A celebrated and controversial hypothesis suggests that some biological systems—parts,
aspects, or groups of them—may extract important functional benefits from operating at the …

The availability of time series of the evolution of the properties of physical systems is
increasing, stimulating the development of many novel methods for the extraction of …

This paper analyzes the effect of the Russia–Ukraine conflict on the crude oil market and the
chain effect of the stock market in importing and exporting countries. We apply a multi-fractal …

Following the publication of the Task Force document on heart rate variability (HRV) in 1996,
a number of articles have been published to describe new HRV methodologies and their …

In recent years there has been substantial support for heart rate variability biofeedback
(HRVB) as a treatment for a variety of disorders and for performance enhancement. Since …

Fractals are fascinating, not only for their aesthetic appeal but also for allowing the
investigation of physical properties in non-integer dimensions. In these unconventional …

Fractal structures are found in biomedical time series from a wide range of physiological
phenomena. The multifractal spectrum identifies the deviations in fractal structure within time …

The human organism comprises various physiological and organ systems, each with its own
structural organization and functional complexity, leading to complex, transient, fluctuating …

Heart rate variability (HRV) refers to various methods of assessing the beat-to-beat variation
in the heart over time, in order to draw inference on the outflow of the autonomic nervous …

The newly inaugurated Research Resource for Complex Physiologic Signals, which was
created under the auspices of the National Center for Research Resources of the National …