73 research outputs found
Dissipation Factors of Spherical Current Modes on Multiple Spherical Layers
Radiation efficiencies of modal current densities distributed on a spherical
shell are evaluated in terms of dissipation factor. The presented approach is
rigorous, yet simple and straightforward, leading to closed-form expressions.
The same approach is utilized for a two-layered shell and the results are
compared with other models existing in the literature. Discrepancies in this
comparison are reported and reasons are analyzed. Finally, it is demonstrated
that radiation efficiency potentially benefits from the use of internal volume
which contrasts with the case of the radiation Q-factor.Comment: 5 pages, 5 figure
Inversion-Free Evaluation of Nearest Neighbors in Method of Moments
A recently introduced technique of topology sensitivity in method of moments
is extended by the possibility of adding degrees-of-freedom (reconstruct) into
underlying structure. The algebraic formulation is inversion-free, suitable for
parallelization and scales favorably with the number of unknowns. The
reconstruction completes the nearest neighbors procedure for an evaluation of
the smallest shape perturbation. The performance of the method is studied with
a greedy search over a Hamming graph representing the structure in which
initial positions are chosen from a random set. The method is shown to be
effective data mining tool for machine learning-related applications.Comment: 5 pages, 8 figures (one of them is animated), 1 table, accepted to
AWP
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