Multidimensional Perception

http://portal.acm.org/citation.cfm?id=1938466.1938468

Multidimensional causality and passivity of linear and nonlinear systems arising from physics

Authors: Alfred Fettweis Lehrstuhl fuer Nachrichetntechnik, Ruhr Universitaet, Bochum, Germany 44780 Sankar Basu National Science Foundation, Arlington, USA 22101 Published in: · Journal Multidimensional Systems and Signal Processing archive Volume 22 Issue 1-3, March 2011 Kluwer Academic Publishers Hingham, MA, USA table of contents doi>10.1007/s11045-010-0135-y

We start with the general notions of causality, passivity, losslessness and related concepts for a class of multidimensional systems, in particular with multidimensional causality and passivity, arising from physical considerations. While such definitions are nowhere restricted to linear systems we show that when applied to linear systems with constant parameters (coefficients) they boil down to standard notions of passivity described by positive real functions and matrices, or equivalently, by bounded real functions and matrices in several complex variables.