There is a well known one–parameter family of left invariant CR structures on SU(2) ∼= S. We show how purely algebraic methods can be used to explicitly compute the canonical Cartan connections associated to these structures and their curvatures. We also obtain explicit descriptions of tractor bundles and tractor connections.

Nacrtak Mechanized felling was introduced in Slovenia at the beginning of this decade, and before that Slovenian forestry relied on motor manual felling and tractor skidding or cable crane yarding. In this research we are dealing with wood forwarding. Model skidding maps were built, using terrain classification and decision support systems for forwarders and tractor trailers. The purpose of thi...

BACKGROUND Indian tractor drivers operate their tractors and other implements/equipment in an environment which can have extreme temperatures and high level of suspended particulate matter. In addition, Indian tractors do not have adequate vibration and noise attenuating designs features. This cross-sectional study compares the hearing status of tractor driving farmers (TDFs) (study group) and ...

The force measuring device is designed to the study of the relationship between vibration amplitude, frequency, speed and traction resistance of the tractor If the design of the force measuring device which consists of a force measuring frame and three octagonal ring transducers is successful, the goal of real-time monitoring of the traction resistance in the process of vibrating sub soil may b...

Operator exposure to high levels of whole-body vibration (WBV) presents risks to health and safety and it is reported to worsen or even cause back injuries. Work activities resulting in operator exposure to whole-body vibration have a common onset in off-road work such as farming. Despite the wide variability of agricultural surface profiles, studies have shown that with changing soil profile a...

Trailer reversing is a problem frequently considered in the literature, usually with fairly complex non-linear control theory based approaches. In this paper, we overview our simple method for stabilizing a tractor-trailer system to a trajectory based on the notion of controlling the hitch-angle of the trailer rather than the steering angle of the tractor. The performance of this control method...

In this article we describe the formulation of null geodesics as null conformal geodesics and their description in the tractor formalism. A conformal extension theorem through an isotropic singularity is proven by requiring the boundedness of the tractor curvature and its derivatives to sufficient order along a congruence of null conformal geodesic. This article extends earlier work by Tod and ...