Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Limits to inertial vibration power harvesting: power-spectral-density
  approach and its applications   Maximum output powers of vibration-driven inertial power harvesters reported
in literature exhibit sizable variations, even when normalized by the device
weight or their maximum linear size. To help establish a common benchmark, we
present a power-spectral-density based approach for estimating the maximum
power that can be obtained using a resonant inertial power harvester from a
random (aperiodic) vibration source with a given power spectral density. In the
simplest case of unlimited harvester size, the maximum obtainable power is
simply proportional to the maximum value of the power spectral density of
vibration acceleration. We describe in detail the underlying theory and the
practical method for evaluating these limits. We also present a simple
analytical formula to estimate the minimum harvester size required for
obtaining the maximum possible power. Specific power limits are derived as
function of harvester size for three practical examples of vibration sources:
(a) pneumatic power tool, (b) the body of an idling Mazda RX7 sports car, and
(c) human walking motion. Characteristic power spectra and optimum design
parameters (quality factor and resonant frequency) are presented for both
translational and rotational harvesters. Translational harvesters generally
outperform rotational ones for realistic harvester sizes, with the power tool
vibrations yielding a practical power limit of ~300 mW per gram of inertial
mass, followed by walking at ~1mW/g, while the vibrations of a car body yield
~0.1 mW/g or less.

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The categories of this paper are: stat
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The categories of this paper are: cs
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
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The categories of this paper are: funct-an
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: math
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat