Inference for autoregressive and moving average models with extreme value distribution via simulation study

Time series analysis has emerged as one of the most important statistical discipline and it has been applied in different fields over the years. Literature reviews show that independent identical distributed Gaussian random variables is not suitable for modelling extreme events. We evaluate the impa...

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Main Author: Samuel, Bako Sunday
Format: Thesis
Language:English
Published: 2015
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Online Access:http://psasir.upm.edu.my/id/eprint/57064/1/FS%202015%205RR.pdf
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spelling my-upm-ir.570642017-08-23T04:22:46Z Inference for autoregressive and moving average models with extreme value distribution via simulation study 2015-05 Samuel, Bako Sunday Time series analysis has emerged as one of the most important statistical discipline and it has been applied in different fields over the years. Literature reviews show that independent identical distributed Gaussian random variables is not suitable for modelling extreme events. We evaluate the impact of dependence on the parameter estimates of Autoregressive (AR) and Moving Average (MA) processes with Gumbel distributed innovation. The performance of the parameter estimates of the Gumbelgeneralised Pareto distribution fitted to the autoregressive and moving average processes and their respective cluster maxima is also assess. The extension of time series to extreme value theory can be achieved by inducing time dependence in the underlying state of an extreme value process. Extreme values occur in clusters in the presence of dependence. Gumbel distribution, a member of the family of the generalised extreme value distribution is the possible limit for the entire range of tail behaviour between polynomial decrease and essentially a finite endpoint and it is known to fit well in many situations. It is important to make general statements that characterises time series extreme models over a range of sample sizes with varying degree of dependence. Such general characterisation for a given model is useful for the extremal behaviour of physical processes. To achieve our objectives, a stationary autoregressive and moving average models with Gumbel distributed innovation is proposed and we characterise the short-term dependence among maxima, arising from light-tailed Gumbel distribution over a range of sample sizes with varying degrees of dependence. Dependence is induced through a linear filter operation. The linear filter operation takes a weighted sum of past innovations. The estimate of the maximum likelihood of the parameters of the Gumbel autoregressive and Gumbel moving average processes and their respective residuals are evaluated. Gumbel-AR(1) and Gumbel-MA(1) was fitted to the Gumbel-generalised Pareto distribution and we evaluate the performance of the parameter estimates fitted to the cluster maxima and the original series. Ignoring the effect of dependence leads to overestimation of the location parameter of the Gumbel-AR(1) and Gumbel-MA(1) processes respectively. The estimate of the location parameter of the autoregressive process using the residuals gives a better estimate. The estimate of the scale parameter perform marginally better for the original series than the residual estimate. The degree of clustering increases as dependence is enhance for both the AR and MA processes. The Gumbel-AR(1) and Gumbel-MA(1) are fitted to the Gumbel-generalised Pareto distribution show that the estimates of the scale and shape parameters fitted to the cluster maxima perform better as sample size increases, however, ignoring the effect of dependence leads to an underestimation of the parameter estimates of the scale parameter. The shape parameter of the original series gives a superior estimate compare to the threshold excesses fitted to the Gumbel-generalised Pareto distribution. Autoregression (Statistics) Time-series analysis Estimation theory 2015-05 Thesis http://psasir.upm.edu.my/id/eprint/57064/ http://psasir.upm.edu.my/id/eprint/57064/1/FS%202015%205RR.pdf application/pdf en public masters Universiti Putra Malaysia Autoregression (Statistics) Time-series analysis Estimation theory
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
topic Autoregression (Statistics)
Time-series analysis
Estimation theory
spellingShingle Autoregression (Statistics)
Time-series analysis
Estimation theory
Samuel, Bako Sunday
Inference for autoregressive and moving average models with extreme value distribution via simulation study
description Time series analysis has emerged as one of the most important statistical discipline and it has been applied in different fields over the years. Literature reviews show that independent identical distributed Gaussian random variables is not suitable for modelling extreme events. We evaluate the impact of dependence on the parameter estimates of Autoregressive (AR) and Moving Average (MA) processes with Gumbel distributed innovation. The performance of the parameter estimates of the Gumbelgeneralised Pareto distribution fitted to the autoregressive and moving average processes and their respective cluster maxima is also assess. The extension of time series to extreme value theory can be achieved by inducing time dependence in the underlying state of an extreme value process. Extreme values occur in clusters in the presence of dependence. Gumbel distribution, a member of the family of the generalised extreme value distribution is the possible limit for the entire range of tail behaviour between polynomial decrease and essentially a finite endpoint and it is known to fit well in many situations. It is important to make general statements that characterises time series extreme models over a range of sample sizes with varying degree of dependence. Such general characterisation for a given model is useful for the extremal behaviour of physical processes. To achieve our objectives, a stationary autoregressive and moving average models with Gumbel distributed innovation is proposed and we characterise the short-term dependence among maxima, arising from light-tailed Gumbel distribution over a range of sample sizes with varying degrees of dependence. Dependence is induced through a linear filter operation. The linear filter operation takes a weighted sum of past innovations. The estimate of the maximum likelihood of the parameters of the Gumbel autoregressive and Gumbel moving average processes and their respective residuals are evaluated. Gumbel-AR(1) and Gumbel-MA(1) was fitted to the Gumbel-generalised Pareto distribution and we evaluate the performance of the parameter estimates fitted to the cluster maxima and the original series. Ignoring the effect of dependence leads to overestimation of the location parameter of the Gumbel-AR(1) and Gumbel-MA(1) processes respectively. The estimate of the location parameter of the autoregressive process using the residuals gives a better estimate. The estimate of the scale parameter perform marginally better for the original series than the residual estimate. The degree of clustering increases as dependence is enhance for both the AR and MA processes. The Gumbel-AR(1) and Gumbel-MA(1) are fitted to the Gumbel-generalised Pareto distribution show that the estimates of the scale and shape parameters fitted to the cluster maxima perform better as sample size increases, however, ignoring the effect of dependence leads to an underestimation of the parameter estimates of the scale parameter. The shape parameter of the original series gives a superior estimate compare to the threshold excesses fitted to the Gumbel-generalised Pareto distribution.
format Thesis
qualification_level Master's degree
author Samuel, Bako Sunday
author_facet Samuel, Bako Sunday
author_sort Samuel, Bako Sunday
title Inference for autoregressive and moving average models with extreme value distribution via simulation study
title_short Inference for autoregressive and moving average models with extreme value distribution via simulation study
title_full Inference for autoregressive and moving average models with extreme value distribution via simulation study
title_fullStr Inference for autoregressive and moving average models with extreme value distribution via simulation study
title_full_unstemmed Inference for autoregressive and moving average models with extreme value distribution via simulation study
title_sort inference for autoregressive and moving average models with extreme value distribution via simulation study
granting_institution Universiti Putra Malaysia
publishDate 2015
url http://psasir.upm.edu.my/id/eprint/57064/1/FS%202015%205RR.pdf
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