Pub Date : 2022-05-06DOI: 10.1080/14942119.2022.2071142
M. Johansson, Emanuel Erlandsson, Thomas Kronholm, O. Lindroos
ABSTRACT In many parts of the world, contractors account for the main share of harvesting work. Harvesting is characterized by innate complexity and volatility, and this can affect contractors’ workflow and ultimately their profitability. Thus, there is certainly a need for flexibility in harvesting service provision and procedures, but our current knowledge about contractors’ workflow variations are limited. This study investigates workflow variations in harvesting services by comparing monthly variations between contractors’ workload in terms of harvested volumes and the time spent on operations. The data originates from 77 machines belonging to contractors and their harvesting of 6.6 million m3 of roundwood in Sweden during a two-year period. The results indicate differences between contractors’ workflow variations which can be attributed to the number of machines, machine sizes, and the workload in harvested volume and hours. These findings are relevant for guiding both the customer and contractor in this business relationship, and they could also serve as a basis for further research on the need for flexibility to effectively increase and decrease volume production in harvesting services.
{"title":"The need for flexibility in forest harvesting services – a case study on contractors’ workflow variations","authors":"M. Johansson, Emanuel Erlandsson, Thomas Kronholm, O. Lindroos","doi":"10.1080/14942119.2022.2071142","DOIUrl":"https://doi.org/10.1080/14942119.2022.2071142","url":null,"abstract":"ABSTRACT In many parts of the world, contractors account for the main share of harvesting work. Harvesting is characterized by innate complexity and volatility, and this can affect contractors’ workflow and ultimately their profitability. Thus, there is certainly a need for flexibility in harvesting service provision and procedures, but our current knowledge about contractors’ workflow variations are limited. This study investigates workflow variations in harvesting services by comparing monthly variations between contractors’ workload in terms of harvested volumes and the time spent on operations. The data originates from 77 machines belonging to contractors and their harvesting of 6.6 million m3 of roundwood in Sweden during a two-year period. The results indicate differences between contractors’ workflow variations which can be attributed to the number of machines, machine sizes, and the workload in harvested volume and hours. These findings are relevant for guiding both the customer and contractor in this business relationship, and they could also serve as a basis for further research on the need for flexibility to effectively increase and decrease volume production in harvesting services.","PeriodicalId":55998,"journal":{"name":"International Journal of Forest Engineering","volume":"34 1","pages":"13 - 25"},"PeriodicalIF":1.9,"publicationDate":"2022-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46703383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-26DOI: 10.1080/14942119.2022.2068291
Simon Schmiedel, Daniel Beaudoin, M. Rönnqvist
ABSTRACT Working methods used by harvester operators greatly affect their productivity. However, there might be further improvements in the ability to use multiple working methods by choosing the right method for the stand being harvested. The aim of this study was to assess the productivity of multiple working methods in an array of stand characteristics and to quantify the productivity gains of adapting the operator’s working method to the stand. To do so, we developed a discrete-event simulation model of a harvester. In total, 36 working methods were simulated in 50 different forest corridors of varying tree densities and tree heights, in clear-cut scenarios. While we observed differences in productivity of up to 18.56% between working methods in the same corridor, no method outperformed the others in all conditions. Some working methods were found to be unproductive in every stand condition, and the largest productivity gains came from avoiding them. The upper bound of the productivity gains from adapting the working method to the stand was 2.66%. These results suggest adapting the working method to the stand may not be worthwhile for harvester operators.
