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Optimising Archaeologic Ceramics XRF Analyses

Bergman, Jakob LU and Lindahl, Anders LU (2015) CoDaWork'15 In Proceedings of the 6th International Workshop on Compositional Data Analysis p.29-37
Abstract
We present the first results of an experiment which is aimed at ultimately producing recommendations for analysing archaeologic ceramics specimens using hand held XRF analysis devices. In the experiment we study the effects of different measurement durations, different number of measured points, and three different types of surface treatments (breakage, polished, grounded) when analysing ceramics specimens, while controlling for nine different types of clay and three different types of temper (no temper, sand, rock), in total almost 1000 analysed points. For each measurement, the proportions of 36 different elements and all other elements are estimated. In those cases with multiple measurements of a specimen, the compositional centre of... (More)
We present the first results of an experiment which is aimed at ultimately producing recommendations for analysing archaeologic ceramics specimens using hand held XRF analysis devices. In the experiment we study the effects of different measurement durations, different number of measured points, and three different types of surface treatments (breakage, polished, grounded) when analysing ceramics specimens, while controlling for nine different types of clay and three different types of temper (no temper, sand, rock), in total almost 1000 analysed points. For each measurement, the proportions of 36 different elements and all other elements are estimated. In those cases with multiple measurements of a specimen, the compositional centre of the measurements is calculated. A complicating issue in the analysis is the large number of parts found to be below detection limit; 13 elements have more than 50 % of the measurements below detection limit and for more than half of those (almost) all measurements are below detection limit. We try nine different strategies for imputing the values. Each estimated elemental composition is compared to a reference estimate using the simplicial distance. The log distances are finally analysed using analysis of variance with main and interaction effects. We find that the different surface treatments have the greatest effect on the distances: grounded specimens yield the most accurate estimates and polished surfaces the least. We also find a significant effect of increasing the number of measured points, but less effect of increasing the duration of the measurements. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Archaeologic XRF analyses, Archaeometric experiment, Ceramics analysis, Elemental composition analysis, Simplicial distance
in
Proceedings of the 6th International Workshop on Compositional Data Analysis
editor
Thió-Henestrosa, Santiago and Martín Fernández, Josep Antoni
pages
29 - 37
conference name
CoDaWork'15
ISBN
978-84-8458-451-3
language
English
LU publication?
yes
id
1aabc554-f9f0-43ed-b8b7-23ff201ebfc2 (old id 5471701)
alternative location
http://dugi-doc.udg.edu/handle/10256/150
date added to LUP
2015-08-21 10:49:27
date last changed
2016-04-16 12:34:40
@misc{1aabc554-f9f0-43ed-b8b7-23ff201ebfc2,
  abstract     = {We present the first results of an experiment which is aimed at ultimately producing recommendations for analysing archaeologic ceramics specimens using hand held XRF analysis devices. In the experiment we study the effects of different measurement durations, different number of measured points, and three different types of surface treatments (breakage, polished, grounded) when analysing ceramics specimens, while controlling for nine different types of clay and three different types of temper (no temper, sand, rock), in total almost 1000 analysed points. For each measurement, the proportions of 36 different elements and all other elements are estimated. In those cases with multiple measurements of a specimen, the compositional centre of the measurements is calculated. A complicating issue in the analysis is the large number of parts found to be below detection limit; 13 elements have more than 50 % of the measurements below detection limit and for more than half of those (almost) all measurements are below detection limit. We try nine different strategies for imputing the values. Each estimated elemental composition is compared to a reference estimate using the simplicial distance. The log distances are finally analysed using analysis of variance with main and interaction effects. We find that the different surface treatments have the greatest effect on the distances: grounded specimens yield the most accurate estimates and polished surfaces the least. We also find a significant effect of increasing the number of measured points, but less effect of increasing the duration of the measurements.},
  author       = {Bergman, Jakob and Lindahl, Anders},
  editor       = {Thió-Henestrosa, Santiago and Martín Fernández, Josep Antoni},
  isbn         = {978-84-8458-451-3},
  keyword      = {Archaeologic XRF analyses,Archaeometric experiment,Ceramics analysis,Elemental composition analysis,Simplicial distance},
  language     = {eng},
  pages        = {29--37},
  series       = {Proceedings of the 6th International Workshop on Compositional Data Analysis},
  title        = {Optimising Archaeologic Ceramics XRF Analyses},
  year         = {2015},
}