Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Constructing Trivariate B-splines with Positive Jacobian by Pillow
  Operation and Geometric Iterative Fitting   The advent of isogeometric analysis has prompted a need for methods to
generate Trivariate B-spline Solids (TBS) with positive Jacobian. However, it
is difficult to guarantee a positive Jacobian of a TBS since the geometric
pre-condition for ensuring the positive Jacobian is very complicated. In this
paper, we propose a method for generating TBSs with guaranteed positive
Jacobian. For the study, we used a tetrahedral (tet) mesh model and segmented
it into sub-volumes using the pillow operation. Then, to reduce the difficulty
in ensuring a positive Jacobian, we separately fitted the boundary curves and
surfaces and the sub-volumes using a geometric iterative fitting algorithm.
Finally, the smoothness between adjacent TBSs is improved. The experimental
examples presented in this paper demonstrate the effectiveness and efficiency
of the developed algorithm.

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The categories of this paper are: physics
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The categories of this paper are: plasm-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: q-bio
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The categories of this paper are: chem-ph
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: adap-org
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The categories of this paper are: funct-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: math