Figure 1 compares our mixture of spherical Gaussians (SG) basis to spherical harmonics (SH) and zonal harmonics (ZH) [Sloan et al. 2005]. A simple 2-lobe fit with our basis provides good accuracy; error decreases further with more lobes. Asymptotic error decrease in our model compares favorably with increasing order of spherical harmonics and with increasing order and number of lobes in the ZH ...

A configuration of particles confined to a sphere is balanced if they are in equilibrium under all force laws (that act between pairs of points with strength given by a fixed function of distance). It is straightforward to show that every sufficiently symmetrical configuration is balanced, but the converse is far from obvious. In 1957 Leech completely classified the balanced configurations in R...

In this paper, we study the problem of reconstructing the polyhedral structures and geometric positions of a general nD polyhedral scene from a single 2D line drawing. With the idea of local construction and propagation, we propose several powerful techniques for structural reconstruction (i.e. face identification) and geometric reconstruction (i.e. realizability and parametrization). Our struc...

Archimedes was the first to systematically find the centers of gravity of various solid bodies and to apply this concept in determining stable configurations of floating bodies. In this paper, we discuss an error in a proof developed by Archimedes that involves determining whether a uniform, spherical cap will float stably with its base horizontal in a liquid on a spherical Earth. We present a ...

The magnetic field due to a given current distribution, the interaction energy of a current distribution with an arbitrary external magnetic field, and the magnetostatic interaction energy between two current distributions are decomposed into multipolar components using spherical harmonic expansions. Diamagnetic interactions and the spin contributions to the multipole expansions are also discus...

We study the operator product expansion in the bosonic SU(2)0 and SUSY SU(2)2 WZNW models. We find that these OPEs contain both logarithmic operators and new conserved currents, leading to an extension of the symmetry group.

In this article we generalize both ordinary and permutation voltage constructions to obtain all branched coverings of maps. We approach a map as a set of flags together with three fixed-point-free involutions and relate this approach with other standard representations. We define a lift as a function from these flags into a group. Ordinary voltage and ordinary current assignments are special ca...

The probing of aligned and oriented molecules or atoms by electric quadrupole and magnetic dipole transitions is described using the spherical tensor formalism. The case of cylindrical symmetry is treated explicitly. It is shown how moments of t h e initial angular momentum distribution up to rank 4 are obtainable using electric quadrupole radiation. The interference between electric quadrupole...

A nuclear mass formula is constructed which is composed of two parts, one describing the general trend of the masses as a function of Z and N and the other representing deviations of individual masses from this general trend. These deviations are referred to as shell energies in a broad sense. The shell energies of spherical nuclei are calculated with use of a spherical single-particle potentia...

Sphericity and roundness have been employed in sedimentological and geomorphological studies to represent the gross shape of a gravel particle. The original complex definitions of gravel sphericity and roundness led to the use of visual charts or simplified parameters. Although the accurate derivation of sphericity requires the surface area of a gravel particle, manual measurement of the area i...