Splitting spunlaid composite filament is a most significant technique to manufacture nonwoven with microfibers. The splitting effect of composite filament is a direct impact on the performance of the final products. The paper summarizes present methods of splitting composite fibers at home or abroad, and the principle and characteristic of each method is also described in order to discuss the m...

Global Krylov subspace methods are the most efficient and robust methods to solve generalized coupled Sylvester matrix equation. In this paper, we propose the nested splitting conjugate gradient process for solving this equation. This method has inner and outer iterations, which employs the generalized conjugate gradient method as an inner iteration to approximate each outer iterate, while each...

the problem of downward continuation of the gravity field from the earth’s surface to the reference ellipsoid arises from the fact that the solution to the boundary value problem for geoid determination without applying stokes formula is sought in terms of the disturbing potential on the ellipsoid but the disturbing gravity observations are only available on the earth’s surface. downward contin...

In this article, we investigate sufficient conditions for existence of maximal and minimal solutions to a coupled system of highly nonlinear differential equations of fractional order with mixed type boundary conditions. To achieve this goal, we apply monotone iterative technique together with the method of upper and lower solutions. Also an error estimation is given to check the accuracy of th...

Statistical reconstruction methods for X-ray CT rely on regularization to yield good quality images. We propose and investigate a specific type of nonquadratic regularization for 3-D CT reconstruction that corresponds to applying a 2-D orthonormal wavelet transform (OWT) on trans-axial slices and finite differences (FD) along the axial direction. We use an iterative variable-splitting-based alt...

A Class of Splitting Preconditioners for the iterative solution of Linear Systems arising from Interior Point Methods for Linear Programming Problems needs to find a base by a sophisticated process based in a lying rectangular LU factorization, that involves reordering columns many times until certain conditions are satisfied. At the same time, it is necessary to prevent excessive fill-in in L ...

We consider sequential, i.e., Gauss-Seidel type, subspace correction methods for the iterative solution of symmetric positive definite variational problems, where the order of subspace correction steps is not deterministically fixed as in standard multiplicative Schwarz methods. Here, we greedily choose the subspace with the largest (or at least a relatively large) residual norm for the next up...

The paper addresses the problem of indexing data for k nearest neighbors (k-nn) search. Given a collection of data objects and a similarity measure the searching goal is to find quickly the k most similar objects to a given query object. We present a top-down indexing method that employs a widely used scheme of indexing algorithms. It starts with the whole set of objects at the root of an index...

Iterative reconstruction methods with regularization become more and more popular. In the literature, amazing results are reported that are able to reconstruct images from very few views and from trajectories that do not acquire complete data sets such as would be required for analytical reconstruction methods. A large disadvantage of iterative methods is their high computational demand. Bruder...