Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Efficient sliding locomotion of three-link bodies   We study the efficiency of sliding locomotion for three-link bodies in the
presence of dry (Coulomb) friction. Friction coefficient space can be
partitioned into several regions, each with distinct types of efficient
kinematics. These include kinematics resembling lateral undulation with very
anisotropic friction, small-amplitude reciprocal kinematics, very large
amplitude kinematics near isotropic friction, and kinematics that are very
asymmetric about the flat state. In the two-parameter shape space, zero net
rotation for elliptical trajectories occurs mainly with bilateral or antipodal
symmetry. These symmetric subspaces have about the same peak efficiency as the
full space but with much smaller dimension. Adding modes with two or three
times the basic frequency greatly increases the numbers of local optimal for
efficiency, but only modestly increases the peak efficiency. Random ensembles
with higher frequencies have efficiency distributions that peak near a certain
nonzero value and decay rapidly up to the maximum efficiency. A stochastic
optimization algorithm is developed to compute optima with higher frequencies.
These are simple closed curves, sharpened versions of the elliptical optima in
most cases, and achieve much higher efficiencies mainly for small normal
friction. With a linear resistance law, the optimal trajectories are similar in
much of friction coefficient space, and relative efficiencies are much lower
except with very large normal friction.

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The categories of this paper are: cs
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The categories of this paper are: nlin
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The categories of this paper are: hep-th
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The categories of this paper are: eess
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The categories of this paper are: q-bio
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The categories of this paper are: math
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The categories of this paper are: stat
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: gr-qc
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The categories of this paper are: astro-ph
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The categories of this paper are: econ
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The categories of this paper are: nucl-th