Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The Channel as a Traffic Sensor: Vehicle Detection and Classification
  based on Radio Fingerprinting
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph