waves-16-arma

git clone https://git.igankevich.com/waves-16-arma.git
Log | Files | Refs

commit 028a90c6e8e30d05fcdc917534a1dfdaff1d914e
parent 53199fcfd1024b62726397f0b2e27499cb5a052b
Author: Ivan Gankevich <igankevich@ya.ru>
Date:   Mon, 29 May 2017 17:29:57 +0300

Edit related work.

Diffstat:
arma.org | 70+++++++++++++++++++++++++++++++++++-----------------------------------
1 file changed, 35 insertions(+), 35 deletions(-)

diff --git a/arma.org b/arma.org @@ -121,41 +121,41 @@ long-term simulation. * Related work ** Ocean wave modelling -One of the first application of ARMA model for oceanological processes modelling -was done in\nbsp{}cite:rozhkov1990. Another approach to modelling wind waves is -possible in terms of the representation of a stochastic moving surface as a -linear transformation of white noise with memory. These methods are one of the -most popular ways of modelling stationary ergodic Gaussian random processes with -given correlation characteristics\nbsp{}cite:box1976time. However, these methods -were not used to simulate wind waves for a long time. The first attempts to -model two-dimensional disturbances were undertaken in the early 70's -(cf.\nbsp{}cite:kostecki1972stochastic), and the impetus for this was the -development of the resonance theory of waves in wind. However, the formal -mathematical framework was developed in\nbsp{}cite:rozhkov1990,gurgenidze1988. -They built a one-dimensional model of ocean waves, on the basis of an -autoregressive-moving average (ARMA) model. - -In\nbsp{}cite:spanos1982arma ARMA model is used to generate time series spectrum of -which is compatible with Pierson---Moskowitz (PM) approximation of ocean wave -spectrum. The authors carry out experiments for one-dimensional AR, MA and ARMA -models. They mention excellent agreement between target and initial spectra and -higher performance of ARMA model compared to models based on summing large -number of harmonic components with random phases. The also mention that in order -to reach agreement between target and initial spectrum MA model require lesser -number of coefficients than AR model. In\nbsp{}cite:spanos1996efficient the authors -generalise ARMA model coefficients determination formulae for multi-variate -(vector) case. - -In\nbsp{}cite:fusco2010short AR model is used to predict swell waves to control -wave-energy converters (WEC) in real-time. In order to make WEC more efficient -its internal oscillator frequency should match the one of ocean waves. The -authors treat wave elevation as time series and compare performance of AR model, -neural networks and cyclical models in forecasting time series future values. AR -model gives the most accurate prediction of low-frequency swell waves for up to -two typical wave periods. It is an example of successful application of AR -process to ocean wave modelling. - -One thing that distinguishes present work with respect to afore-mentioned ones +Another approach to simulating sea waves involves representing stochastic moving +surface as a linear transformation of white noise with memory, which allows to +model stationary ergodic Gaussian random process with given correlation +characteristics\nbsp{}cite:box1976time. The first attempts to model +two-dimensional disturbances were undertaken +in\nbsp{}cite:kostecki1972stochastic, which resulted in the development of the +resonance theory of wind waves, and the formal mathematical framework was +developed in\nbsp{}cite:rozhkov1990,gurgenidze1988 --- the authors built a +one-dimensional model of ocean waves based on autoregressive-moving +average (ARMA) model. + +One-dimensional ARMA model does not have some of the LH model deficiencies: it +is both computationally efficient and requires less number of coefficients to +converge. In\nbsp{}cite:spanos1982arma ARMA model is used to generate time +series spectrum of which is compatible with Pierson---Moskowitz (PM) +approximation of ocean wave spectrum. The authors carry out experiments for +one-dimensional AR, MA and ARMA models. They mention excellent agreement between +target and initial spectra and higher performance of ARMA model compared to +models based on summing large number of harmonic components with random phases. +They also mention that in order to reach agreement between target and initial +spectrum MA model require lesser number of coefficients than AR model. +In\nbsp{}cite:spanos1996efficient the authors generalise ARMA model coefficients +determination formulae for multi-variate case. + +AR model was successfully applied to predict evolution of propagating wave +profiles based on instantaneous wave recordings. In\nbsp{}cite:fusco2010short AR +model is used to predict swell waves to control wave-energy converters (WEC) in +real-time. In order to make WEC more efficient its internal oscillator frequency +should match the one of ocean waves. The authors treat wave elevation as time +series and compare performance of AR model, neural networks and cyclical models +in forecasting time series future values. AR model gives the most accurate +prediction of low-frequency swell waves for up to two typical wave periods. It +is an example of successful application of AR process to ocean wave modelling. + +The feature that distinguishes present work with respect to afore-mentioned ones is the study of three-dimensional (2D in space and 1D in time) ARMA model, which is mostly a different problem. 1. Yule---Walker system of equations, which are used to determine AR