Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A noise reduction method for force measurements in water entry
  experiments based on the Ensemble Empirical Mode Decomposition   In this paper a denoising strategy based on the EEMD (Ensemble Empirical Mode
Decomposition) is used to reduce the background noise in non-stationary
signals, which represent the forces measured in scaled model testing of the
emergency water landing of aircraft, generally referred to as ditching.
Ditching tests are performed at a constant horizontal speed of 12 m/s and a
vertical velocity at the beginning of the impact of 0.45 m/s. The measured data
are affected by a large amplitude broadband noise, which has both mechanical
and electronic origin. Noise sources cannot be easily avoided or removed, since
they are associated with the vibrations of the structure of the towing carriage
and to the interaction between the measurement chain and the electromagnetic
fields. The EEMD noise reduction method is based on the decomposition of the
signal into modes and on its partial reconstruction using the residue, the
signal-dominant modes and some further modes treated with a thresholding
technique, which helps to retain some of the sharp features of the signal. The
strategy is developed and tested first on a synthetic signal with a
superimposed and known background noise. The method is then verified on the
measurement of the inertial force acting on the fuselage when it is moving in
air, as in this case the added mass is negligible and the denoised force should
equal the product of the mass by the acceleration, both of them being known.
Finally, the procedure is applied to denoise the forces measured during the
actual ditching experiments. The results are superior to those obtained by
other classical filtering methods, such as a moving average filter and a
low-pass FIR filter, particularly due to the enhanced capabilities of the
EEMD-denoising strategy here developed to preserve the sharp features of the
signals and to reduce the residual low-frequency oscillations of spurious
origin.

14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph