Zobrazeno 1 - 10
of 22
pro vyhledávání: '"Harstela, Pertti"'
Publikováno v:
Silva Fennica, Vol 44, Iss 3 (2010)
Economic result of forest regeneration chains, based either on spot mounding or on disc trenching and planting of Norway spruce (Picea abies [L.] Karst.) seedlings, were clarified and compared to each other. First, effects of soil preparation method
Externí odkaz:
https://doaj.org/article/630baa08b169426bad9d4edad49e9a55
Publikováno v:
Silva Fennica, Vol 43, Iss 4 (2009)
Techno-economically reasonable mechanization of tree planting has proved to be a difficult task in the Nordic working conditions. Although planting machines and combinations of base machine and planting device have been developed since the 1970s, mec
Externí odkaz:
https://doaj.org/article/cd673e3077c0412ea70f01494cfa4822
Publikováno v:
Silva Fennica, Vol 37, Iss 1 (2003)
Productivity and costs of packing container seedlings were studied in a mechanised line for packing and disinfecting seedling trays. The hypothesis was that adequate cost-efficiency could be achieved when some common principles of mechanisation were
Externí odkaz:
https://doaj.org/article/f1a7109f89f249aaaabeabd7c7055be1
Autor:
Harstela, Pertti
Publikováno v:
Silva Fennica, Vol 31, Iss 2 (1997)
Many kinds of planning systems have been labelled decision support systems (DSS), but few meet the most important features of real DSSs in planning and control of wood procurement. It has been concluded that many reasons exist to develop DSSs for woo
Externí odkaz:
https://doaj.org/article/bfbdbfb202fc4569b78164b0fe89c044
Publikováno v:
Silva Fennica, Vol 29, Iss 1 (1995)
The first aim of this study was to develop a simulation model describing the flow of different timber qualities to different firms. The second aim was to study preliminary the factors which affect timber distributions. In addition, we tested the hypo
Externí odkaz:
https://doaj.org/article/145c14a4c05e4435b4add6f7168bd111
Autor:
Kantola, Mikko, Harstela, Pertti
Publikováno v:
Silva Fennica, Vol 27, Iss 1 (1993)
The paper discussed the definitions of different Finnish and English terms concerning timber harvesting, and suggests definitions and translations of the terms.
Externí odkaz:
https://doaj.org/article/f68b497fa13c4aeb811cbff1400a321e
Autor:
Harstela, Pertti, Tervo, Leo
Publikováno v:
Silva Fennica, Vol 12, Iss 2 (1978)
A theoretical nomogram was made for estimating the costs of fully mechanized thinning and the driving speed of the machine. Based on this nomogram and the previous studies three harvesting methods were compared; systematic fully mechanized harvesting
Externí odkaz:
https://doaj.org/article/6c2038df2e1240c5a7ffedac7a33bf8f
Autor:
Harstela, Pertti
Publikováno v:
Silva Fennica, Vol 12, Iss 1 (1978)
The concepts central to ergonomic research connected with the amount of strain caused by work was studied. A model was made to describe the process of strain. The model includes the following concepts: load or stress, human input, worker, strain, ren
Externí odkaz:
https://doaj.org/article/e82485c22b514cafbdff703273cd0dd4
Autor:
Harstela, Pertti
Publikováno v:
Silva Fennica, Vol 14, Iss 1 (1980)
In the first part of the study the hindrance of the remaining trees when felling trees by machines working from the strip road in selective thinning was studied on the basis of the literature. In the second part there was geometrically studied the ne
Externí odkaz:
https://doaj.org/article/10cc6f59bc174fdfba25d07183b35748
Autor:
Harstela, Pertti, Maukkonen, Antti
Publikováno v:
Silva Fennica, Vol 17, Iss 2 (1983)
Using literature and a simulator experiment, an ordinary processor and a grapple loader processor were compared in conditions corresponding to thinning later than the first commercial thinning. Visual bucking only was employed in the simulator experi
Externí odkaz:
https://doaj.org/article/61404b9f5da14cb9b1b3dda01b97a36d