The harmonic Lanczos bidiagonalization method can be used to compute the smallest singular triplets of a large matrix A. We prove that for good enough projection subspaces harmonic Ritz values converge if the columns of A are strongly linearly independent. On the other hand, harmonic Ritz values may miss some desired singular values when the columns of A are almost linearly dependent. Furthermo...

We describe the development of a method for the efficient computation of the smallest singular values and corresponding vectors for large sparse matrices [4]. The method combines state-of-the-art techniques that make it a useful computational tool appropriate for large scale computations. The method relies upon Lanczos bidiagonalization (LBD) with partial reorthogonalization [6], enhanced with ...

Using  principle  of  minimum  total  potential  energy  approach  in conjunction  with  Rayleigh-Ritz  method,  the  electro-thermo- mechanical  axial  buckling  behavior  of  piezoelectric  polymeric cylindrical  shell  reinforced  with  double-walled  boron-nitride nanotube  (DWBNNT)  is  investigated. Coupling  between  electrical and mechanical  fields  are  considered  according  to  ...

This paper concerns a harmonic projection method for computing an approximation to an eigenpair (λ, x) of a large matrix A. Given a target point τ and a subspace W that contains an approximation to x, the harmonic projection method returns an approximation (μ + τ, x̃) to (λ, x). Three convergence results are established as the deviation of x from W approaches zero. First, the harmonic Ritz value...

We propose a new method to deal with the essential boundary conditions encountered in deep learning-based numerical solvers for partial differential equations. The trial functions representing by neural networks are non-interpolatory, which makes enforcement of nontrivial matter. Our resorts Nitsche's variational formulation this difficulty, is consistent, and does not require significant extra...

The Rayleigh–Ritz (rr) method is well known as a means of minimizing energy functionals. Despite this, the technique most often employed in practice for minimizing a functional is the numerical solution of the Euler–Lagrange (el) equations derived from the energy functional by variational minimization. In this article we employ the rr method specifically to determine the equilibrium shape of a ...

abstract: the main aim of the vibration energy harvesters is to locally power autonomous devices such as wireless sensors. generally, power levels are low and the environmental benefit of the technology is to replace batteries rather than saving energy per se. piezoelectric vibrational energy harvesters are usually inertial mass based devices, where a cantilever beam with a piezoelectric outer ...

This paper concerns the Rayleigh–Ritz method for computing an approximation to an eigenspace X of a general matrix A from a subspace W that contains an approximation to X . The method produces a pair (N, X̃) that purports to approximate a pair (L,X), where X is a basis for X and AX = XL. In this paper we consider the convergence of (N, X̃) as the sine of the angle between X andW approaches zero. ...

A deeation procedure is introduced that is designed to improve the convergence of an implicitly restarted Arnoldi iteration for computing a few eigenvalues of a large matrix. As the iteration progresses the Ritz value approximations of the eigenvalues of A converge at diierent rates. A numerically stable scheme is introduced that implicitly deeates the converged approximations from the iteratio...