We study linear variable coeecient control problems in descriptor form. Based on a behaviour approach and the general theory for linear diierential algebraic systems we give the theoretical analysis and describe numerically stable methods to determine the structural properties of the system like solvability, regularity, model consistency and redundancy. We also discuss regularization via feedback.

The lattice Boltzmann equations for the linear diffusion modeling in cases of D2Q5, D2Q7 and D2Q9 lattices are considered. Families of the numerical schemes with the dependence on scalar parameter are introduced. The stability analysis of schemes is performed in parameter space. The stability is studied numerically by von Neumann method. Optimal parameter values for the presented families are d...

Traction-separation relationship is an important material characteristic describing the fracture behaviour of quasi-brittle solids. A new numerical scheme for identification of the traction-separation relation by inverse analysis of data obtained from various types of fracture tests is proposed. Due to employing the concept of sequentially linear analysis, the method exhibits a superior numeric...

We present a list of measures for a single trajectory, including measures that require the presence of other trajectories, such as the centrality of a trajectory amidst other trajectories. Then, we introduce three different views in order to extend measures of a single trajectory to a group, namely the representative view, the complete view and the area view. Furthermore, we give measures that ...

For symmetric inde®nite tridiagonal matrices, block LDL factorization without interchanges is shown to have excellent numerical stability when a pivoting strategy of Bunch is used to choose the dimension (1 or 2) of the pivots. Ó 1999 Elsevier Science Inc. All rights reserved. AMS classi®cation: 65F05; 65G05

where p(t) and q(t) are real-valued functions and p(t) 6= 0 for any t ∈ R. In what follows we assume that a(t), b(t), and c(t) satisfy the periodicity conditions a(t+ T ) = a(t), b(t+ T ) = b(t), c(t+ T ) = c(t), t ∈ R. The system (2) (or (3)) is said to be stable if all solutions are bounded on R, unstable if all nontrivial solutions are unbounded on R, and conditionally stable if there exits ...

Chatter stability in milling can be improved significantly using variable pitch cutters. The pitch angles can be optimized for certain chatter frequency and spindle speed ranges using the analytical method presented in the first part of this two-part paper. In this part, the improvement of productivity and surface finish are demonstrated in three example applications. It is shown that chatter s...

The manner in which sma.ll perturbations in the data give rise to a perturbation in the solution of a two point. boundary value problem will determine how effectively the solution can be approximated nmnerically. However ·this 'conditioning' also has a number of other implications that are less obvious. 'rhese include the effec·t on the stability of numerical schemes, the condi·tioning of shoot...

As computational performance becomes more readily available, there will be an increasing variety of interactive graphical applications with iterative numerical techniques at their core. In this paper, we consider how to support the unique demands of such applications. In particular, we focus on how to set up the numerical problems which must be solved. In the context of interactive systems, thi...