We consider graph properties that can be checked from labels, i.e., bit sequences, of logarithmic length attached to vertices. We prove that there exists such a labeling for checking a first-order formula with free set variables in the graphs of every class that is nicely locally clique-width-decomposable. This notion generalizes that of a nicely locally tree-decomposable class. The graphs of s...

Maximal elements of a binary relation on compact subsets of a metric space define a choice function. An infinite extension of transitivity is necessary and sufficient for such a choice function to be nonempty-valued and path independent (or satisfy the outcast axiom). An infinite extension of acyclicity is necessary and sufficient for the choice function to have nonempty values provided the und...

We consider finite volume methods for the numerical solution of conservation laws. In order to achieve high-order accurate numerical approximation to non-linear smooth functions, we introduce a new class of limiter functions for the spatial reconstruction of hyperbolic equations. We therefore employ and generalize the idea of double-logarithmic reconstruction of Artebrant and Schroll [R. Artebr...

We present a fourth order compact nite diierence scheme on the face centered cubic (FCC) grids for the numerical solution of the two dimensional convection diiusion equation. The seven point formula is deened on a regular hexagon, where the strategy of directional derivative is employed to make the derivation procedure straightforward, eecient, and concise. A corresponding multigrid method is d...

This paper presents the results of using high-order compact schemes with a high-order filter on multi-block domains. The Linearized Euler Equations (LEE) are solved on a uniform mesh for benchmark problems in one and two dimensions. Also a two dimensional mixing layer is solved by using LargeEddy Simulation (LES). Three different boundary schemes are compared. The results compare well with the ...

In this note we characterize the compact weighted Frobenius-Perron operator $p$ on $L^1(Sigma)$ and determine their spectra. We also show that every weakly compact weighted Frobenius-Perron operator on $L^1(Sigma)$ is compact.

in this paper, a complete description concerning linear operators of banach spaces with range in lipschitz algebras $lip_al(x)$ is provided. necessary and sufficient conditions are established to ensure boundedness and (weak) compactness of these operators. finally, a lower bound for the essential norm of such operators is obtained.

the purpose of this paper is to introduce the concept of pairwise f-closedness in bitopological spaces. this space contains both of pairwise strongcompactness and pairwise s-closedness and contained in pairwise quasi h-closedness. the characteristics and relationships concerning this new class ofspaces with other corresponding types are established. moreover, several ofits basic and important p...

A three-point nonuniform combined compact difference (NCCD) scheme with sixth-order accuracy is proposed for numerical models. The NCCD scheme is a generalization of the previously proposed combined compact difference (CCD) scheme with a global Hermitan polynomial spline and has major improved features such as error and computational (CPU) time reduction. For nonperiodic boundaries, additional ...