scholarly journals PRODUTIVIDADE DO TRATOR FLORESTAL CHOCKER SKIDDER NA EXTRAÇÃO DE MADEIRA EM TERRENOS DECLIVOSOS

FLORESTA ◽  
2015 ◽  
Vol 45 (3) ◽  
pp. 625
Author(s):  
Eduardo Silva Lopes ◽  
Carlos Cavassin Diniz
Keyword(s):  
Timber Harvesting ◽  
Operational Cycle ◽  
Terrain Slope ◽  
Planning Optimization ◽  
Machine Productivity ◽  
Work Cycle ◽  
Efficient Planning ◽  
Steep Terrain ◽  
Reduction Machine ◽  
Engagement And Disengagement

Este trabalho objetivou analisar os tempos do ciclo operacional e a produtividade do trator florestal chocker skidder na extração de madeira em diferentes classes de declividade e distância, visando gerar informações para o planejamento eficiente das operações e o melhor aproveitamento dos recursos disponíveis. O trabalho foi realizado em uma empresa florestal localizada no município de Itararé, SP. Foi realizado um estudo de tempos e movimentos do ciclo operacional, determinando disponibilidade mecânica, disponibilidade técnica, eficiência operacional e produtividade da máquina em diferentes condições de distância de extração e declividade do terreno. Os resultados indicaram que as atividades que consumiram a maior parte do tempo do ciclo de trabalho foram o “arraste do cabo e engate” e “desengate das correntes”, com 28% e 11% do tempo total, respectivamente. Houve redução da produtividade da máquina com o aumento da declividade do terreno, sendo mais evidente nas menores distâncias de extração e mostrando a sensibilidade dessa variável nessa condição operacional.AbstractProductivity of forestry tractor chocker skidder in extraction of wood on steep terrain. The objective of this study was to evaluate the time consumed by the elements of the work cycle and the productivity of a chocker skidder in extraction of wood at different slope terrain and distances classes, generating information for efficient planning of operations and better utilization of available resources. The study was conducted in a forestry company located in the municipality of Itararé, São Paulo State. A motion and time study of the operational cycle was performed, determining the mechanical availability, technical availability, operational efficiency and productivity of the machine in different conditions of extraction distance and terrain slope. The results showed that elements of the work cycle which most time consuming were the "drag cable and engagement" and "disengagement of the currents" that consumed the greatest operational cycle of the machine with 28% and 11% of the total time, respectively. A reduction machine productivity with increasing of the terrain slope, being stronger in the smaller extraction distances and, showing the sensitivity of this variable in this operating condition.Keywords: Timber harvesting; operational planning; optimization.

scholarly journals EFEITO DE VARIÁVEIS OPERACIONAIS NA PRODUTIVIDADE DE UM HARVESTER DE PNEUS NO DESBASTE DE PINUS

FLORESTA ◽  
2017 ◽  
Vol 47 (4) ◽  
pp. 417 ◽  
Author(s):  
Eduardo Silva Lopes ◽  
Felipe Martins Oliveira ◽  
Bruna Letícia Roza
Keyword(s):  
Pinus Taeda ◽  
Operational Efficiency ◽  
Average Volume ◽  
Operational Cycle ◽  
Terrain Slope ◽  
Operational Variables ◽  
Machine Productivity ◽  
Significant Difference ◽  
Pinus Taeda L ◽  
Individual Trees

Objetivou-se avaliar o efeito da declividade do terreno, volume da árvore e tempo do ciclo operacional na produtividade de um harvester de pneus no desbaste de povoamento de pinus. O estudo foi realizado em uma empresa florestal no estado do Paraná, em povoamento de Pinus taeda L. submetido ao primeiro desbaste comercial aos 10 anos de idade, o qual foi realizado de forma sistemática na 7ª linha de plantio e seletivo nas linhas adjacentes. Foi realizado um estudo de tempos e movimentos da operação de corte pelo método de cronometragem de tempos contínuos, determinando-se a disponibilidade mecânica, a eficiência operacional e a produtividade. Foram ajustados modelos para estimar a produtividade da máquina em função do volume médio individual das árvores e do tempo do ciclo operacional em diferentes declividades do terreno. Os resultados mostraram que a disponibilidade mecânica e a eficiência operacional média foram de 91% e 83%, respectivamente. A produtividade média da máquina foi de 15,4 m³/he, não apresentando diferença significativa entre as declividades do terreno. Houve aumento significativo da produtividade da máquina no corte de árvores com volume médio acima de 0,19 m³. As variáveis declividade do terreno, volume da árvore e tempo do ciclo operacional explicaram 69% da produtividade do harvester na execução do corte em povoamentos de pinus submetidos ao primeiro de desbaste, podendo tais informações ser usadas no planejamento das operações florestais.Palavras-chave: Corte florestal; desbaste mecanizado; produtividade. AbstractEffect of operational variables on the productivity of a harvest of tire in thinning of pine. The aim of this study was to evaluate the effect of terrain slope, tree volume and time of the operational cycle on the productivity of a wheeled harvester in the thinning of a pine stand. The study was in a Pinus taeda L. plantation under first thinning at 10 years old, carried out systematically at 7th row and selective in adjacent rows, conducted in a forestry company in Paraná, Brazil. A motion and time study of the cutting operational cycle was carried out, determining the mechanical availability, operational efficiency and productivity. Models were fitted to estimate the machine productivity in function of average volume of individual trees and time of operational cycle in the different slope conditions. The results showed that the average mechanical availability and operational efficiency were 91% and 83%, respectively. The machine average productivity was 15.4 m³/eh, with no significant difference between the terrain slopes. There was significant increase in productivity of machine at the cut trees with average volume above 0.19 m³. The terrain slope, tree volume and time of the operational cycle variables explained 69% of the harvester productivity in the cutting of pine stands submitted to the first thinning. These information can be used in the planning of forestry operations.Keywords: Forest cutting; thinning mechanized; productivity. 

scholarly journals Evaluation of Salvage Logging Productivity and Costs in the Sensitive Forests of Bulgaria

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 309
Author(s):  
Stanimir Stoilov ◽  
Andrea R. Proto ◽  
Georgi Angelov ◽  
Salvatore F. Papandrea ◽  
Stelian Alexandru Borz
Keyword(s):  
Cycle Time ◽  
Operational Efficiency ◽  
Fixed Costs ◽  
Labor Costs ◽  
Salvage Logging ◽  
Operational Conditions ◽  
Work Cycle ◽  
Wet Snow ◽  
Productivity Rate ◽  
Steep Terrain

Steep terrain harvesting can only be implemented by a limited set of operational alternatives; therefore, it is important to be efficient in such conditions, in order to avoid incurring high costs. Harvesting abiotically-disturbed forests (salvage harvests caused by wet snow), which is becoming common these days, can significantly impact the operational efficiency of extraction operations. This study was implemented in order to evaluate the performance of truck-mounted uphill cable yarding operations in salvage logging deployed in coniferous stands. A time study was used to estimate the productivity and yarding costs, and predictive models were developed in order to relate the time consumption and productivity to the relevant operational factors, including the degree of wood damage. The average operational conditions were characterized by an extraction distance of 101 m and a lateral yarding distance of 18 m, resulting in a productivity rate of 20.1 m3 h−1. In response to different kind of delays, the productivity rate decreased to 12.8 m3 h−1. Under the prevailing conditions, lateral yarding accounted for 32% of the gross work cycle time, and for 50% of the delay-free work cycle time of the machine. Decreasing the lateral yarding distance and increasing the payload volume to the maximum capacity of the machine would eventually lead to a yarding productivity of close to 30 m3 per SMH (scheduled machine hour). The calculation of the gross costs of uphill yarding showed that the labor costs (35.7%) were slightly higher than the fixed costs (32.9%), and twice as high compared to the variable costs (17.7%). The remote control of the carriage, mechanical slack-pulling mechanisms, and radio-controlled chokers are just some of the improvements that would have led to increments in operational efficiency.

