Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Review on Fish Swimming and Bird/Insect Flight   This expository review is devoted to fish swimming and bird/insect flight.
(i) The simple waving motion of an elongated flexible ribbon plate of constant
width, immersed in a fluid at rest, propagating a wave distally down the plate
to swim forward is first considered to provide a fundamental concept on energy
conservation. It is generalized to include variations in body width and
thickness, vortex shedding from appended dorsal, ventral and caudal fins to
closely simulate fish swimming for which a nonlinear theory is presented for
large-amplitude propulsion. (ii) For bird flight, the pioneering studies on
oscillating rigid wings are briefed, followed by presenting a nonlinear
unsteady theory for flexible wing with arbitrary variations in shape and
trajectory with a comparative study with experiments. (iii) For insect flight,
more recent advances are reviewed under aerodynamic theory and modeling,
computational methods, and experiments, on forward and hovering flights with
producing leading-edge vortex to give unsteady high lift. (iv) Prospects are
explored on extracting intrinsic flow energy by fish and bird to gain thrust
for propulsion. (v) The mechanical and biological principles are drawn together
for unified studies on the energetics in deriving metabolic power for animal
locomotion, leading to a surprising discovery that the hydrodynamic viscous
drag on swimming fish is largely associated with laminar boundary layers, thus
drawing valid and sound evidences for a resolution to the fish-swim paradox
proclaimed by Gray (1936, 1968).

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The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: adap-org
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The categories of this paper are: hep-lat
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The categories of this paper are: eess
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-th
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The categories of this paper are: patt-sol
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The categories of this paper are: q-bio
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The categories of this paper are: quant-ph
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The categories of this paper are: cond-mat