Change search
ReferencesLink to record
Permanent link

Direct link
Analys av fiberlängdsfördelning hos gran (Picea Abies) och tall (Pinus Sylvestris)
Umeå University, Faculty of Science and Technology, Department of Mathematics and Mathematical Statistics.
2007 (Swedish)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

Tree fiber lengths controls properties like strength and smoothness in paper and other wood products. For forest researchers it is of interest to be able to determine the fiber lengths in standing trees. Mörling et al. (2003), among others, have developed methods to estimate fiber length distributions in standing trees without damaging them. The methods require knowledge of the type of distribution that fiber lengths follow. In this thesis fiber lengths from spruce and pine are examined from 30mm high sticks. The purpose is to find a type of distribution that is flexible enough to capture many different kinds of fiber length distributions observed in the trees. The thesis continues the diploma work of Per Liv (2005) where five types of distributions were studied on fiber length data from spruce. He concluded that the distributions he tested were too symmetric to fit well to the data.

Here three other distributions were tested whose parameters were estimated using the maximum likelihood method and compared to the distributions from Liv’s work. The generalized gamma distribution turned out to describe fiber length data very well from both spruce and pine. Therefore one chapter is devoted to examples of discussions of hypothesis from forestry using this distribution. 

Place, publisher, year, edition, pages
2007. , 35 p.
National Category
Probability Theory and Statistics
URN: urn:nbn:se:umu:diva-51363OAI: diva2:479234
Physics, Chemistry, Mathematics
Available from: 2012-03-01 Created: 2012-01-17 Last updated: 2012-03-01Bibliographically approved

Open Access in DiVA

fulltext(424 kB)139 downloads
File information
File name FULLTEXT01.pdfFile size 424 kBChecksum SHA-512
Type fulltextMimetype application/pdf

By organisation
Department of Mathematics and Mathematical Statistics
Probability Theory and Statistics

Search outside of DiVA

GoogleGoogle Scholar
Total: 139 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 74 hits
ReferencesLink to record
Permanent link

Direct link