{"title":"Stand-specific working methods for harvester operators: a simulation study","authors":"Simon Schmiedel, Daniel Beaudoin, M. Rönnqvist","doi":"10.1080/14942119.2022.2068291","DOIUrl":"https://doi.org/10.1080/14942119.2022.2068291","url":null,"abstract":"ABSTRACT Working methods used by harvester operators greatly affect their productivity. However, there might be further improvements in the ability to use multiple working methods by choosing the right method for the stand being harvested. The aim of this study was to assess the productivity of multiple working methods in an array of stand characteristics and to quantify the productivity gains of adapting the operator’s working method to the stand. To do so, we developed a discrete-event simulation model of a harvester. In total, 36 working methods were simulated in 50 different forest corridors of varying tree densities and tree heights, in clear-cut scenarios. While we observed differences in productivity of up to 18.56% between working methods in the same corridor, no method outperformed the others in all conditions. Some working methods were found to be unproductive in every stand condition, and the largest productivity gains came from avoiding them. The upper bound of the productivity gains from adapting the working method to the stand was 2.66%. These results suggest adapting the working method to the stand may not be worthwhile for harvester operators.","PeriodicalId":55998,"journal":{"name":"International Journal of Forest Engineering","volume":"33 1","pages":"250 - 261"},"PeriodicalIF":1.9,"publicationDate":"2022-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43312710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-24DOI: 10.1080/14942119.2022.2061889
A. O. Akay, M. Akgul, A. İ. Esin, N. Şenturk
ABSTRACT The aim of this study is to analyze the forestry sector and the total work-related occupational accidents in Turkey in terms of incidence rate (IR), frequency rate (FR) and severity rate (SR) between 2008 and 2018 to compare those rates with some other sectors (mining, construction, metal and textile). According to the evaluation results, the IR and FR in the forestry sector are 41.1% and 40.8%, respectively, of all sector values in Turkey, while there is a negligible difference between the SR. The forestry sector, in terms of fatal occupational accidents, for both IR and FR showed a similar tendency across Turkey; non-fatal accident rates had lower values across the country. Moreover, it has been concluded that the forestry sector has generally better values than the metal, mining, and construction sectors and worse than the textile sector. In order to ensure safer performance in occupational accidents in the forestry sector, it is important to establish policies to increase awareness of occupational health and safety, since forest workers are exposed to different climate, topography, and vegetation types in terms of working conditions. In future studies, long-term evaluation of the data sets will increase the accuracy of occupational accidents evaluation models.
{"title":"Evaluation of occupational accidents in forestry in terms of incidence, frequency, and severity rates in Turkey","authors":"A. O. Akay, M. Akgul, A. İ. Esin, N. Şenturk","doi":"10.1080/14942119.2022.2061889","DOIUrl":"https://doi.org/10.1080/14942119.2022.2061889","url":null,"abstract":"ABSTRACT The aim of this study is to analyze the forestry sector and the total work-related occupational accidents in Turkey in terms of incidence rate (IR), frequency rate (FR) and severity rate (SR) between 2008 and 2018 to compare those rates with some other sectors (mining, construction, metal and textile). According to the evaluation results, the IR and FR in the forestry sector are 41.1% and 40.8%, respectively, of all sector values in Turkey, while there is a negligible difference between the SR. The forestry sector, in terms of fatal occupational accidents, for both IR and FR showed a similar tendency across Turkey; non-fatal accident rates had lower values across the country. Moreover, it has been concluded that the forestry sector has generally better values than the metal, mining, and construction sectors and worse than the textile sector. In order to ensure safer performance in occupational accidents in the forestry sector, it is important to establish policies to increase awareness of occupational health and safety, since forest workers are exposed to different climate, topography, and vegetation types in terms of working conditions. In future studies, long-term evaluation of the data sets will increase the accuracy of occupational accidents evaluation models.","PeriodicalId":55998,"journal":{"name":"International Journal of Forest Engineering","volume":"34 1","pages":"26 - 34"},"PeriodicalIF":1.9,"publicationDate":"2022-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59938016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-22DOI: 10.1080/14942119.2022.2064654
Michael Starke, C. Geiger
ABSTRACT When assessing forest road conditions, information about waterlogged areas on gravel roads brings high practical value when used as an indicator for road wear. Around these perimeters, lowered binding forces of the construction material reduce the stability of the road, which induces accelerated road damage. When a road is actively used to access a logging site under humid weather or thawing conditions, road wear can build up fast and make further use of the road critical. In this study, a deep learning algorithm was trained to test the detection of a combined observation of waterlogged appearances on forest roads from video and image data, collected from a passing vehicle’s perspective. The training of a YOLO v5s model achieved an F1-score of 0.59 and shows the applicability of this approach with high confidence of detection. Evaluating further training characteristics such as precision, recall, and the object size-related detection confidence reveals challenges for a successful application in terms of undetected objects, variation of objects in the training step, the required amount of training data and the object distance focused.
{"title":"Machine vision based waterlogged area detection for gravel road condition monitoring","authors":"Michael Starke, C. Geiger","doi":"10.1080/14942119.2022.2064654","DOIUrl":"https://doi.org/10.1080/14942119.2022.2064654","url":null,"abstract":"ABSTRACT When assessing forest road conditions, information about waterlogged areas on gravel roads brings high practical value when used as an indicator for road wear. Around these perimeters, lowered binding forces of the construction material reduce the stability of the road, which induces accelerated road damage. When a road is actively used to access a logging site under humid weather or thawing conditions, road wear can build up fast and make further use of the road critical. In this study, a deep learning algorithm was trained to test the detection of a combined observation of waterlogged appearances on forest roads from video and image data, collected from a passing vehicle’s perspective. The training of a YOLO v5s model achieved an F1-score of 0.59 and shows the applicability of this approach with high confidence of detection. Evaluating further training characteristics such as precision, recall, and the object size-related detection confidence reveals challenges for a successful application in terms of undetected objects, variation of objects in the training step, the required amount of training data and the object distance focused.","PeriodicalId":55998,"journal":{"name":"International Journal of Forest Engineering","volume":"33 1","pages":"243 - 249"},"PeriodicalIF":1.9,"publicationDate":"2022-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48748482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-19DOI: 10.1080/14942119.2022.2055442
S. Sadeghi, A. Solgi, P. Tsioras
ABSTRACT Machine traffic during wood harvesting causes damage to forest soils. Whereas increased soil damage has been associated with increased traffic frequency and soil water content, the impact of travel speed on soil disturbance, still remains unclear. We examined the effects of traffic frequency, travel speed, and soil water content on the dry bulk density, total porosity and rut depth of skidding trail soil in an Iranian temperate forest. The studied treatments included combinations of five traffic frequencies (1, 3, 7, 10, and 15 passes) of a rubber-tired skidder, three levels of travel speed (1, 3, and 5 m s−1) and two levels of soil water content (18% and 31%). The impact on soil properties was greatest during the initial skidder passes. At higher water content, only one skidder pass was required to cause substantial increases in soil bulk density compared to the control plots, at all travel speed levels. Regardless of traffic frequency and water content, a lower travel speed caused substantially greater increases in dry bulk density and greater decreases in soil porosity than did a higher travel speed. Furthermore, higher soil water content resulted in deeper ruts at all combinations of traffic intensity and travel speed. In conclusion, fewer skidder passes at a slower travel speed were required to achieve substantial soil disturbance than was the case at a faster travel speed, possibly due to the higher amount of vibration, and consequently compaction exerted during a machine pass at a slower speed.
摘要木材采伐过程中的机器运输会对森林土壤造成破坏。尽管土壤破坏的增加与交通频率和土壤含水量的增加有关，但行驶速度对土壤扰动的影响仍不清楚。我们研究了交通频率、行驶速度和土壤含水量对伊朗温带森林中打滑小道土壤干容重、总孔隙度和车辙深度的影响。所研究的处理包括橡胶疲劳集材机的五种通行频率（1、3、7、10和15次通行）、三个行驶速度水平（1、三和5 m s−1）和两个土壤含水量水平（18%和31%）的组合。对土壤性质的影响在最初的集材机道次中最大。在含水量较高的情况下，在所有行驶速度水平下，与对照地块相比，只需要一次集材机通过即可使土壤容重显著增加。无论交通频率和含水量如何，与较高的行驶速度相比，较低的行驶速度导致干体积密度显著增加，土壤孔隙度显著降低。此外，在交通强度和行驶速度的所有组合下，较高的土壤含水量都会导致更深的车辙。总之，与在较快行进速度下的情况相比，在较慢行进速度下需要较少的集材机通过来实现实质性的土壤扰动，这可能是由于较高的振动量，以及因此在较慢速度的机器通过期间施加的压实。
{"title":"Effects of traffic intensity and travel speed on forest soil disturbance at different soil moisture conditions","authors":"S. Sadeghi, A. Solgi, P. Tsioras","doi":"10.1080/14942119.2022.2055442","DOIUrl":"https://doi.org/10.1080/14942119.2022.2055442","url":null,"abstract":"ABSTRACT Machine traffic during wood harvesting causes damage to forest soils. Whereas increased soil damage has been associated with increased traffic frequency and soil water content, the impact of travel speed on soil disturbance, still remains unclear. We examined the effects of traffic frequency, travel speed, and soil water content on the dry bulk density, total porosity and rut depth of skidding trail soil in an Iranian temperate forest. The studied treatments included combinations of five traffic frequencies (1, 3, 7, 10, and 15 passes) of a rubber-tired skidder, three levels of travel speed (1, 3, and 5 m s−1) and two levels of soil water content (18% and 31%). The impact on soil properties was greatest during the initial skidder passes. At higher water content, only one skidder pass was required to cause substantial increases in soil bulk density compared to the control plots, at all travel speed levels. Regardless of traffic frequency and water content, a lower travel speed caused substantially greater increases in dry bulk density and greater decreases in soil porosity than did a higher travel speed. Furthermore, higher soil water content resulted in deeper ruts at all combinations of traffic intensity and travel speed. In conclusion, fewer skidder passes at a slower travel speed were required to achieve substantial soil disturbance than was the case at a faster travel speed, possibly due to the higher amount of vibration, and consequently compaction exerted during a machine pass at a slower speed.","PeriodicalId":55998,"journal":{"name":"International Journal of Forest Engineering","volume":"33 1","pages":"146 - 154"},"PeriodicalIF":1.9,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49447161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-17DOI: 10.1080/14942119.2022.2058258
