Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Study of Complex Mechanical Oscillators using an Inexpensive
  Computer Acquisition and Processing System   An inexpensive analog-to-digital converter has been built around the game
port of the IBM personal computer. Using a single field effect transistor (FET)
and three carbon resistors, it allows the game card to measure voltage, instead
of its usual measurement of resistance. Since power for the FET is drawn from
the game port, the total cost of components, external to the computer, is very
low at about one U.S. dollar. The converter is linear enough for many
applications, and is presently used to study the complex free decay of a long
period physical pendulum. Software support is via QuickBasic, and the
hardware/software package design was influenced by a consideration of amateur
seismology needs.

15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
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The categories of this paper are: eess
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
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The categories of this paper are: funct-an
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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