Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Reconstruction of Lame moduli and density at the boundary enabling
  directional elastic wavefield decomposition
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th