2,876 research outputs found
Mental Workload of Voice Interactions with 6 Real-World Driver Interfaces
Hands-free voice interaction is an increasingly common option in new vehicles. Recent research suggests that hands-free interactions with speech-to-text systems may require significantly more cognitive effort than previously anticipated. This high level of mental workload may both keep drivers from using the technology and potentially create additional safety concerns for the driver. However, little prior research has measured the cognitive demands of simple voice based tasks using real-world systems. The current study evaluated the mental demands of a small set of auditory-vocal vehicle commands using five 2013 and one 2012 model year OEM infotainment systems. Results indicate that well executed voice systems impose little additional cognitive demand while poorly executed systems may significantly elevate workload
Cognitive Distraction Impairs Drivers\u27 Anticipatory Glances: An On-Road Study
This study assessed the impact of cognitive distraction on driversâ anticipatory glances. Participants drove an instrumented vehicle and executed a number of secondary tasks associated with increasing levels of mental workload including: listening to the radio or audiobook, talking on a handheld or hands-free cellphone, interacting with a voice-based e-mail/text system, and executing a highly demanding task (Operational Span task; OSPAN). Driversâ visual scanning behavior was recorded by four different high definition cameras and coded offline frame-by-frame. Visual scanning behavior at road intersections with crosswalks was targeted because distraction is one of the major causes of accidents at these locations (NHTSA, 2010a). Despite the familiarity of the locations, results showed that as the secondary-task became more cognitively demanding drivers reduced the amount of anticipatory glances to potential hazards locations. For example, while interacting with a high fidelity voice-based email/text system, the probability of executing a complete scan of the intersection was reduced by 11% compared to the no-distraction control condition. These results document the effects of cognitive distraction on driversâ visual scanning for potential hazards and highlight the detrimental role of voice based systems on driving behavior
Assessing Cognitive Distraction Using Event Related Potentials
This report examines the utility of using Event-Related Brain Potentials (ERPs) to evaluate cognitive distraction in the context of driving an automobile. Across two studies, ERPs (both P300 latency and P300 amplitude) were found to be effective in quantifying the cognitive workload experienced by drivers when they interact with in-vehicle voice-command systems
AEGIS: New Evidence Linking Active Galactic Nuclei to the Quenching of Star Formation
Utilizing Chandra X-ray observations in the All-wavelength Extended Groth
Strip International Survey (AEGIS) we identify 241 X-ray selected Active
Galactic Nuclei (AGNs, L > 10^{42} ergs/s) and study the properties of their
host galaxies in the range 0.4 < z < 1.4. By making use of infrared photometry
from Palomar Observatory and BRI imaging from the Canada-France-Hawaii
Telescope, we estimate AGN host galaxy stellar masses and show that both
stellar mass and photometric redshift estimates (where necessary) are robust to
the possible contamination from AGNs in our X-ray selected sample. Accounting
for the photometric and X-ray sensitivity limits of the survey, we construct
the stellar mass function of X-ray selected AGN host galaxies and find that
their abundance decreases by a factor of ~2 since z~1, but remains roughly flat
as a function of stellar mass. We compare the abundance of AGN hosts to the
rate of star formation quenching observed in the total galaxy population. If
the timescale for X-ray detectable AGN activity is roughly 0.5-1 Gyr--as
suggested by black hole demographics and recent simulations--then we deduce
that the inferred AGN "trigger" rate matches the star formation quenching rate,
suggesting a link between these phenomena. However, given the large range of
nuclear accretion rates we infer for the most massive and red hosts, X-ray
selected AGNs may not be directly responsible for quenching star formation.Comment: 12 pages. Submitted to ApJ. Comments welcom
Using Published HRTFS with Slab3D: Metric-Based Database Selection and Phenomena Observed
Presented at the 20th International Conference on Auditory Display (ICAD2014), June 22-25, 2014, New York, NY.In this paper, two publicly available head-related transfer function (HRTF) database collections are analyzed for use with the open-source slab3d rendering system. After
conversion to the slab3d HRTF database format (SLH), a set of visualization tools and a five-step metric-based process are used to select a subset of databases for general use. The goal
is to select a limited subset least likely to contain anomalous
behavior or measurement error. The described set of open-source
tools can be applied to any HRTF database converted
to the slab3d format
Pretreatment with phenoxybenzamine attenuates the radial artery's vasoconstrictor response to α-adrenergic stimuli
AbstractBackgroundAlthough the radial artery bypass conduit has excellent intermediate-term patency, it has a proclivity to vasospasm. We tested the hypothesis that brief pretreatment of a radial artery graft with the irreversible adrenergic antagonist phenoxybenzamine attenuates the vasoconstrictor response to the vasopressors phenylephrine and norepinephrine compared with the currently used papaverine/lidocaine.MethodsSegments of human radial artery grafts were obtained after a 30-minute intraoperative pretreatment with a solution containing 20 mL of heparinized blood, 0.4 mL of papaverine (30 mg/mL), and 1.6 mL of lidocaine (1%). The segments were transported to the laboratory and placed into a bath containing Krebs-Henseleit solution and 10, 100, or 1000 ÎŒmol/L phenoxybenzamine or vehicle. The segments were tested in organ chambers for contractile responses to increasing concentrations of phenylephrine and norepinephrine (0.5-15 ÎŒmol/L).ResultsContractile responses to 15 ÎŒmol/L phenylephrine in control radial artery segments averaged 44.2% ± 9.1% of the maximal contractile response to 30 mmol/L KCl. Papaverine/lidocaine modestly attenuated contraction to 15 ÎŒmol/L phenylephrine (32.1% ± 5.9%; P = .22), but 1000 ÎŒmol/L phenoxybenzamine completely abolished radial artery contraction (â7.2% ± 4.4%; P < .001). The effect of 10 and 100 ÎŒmol/L phenoxybenzamine on attenuating vasocontraction was intermediate between 1000 ÎŒmol/L phenoxybenzamine and papaverine/lidocaine. Responses to 15 ÎŒmol/L norepinephrine in control radial artery segments averaged 54.7% ± 7.5% of maximal contraction to 30 mmol/L KCl. Papaverine/lidocaine modestly attenuated the contraction response of radial artery segments (35.6% ± 5.1%; P = .04). In contrast, 1000 ÎŒmol/L phenoxybenzamine showed the greatest attenuation of norepinephrine-induced contraction (â10.5% ± 2.0%; P < .001).ConclusionsA brief pretreatment of the human radial artery bypass conduit with 1000 ÎŒmol/L phenoxybenzamine completely attenuates the vasoconstrictor responses to the widely used vasopressors norepinephrine and phenylephrine. Papaverine/lidocaine alone did not block vasoconstriction to these α-adrenergic agonists
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Fermi Level Engineering of Passivation and Electron Transport Materials for p-Type CuBiâOâ Employing a HighâThroughput Methodology
Metal oxide semiconductors are promising for solar photochemistry if the issues of excessive charge carrier recombination and material degradation can be resolved, which are both influenced by surface quality and interface chemistry. Coating the semiconductor with an overlayer to passivate surface states is a common remedial strategy but is less desirable than application of a functional coating that can improve carrier extraction and reduce recombination while mitigating corrosion. In this work, a dataâdriven materials science approach utilizing highâthroughput methodologies, including inkjet printing and scanning droplet electrochemical cell measurements, is used to create and evaluate multiâelement coating libraries to discover new classes of candidate passivation and electronâselective contact materials for pâtype CuBiâOâ. The optimized overlayer (Cu_(1.5)TiOâ) improves the onset potential by 110 mV, the photocurrent by 2.8Ă, and the absorbed photonâtoâcurrent efficiency by 15.5% compared to nonâcoated photoelectrodes. It is shown that these enhancements are related to reduced surface recombination through passivation of surface defect states as well as improved carrier extraction efficiency through Fermi level engineering. This work presents a generalizable, highâthroughput method to design and optimize passivation materials for a variety of semiconductors, providing a powerful platform for development of highâperformance photoelectrodes for incorporation into solarâfuel generation systems
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Design of the Subpopulations and Intermediate Outcome Measures in COPD (SPIROMICS) AIR Study.
IntroductionPopulation-based epidemiological evidence suggests that exposure to ambient air pollutants increases hospitalisations and mortality from chronic obstructive pulmonary disease (COPD), but less is known about the impact of exposure to air pollutants on patient-reported outcomes, morbidity and progression of COPD.Methods and analysisThe Subpopulations and Intermediate Outcome Measures in COPD (SPIROMICS) Air Pollution Study (SPIROMICS AIR) was initiated in 2013 to investigate the relation between individual-level estimates of short-term and long-term air pollution exposures, day-to-day symptom variability and disease progression in individuals with COPD. SPIROMICS AIR builds on a multicentre study of smokers with COPD, supplementing it with state-of-the-art air pollution exposure assessments of fine particulate matter, oxides of nitrogen, ozone, sulfur dioxide and black carbon. In the parent study, approximately 3000 smokers with and without airflow obstruction are being followed for up to 3 years for the identification of intermediate biomarkers which predict disease progression. Subcohorts undergo daily symptom monitoring using comprehensive daily diaries. The air monitoring and modelling methods employed in SPIROMICS AIR will provide estimates of individual exposure that incorporate residence-specific infiltration characteristics and participant-specific time-activity patterns. The overarching study aim is to understand the health effects of short-term and long-term exposures to air pollution on COPD morbidity, including exacerbation risk, patient-reported outcomes and disease progression.Ethics and disseminationThe institutional review boards of all the participating institutions approved the study protocols. The results of the trial will be presented at national and international meetings and published in peer-reviewed journals
Stellar Mass--Gas-phase Metallicity Relation at : A Power Law with Increasing Scatter toward the Low-mass Regime
We present the stellar mass ()--gas-phase metallicity relation (MZR)
and its scatter at intermediate redshifts () for 1381 field
galaxies collected from deep spectroscopic surveys. The star formation rate
(SFR) and color at a given of this magnitude-limited ( AB)
sample are representative of normal star-forming galaxies. For masses below
, our sample of 237 galaxies is 10 times larger than those
in previous studies beyond the local universe. This huge gain in sample size
enables superior constraints on the MZR and its scatter in the low-mass regime.
We find a power-law MZR at :
. Our MZR
shows good agreement with others measured at similar redshifts in the
literature in the intermediate and massive regimes, but is shallower than the
extrapolation of the MZRs of others to masses below . The SFR
dependence of the MZR in our sample is weaker than that found for local
galaxies (known as the Fundamental Metallicity Relation). Compared to a variety
of theoretical models, the slope of our MZR for low-mass galaxies agrees well
with predictions incorporating supernova energy-driven winds. Being robust
against currently uncertain metallicity calibrations, the scatter of the MZR
serves as a powerful diagnostic of the stochastic history of gas accretion, gas
recycling, and star formation of low-mass galaxies. Our major result is that
the scatter of our MZR increases as decreases. Our result implies that
either the scatter of the baryonic accretion rate or the scatter of the
-- relation increases as decreases. Moreover, our
measures of scatter at appears consistent with that found for local
galaxies.Comment: 18 pages, 10 figures. Accepted by ApJ. Typos correcte
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