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Some statistical aspects of LULU smoothers

Thesis (PhD (Statistics and Actuarial Science))--University of Stellenbosch, 2007.

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Main Author: Jankowitz, Maria Dorothea
Other Authors: Conradie, W. J.
Format: Thesis
Language:English
Published: Stellenbosch : University of Stellenbosch 2008
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access_status_str Open Access
author Jankowitz, Maria Dorothea
author2 Conradie, W. J.
author_browse Conradie, W. J.
Jankowitz, Maria Dorothea
author_facet Conradie, W. J.
Jankowitz, Maria Dorothea
author_sort Jankowitz, Maria Dorothea
collection Thesis
dc_rights_str_mv University of Stellenbosch
description Thesis (PhD (Statistics and Actuarial Science))--University of Stellenbosch, 2007.
format Thesis
id oai:scholar.sun.ac.za:10019.1/1124
institution Stellenbosch University (South Africa)
language English
last_indexed 2026-06-10T12:43:13.574Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2008
publishDateRange 2008
publishDateSort 2008
publisher Stellenbosch : University of Stellenbosch
publisherStr Stellenbosch : University of Stellenbosch
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source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/1124 Some statistical aspects of LULU smoothers Jankowitz, Maria Dorothea Conradie, W. J. De Wet, Tertius University of Stellenbosch. Faculty of Economic and Management Sciences. Dept. of Statistics and Actuarial Science. Smoothing (Statistics) Estimation theory Dissertations -- Statistics and actuarial science Theses -- Statistics and actuarial science Thesis (PhD (Statistics and Actuarial Science))--University of Stellenbosch, 2007. The smoothing of time series plays a very important role in various practical applications. Estimating the signal and removing the noise is the main goal of smoothing. Traditionally linear smoothers were used, but nonlinear smoothers became more popular through the years. From the family of nonlinear smoothers, the class of median smoothers, based on order statistics, is the most popular. A new class of nonlinear smoothers, called LULU smoothers, was developed by using the minimum and maximum selectors. These smoothers have very attractive mathematical properties. In this thesis their statistical properties are investigated and compared to that of the class of median smoothers. Smoothing, together with related concepts, are discussed in general. Thereafter, the class of median smoothers, from the literature is discussed. The class of LULU smoothers is defined, their properties are explained and new contributions are made. The compound LULU smoother is introduced and its property of variation decomposition is discussed. The probability distributions of some LULUsmoothers with independent data are derived. LULU smoothers and median smoothers are compared according to the properties of monotonicity, idempotency, co-idempotency, stability, edge preservation, output distributions and variation decomposition. A comparison is made of their respective abilities for signal recovery by means of simulations. The success of the smoothers in recovering the signal is measured by the integrated mean square error and the regression coefficient calculated from the least squares regression of the smoothed sequence on the signal. Finally, LULU smoothers are practically applied. Doctoral 2008-03-27T11:48:58Z 2010-06-01T08:13:03Z 2008-03-27T11:48:58Z 2010-06-01T08:13:03Z 2007-12 Thesis http://hdl.handle.net/10019.1/1124 en University of Stellenbosch 2521458 bytes application/pdf application/pdf Stellenbosch : University of Stellenbosch
spellingShingle Smoothing (Statistics)
Estimation theory
Dissertations -- Statistics and actuarial science
Theses -- Statistics and actuarial science
Jankowitz, Maria Dorothea
Some statistical aspects of LULU smoothers
title Some statistical aspects of LULU smoothers
title_full Some statistical aspects of LULU smoothers
title_fullStr Some statistical aspects of LULU smoothers
title_full_unstemmed Some statistical aspects of LULU smoothers
title_short Some statistical aspects of LULU smoothers
title_sort some statistical aspects of lulu smoothers
topic Smoothing (Statistics)
Estimation theory
Dissertations -- Statistics and actuarial science
Theses -- Statistics and actuarial science
url http://hdl.handle.net/10019.1/1124
work_keys_str_mv AT jankowitzmariadorothea somestatisticalaspectsoflulusmoothers