Frame by frame? A contrasting research framework for time experience

The way we experience the world has an inherently temporal aspect; events follow the ones before in a linear fashion. Our experience presents to us in the form of a fleeting present with no clearly demarcated beginning or end, always imbued within an evanescent stream of perceptions and thoughts. While different approaches from cognitive science and related fields share the view that this temporal aspect is fundamental to our phenomenology, our experience of time seems in direct tension with the physically grounded, widespread notion of discrete state-space transitions that underpin so much of modern cognitive science and artificial life. In other words, while state-space transitions seem to correctly characterize most cognitive phenomena, it isn’t clear how this relates to the fluid and evanescent temporality of our experience. We present a formal framework centered on the idea of how sensory-perception incompleteness translates into temporally dense constructions of the perceptual present.</p

Rail-wheel friction quantification and its variability under lab and field trial conditions

Friction forces (often referred to as adhesion or traction forces) at the wheel/rail interface can vary dramatically due to changing environmental and contact conditions. The causes of this variance are partially documented, but it is not fully understood. Friction forces affect wheel and rail wear, traction energy usage, vehicle dynamics and safety through braking performance. A range of different portable railhead tribometers are used in the field to measure friction, but until recently have been limited in their performance, being unable to measure low friction situations or have made use of an unrealistic contact geometry. Recent developments have improved this situation but there is currently a lack of published field data which is required for validation, benchmarking and comparison between other studies and test rigs, as well as for input to multi-body dynamics simulations of railway vehicles. Friction studies in general are often undertaken for a specific period of time or under closely controlled conditions which makes it difficult to understand the true range of conditions occurring in the wheel/rail contact. In this paper an extensive dataset of railhead measurements is presented, using two types of measuring devices and three railhead conditions throughout a 4-week test period. Confidence in tribometer results was gained by comparing between established laboratory friction test rigs and methodologies. The results provide an insight into the friction variance and transient conditions that would occur on the railhead during operational use.</p

Additional file 1: of Comparing doctors’ legal compliance across three Australian states for decisions whether to withhold or withdraw life-sustaining medical treatment: does different law lead to different decisions?

Comparison of AMPCo database and study sample. This file compares the demographic data from the AMPCo database with that of the participants in the study sample. (PDF 87 kb