In this paper, we present a novel algorithm for adaptive fuzzy segmentation of MRI data and estimation of intensity inhomogeneities using fuzzy logic. MRI intensity inhomogeneities can be attributed to imperfections in the RF coils or some problems associated with the acquisition sequences. The result is a slowly-varying shading artifact over the image that can produce errors with conventional ...

The problem of construction of a general ihomogeneous solution of D-dimensional Einstein equations with any matter sources satisfying the inequality ǫ ≥ p in the vicinity of a cosmological singularity is considered. It is shown that near the singularity a local behavior of metric functions is described by a billiard on a space of a constant negative curvature. The billiard is shown to have a fi...

In this paper we propose a method to include skull inhomogeneities in the EEG forward/inverse calculation by parcellating the skull based on a combination of skull anatomy and thickness. We show that it is enough to determine a few skull parameters (4 6) in the inverse search to capture the skull inhomogeneities if we also include the thickness. The validity of the linear relation between skull...

Structural inhomogeneities are observed in RF sputtered C079Cr21 layers, studied for perpendicular magnetic recording. The effective perpendicular anisotropy is strongly affected by the occurrence of inhomogeneities in the growth direction (e.g. an initial layer), which can be diminished by changing the substrate or by using a Ge underlayer. Lateral inhomogeneities (e.g. due to segregation) hav...

In earlier work [8] we have derived a very general representation formula for the voltage perturbation caused by volumetrically small inhomogeneities in an otherwise known conductor. The ingredients of this formula are (1) a limiting probability measure, (2) a “background” fundamental solution, and (3) an “effective” polarization tensor. In [9] we proved optimal average bounds on the very essen...

This review examines the localization of one-dimensional nonlinear waves in an inhomogeneous multiphase medium. Particular attention is devoted to the localization of two types of waves, namely, solitary waves (domains) and switching waves that are the separation boundaries between the corresponding phases (domain walls). The localized state of such waves on both point and slowly-varying (in sp...

The use of short pulse laser for minimally invasive detection scheme has become an indispensable tool in the technological arsenal of modern medicine and biomedical engineering. In this work, a time-resolved technique has been used to detect tumors/inhomogeneities in tissues by measuring transmitted and reflected scattered temporal optical signals when a short pulse laser source is incident on ...

We propose a unified approach to the investigation of processes dynamic interaction thin elastic inhomogeneities with an medium. It is based on methods theory singular perturbations in constructing mathematical models contact components systems subsequent application null-field method for analysis wave fields composites. This proves be efficient studying phenomenon waves local or multiple inhom...

An investigation was performed of the effectiveness of a time-resolved method for imaging very-low-contrast features embedded in highly scattering media. Experiments employed slabs of breastlike material into which were inserted small cylindrical objects having either a scattering or an absorption coefficient of 4, 2, 1.5, and 1.1 times greater than the surrounding medium. An attempt was made t...

Materials with high magnetic susceptibility cause local inhomogeneities in the main field of the magnetic resonance (MR) tomograph. These inhomogeneities lead to loss of phase coherence, and thus to a rapid loss of signal in the image. In our research we investigated inhomogeneous field of magnetic implants such as magnetic fibers, designed for inner suture during surgery. The magnetic field in...