For realcompact spaces X and Y we give a complete description of the linear biseparating maps between spaces of vector-valued continuous functions on X and Y , where special attention is paid to spaces of vector-valued bounded continuous functions. These results are applied to describe the linear isometries between spaces of vector-valued bounded continuous and uniformly continuous functions.

We show that a pointwise convergent sequence (n) n2IN of continuous collineations of a compact projective plane converges uniformly if and only if the pointwise limit of (n) n2IN has a quadrangle in its image. Moreover is then a continuous collineation. Furthermore, we derive that a homomorphism between topological projective planes is continuous if and only if it is continuous at some point.

Article history: Received 2 April 2014 Available online 2 July 2014 Submitted by P. Nevai

In this note we state some results concerning the perturbation problem of strongly continuous semigroups on a Banach space X and provide some new characterizations of the uniformly continuous semigroups on X.

This contribution reviews theory, algorithms, and validation results for system identification of continuous-time state-space models from finite inputoutput sequences. The algorithms developed are autoregressive methods, methods of subspace-based model identification and stochastic realization adapted to the continuous-time context. The resulting model can be decomposed into an input-output mod...