D. Bergström, Raul Fernandez-Lacruz, Teresa de la Fuente, Christian Höök, N. Krajnc, J. Malinen, Y. Nuutinen, M. Triplat, T. Nordfjell
ABSTRACT Biomass derived from small-diameter, dense, thinning stands is largely underutilized within the European Union, mainly because of in-effective harvesting methods and cutting technology, leading to high supply costs. Therefore, the efficacy of boom-corridor thinning (BCT) and selective thinning (ST) on harvester felling and bunching productivity was compared for the first thinning of whole tree biomass in small-diameter, dense stands. BCT working method is when trees are cut with linear movements of the harvester’s boom reach, along narrow corridors, instead of cutting each tree selectively (ST). Trials were performed in six forest stands, one in Sweden, two in Finland, and three in Slovenia, using the same harvester and operator. A time-and-motion study was carried out in 64 pre-marked study units (32 replications per method), across a variety of stand conditions. The biomass removal for both treatments averaged 40.2 dry t ha -1 and BCT productivity averaged 5.4 dry t PMh -1. For BCT, harvester work time consumption (sec tree -1) and productivity (dry t PMh -1) were on average 27% lower and 16% higher, respectively, compared with ST. The effectiveness of the accumulating felling head technology used could potentially be increased by implementing a feed-roller system when handling excessive tree lengths. Developing dedicated harvesting technology for BCT could further boost productivity, facilitating cost-effective and sustainable utilization of low-value small-diameter tree biomass and replacing fossil resources.
{"title":"Effects of boom-corridor thinning on harvester productivity and residual stand structure","authors":"D. Bergström, Raul Fernandez-Lacruz, Teresa de la Fuente, Christian Höök, N. Krajnc, J. Malinen, Y. Nuutinen, M. Triplat, T. Nordfjell","doi":"10.1080/14942119.2022.2058258","DOIUrl":"https://doi.org/10.1080/14942119.2022.2058258","url":null,"abstract":"ABSTRACT Biomass derived from small-diameter, dense, thinning stands is largely underutilized within the European Union, mainly because of in-effective harvesting methods and cutting technology, leading to high supply costs. Therefore, the efficacy of boom-corridor thinning (BCT) and selective thinning (ST) on harvester felling and bunching productivity was compared for the first thinning of whole tree biomass in small-diameter, dense stands. BCT working method is when trees are cut with linear movements of the harvester’s boom reach, along narrow corridors, instead of cutting each tree selectively (ST). Trials were performed in six forest stands, one in Sweden, two in Finland, and three in Slovenia, using the same harvester and operator. A time-and-motion study was carried out in 64 pre-marked study units (32 replications per method), across a variety of stand conditions. The biomass removal for both treatments averaged 40.2 dry t ha -1 and BCT productivity averaged 5.4 dry t PMh -1. For BCT, harvester work time consumption (sec tree -1) and productivity (dry t PMh -1) were on average 27% lower and 16% higher, respectively, compared with ST. The effectiveness of the accumulating felling head technology used could potentially be increased by implementing a feed-roller system when handling excessive tree lengths. Developing dedicated harvesting technology for BCT could further boost productivity, facilitating cost-effective and sustainable utilization of low-value small-diameter tree biomass and replacing fossil resources.","PeriodicalId":55998,"journal":{"name":"International Journal of Forest Engineering","volume":"33 1","pages":"226 - 242"},"PeriodicalIF":1.9,"publicationDate":"2022-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41996176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-11DOI: 10.1080/14942119.2022.2051159
L. Bont, Laura Ramstein, F. Frutig, J. Schweier
ABSTRACT Cable-based technologies are the backbone of timber harvesting on steep slopes. To simplify the cable road design process, the QGIS plugin Seilaplan was recently developed. Seilaplan is tailored for Central European cable yarder technology, with standing skylines. To analyze and predict the load path and occurring forces, the close-to-catenary Zweifel approach is implemented in Seilaplan. The aim of this study was to validate the catenary analyses (deflection and skyline tensile force) under realistic, heavy load conditions for multi-span cable roads. The main finding is that sufficient accuracy, for practical applications under real loading configurations and cable road settings, can be achieved by applying the Zweifel approach. This holds for both the predicted static skyline tensile force, for which a deviation of −3.5 % to +12.7 % was measured (root mean square error [RMSE] = 7 kN), and for the deflection, which deviated from measured values by −0.73 m to +0.9 m (RMSE = 0.5 m). A slight limitation of the implemented Zweifel approach is the missing aspect of the mainline loading, in particular for steep spans.
