Keldysh Institute of Applied Mathematics

About: Keldysh Institute of Applied Mathematics is a facility organization based out in Moscow, Russia. It is known for research contribution in the topics: Plasma & Computer science. The organization has 1843 authors who have published 3911 publications receiving 28977 citations. The organization is also known as: Federal State Institution of Science Institute of Applied Mathematics. Keldysh of the Russian Academy of Sciences.

Estimation of the Distance between True and Numerical Solutions

Abstract: Given an ensemble of numerical solutions generated by different algorithms that are guaranteed to have different errors, the triangle inequality is used to find a neighborhood of a numerical solution that contains the true one. By analyzing the distances between the numerical solutions, the latter can be ranged according to their error magnitudes. Numerical tests for the two-dimensional compressible Euler equations demonstrate the possibility of comparing the errors of different methods and determining a domain containing the true solution.

On the normal mode instability of modons and Wu-Verkley waves

Abstract: The normal mode instability of steady Wu-Verkley (1993) wave and modons by Verkley (1984, 1987, 1990) and Neven (1992) is considered. All these flows are solutions to the vorticity equation governing the motion of an ideal incompressible fluid on a rotating sphere. A conservation law for infinitesimal perturbations to each solution is derived and used to obtain a necessary condition for its exponential instability. By these conditions, Fjortoft's (1953) average spectral number of the amplitude of an unstable mode must be equal to a specific number that depends on the degree of the solution in its inner and outer regions as well as on spectral distribution of the mode energy in these regions. Some properties of the conditions for different types of modons are discussed. The maximum growth (and decay) rate of the modes is estimated, and the orthogonality of the amplitude of each unstable, decaying, or non-stationary mode to the basic solution is shown in the energy inner product. The new instabilit...

Transparent Boundary Conditions for the Elastic Waves in Anisotropic Media

Abstract: •A novel approach to generate numerical LRBCsfor anisotropic time-domain wave propagation problems is proposed and implemented in 2D•LRBCsare efficient in both isotropic and anisotropic media, including the case where PML approach fails (case IV)•LRBC operator does not depend on the meshing inside the computational domain•LRBC efficiency (amplitude of reflected waves) can be automatically controlled during generation of the operator•It is possible to generate in advance a library of LRBC matrices for given media parameters and geometry of computational domain•The algorithm is highly parallelized

One-Dimensional Interpolation Inequalities, Carlson–Landau Inequalities, and Magnetic Schrödinger Operators

Abstract: In this paper we prove refined first-order interpolation inequalities for periodic functions and give applications to various refinements of the Carlson--Landau-type inequalities and to magnetic Schrodinger operators. We also obtain Lieb-Thirring inequalities for magnetic Schrodinger operators on multi-dimensional cylinders.

Walking Mobile Robot with Manipulator-Tripod

Abstract: This paper describes the design of an autonomous mobile robot of a small class, equipped with manipulator-tripod with a swivel block. The robot movements software optimization methods are shown here. The positional problem of manipulator pickup device changing over from the starting position to the set finite one was solved. The trajectory and the law of motion along the trajectory from the minimum pickup device acceleration were synthesized.