315 research outputs found
Context information captures acceptability of alerts to pedestrians
Includes summary document and presentation slides.This presentation discusses a research method used to evaluate the design of the alerting logic of an automotive pedestrian warning system. We show how an empirical approach to quantifying the relative level with which drivers are likely to accept pedestrian alerts can be used to define an alerting algorithm. We used the method to investigate a range of contextual factors likely to influence driver acceptance of pedestrian alerts
Military teams - A demand for resilience
The article of record as published may be found at http://dx.doi.org/10.3233/WOR-162298BACKGROUND: The Royal Norwegian Naval Academy (RNoNA) has an interest in enhancing military teams’ knowledge, skills and abilities to deal with complex situations and environments. OBJECTIVE: The objective is to document the need for resilience in military teams and to expand the understanding of how such behavior can be meaningfully instilled through team training interventions. METHOD: Norwegian military subject matter experts (SMEs) assessed the performance of military teams participating in complex military training exercises. Eight cadet teams at the RNoNA were assessed during two separate 4-hour simulator training exercises and a 48-hour live training exercise. RESULTS: Positive Spearman rank correlation coefficients between resilience assessments in the simulator training exercises and the live training exercise were strongest when the simulator scenario emphasized resilience factors inherent in the live exercise, and weakest when the simulator scenario did not facilitate the task demands in the live exercise. CONCLUSION: The study showed that resilience assessed in teams during simulator training exercises predicted their resilient behavior in a subsequent live training exercise and that the proper design of scenario-based simulator training can realistically and effectively represent resilience stressors found in live operations.This work was sponsored by The Royal Norwegian Naval Academy
Shouldn’t Cars React as Drivers Expect?
The objective of this project is to develop and test a multi-method empirical approach for predicting drivers’ assessments of the level of acceptability of a warning issued in response to accidents, near-accidents, and other incidents. The role of humans (drivers) in the pre-crash phase means that systems that protect occupants and pedestrians must be seen as distributed, cognitive systems. Driver acceptance therefore has to be an important design goal. One obstacle to acceptance is the human dislike for false alarms. An approach to overcoming driver dislike for false alarms is to focus on driver expectations and to design systems to issue alarms when and only when the driver is likely to accept them. In this paper we discuss one such approach
Using Manual Measurements on Event Recorder Video and Image Processing Algorithms to Extract Optical Parameters and Range
Vehicle kinematics and optical parameters such as optical angle, optical expansion rate, and tau are thought to underlie drivers’ ability to avoid and handle critical traffic situations. Analyses of these parameters in naturalistic driving data with video, such as commercial event recordings of near-crashes and crashes, can provide insight into driver behavior in critical traffic situations. This paper describes a pair of methods, one for the range to a lead vehicle and one for its optical angle, that are derived from image processing mathematics and that provide driver behavior researchers with a relatively simple way to extract optical parameters from video-based naturalistic data when automatic image processing is not possible. The methods begin with manual measurements of the size of other road users on a video on a screen. To develop the methods, 20 participants manually measured the width of a lead vehicle on 14 images where the lead vehicle was placed at different distances from the camera. An on-market DriveCam Event Recorder was used to capture these images. A linear model that corrects distortion and modeling optics was developed to transform the on-screen measurements distance (range) to and optical angle of the vehicle. The width of the confidence interval for predicted range is less than 0.1m when the actual distance is less than 10m and the lead-vehicle width estimate is correct. The methods enable driver behavior researchers to easily and accurately estimate useful kinematic and optical parameters from videos (e.g., of crashes and nearcrashes) in event-based naturalistic driving data
XMM-Newton Observations of MBM 12: More Constraints on the Solar Wind Charge Exchange and Local Bubble Emissions
