Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Kernel-Based Structural Equation Models for Topology Identification of
  Directed Networks
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph