Search results for "Transform"

Methods of Digital Hilbert Optics in the Analysis and Objects’ Recognition

2016

This paper describes methods on how to increase the effectiveness of objects’ pictures identification based on correlation methods. The main concept of increasing the discriminant effectiveness is based on highlighting of characteristic points of recognized objects by applying Hilbert transformations. Study of the effectiveness of Digital Hilber Optics (DHO) have been performed on a set of aircrafts, whose models rendered first as binary images, and then as grayscale. It has been performed a very detailed analysis of requirements on resources of information system’s which would in a real world support the discriminatory decision of objects’ class for which the sample database has been creat…

Overlapping self-affine sets of Kakeya type

2009

We compute the Minkowski dimension for a family of self-affine sets on the plane. Our result holds for every (rather than generic) set in the class. Moreover, we exhibit explicit open subsets of this class where we allow overlapping, and do not impose any conditions on the norms of the linear maps. The family under consideration was inspired by the theory of Kakeya sets.

Positivity, complex FIOs, and Toeplitz operators

2018

International audience; We establish a characterization of complex linear canonical transformations that are positive with respect to a pair of strictly plurisubharmonic quadratic weights. As an application, we show that the boundedness of a class of Toeplitz operators on the Bargmann space is implied by the boundedness of their Weyl symbols.

Rigidity of quasisymmetric mappings on self-affine carpets

2016

We show that the class of quasisymmetric maps between horizontal self-affine carpets is rigid. Such maps can only exist when the dimensions of the carpets coincide, and in this case, the quasisymmetric maps are quasi-Lipschitz. We also show that horizontal self-affine carpets are minimal for the conformal Assouad dimension.

Invariant deformation theory of affine schemes with reductive group action

2015

We develop an invariant deformation theory, in a form accessible to practice, for affine schemes $W$ equipped with an action of a reductive algebraic group $G$. Given the defining equations of a $G$-invariant subscheme $X \subset W$, we device an algorithm to compute the universal deformation of $X$ in terms of generators and relations up to a given order. In many situations, our algorithm even computes an algebraization of the universal deformation. As an application, we determine new families of examples of the invariant Hilbert scheme of Alexeev and Brion, where $G$ is a classical group acting on a classical representation, and describe their singularities.

Canonical Perturbation Theory with Several Degrees of Freedom

2001

We extend the perturbation theory of the previous chapter by going one order further and permitting several degrees of freedom. So let the unperturbed problem H0(J k 0) be solved.

Analytic high-order Douglas–Kroll–Hess electric field gradients

2007

In this work we present a comprehensive study of analytical electric field gradients in hydrogen halides calculated within the high-order Douglas-Kroll-Hess (DKH) scalar-relativistic approach taking picture-change effects analytically into account. We demonstrate the technical feasibility and reliability of a high-order DKH unitary transformation for the property integrals. The convergence behavior of the DKH property expansion is discussed close to the basis set limit and conditions ensuring picture-change-corrected results are determined. Numerical results are presented, which show that the DKH property expansion converges rapidly toward the reference values provided by four-component met…

Some contributions to the theory of transformation monoids

2019

The aim of this paper is to present some contributions to the theory of finite transformation monoids. The dominating influence that permutation groups have on transformation monoids is used to describe and characterise transitive transformation monoids and primitive transitive transformation monoids. We develop a theory that not only includes the analogs of several important theorems of the classical theory of permutation groups but also contains substantial information about the algebraic structure of the transformation monoids. Open questions naturally arising from the substantial paper of Steinberg [A theory of transformation monoids: combinatorics and representation theory. Electron. J…

Clause de réserve de propriété. Charge de la preuve de l'existence en nature des marchandises revendiquées, Conséquences du défaut d'inventaire

1992

International audience; (Com. 1er oct. 1991, Aubert ès qualité c/ Soc. Félice Tabasso)

Chemotactic migration of human diploid fibroblasts is inhibited by contactinhibin.

1992