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A comparison of two methods of data collection for modelling productivity of harvesters: manual time study and follow-up study using on-board-computer stem records / Julia Brewer in Annals of forest research, vol 61 n° 1 (January - June 2018)  

Public [article]  inAnnals of forest research > vol 61 n° 1 (January - June 2018) . - pp 109 - 124 Titre : A comparison of two methods of data collection for modelling productivity of harvesters: manual time study and follow-up study using on-board-computer stem records Type de document : Article/Communication Auteurs : Julia Brewer, Auteur ; Bruce Talbot, Auteur ; Helmer Belbo, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 109 - 124 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative [Termes IGN] coupe (sylviculture) [Termes IGN] diamètre à hauteur de poitrine [Termes IGN] modèle numérique [Termes IGN] Pinus patula [Termes IGN] productivité [Termes IGN] récolte de bois [Vedettes matières IGN] Sylviculture Résumé : (auteur) Productivity of a mechanized P. patula cut-to-length harvesting operation was estimated and modelled using two methods of data collection: manual time study and follow-up study using StanForD stem files. The objective of the study was to compare the productivity models derived using these two methods to test for equivalence. Manual time studies were completed on four different machines and their operators. Two Ponsse Bear harvesters fitted with H8 heads, and two Ponsse Beaver harvesters, fitted with H6 heads, were included. All machines were equipped with Ponsse Opti2 information system. All four operators had approximately 1 year of experience working with their respective machines. The four machines worked in separate four-tree-wide harvesting corridors, and they each harvested 200 trees. Individual tree diameter at breast height (DBH), and height measurements were made manually. Subsequently, data on the trees in each study were extracted from the StanForD stem reports from each of the harvesters. Cycle times in the stem reports were determined based on the difference between consecutive harvest timestamps. The two methods were compared in terms of their abilities to estimate equivalent measures for tree DBH, volume, and productivity. In all four cases, significant differences were found between the DBH and volume measures derived using the two methods. Subsequently, the volume measures from the manual methods were used as the basis for productivity calculations. Results of the productivity comparisons found no significant differences between the models developed from the two methods. These results suggest that equivalent productivity models can be developed in terms of time using either method, however volume discrepancies indicate a need to reconcile bark and volume functions with the high variability experienced in the country. Numéro de notice : A2019-559 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.15287/afr.2018.962 Date de publication en ligne : 13/04/2019 En ligne : https://doi.org/10.15287/afr.2018.962 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93343 [article]