A fast algorithm for the approximation of a low rank LU decomposition is presented. In order to achieve a low complexity, the algorithm uses sparse random projections combined with FFTbased random projections. The asymptotic approximation error of the algorithm is analyzed and a theoretical error bound is presented. Finally, numerical examples illustrate that for a similar approximation error, ...

In this study, a new method is presented, based on genetic algorithms for determining object parameters such as radii and/or attenuation coefficients with some assumptions and estimating a cross-sectional image of an object from its projections obtained by X ray illumination. After it was tested for projections degraded by different random noise levels, it was observed that the genetic and fuzz...

In this paper, Novikov's inversion formula of the attenuated two-dimensional (2D) Radon transform is applied to the reconstruction of attenuated fan-beam projections acquired with equal detector spacing and of attenuated cone-beam projections acquired with a flat planar detector and circular trajectory. The derivation of the fan-beam algorithm is obtained by transformation from parallel-beam co...

Optimal Nonlinear Energy Sink (NES) is employed in vibration suppression of the beams subjected to successive moving loads in this paper. As a real application, a typical railway bridge is dynamically modeled by a single-span beam and a traveling high-speed train is simulated by a series of successive moving loads. Genetic algorithm is employed as the optimization technique and optimal paramete...

Litchi downy blight caused by Peronophythora litchii is the most serious disease in litchi production, storage and transportation. Existing identification technology has difficulty identifying sufficiently early, resulting economic losses. Thus, use of diffuse reflectance spectroscopy to identify at different stages disease, particularly achieve early blight, very important. The spectral data f...

Tomography deals with the reconstruction of images from their projections. In this paper we focus on tomographic reconstruction of binary images (i.e., black-and-white) that do not have an intrinsic lattice structure from a small number of projections. We describe how the reconstruction problem from only two projections can be formulated as a network flow problem in a graph, which can be solved...