We present the first analysis of an XMM-Newton observation of the nearby molecular cloud MBM 12. We find that in the direction of MBM 12 the total O VII (0.57 keV) triplet emission is 1.8(+0.5/-0.6) photons/sq cm/s/sr (or Line Units - LU) while for the O VIII (0.65 keV) line emission we find a 3(sigma) upper limit of <1 LU. We also use a heliospheric model to calculate the O VII and O VIII emission generated by Solar Wind Charge-eXchange (SWCX) which we compare to the XMM-Newton observations. This comparison provides new constraints on the relative heliospheric and Local Bubble contributions to the local diffuse X-ray background. The heliospheric SWCX model predicts 0.82 LU for O VII, which accounts for approx. 46+/-15% of the observed value, and 0.33 LU for the O VIII line emission consistent with the XMM-Newton observed value. We discuss our results in combination with previous observations of the MBM 12 with CHANDRA and Suzaku
Chandra ACIS Survey of M33 (ChASeM33): The enigmatic X-ray emission from IC131
We present the first X-ray analysis of the diffuse hot ionized gas and the
point sources in IC131, after NGC604 the second most X-ray luminous giant HII
region in M33. The X-ray emission is detected only in the south eastern part of
IC131 (named IC131-se) and is limited to an elliptical region of ~200pc in
extent. This region appears to be confined towards the west by a hemispherical
shell of warm ionized gas and only fills about half that volume. Although the
corresponding X-ray spectrum has 1215 counts, it cannot conclusively be told
whether the extended X-ray emission is thermal, non-thermal, or a combination
of both. A thermal plasma model of kT_e=4.3keV or a single power law of
Gamma=2.1 fit the spectrum equally well. If the spectrum is purely thermal
(non-thermal), the total unabsorbed X-ray luminosity in the 0.35-8keV energy
band amounts to L_X = 6.8(8.7)x10^35erg/s. Among other known HII regions
IC131-se seems to be extreme regarding the combination of its large extent of
the X-ray plasma, the lack of massive O stars, its unusually high electron
temperature (if thermal), and the large fraction of L_X emitted above 2keV
(~40-53%). A thermal plasma of ~4keV poses serious challenges to theoretical
models, as it is not clear how high electron temperatures can be produced in
HII regions in view of mass-proportional and collisionless heating. If the gas
is non-thermal or has non-thermal contributions, synchrotron emission would
clearly dominate over inverse Compton emission. It is not clear if the same
mechanisms which create non-thermal X-rays or accelerate CRs in SNRs can be
applied to much larger scales of 200pc. In both cases the existing theoretical
models for giant HII regions and superbubbles do not explain the hardness and
extent of the X-ray emission in IC131-se.Comment: 28 pages, 7 figures and 2 tables. Accepted for publication in ApJ.
For a high resolution version of the paper see
http://hea-www.harvard.edu/vlp_m33_public/publications.htm
Chandra ACIS Survey of M33 (ChASeM33): A First Look
We present an overview of the Chandra ACIS Survey of M33 (ChASeM33): A Deep
Survey of the Nearest Face-on Spiral Galaxy. The 1.4 Ms survey covers the
galaxy out to R \approx 18\arcmin (\approx 4 kpc). These data provide the
most intensive, high spatial resolution assessment of the X-ray source
populations available for the confused inner regions of M33. Mosaic images of
the ChASeM33 observations show several hundred individual X-ray sources as well
as soft diffuse emission from the hot interstellar medium. Bright, extended
emission surrounds the nucleus and is also seen from the giant \hii regions NGC
604 and IC 131. Fainter extended emission and numerous individual sources
appear to trace the inner spiral structure. The initial source catalog, arising
from ~2/3 of the expected survey data, includes 394 sources significant
at the confidence level or greater, down to a limiting luminosity
(absorbed) of 1.6\ergs{35} (0.35 -- 8.0 keV). The hardness ratios of the
sources separate those with soft, thermal spectra such as supernova remnants
from those with hard, non-thermal spectra such as X-ray binaries and background
active galactic nuclei. Emission extended beyond the Chandra point spread
function is evident in 23 of the 394 sources. Cross-correlation of the ChASeM33
sources against previous catalogs of X-ray sources in M33 results in matches
for the vast majority of the brighter sources and shows 28 ChASeM33 sources
within 10\arcsec of supernova remnants identified by prior optical and radio
searches. This brings the total number of such associations to 31 out of 100
known supernova remnants in M33.Comment: accepted for publication ApJS, full resolution images and complete
tables available at http://hea-www.harvard.edu/vlp_m33_public
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