Effects of Retroreflector Placement on the Nighttime Conspicuity of Pedestrians: An Open-Road Study

2007 ◽  
Vol 51 (24) ◽  
pp. 1565-1568 ◽  
Author(s):  
Stacy A. Balk ◽  
Justin S. Graving ◽  
Ryan G. Chanko ◽  
Richard A. Tyrrell
Keyword(s):  
Biological Motion ◽  
Class Ii ◽  
Left Shoulder ◽  
Test Vehicle ◽  
Safety Devices ◽  
Road Study ◽  
Open Road

While considerable data indicate that positioning retroreflective markings on a pedestrian's extremities can dramatically enhance nighttime conspicuity, most relevant safety devices (vests) limit coverage to the torso. We asked 120 participants to press a button whenever they recognized that a pedestrian was present during a short drive at night. A test pedestrian wearing different configurations of retroreflective markings was positioned on the left shoulder of an unilluminated two-lane roadway. Compared to an ANSI class-II vest alone, response distances were significantly greater when the vest was supplemented with ankle markings and when a full biological motion configuration was worn. Conspicuity was also greater when the pedestrian was walking and when facing the approaching test vehicle. Relative to a full eleven-element biological motion configuration, adding just two retroreflective ankle straps to a conventional safety vest is considerably more practical while still providing substantial conspicuity benefits.

Traffic Sign Legibility for Different Sign Background Colors: Results of an Open Road Study at Freeway Speeds

2008 ◽  
Vol 52 (23) ◽  
pp. 1855-1859 ◽  
Author(s):  
Dillon Funkhouser ◽  
Susan Chrysler ◽  
Alicia Nelson ◽  
Eun Sug Park
Keyword(s):  
Traffic Sign ◽  
Road Study ◽  
Open Road

scholarly journals The Conspicuity Benefits of Rear-Facing Bike Lights in Daylight

2019 ◽  
Vol 63 (1) ◽  
pp. 1937-1938
Author(s):  
Darlene E. Edewaard ◽  
Ellen C. Szubski ◽  
Richard A. Tyrrell
Keyword(s):  
Light Intensity ◽  
Biological Motion ◽  
Motor Vehicle ◽  
Viewing Distance ◽  
Subjective Ratings ◽  
Test Vehicle ◽  
Vehicle Traffic ◽  
Optimal Intensity

Cycling with motor vehicle traffic on roadways is inherently risky for bicyclists, and it is important for bicyclists to make themselves conspicuous to drivers. This experiment used a closed-road method to test the daytime conspicuity of rear-facing bike lights. Participants provided subjective ratings of conspicuity from a test vehicle parked at two different distances from a bicyclist pedaling on a stationary bicycle with one of 16 configurations of bike lights. Some configurations featured lights on the bicyclist’s ankles to highlight the bicyclist’s biological motion. The results of this experiment provide a better understanding of the relative conspicuity benefits of bike lights in daylight as a function of light intensity, light placement, and viewing distance. The findings offer useful insights on the optimal intensity and placement of bike lights to enhance their own conspicuity during daylight.

Effects of retroreflector placement on the nighttime conspicuity of pedestrians: An open-road study

2007 ◽  
Author(s):  
Stacy A. Balk ◽  
Justin S. Graving ◽  
Ryan G. Chanko ◽  
Richard A. Tyrrell
Keyword(s):  
Road Study ◽  
Open Road

Electron microscopy analysis of degenerating pancreatic ß cells in transgenic mice expressing the MHC Class I antigen Dd

1990 ◽  
Vol 48 (3) ◽  
pp. 548-549
Author(s):  
T. A. Stewart ◽  
D. Liggitt ◽  
S. Pitts ◽  
L. Martin ◽  
M. Siegel ◽  
...  
Keyword(s):  
Type I Diabetes ◽  
Disease Process ◽  
Class Ii ◽  
Class I ◽  
Type I ◽  
Aberrant Expression ◽  
Mhc Molecules ◽  
Endogenous Insulin ◽  
Class Ii Mhc ◽  
Ifn Γ

Insulin-dependant (Type I) diabetes mellitus (IDDM) is a metabolic disorder resulting from the lack of endogenous insulin secretion. The disease is thought to result from the autoimmune mediated destruction of the insulin producing ß cells within the islets of Langerhans. The disease process is probably triggered by environmental agents, e.g. virus or chemical toxins on a background of genetic susceptibility associated with particular alleles within the major histocompatiblity complex (MHC). The relation between IDDM and the MHC locus has been reinforced by the demonstration of both class I and class II MHC proteins on the surface of ß cells from newly diagnosed patients as well as mounting evidence that IDDM has an autoimmune pathogenesis. In 1984, a series of observations were used to advance a hypothesis, in which it was suggested that aberrant expression of class II MHC molecules, perhaps induced by gamma-interferon (IFN γ) could present self antigens and initiate an autoimmune disease. We have tested some aspects of this model and demonstrated that expression of IFN γ by pancreatic ß cells can initiate an inflammatory destruction of both the islets and pancreas and does lead to IDDM.

Preparation of integrated circuits for TEM electromigration in situ studies

1986 ◽  
Vol 44 ◽  
pp. 882-883
Author(s):  
J. V. Maskowitz ◽  
W. E. Rhoden ◽  
D. R. Kitchen ◽  
R. E. Omlor ◽  
P. F. Lloyd
Keyword(s):  
Integrated Circuits ◽  
Crystallographic Orientation ◽  
Silicon Wafers ◽  
Minimum Size ◽  
Test Vehicle ◽  
In Situ Studies ◽  
Boron Doped ◽  
Doped Silicon ◽  
Drill Holes

The fabrication of the aluminum bridge test vehicle for use in the crystallographic studies of electromigration involves several photolithographic processes, some common, while others quite unique. It is most important to start with a clean wafer of known orientation. The wafers used are 7 mil thick boron doped silicon. The diameter of the wafer is 1.5 inches with a resistivity of 10-20 ohm-cm. The crystallographic orientation is (111).Initial attempts were made to both drill and laser holes in the silicon wafers then back fill with photoresist or mounting wax. A diamond tipped dentist burr was used to successfully drill holes in the wafer. This proved unacceptable in that the perimeter of the hole was cracked and chipped. Additionally, the minimum size hole realizable was > 300 μm. The drilled holes could not be arrayed on the wafer to any extent because the wafer would not stand up to the stress of multiple drilling.

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