I develop an implicit finite-difference migration method for vertical transversely isotropic (VTI) media with laterally varying anisotropy parameters. I approximate the dispersion relation of VTI media with a rational function series, the coefficients of which are estimated by least-squares optimization. These coefficients are functions of Thomsen anisotropy parameters. They are calculated and ...

The study presents the development of an integrated model that optimises the performances of Neural Nets (NN) and dispersion models developed by the authors. Supervised NN models and dispersion models are two important techniques for evaluating air pollution concentrations. In our work we filter the concentration levels produced by an air pollution model with an NN to account for disagreement b...

Seed dispersal permits the colonization of favorable habitats and generation of new populations, facilitating escape from habitats that are in decline. There is little experimental evidence of the factors that limit epiphyte dispersion towards their hosts. In a tropical dry forest in central Mexico, we monitored the phenology of dispersion of epiphyte species of the genus Tillandsia; we tested ...

in this paper we are going to show the importance of mode identification in microtremor array analysis. the idea come from four concentric ambient noise array recordings with aperture 100 to 1000 meters, performed in southern urban area of tehran near the shrine of imam khomeini. these measurements were part of a comprehensive research project with the aim of determination of deep shear wave ve...

background anthracyclines are important components of many chemotherapeutic protocols. the present study aimed to evaluate the repolarization changes in electrocardiography (ecg) which may predict drug induced arrhythmia. materials and methods in this cross-sectional study, the recorded ecgs were assessed for qt dispersion (qtd), qt corrected dispersion (qtcd), t peak to tend dispersion (tped),...

The prime aim of this research is to support decision making, e.g., air quality impact analysis, human health assessment, through spatially modelling traffic-induced air pollution dispersion in urban areas at street level. Based on the information needed in decision making, a framework for a street level air quality decision support system is established, which is composed of basically three pa...

The stochastic trajectory-based (Lagrangian) approach has gained increasing importance and sophistication in atmospheric transport and dispersion modelling over the last few decades. State-of-the-art Lagrangian particle dispersion model (LPDMs) are used to compute trajectories of a large number of ‘marked’ particles and numerically simulate the dispersion of a pollutant (passive tracer) in the ...

A method of calculating dispersion curves for guided waves in slight, azimuthally anisotropic formations is developed with perturbation theory. The fluid is assumed to be inviscid, the formation perfectly elastic and homogeneous, and the ·borehole wall cylindrical. The first step is calculating the elastic moduli for a transversely isotropic formation whose moduli are close to those for the azi...

The reported compressional wave speed dispersion and attenuation could be explained by a modified gap stiffness model incorporated into the Biot model (the BIMGS model). In contrast, shear wave speed dispersion and attenuation have not been investigated in detail. No measurements of shear wave speed dispersion have been reported, and only Brunson's data provide the frequency characteristics of ...

A method is described to make a direct measurement of the horizontal and vertical momentum dispersion of the electron and positron beams as they pass through the chromatic correction sections (CCS) of tbe SLC final focus systems. The metbod is advantageous since it cleanly separates betatron components of the beam size from dispersive components, can be measured during standard colliding beams ...