Timber-Harvesting Mechanization in the Western United States: An Industry Survey

1988 ◽  
Vol 3 (2) ◽  
pp. 33-36 ◽  
Author(s):  
Donald D. Schuh ◽  
Loren D. Kellogg
Keyword(s):  
United States ◽  
Timber Harvesting ◽  
Monetary Incentive ◽  
Western United States ◽  
Formal Training ◽  
Transportation Equipment ◽  
Industry Survey ◽  
Steep Terrain

Abstract A survey of mechanized harvesting operations in the western United States located more than 140 timber companies and logging contractors using nontraditional manufacturing or transportation equipment during 1985. The operations ranged from small contractors owning a single feller-buncher to completely mechanized firms operating delimbers, debarkers, chippers, and felling machines. Most of the mechanized logging was found in Washington, Oregon, and Montana. Equipment breakdowns were the most critical harvesting problem cited by the loggers, followed by decreased production on steep terrain. Few contractors provide formal training for their equipment operators, a factor that may increase the frequency, duration, and severity of equipment downtime. Monetary incentive bonuses were used to spur production by approximately 35% of the responding firms. West. J. Appl. For. 3(2):33-36, April 1988.

scholarly journals Timber Harvesting and Flooding: Emerging Legal Risks and Potential Mitigations

2004 ◽  
Vol 28 (2) ◽  
pp. 69-75 ◽  
Author(s):  
Michael J. Mortimer ◽  
Rien J. M. Visser
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Management Practice ◽  
Strict Liability ◽  
Timber Harvesting ◽  
Water Yield ◽  
Best Management ◽  
Legal Risks ◽  
Steep Terrain ◽  
Flooding Events

Abstract The relationship between timber harvesting in steep terrain and natural calamities such as flooding has recently coalesced as extensive litigation in West Virginia. Accusations that timber harvesting was responsible for widespread flooding includes novel uses of the legal theories of negligence per se and strict liability. Managing for increases in water yield, application of best management practices (BMP), and predictability of flooding events all play a role in whether timber operations are ultimately susceptible to liability for flooding events. The authors suggest that recent legal actions and difficulties in predicting the outcomes of such lawsuits necessitates a fundamental review of best management practice design and implementation. Consideration of water quantity BMP may be warranted. South. J. Appl. For. 28(2):69–75.

scholarly journals Using Conjoint Analyses to Improve Cable Yarder Design Characteristics: An Austrian Yarder Case Study to Advance Cost-Effective Extraction

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 165 ◽  
Author(s):  
Martin Kühmaier ◽  
Hunter Harrill ◽  
Mohammad Ghaffariyan ◽  
Manfred Hofer ◽  
Karl Stampfer ◽  
...  
Keyword(s):  
New Zealand ◽  
Environmental Sustainability ◽  
Online Survey ◽  
Cost Effective ◽  
Timber Harvesting ◽  
User Preferences ◽  
Design Characteristics ◽  
Steep Terrain ◽  
Integrate Design

Steep country harvesting has been identified as the main bottleneck to achieving greater profitability in the forestry sector of New Zealand and Australia. An improvement of efficiency, work safety and environmental sustainability should be realized by developing an advanced steep terrain timber harvesting system based on innovative Austrian technology. To identify the best suitable configuration of a cable yarder for steep terrain harvesting, user preferences based on an online survey (conjoint analysis) have been evaluated to answer the following questions: (1) What attributes of a new yarder design are most important to consumers? (2) Which criteria do stakeholders consider when selecting a cable yarder? (3) What are the weights representing the relative importance of criteria? Using eight specific design scenarios a fourth question, being which cable yarder concept is the best, was also answered. This case study shows that conjoint analyses is an effective tool to assess, rate and subsequently integrate design characteristics. Based on the results of the analysis, a cable yarder prototype will be manufactured in Austria and transferred to New Zealand for testing and demonstration.

scholarly journals A surface metric and software toolbox for EEG electrode grids in the macaque

2020 ◽  
Author(s):  
Fan Li ◽  
Tobias Teichert
Keyword(s):  
Current Approach ◽  
Non Invasive ◽  
Brain Surface ◽  
Manual Intervention ◽  
Planning Optimization ◽  
Efficient Planning ◽  
Eeg Recordings ◽  
The One ◽  
High Level ◽  
The Brain

