Nonlinear Time Series Analysis
Mostrando 1-12 de 49 artigos, teses e dissertações.
-
1. Linear and Nonlinear Heart Rate Variability Analysis in Gonadal Dysgenesis (Swyer Syndrome): A Case Report
Abstract Swyer syndrome is one of the disorders of sexual differentiation. Previous studies have demonstrated increased sympathetic activity with heart rate variability (HRV) analysis with decreasing estradiol levels. One patient presented a pure 46, XY gonadal dysgenesis with female phenotype. Cardiac autonomic modulation was assessed through HRV analysis w
Int. J. Cardiovasc. Sci.. Publicado em: 2021-08
-
2. Long-Term Correlations in São Francisco River Flow: The Influence of Sobradinho Dam
Resumo Neste trabalho estudamos a influência da construção da barragem de Sobradinho na vazão diária do rio São Francisco, Brasil, analisando correlações de longo alcance em séries temporais de magnitude e sinal obtidas a partir da anomalia das vazões utilizando o método Detrended Fluctuation Analysis. A série de magnitude está relacionada com a
Rev. bras. meteorol.. Publicado em: 05/08/2019
-
3. Simple but accurate periodic solutions for the nonlinear pendulum equation
Abstract Despite its elementary structure, the simple pendulum oscillations are described by a nonlinear differential equation whose exact solution for the angular displacement from vertical as a function of time cannot be expressed in terms of an elementary function, so either a numerical treatment or some analytical approximation is ultimately demanded. Su
Rev. Bras. Ensino Fís.. Publicado em: 21/09/2018
-
4. Effects of resistance training protocols on nonlinear analysis of heart rate variability in metabolic syndrome
Despite the various standard non-linear measurements used in autonomic modulation (AM) assessments usually being applied to long time-series, such analyses can sometimes be applied to shorter term series. To overcome this disadvantage, chaotic global methods were formulated by putting together heart rate variability (HRV) linear methods. Chaos provides infor
Braz J Med Biol Res. Publicado em: 11/06/2018
-
5. Fire response of a 3D multi-storey building with buckling restrained braces
Abstract This paper investigates the performance of a three-dimensional multi-storey structure with Buckling Restrained Brace system (BRBs) under fire condition, using a sequentially coupled nonlinear thermal stress analysis. Efficiency of using BRBs in enhancing the strength and stiffness of a structural frame is compared with that of Ordinary Concentricall
Lat. Am. j. solids struct.. Publicado em: 2015-11
-
6. Long-term correlation of the electrocorticogram as a bioindicator of brain exposure to ionizing radiation
Understanding the effects of radiation and its possible influence on the nervous system are of great clinical interest. However, there have been few electrophysiological studies on brain activity after exposure to ionizing radiation (IR). A new methodological approach regarding the assessment of the possible effects of IR on brain activity is the use of line
Braz J Med Biol Res. Publicado em: 12/06/2015
-
7. Caracterização e detecção da não linearidade associada à folga em sistemas aeroelásticos / Characterization and detection of freeplay nonlinearity in aeroelastic systems
A caracterização de não linearidades em aeronaves é fundamental para a solução de problemas aeroelásticos, onde uma relação ótima entre desempenho e segurança é desejável. Sistemas aeroelásticos são inerentemente não lineares. Não linearidades podem ser admitidas no projeto, ou podem surgir a qualquer momento durante a vida útil da aeronave
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/08/2012
-
8. Estimação e previsão da estrutura a termo das taxas de juros usando técnicas de inteligência computacional / Term structure of interest rate modeling and forecasting using computational intelligence techniques
This work proposes the term structure of interest rates modeling and forecasting using computational intelligence techniques, based on data from the US and Brazilian fixed income markets. The yield curve modeling includes the use of some evolutionary computation methods like Genetic Algorithms, Differential Evolution and Evolution Strategies in comparison wi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/06/2012
-
9. Transformações em modelos de séries temporais / Transformations in time series models
Cordeiro and Andrade (2009) incorporate the idea of transforming the response variable to the GARMA model, generalized autoregressive moving average, introduced by Benjamin et al. (2003), thus developing the TGARMA model, transformed generalized autoregressive moving average. The goal of this thesis is to develop the TGARMA model introduced by Cordeiro and A
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/05/2012
-
10. Estimação indireta de modelos R-GARCH / Indirect inference of R-GARCH models
Linear processes do not capture the structure of financial data. There is a large variety of nonlinear models available in literature. The class of ARCH models (Autoregressive Conditional Heterokedastic) was introduced by Engle (1982) in order to estimate inflation\ s variance. The idea is that, in this class, returns are serially uncorrelated, but the volat
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/03/2012
-
11. Estabilidad de la estimación de la onda anual en escala diaria de la temperatura
The choice of estimation of deterministic effect method in climate series is usually the starting point for most studies on climate variability. This decision is more sensitive when the presence of nonlinear phenomena is explored. Therefore, this paper analyzes the robustness and stability of different methods to estimate the annual cycle in time series of d
Rev. bras. meteorol.. Publicado em: 2012-12
-
12. Caracterização da conectividade entre regiões cerebrais via entropia aproximada e causalidade de Granger. / Brain connectivity characterization via approximate entropy and Granger causality.
Essa dissertação apresenta o desenvolvimento métodos para caracterização da conectividade entre séries temporais neurofisiológicas. Utilizam-se metodologias provenientes da Teoria da Informação Entropias Aproximada e Amostral para representar a complexidade da série no tempo, o que permite inferir como sua variabilidade se transfere a outras sequê
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/08/2011