Information on the productivity, costs and applications of the logging system is a key component in the evaluation of management plans for the rehabilitation and utilization of Caspian forests. Skidding and road construction costs are expensive forest operations. Determining the optimum forest road network density is one of the most important factors in sustainable forest management. Logging me...

The optimum road spacing has been studied by many researches. It is an important step of forest road network planning. The goals of this study are determining the optimum road spacing in Kheiroudkenar forest of Nowshahr in Northern Iran and study of effect of kind of skidder on skidding cost and road spacing. Continues time study method was used to determine the production rate of TAF and Timbe...

In 1953, drivers in the United States became involved in 31,450 fatal and 1,302,000 non-fatal accidents. Many of these accidents were primarily the fault of the drivers involved, but a great number might have been minimized or prevented by safer highways. Although many factors are involved in the building of safety into highways, one of the more important items is the resistance of pavement sur...

This paper proposes a robust tracking controller based on a Generalized Extended State Observer (GESO) method for a wheeled mobile robot (WMR) with unknown skidding and slipping. Skidding and slipping of a WMR are inevitable in practice. We regard skidding and slipping as disturbances and modify the dynamics model to consider them simply. Then, we adopt the GESO to design...

Nacrtak The authors tested two alternative treatments for small wood extraction in protected conservation areas, respectively based on direct skidding by small crawler tractors and integrated horse bunching and crawler tractor skidding. The integration of horse bunching with tractor skidding proved cheaper than direct tractor skidding, and allowed extending the distance range of horse skidding....

In this paper authors consider the problem of practical stabilization of wheeled mobile robot equipped with skid-steering drive (also know as SSMR). The kinematic model of SSMR is approximated by kinematics of unicycle including small perturbation term which describes limited skidding effect. It is justified that SSMR can be regarded as a system with non-stationary first order nonholonomic cons...

Skidding by means of heavy forestry machinery can affect soil physical properties. We assessed the effects of ground based skidding on soil bulk density and total porosity under the Iranian mountainous forest conditions. Treatments included a combination of four levels of traffic intensity (1, 3, 6, and 15 passes) of a Timberjack 450C rubber skidder and two levels of slope (<20% and >20%). The ...

information on the productivity, costs and applications of the logging system is a key component in the evaluation of management plans for the rehabilitation and utilization of caspian forests. skidding and road construction costs are expensive forest operations. determining the optimum forest road network density is one of the most important factors in sustainable forest management. logging me...

This study was executed to determine the plant species of herbaceous cover in a skid road subjected to soil compaction due to timber skidding in a beech (Fagus orientalis Lipsky.) stand. Our previous studies have shown that ground based timber skidding destroys the soils extremely, and degradations on ecosystem because of the timber skidding limit recovery and growth of plant cover on skid road...

This study examined the influence of turn radius on velocity and energy profiles when skidding and step turning during more and less effective downhill turns while cross-country skiing. Thirteen elite female cross-country skiers performed single turns with a 9- or 12-m radius using the skidding technique and a 12- or 15-m radius with step turning. Mechanical parameters were monitored using a re...