AbstractBackgroundThe past years have seen increased appreciation of non-invasive extracranial electroencephalographic (EEG) recordings in non-human primates (NHP) as a tool for translational research. In humans, the international 10-20 system or extensions thereof provide standardized electrode positions that enable easy comparison of data between subjects and laboratories. In the NHP, no such generally accepted, standardized placement system is available.New MethodHere we introduce a surface metric and software package (NHP1020) that automates the planning of large, approximately evenly spaced electrode grids on the NHP skull.ResultsThe system is based on one CT and one MRI image and requires the user to specify two intracranial markers. Based on this, the software defines electrode positions on the brain surface using a surface-based spherical metric similar to the one used by the international 10-20 system. The electrode positions are then projected to the surface of the skull. Standardized electrode grids can be shared, imported or defined with few high-level commands.Existing MethodsNHP EEG electrodes are often placed on an individual basis relative to extracranial markers, or relative to underlying neural structures. Both approaches are time-consuming and require manual intervention. Furthermore, the use of extracranial markers in this species may be more problematic than in humans, because cranial muscles and ridges are larger and keep maturing long into adulthood thus potentially affecting electrode positions.ConclusionThe key advantage of the current approach is the automated and objective identification of corresponding electrode positions in different animals. Automation was made possible by the use of a two-dimensional metric on the brain surface which has a simpler, i.e., more convex and sphere-like anatomy than the skull. This enables fast and efficient planning, optimization and calculation of large electrode grids.

scholarly journals Retroactive comparison of operator-designed and computer-generated skid-trail networks on steep terrain

2020 ◽  
Vol 29 (1) ◽  
pp. eSC01
Author(s):  
Marco Antonio Contreras ◽  
David L Parrott ◽  
Jeffrey W Stringer
Keyword(s):  
Cost Minimization ◽  
Timber Harvest ◽  
Timber Harvesting ◽  
Economic Benefits ◽  
Eastern Kentucky ◽  
Digital Elevation ◽  
Soil Disturbances ◽  
Steep Terrain ◽  
Elevation Model ◽  
The University

Aim of the study: Quantify potential economic benefits of implementing computer-generated skid-trail networks over the traditional operator-designed skid-trail networks on steep terrain ground-based forest operations.Area of study: A 132-ha harvest operation conducted at the University of Kentucky’s Robinson Forest in eastern Kentucky, USA.Materials and methods: We compared computer-generated skid-trail network with an operator-designed network for a 132-ha harvest. Using equipment mounted GPS data and a digital elevation model (DEM), we identified the original operator-designed skid-trail network. Pre-harvest conditions were replicated by re-contouring terrain slopes over skid-trails to simulate the natural topography and by spatially distributing the harvestable volume based on pre-harvest inventories and timber harvest records. An optimized skid-trail network was designed using these pre-harvest conditions and compared to the original, operator-designed network.Main results: The computer-generated network length was slightly longer than the operator-designed network (53.7 km vs. 51.7 km). This also resulted in a slightly longer average skidding distance (0.71 km vs. 0.66 km) and higher total harvesting costs (5.1 $ ton-1 vs. 4.8 $ ton-1).  However, skidding costs of the computer-generated network were slightly lower (4.2 $ ton-1 vs. 4.3 $ ton-1).  When comparing only major skid-trails, those with ≥ 20 machine passes, the computer-generated skid-trail network was 28% shorter than the operator network (9.4 km vs. 13.1 km). Research highlight: This assessment offers evidence that computer-generated networks could be used to generate efficient skid-trails, help determine skidding costs, and assess further potential economic and environmental benefits.Key words: timber harvesting; forest operations; network optimization; soil disturbances; cost minimization.

Investigating Engagement and Disengagement in College Students' Epistemic Beliefs Profiles

2018 ◽  
Author(s):  
Xingya Xu ◽  
Michelle Buehl ◽  
Angela D. Miller ◽  
Samantha Ives ◽  
Anthony Arciero ◽  
...  
Keyword(s):  
College Students ◽  
Epistemic Beliefs ◽  
Engagement And Disengagement
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