Entropy,
Год журнала:
2023,
Номер
25(9), С. 1364 - 1364
Опубликована: Сен. 21, 2023
Entropy-based
and
fractal-based
metrics
derived
from
heart
rate
variability
(HRV)
have
enriched
the
way
cardiovascular
dynamics
can
be
described
in
terms
of
complexity.
The
most
commonly
used
multifractal
testing,
a
method
using
q
moments
to
explore
range
fractal
scaling
small-sized
large-sized
fluctuations,
is
based
on
detrended
fluctuation
analysis,
which
examines
power–law
relationship
standard
deviation
with
timescale
measured
signal.
A
more
direct
testing
structure
exists
Shannon
entropy
bin
(signal
subparts)
proportion.
This
work
aims
reanalyze
HRV
during
cognitive
tasks
obtain
new
markers
complexity
provided
by
entropy-based
spectra
proposed
Chhabra
Jensen
1989.
Inter-beat
interval
durations
(RR)
time
series
were
obtained
28
students
comparatively
baseline
(viewing
video)
three
tasks:
Stroop
color
word
task,
stop-signal,
go/no-go.
estimators
extracted
f/α
singularity
spectrum
RR
magnitude
increment
series,
established
q-weighted
stable
(log–log
linear)
power
laws,
namely:
(i)
whole
width
(MF)
calculated
as
αmax
−
αmin;
specific
representing
fluctuations
(MFlarge)
α0
αq+;
(MFsmall)
αq−
α0.
As
main
results,
had
MF
signature
while
MFlarge
was
rather
these
could
represent
different
aspects
complete
picture
cognitive–autonomic
interplay
discussed,
previously
entropy-
markers,
introduction
distribution
(DistEn),
marker
recently
associated
specifically
control.
Abstract
Seismic
activity
has
complexity
and
randomness,
its
temporal
spatial
distribution
complexity,
stage,
level,
inheritance.
The
study
of
the
characteristics
seismic
is
great
significance
to
understanding
law
activity,
such
as
that
time
series
seismicity
in
belt
consistent
with
geographical
structure,
prediction
risk,
other
research
related
earthquake.
This
article
selects
data
catalog
whole
Eurasian
object.
Based
on
geological
environment
tectonic
characteristics,
multifractal
analysis
method
used
for
directory.
results
show
zones
obvious
structure
complex
scales,
which
can
well
reveal
space.
In
terms
series,
area
D∞
{D}_{{\rm{\infty
}}}
decreases
significantly
energy
before
occurrence
a
large
earthquake,
highly
correlated
structure.
Spatially,
intensity
infinite
sparse,
showing
clustering.
Therefore,
it
basic
rule
effectively
lay
certain
theoretical
foundation
earthquake
prevention
control
this
zone.
Physical review. E,
Год журнала:
2024,
Номер
109(4)
Опубликована: Апрель 15, 2024
Anomalous
diffusion
processes,
characterized
by
their
nonstandard
scaling
of
the
mean-squared
displacement,
pose
a
unique
challenge
in
classification
and
characterization.
In
previous
study
[Mangalam
et
al.,
Phys.
Rev.
Res.
5,
023144
(2023)],
we
established
comprehensive
framework
for
understanding
anomalous
using
multifractal
formalism.
The
present
delves
into
potential
spectral
features
effectively
distinguishing
trajectories
from
five
widely
used
models:
fractional
Brownian
motion,
scaled
continuous-time
random
walk,
annealed
transient
time
L\'evy
walk.
We
generate
extensive
datasets
comprising
${10}^{6}$
these
models
extract
multiple
spectra
each
trajectory
to
accomplish
this.
Our
investigation
entails
thorough
analysis
neural
network
performance,
encompassing
derived
varying
numbers
spectra.
also
explore
integration
traditional
feature
datasets,
enabling
us
assess
impact
comprehensively.
To
ensure
statistically
meaningful
comparison,
categorize
concept
groups
train
networks
designated
group.
Notably,
several
demonstrate
similar
levels
accuracy,
with
highest
performance
observed
utilizing
moving-window
characteristics
$p$
varation
features.
Multifractal
features,
particularly
those
three
involving
different
timescales
cutoffs,
closely
follow,
highlighting
robust
discriminatory
potential.
Remarkably,
exclusively
trained
on
single
spectrum
exhibits
commendable
surpassing
other
groups.
summary,
our
findings
underscore
diverse
potent
efficacy
enhancing
predictive
capacity
machine
learning
classify
processes.
Perceptual and Motor Skills,
Год журнала:
2023,
Номер
130(2), С. 622 - 657
Опубликована: Янв. 4, 2023
An
adaptive
response
to
unexpected
perturbations
requires
near-term
and
long-term
adjustments
over
time.
We
used
multifractal
analysis
test
how
nonlinear
interactions
across
timescales
might
support
an
following
unpredictable
perturbation.
reanalyzed
torque
data
from
44
young
24
older
adults
who
performed
a
single-leg
squat
task
challenged
by
mechanical
perturbation
secondary
visual-cognitive
task.
report
three
findings:
(a)
nonlinearity
interacted
with
pre-perturbation
production
error
presage
greater
pre-voluntary
feedforward
increases
voluntary
reductions,
respectively,
in
post-perturbation
error;
(b)
presaged
relatively
smaller
than
standard
deviations
of
both
torques
(c)
increased
demand
(e.g.,
age-related
changes
dexterity
dual-task
settings)
led
presaging
reduced
error.
All
these
results
were
consistent
our
expectations,
except
that
knee
torque-dependent
increase
appeared
later
for
younger
participants.
This
correlational
modeling
offered
theoretical
clarity
on
the
possible
roles
timescales,
moderating
feedback
processes,
stability
when
deviation
is
large
demands
are
strong.
Thus,
usefully
describes
movement
variability
even
paired
classical
descriptors
like
deviation.
discuss
potential
insights
findings
understanding
suprapostural
developing
rehabilitative
interventions.
International Journal of Finance & Economics,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 6, 2025
ABSTRACT
Despite
the
increasing
concentration
on
budding,
but
yet
immature,
green
investment
markets,
less
empirical
information
is
known
their
multifractal
and
efficiency
behaviour,
with
no
study
particularly
linking
these
to
crude
oil
market.
In
addition,
how
recent
COVID‐19
affects
multifractality
cross‐correlation
between
price
assets
remains
unexamined
in
literature.
Filling
gaps,
this
employs
novel
techniques
that
cut
across
univariate,
multiscale,
analyses.
We
find
all
are
strongly
behaviour
before
during
pandemic,
although
pandemic
intensifies
persistence
market
inefficiency.
Moreover,
established
vary
scales,
thereby
making
it
be
complex
heterogeneous.
On
a
final
note,
has
strong
assets,
more
pronounced
pandemic.
Thus,
markets
closely
knitted.
These
findings
followed
suitable
policy
implications
for
investors
who
desire
effectively
assess
manage
financial
risks
policymakers
optimal
performance
of
achieve
goal
carbon‐friendly
economy.