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	Provedor de dados AgEcon (3) ArchiMer (3) Bragantia (2) REA (1) Autor Lazure, Pascal (3) Ben Ismail, Dhouha Kbaier (2) Carvalho,José Ruy Porto de (2) González,Antonio Paz (2) Puillat, Ingrid (2) Vieira,Sidney Rosa (2) Almeida,Laura T. de (1) Ceddia,Marcos Bacis (1) Ferreira,Fernanda L. V. (1) Karp, Larry S. (1) Kbaier-ben Ismail, Dhouha (1) Lee, In Ho (1) Mupondwa, Edmund K. (1) Puillat Felix, Ingrid (1) Rodrigues,Lineu N. (1) Silva,Demetrius D. da (1) Sinha, Dipendra (1) Teixeira,David B. de S. (1) Mais... Palavra-chave Stationarity (9) Time series (3) Wavelets (3) Cointegration (2) Cross correlation (2) Empirical mode decomposition (EMD) (2) Hilbert spectral analysis (HSA) (2) Hilbert-Huang transform (HHT) (2) Scale of variation (2) Semivariograms (2) Time-dependent intrinsic correlation (TDIC) (2) Topography (2) Augmented Dickey-Fuller tests (1) C22 (1) C72 (1) Continuous wavelet transform (1) Cross-correlation (1) D83 (1) Disaggregated data (1) Empirical mode decomposition (1) Mais... Tipo do documento Info:eu-repo/semantics/article (3) Text (3) Working or Discussion Paper (2) Conference Paper or Presentation (1) Ano 2021 (1) 2016 (2) 2015 (1) 2010 (2) 2005 (1) 2000 (1) 1999 (1) Mais... País Brazil (3) France (3) United States (3) Idioma Inglês (9)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 9 Primeira ... 1 ... Última Advanced spectral analysis and cross correlation based on the empirical mode decomposition: application to the environmental time series ArchiMer Ben Ismail, Dhouha Kbaier; Lazure, Pascal; Puillat, Ingrid. Abstract—In marine sciences, time series are often nonlinear and nonstationary. Adequate and specific methods are needed to analyze such series. In this paper, an application of the Empirical Mode Decomposition method (EMD) associated to the Hilbert Spectral Analysis (HSA) is presented. Furthermore, EMD based Time Dependent Intrinsic Correlation (TDIC) analysis is applied to consider the correlation between two nonstationary time series. Four temperature time series obtained from automatic measurements in nearshore waters of the Réunion island are considered, recorded every ten minutes from July 2011 to January 2012. The application of the EMD on these series and the estimation of their power spectra using the HSA are illustrated. The authors identify... Tipo: Text Palavras-chave: Augmented Dickey-Fuller tests; Cross correlation; Empirical mode decomposition (EMD); Hilbert spectral analysis (HSA); Hilbert-Huang transform (HHT); Stationarity; Time-dependent intrinsic correlation (TDIC); Time series; Wavelets. Ano: 2015 URL: http://archimer.ifremer.fr/doc/00270/38077/36205.pdf Application of Hilbert-Huang decomposition to temperature and currents data in the Réunion island ArchiMer Kbaier-ben Ismail, Dhouha; Lazure, Pascal; Puillat Felix, Ingrid. In marine sciences, time series are often nonlinear and nonstationary. Their analysis faces new challenges and thus requires the implementation of adequate and specific methods. We use the Hilbert-Huang Transform (HHT) for the spectral analysis of high frequency sampled time series in near shore waters of the Réunion island, located in the Indian Ocean 700 km east of Madagascar. We focus particularly on automatic measurements of sea level fluctuations, temperature records and current data sets at four different stations in the island. We look at the contribution of different Intrinsic Mode Functions (IMFs) obtained by the Empirical Mode Decomposition (EMD) and also compare the Hilbert spectra with the wavelet spectra. The inertial wave and several... Tipo: Text Palavras-chave: Cross correlation; Empirical mode decomposition (EMD); Hilbert spectral analysis (HSA); Hilbert-Huang transform (HHT); Stationarity; Time-dependent intrinsic correlation (TDIC); Time series; Wavelets. Ano: 2016 URL: http://archimer.ifremer.fr/doc/00383/49392/49822.pdf Detrending non stationary data for geostatistical applications Bragantia Vieira,Sidney Rosa; Carvalho,José Ruy Porto de; Ceddia,Marcos Bacis; González,Antonio Paz. The use of geostatistics requires at least that the intrinsic hypothesis be satisfied. The presence of a trend in the data invalidates this hypothesis. One of the ways of solving this problem is by subtracting a function fitted to the original data and working with the residuals. This technique also represents a change to a smaller scale of the variability and surface roughness. This paper describes the detrending technique of subtracting a trend surface fitted by the least squares method and discusses the results using topographical data as examples. The objective is to show how the detrending technique works for different scales and degrees of trend and how to interpret the results. It is shown that the simplest the surfaces fitted that does the work of... Tipo: Info:eu-repo/semantics/article Palavras-chave: Semivariograms; Stationarity; Topography; Scale of variation. Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052010000500002 Export Instability, Investment and Economic Growth in Asian Countries: A Time Series Analysis AgEcon Sinha, Dipendra. In this study, we look at the relationship between export stability, investment and economic growth in nine Asian countries using time series data. The few previous time series studies in this area have not paid any attention to stationarity and cointegration issues. We find that in most cases, the variables are non-stationary in their levels and not cointegrated. These results raise serious doubts about the results of these studies. The results are not uniform across countries casting doubts about the validity of the numerous cross-section studies. For Japan, Malaysia, Philippines and Sri Lanka, we find a negative relationship between export instability and economic growth. For (South) Korea, Myanmar, Pakistan and Thailand, we find a positive relationship... Tipo: Working or Discussion Paper Palavras-chave: Export instability; Growth; Stationarity; Cointegration; Teaching/Communication/Extension/Profession; C22; F49; O11. Ano: 1999 URL: http://purl.umn.edu/28466 Induced Technological Change in Canadian Agriculture Field Crops - Canola and Wheat: 1926-2003 AgEcon Mupondwa, Edmund K.. A tractable two-stage constant elasticity of substitution (CES) production function is applied to disaggregated western Canadian wheat and canola data for 1926-2003 to investigate the induced innovation hypothesis. Time series properties of the data are analyzed using cointegration and error correction to assess causality in differentiating between technological change and factor substitution. The results provide empirical support for the hypothesis with respect to prairie wheat and canola production. Tipo: Conference Paper or Presentation Palavras-chave: Disaggregated data; Induced innovation; Stationarity; Unit roots; Cointegration; Vector error correction model; Research and Development/Tech Change/Emerging Technologies. Ano: 2005 URL: http://purl.umn.edu/19333 Jack knifing for semivariogram validation Bragantia Vieira,Sidney Rosa; Carvalho,José Ruy Porto de; González,Antonio Paz. The semivariogram function fitting is the most important aspect of geostatistics and because of this the model chosen must be validated. Jack knifing may be one the most efficient ways for this validation purpose. The objective of this study was to show the use of the jack knifing technique to validate geostatistical hypothesis and semivariogram models. For that purpose, topographical heights data obtained from six distinct field scales and sampling densities were analyzed. Because the topographical data showed very strong trend for all fields as it was verified by the absence of a sill in the experimental semivariograms, the trend was removed with a trend surface fitted by minimum square deviation. Semivariogram models were fitted with different... Tipo: Info:eu-repo/semantics/article Palavras-chave: Semivariograms; Stationarity; Topography; Scale of variation. Ano: 2010 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052010000500011 Statistical properties and time-frequency analysis of temperature, salinity and turbidity measured by the MAREL Carnot station in the coastal waters of Boulogne-sur-Mer (France) ArchiMer Ben Ismail, Dhouha Kbaier; Lazure, Pascal; Puillat, Ingrid. In marine sciences, many fields display high variability over a large range of spatial and temporal scales, from seconds to thus ousands of years. The longer and longer recorded time series, with an increasing sampling frequency, in this field are often nonlinear, nonstationary, multiscale and noisy. Their analysis faces new challenges and thus requires the implementation of adequate and specific methods. The objective of this paper is to highlight time series analysis methods already applied in econometrics, signal processing, health,etc. to the environmental marine domain, assess advantages and inconvenients and compare classical techniques with more recent ones. Temperature, turbidity and salinity are important quantities for ecosystem studies. The... Tipo: Text Palavras-chave: Continuous wavelet transform; Cross-correlation; Empirical mode decomposition; Hilbert Huang Transform; Stationarity; Time dependent intrinsic correlation; Time series; Wavelets. Ano: 2016 URL: http://archimer.ifremer.fr/doc/00324/43519/43050.pdf TIME SERIES TRENDS OF STREAMFLOW AND RAINFALL IN THE SANTO ANTÔNIO RIVER BASIN, BRAZIL REA Ferreira,Fernanda L. V.; Rodrigues,Lineu N.; Silva,Demetrius D. da; Teixeira,David B. de S.; Almeida,Laura T. de. ABSTRACT Detecting trends in streamflow and rainfall series can have great significance for proper water resource management. Thus, the objective of this study was to analyze the trends of historical streamflow and rainfall series using nonparametric statistical tests. A historical series of pluviometric and fluviometric gauges, which belong to the hydrometeorological network of the Brazilian Water National Agency in the Santo Antônio River Basin, Brazil, from 1985 to 2014 were used. By applying statistical tests, it was found that the time series are independent and random, and from the total 24 rainfall gauges evaluated, 12 presented nonstationary behavior, exhibiting mostly decreasing trends. Based on the six fluviometric gauges used for the annual... Tipo: Info:eu-repo/semantics/article Palavras-chave: Stationarity; Run test; Mann Kendall test; Pettitt test. Ano: 2021 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162021000100047 Time-Consistent Policies AgEcon Karp, Larry S.; Lee, In Ho. In many cases the optimal open-loop policy to influence agents who solve dynamic problems is time-inconsistent. We show how to construct a time-consistent open-loop policy rule. We also consider an additional restriction under which the time-consistent open-loop policy is stationary. We use examples to illustrate the properties of these tax rules. Tipo: Working or Discussion Paper Palavras-chave: Time inconsistency; Open-loop policies; Stationarity; Public Economics; C72; D83. Ano: 2000 URL: http://purl.umn.edu/6275 Registros recuperados: 9 Primeira ... 1 ... Última

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