The inversion of electron density from total electron content (TEC) measurements of GPS radio occultation is investigated by means of simulated data from the International Reference Ionosphere IRI-2001 and observations by the GPS/MET satellite experiment. In both cases a meridional slice of electron density is derived for northern summer solstice June/July 1995 from the midnight to the noon sec...

We find a large class of integral operators which allow a systematic and explicit diagonalization. These operators generalize Abel’s integral operator, for which such a diagonalization has recently been found.

We solve the problem of inversion of an extended Abel-Jacobi map

Classical Gon£arov polynomials are polynomials which interpolate derivatives. Delta Gon£arov polynomials are polynomials which interpolate delta operators, e.g., forward and backward difference operators. We extend fundamental aspects of the theory of classical bivariate Gon£arov polynomials and univariate delta Gon£arov polynomials to the multivariate setting using umbral calculus. After intro...

In this article we present a new method for reconstructing three-dimensional ~3D! images with cylindrical symmetry from their two-dimensional projections. The method is based on expanding the projection in a basis set of functions that are analytical projections of known well-behaved functions. The original 3D image can then be reconstructed as a linear combination of these well-behaved functio...

In the second half of the 19th century, medical researchers paid increasing attention to the so-called ductless (endocrine) glands. In 1848, German physiologist Arnold Berthold provided the first evidence that one of these glands could secrete a physiologically active substance directly into the bloodstream. A castrated rooster normally exhibited a shrinking of its comb, but Berthold showed tha...

The classical summability methods of Borel (B) and Euler (E(λ), λ > 0) play an important role in many areas of mathematics. For instance, in summability theory they are perhaps the most important methods other than the Cesàro (Cα) and Abel (A) methods, and two chapters of the classic book of Hardy (1949) are devoted to them. In probability, the distinction between methods of Cesàro-Abel and Eul...