Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mod\'elisation de la propagation dans une structure ferm\'ee
  surdimensionn\'ee   The propagation of an electromagnetic wave in closed structures led to
numerous applications ranging from the characterization of materials in
resonating cavities to the measurements using pregnant reverberant EMF. We
created models to study the existence of electromagnetic waves in large closed
structures. There are two ways of excitation in such structures. One of these
methods is based on continuous excitation with specific resonant modes, which
has a variety of applications. The second method consists of a pulsed
excitation similar to the impulse wave radar. This excitation provides other
information. The structures studied were closed by perfectly conducting walls
and the electromagnetic wave was generated in the structure using dipole
antennas. The dimensions (length, width and height) were always much larger
than the wavelength.

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The categories of this paper are: q-bio
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The categories of this paper are: cmp-lg
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: plasm-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
13
The categories of this paper are: quant-ph