Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Fast Algorithm for the Analysis of Scattering by Elongated Cavities   The electromagnetic scattering from elongated, arbitrarily shaped, open-ended
cavities have been studied extensively over the years. In this paper we
introduce the fast encapsulating domain decomposition (EDD) scheme for the
analysis of radar cross section (RCS) of such open-ended cavities. Problem
definition, key principles, analysis, and implementation of the proposed
solution scheme are presented in detail. The EDD advantages stem from domain
decomposition along the elongated dimension and representing the fields on the
cross-sections in the spectral domain, which enables us to separate the fields
into in- and out-going waves. This diagonolizes the translation between the
cross sections, thus reducing the per segment computational complexity from
$O((N^A)^3)$ to $O(N^W(N^A)^2)$, where $N^A$ is the number of aperture unknowns
and $N^W$ is the number of wall unknowns per segment, satisfying $N^W<<N^A$,
since we construct the segmentation step to be small compared to the cross
section. The results of the EDD are demonstrated on an S-shape elongated
open-ended cavity.

28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th