Powered by OpenAIRE graph
Found an issue? Give us feedback
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Journal of Hydrologyarrow_drop_down
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao
Journal of Hydrology
Article . 2006 . Peer-reviewed
License: Elsevier TDM
Data sources: Crossref
versions View all 1 versions
addClaim

Fitting the log-logistic distribution by generalized moments

Authors: Fahim Ashkar; Smail Mahdi;

Fitting the log-logistic distribution by generalized moments

Abstract

Summary The method of generalized moments (GM) is investigated for parameter and quantile estimation in the 2-parameter log-logistic (LL2) model. Point estimators for the shape and scale parameters and quantiles are derived. Asymptotic variances and covariances for these estimators are presented, along with simulation results on the performance of the GM method versus the methods of generalized probability weighted moments (GPWM), of maximum likelihood (ML), and of classical moments applied to Y = ln X . The GPWM and ML methods have already been investigated by the authors. Some mathematical properties of the LL2 model and some relationships between GM and GPWM are highlighted. The simulation results show the GM method to outperform the other competitive methods in the LL2 case, when moment orders are appropriately chosen. It is also shown that a mixture of moments of positive and negative orders is needed for optimal estimation under an LL2 model, and how this mixture can be implemented using the GM method. However, further research into the area of optimal choice of moment orders is still needed. Mixing positive and negative moments in the estimation is demonstrated by a hydrological example involving low stream flow.

  • BIP!
    Impact byBIP!
    selected citations
    These citations are derived from selected sources.
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    70
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Top 10%
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Top 10%
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
Powered by OpenAIRE graph
Found an issue? Give us feedback
selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
70
Top 10%
Top 10%
Average
Upload OA version
Are you the author of this publication? Upload your Open Access version to Zenodo!
It’s fast and easy, just two clicks!