A wide variety of methods based on fractal, entropic or chaotic approaches have been applied to the analysis of complex physiological time series. In this paper, we show that fractal and entropy measures are poor indicators of nonlinearity for gait data and heart rate variability data. In contrast, the noise titration method based on Volterra autoregressive modeling represents the most reliable...

This work proposes a novel technique for the extraction of descriptors of a texture image. The method consists in modeling the image through a complex network, based on the distribution of gray-level intensities. Therefore, we process the adjacency matrix as a geometrical object and compute its fractal dimension. Thus we apply a multiscale transform over the powerlaw fractal curve, obtaining th...

PURPOSE The purpose of the present study was to evaluate inter-arm and inter-gender differences in fractal dimension (FD) and conduction velocity (CV) obtained from multichannel surface electromyographic (sEMG) recordings during sustained fatiguing contractions of the biceps brachii. METHODS A total of 20 recreationally active males (24±6 years) and 18 recreationally active females (22±9 year...

In this paper, the optical properties of one dimensional fractal structures are investigated. We consider six typical fractal photonic structures: the symmetric dual cantor-like fractal structure, the asymmetric dual cantor-like fractal structure, the single cantor-like fractal structure, the symmetric dual golden-section fractal structure, the asymmetric dual golden-section fractal structure a...

ractal geometry provides a basis for modF eling the infinite detail found in nature. Fractal methods are quite popular in computer graphics for modeling natural phenomena such as mountains, clouds, and many kinds of plants. Linear fractal models such as the iterated function system (IFS), recurrent iterated function system (RIFS), and Lindenmeyer systern (L-system) concisely describe complex ob...

The colorimetric organization of RGB color images is investigated through the computation of the correlation integral of their three-dimensional histogram. For natural color images, as a common behavior, the correlation integral is found to follow a power law, with a noninteger exponent characteristic of a given image. This behavior identifies a fractal or multiscale self-similar distribution o...

In this paper we work with nonparametric methods in modeling and analyzing the financial times series. We use the concept of fractal dimension for measuring the complexity of time series of observed financial data. The aim of this paper is to distinguish between the randomness and determinism of the financial information. We will compare the fractal analysis of the selected forward exchange rat...

Keywords: Fractal structure Fractal dimension Box-counting dimension Domain of words Language Regular expression Binary-coded decimal Search tree a b s t r a c t A fractal structure is a tool that is used to study the fractal behavior of a space. In this paper, we show how to apply a new concept of fractal dimension for fractal structures, extending the use of the box-counting dimension to new ...