The Least-Squares Boundary Residual Method is employed in the present paper to develop a computer model of the symmetrical six-port waveguide junction. The analytical formulation is difficult because of the insertion of a metallic post together with a dielectric sleeve into the over-sized cavity of the junction. Computational and experimental tests confirm that the resultant model is able to co...

this paper presents new sensitivity-based methods for detection of structural damage using incomplete noisy modal data. these methods are based on the first-order derivative of modal parameters. changes of natural frequency do not usually provide spatial information on the structural damage. they are also not sensitive to the local damage. in this paper, a new sensitivity function is proposed u...

We consider the behavior of the GMRES method for solving a linear system Ax = b when A is singular or nearly so, i.e., ill conditioned. The (near) singularity of A may or may not affect the performance of GMRES, depending on the nature of the system and the initial approximate solution. For singular A, we give conditions under which the GMRES iterates converge safely to a least-squares solution...

In this paper, a two-stage iterative algorithm is proposed to improve the convergence of Krylov based iterative methods, typically those of GMRES variants. The principle of the proposed approach is to build an external iteration over the Krylov method, and to frequently store its current residual (at each GMRES restart for instance). After a given number of outer iterations, a least-squares min...

Traditional computational approaches toward simulation of radiation and scattering from elastic bodies submerged in an acoustic uid have been primarily based on frequency domain formulations. Classical time-harmonic approaches (including boundary element, nite element, and nite diierence methods) have been eeective for problems involving a limited number of frequencies (narrow band response) an...

This paper studies inference about the values of the parameters in the threshold model in a generalized method of moments (GMM) framework. First, we establish that the extensively studied least squares method leads to substantially oversized tests and confidence intervals when the coeffi cient change is not large. Second, by re-ordering the data to recast the threshold model as a structural bre...

Tone mapping is used to compress the dynamic range of image data without distortion. To HDR images and prevent halo artifacts, a tone method proposed based on least squares method. Our first uses weights for estimation illumination, detail layer obtained by Retinex model. Then, global function with parameter range, fitting histogram equalization. Finally, illumination are fused obtain LDR image...

a truly meshless local petrov-galerkin (mlpg) method is developed for solving 3d elasto-static problems. using the general mlpg concept, this method is derived through the local weak forms of the equilibrium equations, by using test functions, namely, the heaviside function. the moving least squares (mls) are chosen to construct the shape functions, for the mlpg method. the penalty approximatio...

We investigate the application of minimal residual and orthogonal residualsubspace correction methods to singular linear systems Ax = b. Special em-phasis is put on the special case of Krylov subspace methods. If A has index 1(i.e., if all Jordan blocks associated with the eigenvalue λ = 0 of A are 1× 1)the behaviour of these iterative methods is well understood (see, e.g., ...