{"title":"Tensile forces and deflections on skylines of cable yarders: comparison of measurements with close-to-catenary predictions","authors":"L. Bont, Laura Ramstein, F. Frutig, J. Schweier","doi":"10.1080/14942119.2022.2051159","DOIUrl":"https://doi.org/10.1080/14942119.2022.2051159","url":null,"abstract":"ABSTRACT Cable-based technologies are the backbone of timber harvesting on steep slopes. To simplify the cable road design process, the QGIS plugin Seilaplan was recently developed. Seilaplan is tailored for Central European cable yarder technology, with standing skylines. To analyze and predict the load path and occurring forces, the close-to-catenary Zweifel approach is implemented in Seilaplan. The aim of this study was to validate the catenary analyses (deflection and skyline tensile force) under realistic, heavy load conditions for multi-span cable roads. The main finding is that sufficient accuracy, for practical applications under real loading configurations and cable road settings, can be achieved by applying the Zweifel approach. This holds for both the predicted static skyline tensile force, for which a deviation of −3.5 % to +12.7 % was measured (root mean square error [RMSE] = 7 kN), and for the deflection, which deviated from measured values by −0.73 m to +0.9 m (RMSE = 0.5 m). A slight limitation of the implemented Zweifel approach is the missing aspect of the mainline loading, in particular for steep spans.","PeriodicalId":55998,"journal":{"name":"International Journal of Forest Engineering","volume":"33 1","pages":"195 - 216"},"PeriodicalIF":1.9,"publicationDate":"2022-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49453193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-04DOI: 10.1080/14942119.2022.2055411
C. K. Lyons, Jeff Wimer, J. Sessions
ABSTRACT This paper developed six cable logging incident scenarios that were modeled in a simulated environment, and conducted a pilot study in the Pacific Northwest to assess the potential for collecting worker risk assessment data. All the subjects in the pilot study reported that they understood the simulated incidents, and they were able to move around in the simulation to see what they needed. When reporting management requiring conditions (MRC) before performing the simulated task, the subjects consistently identified the first main MRC; however, there was variation in reporting the second main MRC. The results from the pilot study indicate that the simulations effectively modeled the spatial aspects of the incidents; however, the simulations lacked avatars to represent people in the simulations and this may have limited the ability to include cognitive aspects such as communication. Variation in the severity assigned by the subjects to the MRC, and to the unexpected events, revealed important differences in risk sensitivity between the subjects, and the importance of experiential learning in a safe environment when considering energized systems.
