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Structure theorems for nonlinear systems

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Abstract

One of the main results is a proposition to the effect that under some typically mild conditions finite sums of the form

$$\sum\limits_\ell {K_\ell \sigma } \left[ {\sum\limits_m {\eta _{\ell m} Q_m (\cdot) + \rho _\ell } } \right]$$

are dense in an important sense in the set of shift-invariant approximately-finite-memory mapsG(·) that take a certain type of subsetU ofR intoR, whereR is the set of real-valued functions defined onR n orZ n. Here theQ m (·) are linear, σ is any element of a certain set of nonlinear maps fromR toR, and the κ, ρ, and ηℓm are real constants. Approximate representations comprising only affine elements and lattice nonlinearities are also presented.

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Sandberg, I.W. Structure theorems for nonlinear systems. Multidim Syst Sign Process 2, 267–286 (1991). https://doi.org/10.1007/BF01952236

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  • DOI: https://doi.org/10.1007/BF01952236

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