Methods for Extreme Value Statistics Based on Measured Time Series

• Main Author: Haug, Even
• Format: Others
• Language: English
• Published: Norges teknisk-naturvitenskapelige universitet, Institutt for matematiske fag 2008
• Subjects: ntnudaim; SIF3 fysikk og matematikk; Industriell matematikk
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9733

The thesis describes the Average Exceedance Rate (AER) method, which is a method for predicting return levels from sampled time series. The AER method is an alternative to the Peaks over threshold (POT) method, which is based on the assumption that data exceeding a certain threshold will behave asymptotically. The AER methods avoids this assumption by using sub-asymptotic data instead. Also, instead of using declustering to obtain independent data, correlation among the data is dealt with by assuming a Markov-like property. A practical procedure for using the AER method is proposed and tested on two sets of real data. These are a set of wind speed data from Norway and a set of wave height data from the Norwegian continental shelf. From the results, the method appears to give satisfactory results for the wind speed data, but for the wave height data its use appears to be invalid. However, the method itself seems to be robust, and to have certain advantages when compared to the POT method.