Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the elastic-wave imaging and characterization of fractures with
  specific stiffness
18
The categories of this paper are: econ
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat