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"visual performance"
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Were they in the loop during automated driving? Links between visual attention and crash potential
BackgroundA proposed advantage of vehicle automation is that it relieves drivers from the moment-to-moment demands of driving, to engage in other, non-driving related, tasks. However, it is important to gain an understanding of drivers’ capacity to resume manual control, should such a need arise. As automation removes vehicle control-based measures as a performance indicator, other metrics must be explored.MethodsThis driving simulator study, conducted under the European Commission (EC) funded AdaptIVe project, assessed drivers’ gaze fixations during partially-automated (SAE Level 2) driving, on approach to critical and non-critical events. Using a between-participant design, 75 drivers experienced automation with one of five out-of-the-loop (OOTL) manipulations, which used different levels of screen visibility and secondary tasks to induce varying levels of engagement with the driving task: 1) no manipulation, 2) manipulation by light fog, 3) manipulation by heavy fog, 4) manipulation by heavy fog plus a visual task, 5) no manipulation plus an n-back task.ResultsThe OOTL manipulations influenced drivers’ first point of gaze fixation after they were asked to attend to an evolving event. Differences resolved within one second and visual attention allocation adapted with repeated events, yet crash outcome was not different between OOTL manipulation groups. Drivers who crashed in the first critical event showed an erratic pattern of eye fixations towards the road centre on approach to the event, while those who did not demonstrated a more stable pattern.ConclusionsAutomated driving systems should be able to direct drivers’ attention to hazards no less than 6 seconds in advance of an adverse outcome.
Journal Article
Effect of different illumination sources on reading and visual performance
Purpose: To investigate visual performance during reading under different illumination sources.
Methods: This experimental quantitative study included 40 (20 females and 20 males) emmetropic participants with no history of ocular pathology. The participants were randomly assigned to read a near visual task under four different illuminations (400-lux constant): compact fluorescent light (CFL), tungsten light (TUNG), fluorescent tube light (FLUO), and light emitting diode (LED). Subsequently, we evaluated the participants' experiences of eight symptoms of visual comfort.
Results: The mean age of the participants was 19.86 ± 1.09 (range: 18-21) years. There was no statistically significant difference between the reading rates of males and females under the different illuminations (P = 0.99); however, the reading rate was fastest among males under CFL, and among females under FLUO. One way analysis of variance (ANOVA) revealed a strong significant difference (P = 0.001) between males and females (P = 0.002) regarding the visual performance and illuminations.
Conclusion: This study demonstrates the influence of illumination on reading rate; there were no significant differences between males and females under different illuminations, however, males preferred CFL and females preferred FLUO for faster reading and visual comfort. Interestingly, neither preferred LED or TUNG. Although energy-efficient, visual performance under LED is poor; it is uncomfortable for prolonged reading and causes early symptoms of fatigue.
Journal Article
Daylighting evaluation in deep plan office buildings with OPV windows through simulation on Radiance
This research aims to evaluate the OPV window (OPVW) potential application in a deep-plan multi-storey office building, in order to verify its contribution to indoor daylighting quality. OPVW is a cost-effective technology with reduced environmental impact, suitable for application in a multi-story office building due to its potential to adapt to different architectural configurations, lightness and transparency, etc. In an earlier study developed by the authors, an experiment was conducted with a generic office room scale model. Three window materials were compared under real sky conditions (overcast and clear): 3 mm single glass (A scenarios); single glass with OPV (B scenarios); and single glass with application of solar control film (C scenarios). In the present study the same parameters from the experiment were used as input for simulations on Radiance, whose results were compared to previous (work plane illuminance, Daylight Factor and model interior photographs). We found similarities between them. Thus, further results were produced: isolux curves, Daylight Glare Index and render images. The rendered images show a brighter view at A scenarios, and at B and C scenarios. Even if average illuminance is reduced, a better daylight distribution and a reduction in glare are achieved. DGI indicates perceptible glare for some of A scenarios. On the other hand, at most of B and C scenarios, glare was below the perceptible range. Furthermore, the scenarios with OPVW (B scenarios) still show one more advantage: the energy production for artificial lighting when illuminance values are not sufficient.
Journal Article
Cortical magnification in human visual cortex parallels task performance around the visual field
Human vision has striking radial asymmetries, with performance on many tasks varying sharply with stimulus polar angle. Performance is generally better on the horizontal than vertical meridian, and on the lower than upper vertical meridian, and these asymmetries decrease gradually with deviation from the vertical meridian. Here, we report cortical magnification at a fine angular resolution around the visual field. This precision enables comparisons between cortical magnification and behavior, between cortical magnification and retinal cell densities, and between cortical magnification in twin pairs. We show that cortical magnification in the human primary visual cortex, measured in 163 subjects, varies substantially around the visual field, with a pattern similar to behavior. These radial asymmetries in the cortex are larger than those found in the retina, and they are correlated between monozygotic twin pairs. These findings indicate a tight link between cortical topography and behavior, and suggest that visual field asymmetries are partly heritable.
Journal Article
Effect of cylinder power and axis changes on vision in astigmatic participants
To ascertain the impact of altering cylinder (cyl) power and axis on vision in astigmatism.
