Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Knots and their effect on the tensile strength of lumber   When assessing the strength of sawn lumber for use in engineering
applications, the sizes and locations of knots are an important consideration.
Knots are the most common visual characteristics of lumber, that result from
the growth of tree branches. Large individual knots, as well as clusters of
distinct knots, are known to have strength-reducing effects. However, industry
grading rules that govern knots are informed by subjective judgment to some
extent. Thus, the spatial interaction of knots and their relationship with
lumber strength has not been fully understood. This paper reports the results
of a study that investigated and modelled the strength-reducing effects of
knots on a sample of Douglas Fir lumber. Experimental data were obtained by
taking scans of lumber surfaces and applying tensile strength testing. The
modelling approach presented incorporates all relevant knot information in a
Bayesian framework, thereby contributing a more refined way of managing the
quality of manufactured lumber.

7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
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The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc