Consider a stationary Gaussian random field on Rd with spectral density f(λ) that satisfies f(λ)∼c|λ|−θ as |λ|→∞. The parameters c and θ control the tail behavior of the spectral density. c is related to a microergodic parameter and θ is related to a fractal index. For data...

In exploration geophysics the main and initial aim is to determine density of under-research goals which have certain density difference with the host rock. Therefore, we state a method in this paper to determine the density of bouguer plate, the so-called variogram method based on fractal...

An accurate calculation of the fractal dimension of a fracture surface is of prime significance for the quantitative evaluation of mechanical behavior. A laser profilometer is employed to measure a surface roughness of a large sandstone sample. Based on the definition of Minkowski dimension, a...

<Para ID="Par1">The objective of this study was comparative study of artificial neural networks (ANN) and wavelet artificial neural networks (WANN) for time-series groundwater depth data (GWD) forecasting with various curve fractal dimensions. The paper offered a better method of revealing the change...</para>

Karst rocky desertification is one of the major ecological and environmental problems that threaten the sustainable development of southwestern China. This study focuses on a case study of the small watershed in Chenqi where karst rocky desertification is particularly severe. This paper...

In this study, features of financial returns of PSI20 index, related to market efficiency, are captured using wavelet and entropy based techniques. This characterization includes the following points. First, the detection of long memory, associated to low frequencies, and a global measure of the...

Economic theory tells that a command system allocates resources poorly because of the impossibility of economic calculation. Therefore, once prices are freed and start to operate at quasi-equilibrium (market-clearing) levels, the hidden inefficiencies come into the open and a massive resource...

The study concentrated on demonstrating how non-linear modelling can be useful to investigate the behavioural of dynamic economic systems. Using some adequate non-linear models could be a good way to find more refined solutions to actually unsolved problems or ambiguities in economics. Beginning...

The chaos theory assumes that the returns dynamics are not normally distributed and more complex approaches have to be used to study these time series. In fact, the Fractal Market Hypothesis assumes that the returns dynamics are not independent of the investors’ attitudes and represent the...

Economic theory tells that a command system allocates resources poorly because of the impossibility of economic calculation. Therefore, once prices are freed and start to operate at quasi-equilibrium (market-clearing) levels, the hidden inefficiencies come into the open and a massive resource...