Geostatistical Modeling in Presence of Extreme ValuesReportar como inadecuado




Geostatistical Modeling in Presence of Extreme Values - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Outliers, Geostatistical Modeling, Extreme values

Babakhani, Mahshid

Supervisor and department: Deutsch, Clayton V. Civil and Environmental Engineering

Examining committee member and department: Askari Nasab, Hooman Civil and Environmental Engineering Boisver, Jeff B. Civil and Environmental Engineering Leung, Juliana Civil and Environmental Engineering

Department: Department of Civil and Environmental Engineering

Specialization:

Date accepted: 2014-04-29T15:48:09Z

Graduation date: 2014-11

Degree: Master of Science

Degree level: Master's

Abstract: Geostatistical modeling in presence of extreme values needs special attention. Certain extreme high values known as outliers require proper treatment or mineral resources may be overstated. A number of methodologies are proposed in this thesis to identify and manage outliers. The main goal of the outlier management strategies is to keep the outliers but control their influence on local block estimates, if required, by reducing their values.The variogram is an essential geostatistical tool that is highly sensitive to outlier high values. There are alternatives to the experimental traditional variogram. The pairwise relative variogram is known to be a very robust alternative to the experimental traditional variogram in presence of outlier high values. There are two issues with the pairwise relative variogram; 1 an unknown sill, and 2 its convergence to the wrong variogram. Solutions to both of these problems are developed and documented in this thesis. Another contribution of this thesis is a simulation-based approach for cutting outlier values. The volume of influence of an outlier is identified. The uncertainty in the mean of the volume of influence is established by simulation. Then, the outlier value is reduced until the estimated quantity of metal within the identified volume is reasonable relative to the distribution coming from simulation. The outlier management strategies presented in this thesis will provide practical assistance for geological modeling for engineering evaluations.

Language: English

DOI: doi:10.7939-R3VQ2SJ85

Rights: Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.





Autor: Babakhani, Mahshid

Fuente: https://era.library.ualberta.ca/


Introducción



Geostatistical Modeling in Presence of Extreme Values by Mahshid Babakhani A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Mining Engineering Department of Civil and Environmental Engineering University of Alberta ©Mahshid Babakhani, 2014 Abstract Geostatistical modeling in presence of extreme values needs special attention. Certain extreme high values known as outliers require proper treatment or mineral resources may be overstated.
A number of methodologies are proposed in this thesis to identify and manage outliers.
The main goal of the outlier management strategies is to keep the outliers but control their influence on local block estimates, if required, by reducing their values. The variogram is an essential geostatistical tool that is highly sensitive to outlier high values.
There are alternatives to the experimental traditional variogram.
The pairwise relative variogram is known to be a very robust alternative to the experimental traditional variogram in presence of outlier high values.
There are two issues with the pairwise relative variogram; (1) an unknown sill, and (2) its convergence to the wrong variogram.
Solutions to both of these problems are developed and documented in this thesis. Another contribution of this thesis is a simulation-based approach for cutting outlier values.
The volume of influence of an outlier is identified.
The uncertainty in the mean of the volume of influence is established by simulation.
Then, the outlier value is reduced until the estimated quantity of metal within the identified volume is reasonable relative to the distribution coming from simulation.
The outlier management strategies presented in this thesis will provide practical assistance for geological modeling for engineering evaluations. ii To my parents for their endless love and support iii Acknowledgments I would like to express my sincere gratitude to P...





Documentos relacionados