence. This equivalence relation aims to generalize the equivalence of linear time-invarian t systems in the sense of the equality of their transfer functions. Necessary and suÆcient conditions are given for the existence of a realization, aÆne or not. A minimal (i.e...