Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Wavelet Analysis of Cycle-to-Cycle Pressure Variations in an Internal
  Combustion Engine
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics