We consider series of the form ∑ an{n ·x}, where n ∈ Z and {x} is the sawtooth function. They are the natural multivariate extension of Davenport series. Their global (Sobolev) and pointwise regularity are studied and their multifractal properties are derived. Finally, we list some open problems which concern the study of these series.

Vibration signals were measured in a lab-scale fluidized bed to investigate the changes in particle sizes. Experiments were carried out in the bed with a different mass fraction of coarser particles at different superficial gas velocities, and probe heights. The S-statistic test evaluates the dimensionless squared distance between two attractors reconstructed from time series of vibration signa...

The locally adjusted cubic-spline capping (LACC) algorithm is well recognized for its effectiveness in the global time series reconstruction of vegetation biophysical and biochemical parameters. However, application, we often encounter issues, such as identifying positively biased outliers parameters reducing influence long consecutive gaps. In this study, improved LACC to address above two iss...

BACKGROUND We sought to determine whether heart rate variability (HRV), blood pressure (BP) variability, and baroreceptor-heart rate reflex sensitivity can be reliably assessed using finger volume pulse waveforms obtained from the commercially available EndoPAT device. METHODS Non-invasive BP (Finometer Pro as a non-invasive standard) and finger volume (EndoPAT) waveforms were recorded in 65 ...

In the paper an explicit formula for arbitrary $6j$-symbol finite-dimensional irreducible representations of algebra $\mathfrak{gl}_3$ is derived. A written as a result substitution $\pm 1$ into series hypergeometric type, which similar to $\Gamma$-series, simplest example multivariate type. The selection rulers are