929 research outputs found
Analysis of stock market indices with multidimensional scaling and wavelets
Stock market indices SMIs are important measures of financial and economical performance.
Considerable research efforts during the last years demonstrated that these signals have a chaotic
nature and require sophisticated mathematical tools for analyzing their characteristics. Classical
methods, such as the Fourier transform, reveal considerable limitations in discriminating different
periods of time. This paper studies the dynamics of SMI by combining the wavelet transform
and the multidimensional scaling MDS . Six continuous wavelets are tested for analyzing the
information content of the stock signals. In a first phase, the real Shannon wavelet is adopted for
performing the evaluation of the SMI dynamics, while their comparison is visualized by means of
the MDS. In a second phase, the other wavelets are also tested, and the corresponding MDS plots
are analyzed
Analysis of financial data series using fractional Fourier transform and multidimensional scaling
The goal of this study is the analysis of
the dynamical properties of financial data series from
worldwide stock market indexes during the period
2000–2009. We analyze, under a regional criterium,
ten main indexes at a daily time horizon. The methods
and algorithms that have been explored for the
description of dynamical phenomena become an effective
background in the analysis of economical data.
We start by applying the classical concepts of signal
analysis, fractional Fourier transform, and methods of
fractional calculus. In a second phase we adopt the
multidimensional scaling approach. Stock market indexes
are examples of complex interacting systems for
which a huge amount of data exists. Therefore, these
indexes, viewed from a different perspectives, lead to
new classification patterns
Analysis of stock market indices through multidimensional scaling
We propose a graphical method to visualize possible time-varying correlations between fifteen
stock market values. The method is useful for observing stable or emerging clusters of
stock markets with similar behaviour. The graphs, originated from applying multidimensional
scaling techniques (MDS), may also guide the construction of multivariate econometric
models
Analysis of financial indices by means of the windowed Fourier transform
The goal of this study is to analyze the dynamical
properties of financial data series from nineteen worldwide
stock market indices (SMI) during the period 1995–2009.
SMI reveal a complex behavior that can be explored since it
is available a considerable volume of data. In this paper is
applied the window Fourier transform and methods of fractional
calculus. The results reveal classification patterns typical
of fractional order systems
Power law analysis of financial index dynamics
Power law PL and fractional calculus are two faces of phenomena with long memory behavior.
This paper applies PL description to analyze different periods of the business cycle. With such
purpose the evolution of ten important stock market indices DAX, Dow Jones, NASDAQ, Nikkei,
NYSE, S&P500, SSEC, HSI, TWII, and BSE over time is studied. An evolutionary algorithm is
used for the fitting of the PL parameters. It is observed that the PL curve fitting constitutes a good
tool for revealing the signal main characteristics leading to the emergence of the global financial
dynamic evolution
Fractional describing function of systems with Coulomb friction
This paper studies the describing function (DF) of systems constituted by a mass subjected to nonlinear friction. The friction force is decomposed into two components, namely, the viscous and the Coulomb friction. The system dynamics is analyzed in the DF perspective revealing a fractional-order behavior. The reliability of the DF method is evaluated through the signal harmonic contents
Describing function of two masses with backlash
This paper analyzes the dynamical properties of systems with backlash and impact phenomena based on the describing function method. It is shown that this type of nonlinearity can be analyzed in the perspective of the fractional calculus theory. The fractional dynamics is compared with that of standard models
Pathway Weathering in Granitoid Rocks from Central Region of Angola: Geochemical and Mineralogical Data
The Central Region of Angola is characterized by the abundance of granitoid rocks, whose weathering “in situ” originated the so-called residual soils. The textural, geochemical and mineralogical properties of these soils depend not only on the chemical composition of parent rock, but mainly on the local climatic and geomorphological characteristics.
In the study area, sampling sites were selected, which extend from the region of Kwanza- Norte (Kassenda, Dondo) through Kwanza-Sul (Cangulo, Quibala and Waco Kungo) until the plateau of Huambo, where samples of fresh rock, weathered rock and its residual soil were collected along each weathering profile.
Chemical analytical data were determined using X-ray fluorescence (XRF) analysis of the major and minor elements, whereas mineralogical data were determined using X-ray diffraction (XRD), on the samples of rock and on the respective residual soil.
The results obtained and their comparative analysis between the sampling sites, as well as along each weathering profile is presented.
This paper allows contributing to the knowledge of the geochemical weathering in tropical areas, as is the case of Angola
Fractional dynamics in the describing function analysis of nonlinear friction
This paper studies the describing function (DF) of systems constituted by a mass subjected to nonlinear friction. The friction force is decomposed in three components namely, the viscous, the Coulomb and the static forces. The system dynamics is analyzed in the DF perspective revealing a fractional-order behaviour. The reliability of the DF method is evaluated through the signal harmonic content and the limit cycle prediction.N/
Describing function of systems with nonlinear friction
This paper studies the describing function (DF) of systems composed of a mass subjected to nonlinear friction. The friction force is decomposed in three components namely, the viscous, the Coulomb and the static forces. The system dynamics is analyzed in the DF perspective and the reliability of the DF method is evaluated through the signal harmonic content.N/
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