As part of an investigation of the radar backscatter properties of axisymmetric conducting shapes, a study has been made of backscattering by a cone-sphere. This body is comprised of a circular cone with a 25° included cone angle, terminated by a tangent spherical segment. Measurements of backscatter cross sections over all aspect angles are presented for wavelengths in the range from one-tenth...

The Descartes circle theorem states that if four circles are mutually tangent in the plane, with disjoint interiors, then their curvatures (or “bends”) bi = 1 ri satisfy the relation (b1 + b2 + b3 + b4) 2 = 2(b1 + b 2 2 + b 2 3 + b 2 4). We show that similar relations hold involving the centers of the four circles in such a configuration, coordinatized as complex numbers, yielding a complex Des...

Current mosaicing methods use narrow field of view cameras to acquire image data. This poses problems when computing a complete spherical mosaic. First, a large number of images are needed to capture a sphere. Second, errors in mosaicing make it difficult to complete the spherical mosaic without seams. Third, with a hand-held camera it is hard for the user to ensure complete coverage of the sph...

A process is presented for the creation of immersive highdynamic range 3D models from a pair of spherical images. The concept of applying a spherical Delauney triangulation to 3D model creation is introduced and a complete texturing solution is given.

OBJECTIVE To compare manual kinetic perimetry with tangent screen and Goldmann techniques and automated static perimetry with the Humphrey Field Analyzer in the detection and localization of occipital lobe lesions. DESIGN Prospective consecutive comparative case series. PARTICIPANTS Twelve patients with well-defined occipital lobe infarcts on magnetic resonance (MR) imaging were studied. ...

Motivated by image perturbation and the geometry of manifolds, we present a novel method combining these two elements. First, we form a tangent space from a set of perturbed images and observe that the tangent space admits a vector space structure. Second, we embed the approximated tangent spaces on a Grassmann manifold and employ a chordal distance as the means for comparing subspaces. The mat...