Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Plackett-Burman experimental design for pulsed-DC-plasma deposition of
  DLC coatings
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph