title: Instantaneous characterization of time-varying nonlinear systems.
abstract: A nonlinear system may be characterized by an orthogonal functional power series (FPS) computed from cross correlations between input and output variables. "Is the response changing over the course of the experiment?" is a fundamental question encountered in the analysis of both FPS and evoked potentials (EP's). Regression on closed-form functions of time produces a time-varying FPS or EP. Evaluation of these functions at a specified time point produces a system characterization for that instant.
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh, PA 15213.
authors.forename: D
authors.initials: D
authors.lastname: Krieger
authors.forename: T W
authors.initials: TW
authors.lastname: Berger
authors.forename: R J
authors.initials: RJ
authors.lastname: Sclabassi
mesh_terms: D005071:Evoked Potentials; D006801:Humans; D008433:Mathematics; D008959:Models, Neurological; D016012:Poisson Distribution; D012044:Regression Analysis; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors