On Finite Element Approximation in the L...-Norm of Variational Inequalities.
On first experiences with the implementation of a Newton based linear programming approach.
On fuzzy input data and the worst scenario method
In practice, input data entering a state problem are almost always uncertain to some extent. Thus it is natural to consider a set of admissible input data instead of a fixed and unique input. The worst scenario method takes into account all states generated by and maximizes a functional criterion reflecting a particular feature of the state solution, as local stress, displacement, or temperature, for instance. An increase in the criterion value indicates a deterioration in the featured quantity....
On Henrici's transformation in optimization
Henrici’s transformation is a generalization of Aitken’s -process to the vector case. It has been used for accelerating vector sequences. We use a modified version of Henrici’s transformation for solving some unconstrained nonlinear optimization problems. A convergence acceleration result is established and numerical examples are given.
On iterative methods for linearly constrained entropy maximization
On Khachian's Algorithm and Minimal Ellipsoids.
On maximizing a concave function subject to linear constraints by Newton's method
On multigrid for linear complementarity problems with application to American-style options.
On Multi-Grid Methods for Variational Inequalities.
On multipoint constraints in FETI methods
FETI (finite element tearing and interconnecting) based domain decomposition methods are well-established massively parallel methods for solving huge linear systems arising from discretizing partial differential equations. The first steps of FETI decompose the domain into nonoverlapping subdomains, discretize the subdomains using matching grids, and interconnect the adjacent variables by multipoint constraints. However, the multipoint constraints enforcing identification of the corners' variables...
On Newton's Method.
On Newton's polygons, Gröbner bases and series expansions of perturbed polynomial programs
In this note we consider a perturbed mathematical programming problem where both the objective and the constraint functions are polynomial in all underlying decision variables and in the perturbation parameter ε. Recently, the theory of Gröbner bases was used to show that solutions of the system of first order optimality conditions can be represented as Puiseux series in ε in a neighbourhood of ε = 0. In this paper we show that the determination of the branching order and the order of the pole (if...
On numerical solution of a variational inequality of the 4th order by finite element method
The problem of a thin elastic plate, deflection of which is limited below by a rigid obstacle is solved. Using Ahlin's and Ari-Adini's elements on rectangles, the convergence is established and SOR method with constraints is proposed for numerical solution.
On numerical solution of optimal control problems with nonsmooth objectives: Application to economic models
On numerical solution of weight minimization of elastic bodies weakly supporting tension
Shape optimization of a two-dimensional elastic body is considered, provided the material is weakly supporting tension. The problem generalizes that of a masonry dam subjected to its weight and to the hydrostatic pressure. A part of the boundary has to be found so as to minimize a given cost functional. The numerical realization using a penalty method and finite element technique is presented. Some typical results are shown.
On optimal methods in numerical analysis
Round-off error analysis of the gradient method.
On optimizing a maximin nonlinear function subject to replicated quasi-arborescence-like constraints.
In this paper we present the motivation for using the Truncated Newton method in an algorithm that maximises a non-linear function with additional maximin-like arguments subject to a network-like linear system of constraints. The special structure of the network (so-termed replicated quasi-arborescence) allows to introduce the new concept of independent superbasic sets and, then, using second-order information about the objective function without too much computer effort and storage.
On Orthogonal Linear ...1 Approximation.
On parameter estimation in an in vitro compartmental model for drug-induced enzyme production in pharmacotherapy
A pharmacodynamic model introduced earlier in the literature for in silico prediction of rifampicin-induced CYP3A4 enzyme production is described and some aspects of the involved curve-fitting based parameter estimation are discussed. Validation with our own laboratory data shows that the quality of the fit is particularly sensitive with respect to an unknown parameter representing the concentration of the nuclear receptor PXR (pregnane X receptor). A detailed analysis of the influence of that parameter...
On quasi-solution to infeasible linear complementarity problem obtained by Lemke’s method
For a linear complementarity problem with inconsistent system of constraints a notion of quasi-solution of Tschebyshev type is introduced. It’s shown that this solution can be obtained automatically by Lemke’s method if the constraint matrix of the original problem is copositive plus or belongs to the intersection of matrix classes P 0 and Q 0.