Browsing by Subject "Linear equations"
Now showing items 111 of 11

Article
An analytical method for linear elliptic PDEs and its numerical implementation
(2004)A new numerical method for solving linear elliptic boundary value problems with constant coefficients in a polygonal domain is introduced. This method produces a generalized DirichletNeumann map: given the derivative of ...

Article
Differential invariants for quasilinear and semilinear wavetype equations
(2008)In this paper, we consider the class of wavetype equations utt = f (x, t, u) uxx + g (x, t, u, ux, ut) and two special cases of it. We derive the equivalence transformations for these equations and using these transformations, ...

Article
Differential invariants of the onedimensional quasilinear secondorder evolution equation
(2007)We consider evolution equations of the form ut = f(x, u, ux)uxx + g(x, u, ux) and ut = uxx + g(x, u, ux). In the spirit of the recent work of Ibragimov [Ibragimov NH. Laplace type invariants for parabolic equations. Nonlinear ...

Article
Direct methods for spectral approximations in nonconforming domain decompositions
(1998)The application of a conforming spectral collocation method to certain nonconforming domain decompositions leads to global matrices which have a particular block structure. We study the performance of various direct linear ...

Article
Enhanced group analysis and exact solutions of variable coefficient semilinear diffusion equations with a power source
(2009)A new approach to group classification problems and more general investigations on transformational properties of classes of differential equations is proposed. It is based on mappings between classes of differential ...

Article
Filtering for linear systems driven by fractional Brownian motion
(2003)In this paper we study continuous time filtering for linear multidimensional systems driven by fractional Brownian motion processes. We present the derivation of the optimum linear filter equations which involve a pair of ...

Article
Identification and high bandwidth control of hard disk drive servo systems based on sampled data measurements
(2007)One of the key factors that determines the track density of a hard disk drive (HDD) is the performance characteristics of the HDD servo system, the control system that positions the READ/WRITE magnetic head close to the ...

Article
Linearisation and potential symmetries of certain systems of diffusion equations
(2006)We consider systems of two pure onedimensional diffusion equations that have considerable interest in Soil Science and Mathematical Biology. We construct nonlocal symmetries for these systems. These are determined by ...

Conference Object

Article
On the effect of misspecifying the density ratio model
(2006)The density ratio model specifies that the loglikelihood ratio of two unknown densities is of known linear form which depends on some finite dimensional parameters. The model can be broadened to allow for msamples in a ...

Article
Piecewise linear emulation of propagating fronts as a method for determining their speeds
(2003)The selected speed of pushed fronts was found through analytic calculations. The resulting analytic solution constitutes an excellent approximation to the exact propagating front, yielding also the correct value for the ...