Parking and the visual perception of space

Using measured data we demonstrate that there is an amazing correspondence among the statistical properties of spacings between parked cars and the distances between birds perching on a power line. We show that this observation is easily explained by the fact that birds and human use the same mechanism of distance estimation. We give a simple mathematical model of this phenomenon and prove its validity using measured data

Desired clearance around a vehicle while parking or performing low speed maneuvers

AVM and Low Speed Maneuvers: Human Factors Issues ProjectThis experiment examined how close to objects (such as a wall or another vehicle) people would drive when parking. The findings will to be used as a basis for visual and/or auditory warnings provided by parking assistance systems. A total of 16 people (8 ages 18-30, 8 over age 65) served as subjects. Data were collected both for the subjects sitting in the driver’s seat of a 2004 Infinity Q45 and standing outside the vehicle (as if directing someone else to park). Data were collected for the desired clearance distance between the test vehicle and a wall (for safety concerns, the wall was moved instead of the vehicle) in ascending and descending thresholds, for 8 cardinal clock positions. The overall mean distance was 20.4 in for the 640 data points collected, with a range of 2.5 to 48.5 in. As an example of the specific results, when the wall was moved towards the driver and the subject was an observer (outside the car), the desired distances were 17.0, 18.9, 19.1, 20.3, 17.4, 18.7, 14.7, and 15.8 in for 1:30, 3:00, 4:30, 6:00, 7:30, 9:00, 10:30 and 12:00 clock positions. Using the regression method, 1 of the 2 methods developed, desired distance in inches was equal to 9.5 + 1.6 (if the position was to the side or rear) + 6.7 (if a door was to be opened) + 5.7 (if the object was approaching the car) + 4.9 (if the driver’s clearance was estimated) + .07 times the driver’s age.Nissan Research Centerhttp://deepblue.lib.umich.edu/bitstream/2027.42/64471/1/102435.pd

Alternative images for perpendicular parking: a usability study of a multi-camera parking assistance system

AVM and Low Speed Maneuvers: Human Factors Issues ProjectThe parking assistance system evaluated consisted of four outward facing cameras whose images could be presented on a monitor on the center console. The images presented varied in the location of the virtual eye point of the camera (the height above the vehicle and forward depression angle) and the number of camera images (one or multiple) appearing together. In the experiment, 16 drivers (eight under age 30, eight over age 65) parked a 2002 Infiniti Q45 in an 8.5-foot-wide stall. Each subject parked 24 times, using the various image combinations or no assistance at all. Parking clearances (the closest approach distance on the driver and passenger side, distance to a wall in front) declined with practice, stabilizing to 4 inches laterally and 13 inches in front after about three unrecorded practice trials and 15 test trials. Overall, age and sex differences were not large, though older drivers were more variable than younger drivers in how far they parked from the end of a stall. Finally, there were no statistically significant differences among camera image combinations, or differences from no-assistance conditions. Only half of the subjects made significant use of the assistance system, which is not an unusual outcome given its early state of system development. Of the image combinations examined, those with a single image field resulted in subjects parking 2 inches closer to the wall than those with multiple fields. Overall, subjects preferred scenes presenting what appeared to be a single image. Subjects reported that the aerial view was the most helpful.Nissan Research Centerhttp://deepblue.lib.umich.edu/bitstream/2027.42/64470/1/102434.pd

Climatic risks and impacts in South Asia: extremes of water scarcity and excess

This paper reviews the current knowledge of climatic risks and impacts in South Asia associated with anthropogenic warming levels of 1.5°C to 4°C above pre-industrial values in the 21st century. It is based on the World Bank Report “Turn Down the Heat, Climate Extremes, Regional Impacts and the Case for Resilience” (2013). Many of the climate change impacts in the region, which appear quite severe even with relatively modest warming of 1.5–2°C, pose significant hazards to development. For example, increased monsoon variability and loss or glacial meltwater will likely confront populations with ongoing and multiple challenges. The result is a significant risk to stable and reliable water resources for the region, with increases in peak flows potentially causing floods and dry season flow reductions threatening agriculture. Irrespective of the anticipated economic development and growth, climate projections indicate that large parts of South Asia’s growing population and especially the poor are likely to remain highly vulnerable to climate change

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Bone histology provides insights into the life history mechanisms underlying dwarfing in hipparionins

Size shifts may be a by-product of alterations in life history traits driven by natural selection. Although this approach has been proposed for islands, it has not yet been explored in continental faunas. The trends towards size decrease experienced by some hipparionins constitute a good case study for the application of a life history framework to understand the size shifts on the continent. Here, we analysed bone microstructure to reconstruct the growth of some different-sized hipparionins from Greece and Spain. The two dwarfed lineages studied show different growth strategies. The Greek hipparions ceased growth early at a small size thus advancing maturity, whilst the slower-growing Spanish hipparion matured later at a small size. Based on predictive life history models, we suggest that high adult mortality was the likely selective force behind early maturity and associated size decrease in the Greek lineage. Conversely, we infer that resource limitation accompanied by high juvenile mortality triggered decrease in growth rate and a relative late maturity in the Spanish lineage. Our results provide evidence that different selective pressures can precipitate different changes in life history that lead to similar size shifts

The Preservation of Climate‐Driven Landslide Dams in Western Oregon

Bedrock landsliding, including the formation of landslide dams, is a predominant geomorphic process in steep landscapes. Clarifying the importance of hydrologic and seismic mechanisms for triggering deep-seated landslides remains an ongoing effort, and formulation of geomorphic metrics that predict dam preservation is crucial for quantifying secondary landslide hazards. Here, we identify >200 landslide-dammed lakes in western Oregon and utilize dendrochronology and enhanced 14C dating (“wiggle matching”) of “ghost forests” to establish slope failure timing at 20 sites. Our dated landslide dataset reveals bedrock landsliding has been common since the last Cascadia Subduction Zone earthquake in January 1700 AD. Our study does not reveal landslides that date to 1700 AD. Rather, we observe temporal clustering of at least four landslides in the winter of 1889/1890 AD, coincident with a series of atmospheric rivers that generated one of the largest regionally recorded floods. We use topographic and field analyses to assess the relation between dam preservation and topographic characteristics of the impounded valleys. In contrast to previous studies, we do not observe systematic scaling between dam size and upstream drainage area, though dam stability indices for our sites correspond with “stable” dams elsewhere. Notably, we observe that dams are preferentially preserved at drainage areas of ∼1.5 to 13 km2 and valley widths of ∼25 to 80 m, which may reflect the reduced downstream influence of debris flows and the accumulation of mature conifer trees upstream from landslide-dammed lake outlets. We suggest that wood accumulation upstream of landslide dams tempers large stream discharges, thus inhibiting dam incision. © 2021. American Geophysical Union. All Rights Reserved.6 month embargo; first published: 19 March 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]