Using an analytical mathematical model, we studied and contrasted the effects of variations in geometry and volume conductor properties of the torso on epicardial and body surface potentials. The model consists of a spherical heart (blood cavity bounded by a spherical muscle shell that includes a double layer source, and pericardium) eccentrically placed in a spherical torso flung region bounde...

Introduction: With the SENSE Shimming (SSH) approach (1) a method was introduced recently that allows for estimating B0 field inhomogeneities based on a reference image and a series of points on a single free induction decay (FID). The temporal evolution of the FID data is explained by field inhomogeneities, starting from the reference image, making use of the encoding properties of the differe...

We revisit the asymptotic formulas originally derived in [D.J. Cedio-Fengya, S. Moskow, M.S. Vogelius, Identification of conductivity imperfections of small diameter by boundary measurements. Continuous dependence and computational reconstruction, Inverse Problems 14 (1998) 553–595; A. Friedman, M. Vogelius, Identification of small inhomogeneities of extreme conductivity by boundary measurement...

In this paper we consider the unique determination of inhomogeneities together with possible buried obstacles by scattering measurements. Under the assumption that the buried obstacles have only planar contacts with the inhomogeneities, we prove that one can recover both of them by knowing the associated scattering amplitude at a fixed energy.

A large–scale smoothed–out model of the universe ignores small–scale inhomogeneities, but the averaged effects of those inhomogeneities may alter both observational and dynamical relations at the larger scale. This article discusses these effects, and comments briefly on the relation to gravitational entropy.

We consider the inverse problem of identifying locations and certain properties of small inhomogeneities in a homogeneous background medium from boundary measurements on a part of the boundary or dynamic boundary measurements for a finite time interval. Using as weights particular background solutions we develop asymptotic methods based on an appropriate averaging of the data. Short title: Reco...

A large–scale smoothed–out model of the universe ignores small–scale inhomogeneities, but the averaged effects of those inhomogeneities may alter both observational and dynamical relations at the larger scale. This article discusses these effects, and comments briefly on the relation to gravitational entropy.