For wavelength-dispersive analysis of trace elements at near-background concentrations, background subtraction poses special problems because the background is complex and difficult to measure or predict with certainty. Several sources contribute. These include Comptonand Rayleigh-scattered tube continuum radiation, nondiscriminated higher-order radiation, fluorescence of instrument parts, Comp...

one of the most important parts of range doppler algorithm is range cell migration correction. in this part, an interpolation approach is used to estimate data in their correct location. the interpolation method has a great influence on the quality of ultimate image. in this paper the interpolation method and different ways for increasing its accuracy was discussed. the performance of different...

The naturally occurring geogenic elements iodine (I), lithium (Li), and strontium (Sr) have a beneficial effect on human health. Iodine has an essential role in human metabolism while Li and Sr are used, respectively, as a treatment for various mental disorders and for post-menopausal osteoporosis. The aim here is to evaluate the potential for future epidemiological investigations in Denmark of...

The paper studies a geometrically unfitted finite element method (FEM), known as trace FEM or cut FEM, for the numerical solution of Stokes system posed on closed smooth surface. A based standard Taylor-Hood (continuous P2-P1) bulk elements is proposed. so-called volume normal derivative stabilization, from literature an essential ingredient this method. key result proved in inf-sup stability P...

Multi-dimensional Fourier interpolators have become the industry standard for 5D seismic volume reconstruction. However, room for improvement exists and a few key aspects of seismic data reconstruction do require additional study. The latter includes stability in the presence of coherent noise and statics, recovery conditions for extremely sparse data sets and computational efficiency. This pre...

The Sobolev spaces have played an essential role in the research of partial differential equations ever since the mid thirties. In order to handle boundary value problems, and, in particular, traces, the more general scales of space have been introduced, namely Slobodeckii spaces and Besov spaces. It proved that Besov spaces are a suitable replacement for Sobolev spaces in many situations and t...

In this paper, we prove a sharp local well-posedness result for spherically symmetric solutions to quasilinear wave equations with rough initial data, when the spatial dimension is three or higher. Our approach based on Morawetz type energy estimates fractional regularity linear variable $C^1$ coefficients, which rely multiplier method, weighted Littlewood-Paley theory, duality and interpolatio...

Building on the notions of time-variable filtering and the helix coordinate system, we develop software for filters that are smoothly variable in multiple dimensions. Multiscale prediction-error filters (PEFs) can estimate dips from recorded data and use the dip information to fill in unrecorded shot or receiver gathers. The data are typically divided into patches with approximately constant di...

The approach presented in this work uses an interpolation methodology to densify 3D-GPR datasets sharpen the results obtained GPR surveys carried out archaeological environment. It allows estimation of missing data from combined use mathematical transforms, such as Fourier and curvelet predictive filters. This technique makes it possible calculate signal simply by meeting two requirements: freq...