Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Design of engineering systems in Polish mines in the third quarter of
  the 20th century   Participation of mathematicians in the implementation of economic projects in
Poland, in which mathematics-based methods played an important role, happened
sporadically in the past. Usually methods known from publications and verified
were adapted to solving related problems. The subject of this paper is the
cooperation between mathematicians and engineers in Wroc{\l}aw in the second
half of the twentieth century established in the form of an analysis of the
effectiveness of engineering systems used in mining. The results of this
cooperation showed that at the design stage of technical systems it is
necessary to take into account factors that could not have been rationally
controlled before. The need to explain various aspects of future exploitation
was a strong motivation for the development of mathematical modeling methods.
These methods also opened research topics in the theory of stochastic processes
and graph theory. The social aspects of this cooperation are also interesting.

16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs