And in [17, 18], based on semi-definite programming approximation schemes, some algorithms are also given to compute eigenvalues for general tensors with moderate sizes.
Not definitive, just definite.
For prestressing tendons that do not have a definite yield point, a multilinear approximation may be required.
Jevons distinguishes between a 'mean' (the approximation of a definite existing quantity) and an 'average' or 'fictitious mean' (an arithmetical average).
This new method, with a symmetric, positive definite system, is designed to use discontinuous approximations on finite element partitions consisting of arbitrary shape of polygons/polyhedra.
However, this procedure requires Hessian matrix (or an approximation of it) to be positive definite.
The approximation of functions by integral operators with positive definite kernels is widely used in many branches of mathematics, such as approximation theory, representation theory, theory of differential equations, Fourier analysis, and singular integral theory.
Instead of the Hessian (nabla_{xx}^{2} L x,lambda,mu)), we employ a positive definite matrix denoted by H which can be a quasi-Newton approximation or the identity matrix.
These approximations are symmetric, positive semi-definite, and positive definite, respectively.
As an application of these results, we derive a hierarchy of convex LMI inner approximations (affine sections of the cone of positive definite matrices of size m) of the nonconvex set of Schur stable polynomials of given degree n<m.
