Simulated annealing (SA) is a stochastic optimization method with principles taken from the physical process called “annealing” which aims to bring a solid to its ground state or state of minimum energy. SA is known as a simple heuristic tool suitable for providing direct or approximate...

The authors of the paper together with their colleagues have developed and applied a software complex based on the computer algebra system (CAS) ”Mathematica” [1], which allows to model mechanical systems, conduct qualitative investigations and solve some problems of both rigid body...

We investigate the stability of nontrivial nonnegative stationary solutions of semilinear initial-boundary value problems with convex or concave nonlinearity. In the convex case (0)⩽0 implies instability, in the concave case (0)⩾0 implies stability. We also discuss the necessity of the sign...

Let () be a differentiable function on the real line , and let be a point not on the graph (). Define the illumination index of to be the number of distinct tangents to the graph of which pass thru . We prove that if ″ is continuous and nonnegative on , ″ ≥ 0 outside a closed interval of...

It is known that the natural concept of projective representation of a group has also significance for permutation representations (-sets). In this paper the implications of the corresponding idea for -groups are explored. As a consequence, different relations with some well-known concepts as...

In this paper we shall study the oscillation of all positive solutions of the nonlinear delay differential equationandabout their equilibrium points. Also we study the stability of these equilibrium points and prove that every non-oscillatory positive solution tends to the equilibrium point when...

The intermittency of a time series can be defined as its normalized difference in scaling parameters. We establish the central limit theorem for the estimates of intermittency under the null hypothesis of a random walk. Simulations of random walks indicate that the distribution of intermittency...

In this note we present a way of solving linear inverse problems with convex constraints and noisy data. Combining the methods of maximum entropy in the mean and the generalized maximum entropy, we are able to treat both the noiseless and the noisy cases as conceptually the same problem. This...

Boundary-conforming invertible maps from the unit square onto the physical domain generate unfolded grids. On the other hand, if a map is not invertible, it produces folded grids and clearly it cannot be used in computations. The formulation of a variational principle which allows to separate...