Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Improved Algorithms and Coupled Neutron-Photon Transport for
  Auto-Importance Sampling Method   The Auto-Importance Sampling (AIS) method is a Monte Carlo variance reduction
technique proposed for deep penetration problems, which can significantly
improve computational efficiency without pre-calculations for importance
distribution. However, the AIS method is only validated with several simple
examples, and cannot be used for coupled neutron-photon transport. This paper
presents the improved algorithms for the AIS method, including particle
transport, fictitious particles creation and adjustment, fictitious surface
geometry, random number allocation and calculation of the estimated relative
error. These improvements allow the AIS method to be applicable to complicated
deep penetration problems with complex geometry and multiple materials. A
coupled Neutron-Photon Auto-Importance Sampling (NP-AIS) method is proposed to
solve the deep penetration problems of coupled neutron-photon transport using
the improved algorithms. The NUREG/CR-6115 PWR benchmark was calculated by
using the methods of NP-AIS, geometry splitting with Russian roulette and the
analog Monte Carlo, respectively. The calculation results of NP-AIS were in
good agreement with those of geometry splitting with Russian roulette and the
benchmark solutions. The computational efficiency of NP-AIS for both neutron
and photon was much better than that of geometry splitting with Russian
roulette in most cases, and increased by several orders of magnitude compared
with that of the analog Monte Carlo.

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The categories of this paper are: bayes-an
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The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
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The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: econ
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The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
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The categories of this paper are: atom-ph