In a prospective, randomized, participant-masked, crossover clinical trial, 28 astigmatic participants were tested for the following conditions on different days: full sphero-cyl correction and undercorrection by 0.25, 0.50, and 0.75 DC while maintaining spherical equivalence. Axis was also misaligned between -30° and +30°, in 10° steps. For each configuration, monocular high- and low-contrast visual acuities (HCVA, LCVA) were measured at 6 m, and participants rated vision clarity (1-10), vision satisfaction (1-10), and vision acceptability (yes/no). Linear mixed models were used to compare visual performance in the overall group and in low, medium, and high cyl subgroups.
Undercorrecting cyl power affected all groups equally (
≥0.073). Undercorrection by 0.75 DC was significantly different to full cyl power for all variables (
≤0.007), while 0.25 DC undercorrection did not cause any significant decreases (
>0.05). Undercorrection by 0.50 DC was significantly different to full cyl power for HCVA (
=0.006, however not clinically significant) and vision acceptability (
=0.034). Axis misalignment affected the cyl groups differently (
0.001), with the greatest impact in the high cyl group, followed by the medium then the low-cyl group. Misalignment by ±30° caused significant decreases in almost all cases (
≤0.003), while misalignments by ±10° or ±20° caused significant decreases for some cyl groups and test variables.
Undercorrection of cyl by ≤0.50 DC while maintaining spherical equivalence has no significant effect on HCVA, LCVA, vision clarity, and vision satisfaction, while the amount of axis misalignment that can be tolerated is dependent on the cyl power. These results may have practical ophthalmic applications, such as reducing the total number of stock keeping units of toric contact lenses.
Journal Article
Enhancing Product Modelling Process Design and Visual Performance Through Random Forest Optimization
The design cycle's crucial component of manufacturing process optimization includes issue formulation, modeling, simulations, optimization, and deployment. Simulation methodologies are essential to get actual optimization rather than just process improvements. This study proposes a random forest approach for analyzing and optimizing product aesthetics and integrating new technology into design. Virtual display technology lets customers see product performance in detail, making buying easier. Virtual display technology improves user experience and product sales. We use a machine learning technique called random forest to handle complex data and make reliable predictions. We analyze and optimize product aesthetics using design components, material choices, and consumer preferences. Virtual display technology helps us incorporate new technologies into the design. We tried the random forest approach for analyzing and optimizing product aesthetics and virtual display technology. Our results show that random forest forecasts and optimizations increase product attractiveness.. This study emphasizes industrial process optimization and simulation's role in actual optimization. We offer a random forest approach for analyzing and optimizing product aesthetics and integrating new technology into design. Virtual display technology improves software capabilities and gives users a complete understanding of product performance. The outcomes of the proposed system has provided 95% accuracy, 94% precision and 98% recall which enhance process effectiveness and user experience.
Journal Article
Stationary gaze entropy predicts lane departure events in sleep-deprived drivers
Performance decrement associated with sleep deprivation is a leading contributor to traffic accidents and fatalities. While current research has focused on eye blink parameters as physiological indicators of driver drowsiness, little is understood of how gaze behaviour alters as a result of sleep deprivation. In particular, the effect of sleep deprivation on gaze entropy has not been previously examined. In this randomised, repeated measures study, 9 (4 male, 5 female) healthy participants completed two driving sessions in a fully instrumented vehicle (1 after a night of sleep deprivation and 1 after normal sleep) on a closed track, during which eye movement activity and lane departure events were recorded. Following sleep deprivation, the rate of fixations reduced while blink rate and duration as well as saccade amplitude increased. In addition, stationary and transition entropy of gaze also increased following sleep deprivation as well as with amount of time driven. An increase in stationary gaze entropy in particular was associated with higher odds of a lane departure event occurrence. These results highlight how fatigue induced by sleep deprivation and time-on-task effects can impair drivers’ visual awareness through disruption of gaze distribution and scanning patterns.
Journal Article
Impact of Age-Related Vision Changes on Driving
Aging leads to impaired visual function, which can affect driving—a very visually demanding task—and has a direct impact on an individual’s quality of life if their license is withdrawn. This study examined the associations between age-related vision changes and simulated driving performance. To this end, we attempted to determine the most significant visual parameters in terms of evaluating elderly drivers’ eyesight. Twenty-one younger drivers (aged 25–40) were compared to 21 older drivers (aged 56–71). Study participants were assessed for visual acuity, contrast sensitivity, halos, and intraocular straylight, which causes veiling luminance on the retina and degrades vision. Driving performance was evaluated using a driving simulator. The relationships between simulated driving performance and the visual parameters tested were examined with correlation analyses and linear regression models. Older drivers presented impairment in most visual parameters (p < 0.05), with straylight being the most significantly affected (we also measured the associated effect size). Older drivers performed significantly worse (p < 0.05) in the simulator test, with a markedly lower performance in lane stability. The results of the multiple linear regression model evidenced that intraocular straylight is the best visual parameter for predicting simulated driving performance (R2 = 0.513). Older drivers have shown significantly poorer results in several aspects of visual function, as well as difficulties in driving simulator performance. Our results suggest that the non-standardized straylight evaluation could be significant in driver assessments, especially at the onset of age-related vision changes.
Journal Article