Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Implementation of a Direct Coupling Coherent Quantum Observer including
  Observer Measurements   This paper considers the problem of constructing a direct coupling quantum
observer for a quantum harmonic oscillator system. The proposed observer is
shown to be able to estimate one but not both of the plant variables and
produces a measureable output using homodyne detection.

30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph