The Digital image restoration is one of the image processing techniques that deals with the methods used to recover an original image from a degraded image. The proposed work is done for high density impulse noise which is affected by gaussian blur and is solved by using fuzzy filtering techniques for denoising and a Noise Suppressed Steering Kernel for deblurring which is a hybrid method. In t...

The multifrontal LU method is implemented to solve drift-diffusion models with large sparse matrices arising in the simulation and optimization of semiconductor devices. The performance of this method is compared with the LU algorithm without multifrontal scheme on different computers in the case of a realistic double heterojunction transistor. Résumé On emploie un méthode LU multifrontale pour...

This paper proves convergence of variations of the unsymmetric kernel-based collocation method introduced by E. Kansa in 1986. Since then, this method has been very successfully used in many applications, though it may theoretically fail in special situations, and though it had no error bound or convergence proof up to now. Thus it is necessary to add assumptions or to make modifications. Our m...

The selective preference of Chlorella pyrenoidosa for alkali metal cations was found to have the order Rb > K > > > Na. It was demonstrated that a cation of higher preference can replace in the cell cations of lower preference by an ion interchange process.The replacement of Na from the cell by K or Rb occurred against high external Na concentrations up to 450 meq/1 Na.It is suggested that the ...

This paper develops a new algorithm for the discrete time linear filtering problem. The crucial component of this algorithm involves the computation of the singular value decomposition (SVD) of an unsymmetric matrix without explicitly forming its left factor that has a high dimension. The presented algorithm has a good numerical stability and can handle correlated measurement noise without any ...

We investigate the use of sparse approximate-inverse preconditioners for the iterative solution of unsymmetric linear systems of equations. Such methods are of particular interest because of the considerable scope for parallelization. We propose a number of enhancements which may improve their performance. When run in a sequential environment, these methods can perform unfavourably when compare...

PIRO BAND is a library for bidiagonal reduction of unsymmetric banded matrices and tridiagonal reduction of symmetric banded matrices. It supports both real and complex matrices stored in packed band format. The software also can handle single and double precision arithmetic with 32-bit and 64-bit integers. We provide both a C library and MATLAB callable interfaces. The library is about 2 to 7 ...

Implicit time-step numerical integrators for ordinary and evolutionary partial di erential equations need, at each step, the solution of linear algebraic equations that are unsymmetric and often large and sparse. Recently, a block preconditioner based on circulant approximations for the linear systems arising in the boundary value methods (BVMs) was introduced by the author. Here, some circulan...

This paper presents the first hybrid MPI+OpenMP+CUDA implementation of a distributed memory right-looking unsymmetric sparse direct solver (i.e., sparse LU factorization) that uses static pivoting. While BLAS calls can account for more than 40% of the overall factorization time, the difficulty is that small problem sizes dominate the workload, making efficient GPU utilization challenging. This ...

This paper presents an efficient meshless approach for solving electrostatic problems. This novel approach is based on combination of radial basis functions-based meshless unsymmetric collocation method with projection domain decomposition method. Under this new method, we just need to solve a Steklov-Poincaré interface equation and the original problem is solved by computing a series of indepe...