Effective methods for computing turning points of curves implicitly defined by nonlinear equations
Effective semi-analytic integration for hypersingular Galerkin boundary integral equations for the Helmholtz equation in 3D
We deal with the Galerkin discretization of the boundary integral equations corresponding to problems with the Helmholtz equation in 3D. Our main result is the semi-analytic integration for the bilinear form induced by the hypersingular operator. Such computations have already been proposed for the bilinear forms induced by the single-layer and the double-layer potential operators in the monograph The Fast Solution of Boundary Integral Equations by O. Steinbach and S. Rjasanow and we base our computations...
Effects of competition and predation in a three species model
A model which consists of a predator and two prey species is presented. The prey compete for the same limited resource (food). The predator preys on both prey species but with different severity. We show that the coexistence of all three species is possible in a mean-field approach, whereas from Monte Carlo simulation it follows that the stochastic fluctuations drive one of the prey populations into extinction.
Effects of ordering and updating techniques on the performance of the Karmarkar algorithm
Efficiency of cropping system designs via base contrast
The present article is a continuation of previous papers by the same authors devoted to the efficiency of crop rotation experiments. We focus on plans distinguished by the cyclical pattern of the incidence matrix. For practical reasons, we slightly modify the efficiency coefficient. The relation between the resulting efficiency coefficients is examined. In addition, we provide a background material on crop rotation experiments.
Efficient algorithms for solving nonlinear Volterra integro-differential equations with two point boundary conditions.
Efficient Algorithms for Solving Tensor Product Finite Element Equations.
Efficient application of e-invariants in finite element method for an elastodynamic equation
We introduce a new efficient way of computation of partial differential equations using a hybrid method composed from FEM in space and FDM in time domain. The overall computational scheme is explicit in time. The key idea of the suggested way is based on a transformation of standard basis functions into new basis functions. The results of this matrix transformation are e-invariants (effective invariants) with such suitable properties which save the number of arithmetical operations needed for a...
Efficient calculation of sensitivities for optimization problems
Sensitivity information is required by numerous applications such as, for example, optimization algorithms, parameter estimations or real time control. Sensitivities can be computed with working accuracy using the forward mode of automatic differentiation (AD). ADOL-C is an AD-tool for programs written in C or C++. Originally, when applying ADOL-C, tapes for values, operations and locations are written during the function evaluation to generate an internal function representation....
Efficient computation of delay differential equations with highly oscillatory terms
This paper is concerned with the asymptotic expansion and numerical solution of systems of linear delay differential equations with highly oscillatory forcing terms. The computation of such problems using standard numerical methods is exceedingly slow and inefficient, indeed standard software is practically useless for this purpose. We propose an alternative, consisting of an asymptotic expansion of the solution, where each term can be derived either by recursion or by solving a non-oscillatory...
Efficient computation of delay differential equations with highly oscillatory terms
This paper is concerned with the asymptotic expansion and numerical solution of systems of linear delay differential equations with highly oscillatory forcing terms. The computation of such problems using standard numerical methods is exceedingly slow and inefficient, indeed standard software is practically useless for this purpose. We propose an alternative, consisting of an asymptotic expansion of the solution, where each term can be derived either by recursion or by solving a non-oscillatory...
Efficient computation of delay differential equations with highly oscillatory terms
This paper is concerned with the asymptotic expansion and numerical solution of systems of linear delay differential equations with highly oscillatory forcing terms. The computation of such problems using standard numerical methods is exceedingly slow and inefficient, indeed standard software is practically useless for this purpose. We propose an alternative, consisting of an asymptotic expansion of the solution, where each term can be derived either by recursion or by solving a non-oscillatory...
Efficient computation of enclosures for the exact solvents of a quadratic matrix equation.
Efficient Computation of Fourier Transforms on Compact Groups.
Efficient Computing of some Vector Operations over GF(3) and GF(4)
The problem of efficient computing of the affine vector operations (addition of two vectors and multiplication of a vector by a scalar over GF (q)), and also the weight of a given vector, is important for many problems in coding theory, cryptography, VLSI technology etc. In this paper we propose a new way of representing vectors over GF (3) and GF (4) and we describe an efficient performance of these affine operations. Computing weights of binary vectors is also discussed.
Efficient expansion of subspaces in the Jacobi-Davidson method for standard and generalized eigenproblems.
Efficient FORTRAN implementation of the gaussian elimination and Householder reduction algorithms on the IBM 3090 vector multiprocessor
Efficient greedy algorithms for high-dimensional parameter spaces with applications to empirical interpolation and reduced basis methods
We propose two new algorithms to improve greedy sampling of high-dimensional functions. While the techniques have a substantial degree of generality, we frame the discussion in the context of methods for empirical interpolation and the development of reduced basis techniques for high-dimensional parametrized functions. The first algorithm, based on a saturation assumption of the error in the greedy algorithm, is shown to result in a significant reduction of the workload over the standard greedy...
Efficient Implementation of Jacobi's Diagonalization Method on the DAP.
Efficient inexact Newton-like methods with application to problems of the deformation theory of plasticity
Newton-like methods are considered with inexact correction computed by some inner iterative method. Composite iterative methods of this type are applied to the solution of nonlinear systems arising from the solution of nonlinear elliptic boundary value problems. Two main quastions are studied in this paper: the convergence of the inexact Newton-like methods and the efficient control of accuracy in computation of the inexact correction. Numerical experiments show the efficiency of the suggested composite...