Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Internet of Things Search Engine: Concepts, Classification, and Open
  Issues
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio