We introduce an algorithm for the eecient numerical solution of exterior boundary value problems for the Helmholtz equation. The problem is reformulated as an equivalent one on a bounded domain using an exact non-local boundary condition on a circular artiicial boundary. An FFT-based fast Helmholtz solver is then derived for a nite-element discretization on an annular domain. The exterior probl...

it is well known that the matrix exponential function has practical applications in engineering and applied sciences. in this paper, we present some new explicit identities to the exponential functions of a special class of matrices that are known as central-symmetric $x$-form. for instance, $e^{mathbf{a}t}$, $t^{mathbf{a}}$ and $a^{mathbf{a}t}$ will be evaluated by the new formulas in this par...

In this paper we propose a fast method to convert H.264/AVC Integer Transform (IT) coefficients to Discrete Cosine Transform (DCT) coefficients for applications in video transcoding. We derive the transform kernel matrix for converting, in the transform domain, four IT coefficient blocks into one 8 8 × DCT block of coefficients. By exploiting the symmetry of this matrix, we show that the propos...

In this work the transient analysis of a power network excited by indirect lightning is performed directly in time domain. Using the FDTD, we calculate induced currents and voltages in each node for a three-phase power network. The topological analysis of the network where each element (power line and lumped charge) is considered, allows deducing the matrix equation. In this electrical network ...

the purpose of this review article is to characterize all of the parameters regarding the types, polymers used, and release kinetics of matrix tablets. matrix system was the earliest oral extended release platform for medicinal use. matrix tablets are most commonly used methods to modulate the release profile of drugs. they are much desirable and preferred for such therapy because they offer be...

Matrix metalloproteinases (MMPs), also called matrixins, function in the extracellular environment of cells and degrade both matrix and non-matrix proteins. They play central roles in morphogenesis, wound healing, tissue repair and remodelling in response to injury, e.g. after myocardial infarction, and in progression of diseases such as atheroma, arthritis, cancer and chronic tissue ulcers. Th...

The matrix domain promotes plasma-membrane-specific binding of HIV-1 Gag through interaction with an acidic lipid phosphatidylinositol-(4,5)-bisphosphate. In in vitro systems, matrix-bound RNA suppresses Gag interactions with phosphatidylserine, an acidic lipid prevalent in various cytoplasmic membranes, thereby enhancing the lipid specificity of the matrix domain. Here we provide in vitro and ...

We discuss issues related to domain decomposition and multilevel preconditioning techniques which are often employed for solving large sparse linear systems in parallel computations. We introduce a class of parallel preconditioning techniques for general sparse linear systems based on a two level block ILU factorization strategy. We give some new data structures and strategies to construct loca...

Methods for matrix decomposition have found numerous applications in image processing, in particular for the problem of template decomposition. Since existing matrix decomposition techniques are mainly concerned with the linear domain, we consider it timely to investigate matrix decomposition techniques in the nonlinear domain with applications in image processing. The mathematical basis for th...