The context-tree weighting method (Willems, Shtarkov, and Tjalkens [1995]) is a sequential universal source coding method that achieves the Rissanen lower bound [1984] for tree sources. The same authors also proposed context-tree maximizing, a two-pass version of the context-tree weighting method [1993]. Later Willems and Tjalkens [1998] described a method based on ratios (betas) of sequence pr...

Dental age is a somatic maturity indicator with importance in clinical and forensic dentistry. The purpose of this study is to compare the applicability of the Demirjian and Willems methods for dental age estimation in a group of Venezuelan children. Panoramic radiographs of 238 Venezuelan children aged 5-13 years were used to assess dental age using the methods described by Demirjian and Wille...

In this article, we study the problem of estimation in presence disturbances within context behavioral approach developed by J.C. Willems. For purpose, use theory observers introduced Valcher, Willems, Trentelman, and Trumpf, combined with notions invariance, conditioned detectability subspaces. With these tools, provide necessary sufficient conditions for solvability aforementioned together co...

In this paper we prove four cases of the vanishing conjecture of differential operators with constant coefficients and also a conjecture on the Laurent polynomials with no holomorphic parts, which were proposed in [Zh3] by the third named author. We also give two examples to show that the generalizations of both the vanishing conjecture and the Duistermaat-van der Kallen theorem [DK] to Laurent...

Dobbertin, Mills, M\"uller, Pott and Willems conjecture that two families of power mapping are families of APN functions. Here we prove those two conjectures.

The space of rational matrices with xed size and degree is shown to have a manifold structure with bers over a Grassmannian. The bers are homeomorphic to a suitable space of strictly proper rational matrices. This structure is compatible with Willems' partition of external variables into inputs and outputs.

The notion of behaviors introduced by Willems gives a good description of dynamical systems without reference to any particular representation of the system in terms of equations. In this note, we introduce a notion of behaviors that allows us to describe singular systems in a very natural way. The new deenition of behaviors given here is closely related to that of a sheaf over the projective l...

The aims of this study were: first, to determine the accuracy of the Cameriere method for assessing chronological age in children based on the relationship between age and measurement of open apices in teeth and, second, to compare the accuracy of this method with the widely used Demirjian et al. method and with the method proposed by Willems et al. Orthopantomographs taken from white Italian, ...

W Balemans, N Patel, M Ebeling, E Van Hul, W Wuyts, C Lacza, M Dioszegi, F G Dikkers, P Hildering, P J Willems, J B G M Verheij, K Lindpaintner, B Vickery, D Foernzler, W Van Hul . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...