Repeatability in automatic sorting of curved Norway spruce saw logs
Sawn wood from curved logs is prone to have cross grain and contain compression wood, both of which affect the dimensional stability. Different types of curvature can, however, have different effects on both the sawing process and board quality, which is why a standard measure of bow height alon...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Finnish Society of Forest Science
2005-01-01
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| Series: | Silva Fennica |
| Online Access: | https://www.silvafennica.fi/article/388 |
| _version_ | 1818528594577588224 |
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| author | Edlund, Jacob Warensjö, Mats |
| author_facet | Edlund, Jacob Warensjö, Mats |
| author_sort | Edlund, Jacob |
| collection | DOAJ |
| description | Sawn wood from curved logs is prone to have cross grain and contain compression wood, both of which affect the dimensional stability. Different types of curvature can, however, have different effects on both the sawing process and board quality, which is why a standard measure of bow height alone is not enough to sort logs or set the log quality. The aim of this study was to evaluate the repeatability when sorting curved saw logs using a 3D log scanner. In the study, 56 logs were categorized into five different curvature types and four different degrees of curvature severity. The logs were run through a Rema 3D log scanner four times, and the external geometry was recorded. From the geometry data, variables describing log shapes were calculated and used to develop models using linear discriminant analysis, which was used to classify the logs according to curvature type. The accuracy and repeatability were evaluated for the classifications with Cohenâs simple Kappa coefficient. The results of this study showed that it is possible to sort logs by curve type using a 3D log scanner, although sorting by curve type was largely dependent on curve severity. The repeatability test determined that the chance of a curved log being graded identically two consecutive times was 0.40, measured as kappa. |
| first_indexed | 2024-12-11T06:52:01Z |
| format | Article |
| id | doaj.art-cb37db1fb0fc4a7c91874c9348c816c4 |
| institution | Directory Open Access Journal |
| issn | 2242-4075 |
| language | English |
| last_indexed | 2024-12-11T06:52:01Z |
| publishDate | 2005-01-01 |
| publisher | Finnish Society of Forest Science |
| record_format | Article |
| series | Silva Fennica |
| spelling | doaj.art-cb37db1fb0fc4a7c91874c9348c816c42022-12-22T01:16:53ZengFinnish Society of Forest ScienceSilva Fennica2242-40752005-01-0139210.14214/sf.388Repeatability in automatic sorting of curved Norway spruce saw logsEdlund, JacobWarensjö, MatsSawn wood from curved logs is prone to have cross grain and contain compression wood, both of which affect the dimensional stability. Different types of curvature can, however, have different effects on both the sawing process and board quality, which is why a standard measure of bow height alone is not enough to sort logs or set the log quality. The aim of this study was to evaluate the repeatability when sorting curved saw logs using a 3D log scanner. In the study, 56 logs were categorized into five different curvature types and four different degrees of curvature severity. The logs were run through a Rema 3D log scanner four times, and the external geometry was recorded. From the geometry data, variables describing log shapes were calculated and used to develop models using linear discriminant analysis, which was used to classify the logs according to curvature type. The accuracy and repeatability were evaluated for the classifications with Cohenâs simple Kappa coefficient. The results of this study showed that it is possible to sort logs by curve type using a 3D log scanner, although sorting by curve type was largely dependent on curve severity. The repeatability test determined that the chance of a curved log being graded identically two consecutive times was 0.40, measured as kappa.https://www.silvafennica.fi/article/388 |
| spellingShingle | Edlund, Jacob Warensjö, Mats Repeatability in automatic sorting of curved Norway spruce saw logs Silva Fennica |
| title | Repeatability in automatic sorting of curved Norway spruce saw logs |
| title_full | Repeatability in automatic sorting of curved Norway spruce saw logs |
| title_fullStr | Repeatability in automatic sorting of curved Norway spruce saw logs |
| title_full_unstemmed | Repeatability in automatic sorting of curved Norway spruce saw logs |
| title_short | Repeatability in automatic sorting of curved Norway spruce saw logs |
| title_sort | repeatability in automatic sorting of curved norway spruce saw logs |
| url | https://www.silvafennica.fi/article/388 |
| work_keys_str_mv | AT edlundjacob repeatabilityinautomaticsortingofcurvednorwaysprucesawlogs AT warensjomats repeatabilityinautomaticsortingofcurvednorwaysprucesawlogs |