Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On enery-efficient time synchronization based on source clock frequency
  recovery in wireless sensor networks
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys