In this paper we prove that, over a Hilbertian ground field, surfaces with two conic fibrations whose fibres have non-zero intersection product the Hilbert property. We then give an application of result, namely verification property for certain del Pezzo varieties.

We show consistency in the mean integrated quadratic sense of an estimator of the autocorrelation operator in the autoregressive Hilbertian of order one model. Two main cases are considered, and we obtain upper bounds for the corresponding rates. c © 2001 Elsevier Science B.V. All rights reserved MSC: 62G05; 62M10

In this paper we consider random sequences in the background of which specific shorttime random elements can emerge. The theory and constructive methods for recognition of shorttime specific random elements that may emerge in the background of random sequences are expounded. The results of experimental investigations are presented. The prospects for a wider application of the results obtained a...