The theory of adjoint operators is widely used in solving applied multidimensional problems with the Monte Carlo method. Efficient algorithms are constructed using duality principle for many described linear integral equations second kind. On other hand, important applications designing experiments were suggested by G.I. Marchuk and his colleagues their respective works. Some results obtained t...

this paper presents characterizations of m-fuzzifying matroids bymeans of two kinds of fuzzy operators, called m-fuzzifying derived operatorsand m-fuzzifying difference derived operators.

Building on the abstract notion of prolongation developed in [10], the theory of iterative Hasse-Schmidt rings and schemes is introduced, simultaneously generalising difference and (Hasse-Schmidt) differential rings and schemes. This work provides a unified formalism for studying difference and differential algebraic geometry, as well as other related geometries. As an application, Hasse-Schmid...

We are interested in a rigorous derivation of the Kuramoto–Sivashinsky (K-S) equation from a free boundary problem. As a paradigm, we consider a two-dimensional Stefan problem in a strip, a simplified version of a solid-liquid interface model. Near the instability threshold, we introduce a small parameter ε and define rescaled variables accordingly. At fixed ε, our method is based on: definitio...

Abstract. Starting from a general operator representation in the time-frequency domain, this paper addresses the problem of approximating linear operators by operators that are diagonal or band-diagonal with respect to Gabor frames. A characterization of operators that can be realized as Gabor multipliers is given and necessary conditions for the existence of (Hilbert-Schmidt) optimal Gabor mul...

Starting from a general operator representation in the time-frequency domain, this paper addresses the problem of approximating linear operators by operators that are diagonal or band-diagonal with respect to Gabor frames. A characterization of operators that can be realized as Gabor multipliers is given and necessary conditions for the existence of (Hilbert-Schmidt) optimal Gabor multiplier ap...

A new criterion for selective reorthogonalization in the Gram-Schmidt procedure is given. We establish its comportment in presence of rounding errors when the criterion is used with modified Gram-Schmidt algorithm and show counter-example matrices which prove that standard criteria are not always valid. Experimentally, our criterion is fine also for the classical Gram-Schmidt algorithm with reo...

This paper deals with the pole-zero identification of a linear system from a measured input-output record. It is shown that the minimization of a modified version of the squared Kalman equation error can be implemented by an order recursive algorithm in the time domain. The algorithm is based on the Gram-Schmidt orthogonaliza-tion of intertwined Krylov sequences involving a skew self-adjoint li...

Finite-difference simulations of fluid dynamics and magnetohydrodynamics generally require an explicit diffusion operator, either to maintain stability by attenuating gridscale structure, or to implement physical diffusivities such as viscosity or resistivity. If the goal is stability only, the diffusion must act at the grid scale, but should affect structure at larger scales as little as possi...

Recently, Brodsky, Hwang and Schmidt have proposed a newmechanism that gives a transverse spin symmetry at leading twist in semiinclusive deep-inelastic scattering. I show that the new mechanism is compatible with factorization and is due to an transverse-spin asymmetry in the kT distribution of quarks in a hadron (the “Sivers asymmetry”). An earlier proof that the Sivers asymmetry vanishes bec...