{"title":"Developing computer simulations for risk assessment by cable logging rigging crews","authors":"C. K. Lyons, Jeff Wimer, J. Sessions","doi":"10.1080/14942119.2022.2055411","DOIUrl":"https://doi.org/10.1080/14942119.2022.2055411","url":null,"abstract":"ABSTRACT This paper developed six cable logging incident scenarios that were modeled in a simulated environment, and conducted a pilot study in the Pacific Northwest to assess the potential for collecting worker risk assessment data. All the subjects in the pilot study reported that they understood the simulated incidents, and they were able to move around in the simulation to see what they needed. When reporting management requiring conditions (MRC) before performing the simulated task, the subjects consistently identified the first main MRC; however, there was variation in reporting the second main MRC. The results from the pilot study indicate that the simulations effectively modeled the spatial aspects of the incidents; however, the simulations lacked avatars to represent people in the simulations and this may have limited the ability to include cognitive aspects such as communication. Variation in the severity assigned by the subjects to the MRC, and to the unexpected events, revealed important differences in risk sensitivity between the subjects, and the importance of experiential learning in a safe environment when considering energized systems.","PeriodicalId":55998,"journal":{"name":"International Journal of Forest Engineering","volume":"33 1","pages":"217 - 225"},"PeriodicalIF":1.9,"publicationDate":"2022-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41327870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Larix kaempferi (Lamb.) Carr. plantations are a reasonable alternative to timber production for producing high-quality wood for South Korean industrial applications that need appropriate and high-quality practice of silvicultural operations. Weeding and tree pruning operations, which can favor trees in their competition with vegetation, require intensive manual labor. Therefore, the objective of this study was to determine the effect of these operations on the heart rate variability, relative heart rate (RHR), and physical workload of workers in April (spring) and July (summer) months. Our results showed that the mean heart rate variability and RHR for weeding (108.0 bpm and 49.4%, and 105.8 bpm and 46.8% for worker A and B, respectively) and tree pruning (104.5 bpm and 46.1%, and 114.4 bpm and 55.9% for worker A and B, respectively) in July were higher than those in April. In addition, the level of workload in July was characterized as heavy to very heavy, and as moderate to heavy in April. The results from this study provide useful information for appropriate young tree tending operations from the perspective of the safety and health of workers.
{"title":"The impact of season on heart rate variability and workload of workers in young tree tending operations of a Larix kaempferi (Lamb.) Carr. stand: a preliminary study","authors":"Eunjeong Lee, Ki-jeong Baek, Sangtae Lee, Minjae Cho, Yun-Sung Choi, Koo-Hyun Cho","doi":"10.1080/14942119.2022.2049546","DOIUrl":"https://doi.org/10.1080/14942119.2022.2049546","url":null,"abstract":"ABSTRACT Larix kaempferi (Lamb.) Carr. plantations are a reasonable alternative to timber production for producing high-quality wood for South Korean industrial applications that need appropriate and high-quality practice of silvicultural operations. Weeding and tree pruning operations, which can favor trees in their competition with vegetation, require intensive manual labor. Therefore, the objective of this study was to determine the effect of these operations on the heart rate variability, relative heart rate (RHR), and physical workload of workers in April (spring) and July (summer) months. Our results showed that the mean heart rate variability and RHR for weeding (108.0 bpm and 49.4%, and 105.8 bpm and 46.8% for worker A and B, respectively) and tree pruning (104.5 bpm and 46.1%, and 114.4 bpm and 55.9% for worker A and B, respectively) in July were higher than those in April. In addition, the level of workload in July was characterized as heavy to very heavy, and as moderate to heavy in April. The results from this study provide useful information for appropriate young tree tending operations from the perspective of the safety and health of workers.","PeriodicalId":55998,"journal":{"name":"International Journal of Forest Engineering","volume":"33 1","pages":"139 - 145"},"PeriodicalIF":1.9,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47209778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-14DOI: 10.1080/14942119.2022.2044724
J. Heppelmann, B. Talbot, C. Antón Fernández, R. Astrup
ABSTRACT The preservation of the functionality of forest soil is a key aspect in planning mechanized harvesting operations. Therefore, knowledge and information about stand and soil characteristics are vital to the planning process. In this respect, depth-to-water (DTW) maps were reviewed with regard to their potential use as a prediction tool for wheel ruts. To test the applicability of open source DTW maps for prediction of rutting, the ground surface conditions of 20 clear-cut sites were recorded post harvesting, using an unmanned aerial vehicle (UAV). In total, 80 km of machine tracks were categorized by the severity of occurring rut-formations to investigate whether: i) operators intuitively avoid areas with low DTW values, ii) a correlation exists between decreasing DTW values and increasing rut severity, and iii) DTW maps can serve as reliable decision-making tool in minimizing the environmental effects of big machinery deployment. While the machine operators did not have access to these predictions (DTW maps) during the operations, there was no visual evidence that driving through these areas was actively avoided, resulting in a higher density of severe rutting within areas with DTW values <1 m. A logistic regression analysis confirmed that the probability of severe rutting rapidly increases with decreasing DTW values. However, significant differences between sites exist which might be attributed to a series of other factors such as soil type, weather conditions, number of passes and load capacity. Monitoring these factors is hence highly recommended in any further follow-up studies on soil trafficability.
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