Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Team PFDet's Methods for Open Images Challenge 2019   We present the instance segmentation and the object detection method used by
team PFDet for Open Images Challenge 2019. We tackle a massive dataset size,
huge class imbalance and federated annotations. Using this method, the team
PFDet achieved 3rd and 4th place in the instance segmentation and the object
detection track, respectively.

31
The categories of this paper are: ao-sci
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The categories of this paper are: astro-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-ex
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The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-lat
3
The categories of this paper are: physics
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The categories of this paper are: q-fin
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The categories of this paper are: bayes-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol