BACKGROUND Several hepatic cirrhosis-derived noninvasive models have been developed to predict the incidence and outcomes of hepatocellular carcinoma (HCC). We aimed to investigate the prognostic significance of the two novel established cirrhosis-associated models based on gamma-glutamyl transpeptidase (GGT) and platelets in hepatitis B-associated HCC. METHODS We retrospectively evaluated 18...

Offset-dependent reflectivity or amplitude-variationwith-offset AVO analysis of ground-penetrating radar GPR data may improve the resolution of subsurface dielectric permittivity estimates. A horizontally stratified medium has a limiting layer thickness below which thin-bed AVO analysis is necessary. For a typical GPR signal, this limit is approximately 0.75 of the characteristic wavelength of ...

Structural degradation of road pavements has a considerable impact on traffic safety. Roadway surface defects or discontinuities make driving uncomfortable and increase chances of accidents. GPR is an effective and non-destructive technique to discover and trace the causes of road pavement damages so characterizing road integrity. The paper shows the findings of a GPR survey carried out on degr...

Modeling and simulation results of a system analysis of Ground Penetrating Radars (GPR) using Finite Difference Time Domain (FDTD) techniques are presented. Performance issues with GPRs need to be isolated in order to optimize of the radar’s ability to detect and identify buried objects. Using a system engineering approach, FDTD models were used to characterize the variables associated with the...

In this paper, a signal processing technique is developed to reduce clutter due to ground bounce in ground penetrating radar (GPR) measurements. This technique is especially useful when a GPR is used to detect subsurface antipersonnel mines. The GPR clutter is modeled using a simple parametric model. Buried mine and clutter contributions are separated through a pair of coupled iterative procedu...

Ground penetrating radar (GPR) is a nondestructive sensor technology for detecting underground objects. GPR requires large-aperture antennas to survey a remote location precisely because of the expansion of microwaves. We propose a laser-driven GPR (LGPR) that uses microwave radiation from a laser plasma to achieve remote sensing. LGPR is expected to provide good spatial resolution with a small...

Gellenbeck, S. Mercy (Catholic University, Washington, D. C.). Aerobic respiratory metabolism of Staphylococcus aureus from an infected animal. J. Bacteriol. 83:450-455. 1962.-The separation of Staphylococcus aureus from the tissue fluids of an infected guinea pig has allowed a comparison of cells (GPR) separated in this manner with the same strain (PR847) grown on an artificial medium. In gene...

The selection of a near-field or far-field ground-penetrating radar (GPR) model is an important question for an accurate but computationally effective characterization of medium electrical properties using full-wave inverse modeling. In this study, we determined an antenna height threshold for the near-field and farfield full-wave GPR models by analyzing the variation of the spatial derivatives...

In this paper we propose a novel Bayesian kernel based solution for regression in complex fields. We develop the formulation of the Gaussian process for regression (GPR) to deal with complex-valued outputs. Previous solutions for kernels methods usually assume a complexification approach, where the real-valued kernel is replaced by a complexvalued one. However, based on the results in complex-v...

It is well known in B-scan ground penetrating radar (GPR) imagery that the underground scatterers generally exhibit defocused, hyperbolic characteristics. This is mainly due to the data collection scheme and the finite beam width of the main lobe of the GPR antenna. To invert this undesirable effect and obtain focused images, various migration or focusing algorithms have been developed. In this...