Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Acoustic Emission from crumpling paper   From magnetic systems to the crust of the earth, many physical systems that
exibit a multiplicty of metastable states emit pulses with a broad power law
distribution in energy. Digital audio recordings reveal that paper being
crumpled, a system that can be easily held in hand, is such a system. Crumpling
paper both using the traditional hand method and a novel cylindrical geometry
uncovered a power law distribution of pulse energies spanning at least two
decades: (exponent 1.3 - 1.6) Crumpling initally flat sheets into a compact
ball (strong crumpling), we found little or no evidence that the energy
distribution varied systematically over time or the size of the sheet. When we
applied repetitive small deformations (weak crumpling) to sheets which had been
previously folded along a regular grid, we found no systematic dependence on
the grid spacing. Our results suggest that the pulse energy depends only weakly
on the size of the paper regions responsible for sound production.

5
The categories of this paper are: gr-qc
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The categories of this paper are: astro-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: eess
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The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: stat
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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
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The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
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The categories of this paper are: hep-ph
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The categories of this paper are: solv-int