Suchergebnisse

Objective This study investigates the effects of different positions of side-mounted rear-view cameras on distance estimation of drivers. Background Camera-monitor systems bring advantages as compared to conventional rear-view mirrors, such as improved aerodynamics and enlarged field-of-view. Applied research has mainly focused on the comparison between cameras and mirrors or on positioning of in-vehicle monitors. However, the positioning of the exterior camera awaits investigation given that the perspective of the observer at does affect depth perception at large. Method In two experiments, a total of 50 students estimated metric distances to static vehicles presented in realistic or 3D-rendered pictures. The pictures depicted the rearward scene of a car following the driver as viewed through a camera at varying vertical and horizontal positions. The following vehicle's size and environmental information varied among conditions and experiments. Results Lower camera positions led to distance overestimation and higher positions to underestimation. The effect increased as the distance to the following vehicle decreased. Moreover, larger vehicles led to stronger distance underestimation, especially in low camera positions. Interestingly, the main effect of camera position disappeared when the ego-vehicles' back was visible. Conclusion Different rearward viewpoints affect distance estimation of drivers, especially in close distances. However, a visible reference of one's own vehicle seems to mostly compensate this effect. Application In general, the rear-view camera should be mounted rather higher and to the front of the vehicle. Also, the vehicle's back should always be visible. Low camera positions are not recommended.

Objectives: We compare expert opinion with perceptual judgment regarding the influence of color on the perceived height and width of interior rooms.Background: We hypothesize that contrary to popular belief, ceiling and wall lightness have additive effects on perceived height, whereas the lightness contrast between these surfaces is less important. We assessed the intuitions of architectural experts as to which surface colors maximize apparent height and compared these intuitions with psychophysical height and width estimates for rooms differing in ceiling, floor, and wall lightness.Method: Experiment 1 was a survey of architectural experts and nonexperts. Experiments 2 and 3 presented virtual rooms varying in physical height, physical width, and surface lightness.Results: In Experiment 1, both experts and nonexperts erroneously assumed that the lightness contrast between ceiling and walls influences perceived height. Experiment 2 showed that the lightness contrast does not determine apparent height but that ceiling and wall lightness have additive effects. Experiment 3 demonstrated a decrease in perceived width with physical height, whereas the perceived height was not related to physical width. Apparent width was unaffected by ceiling lightness.Conclusion:: Light ceiling and light walls make a room appear higher, whereas floor color has a weaker effect. We also found evidence for an asymmetric interaction between height and width.Application: The question of how to color walls and ceiling to maximize the apparent size of a room can be answered empirically. Aesthetic considerations may interfere with the correct assessment of the effects of color in experts.

Objective: Motion sickness (MS) can be a debilitating side effect associated with motion in real or virtual environments. We analyzed the effect of expectancy on MS and propose and validate a fast and simple MS measure.Background: Several questionnaires measure MS before or after stimulus presentation, but no satisfactory tool has been established to quickly capture MS data during exposure. To fill this gap, we introduce the Fast MS Scale (FMS), a verbal rating scale ranging from zero (no sickness at all) to 20 (frank sickness). Also, little is known about the role of expectancy effects in MS studies. We conducted an experiment that addressed this issue.Method: For this study, 126 volunteers participated in two experiments. During stimulus presentation, participants had to verbally rate the severity of MS every minute before filling in the Simulator Sickness Questionnaire (SSQ). To measure expectancy effects, participants were separated into three groups with either positive, negative, or neutral expectations.Results: We compared the verbal ratings with the SSQ scores. Pearson correlations were high for both the SSQ total score (r = .785) and the nausea subscore (r = .828). No expectancy effects were found.Conclusion: The FMS is a fast and valid method to obtain MS data. It offers the possibility to record MS during stimulus presentation and to capture its time course. We found expectancy not to play a crucial role in MS. However, the FMS has some limitations.Application: The FMS offers improved MS measurement. It is fast and efficient and can be performed online in environments such as virtual reality.

Objective:We investigate effects of the hue, saturation, and luminance of ceiling color on the perceived height of interior spaces.Background:Previous studies have reported that the perceived height of an interior space is influenced by the luminance of the ceiling, but not by the luminance contrast between ceiling and walls: brighter ceilings appeared higher than darker ceilings, irrespective of wall and floor luminance. However, these studies used solely achromatic colors. We report an experiment in which we extend these findings to effects of chromatic ceiling colors.Methods:We presented stereoscopic room simulations on a head-mounted display (Oculus Rift DK2) and varied hue (red, green, blue), saturation (low, high), and luminance (bright, dark) of the ceiling independently of each other.Results:We found the previously reported ceiling luminance effect to apply also to chromatic colors: subjects judged brighter ceilings to be higher than darker ceilings. The remaining color dimensions merely had a very small (hue) or virtually no effect (saturation) on perceived height.Conclusion:In order to maximize the perceived height of an interior space, we suggest painting the ceiling in the brightest possible color. The hue and saturation of the paint are only of minor importance.Application:The present study improves the empirical basis for interior design guidelines regarding effects of surface color on the perceived layout of interior spaces.

Objective This experiment provides a first-of-its-kind driving-simulator study to investigate the feasibility of camera-monitor systems (CMS) with displaced side-mounted cameras in sedans. Background Among the increasing number of studies investigating the replacement of side-mounted rearview mirrors with CMS, the placement of side-mounted cameras has been largely neglected. Moreover, user preferences with respect to camera placement have not been validated in a driving simulator. Past research merely has shown that the vertical camera position can affect distance perception. Method In a driving simulator experiment, we investigated the effects of rearward camera placement on driver acceptance and performance. Thirty-six participants performed multiple lane changes in a last safe-gap paradigm. The camera position, ego-velocity, and velocity of the approaching vehicle varied across the experiment. Results The results suggest a clear preference for a high rearward perspective, whereas participants disliked the lower viewpoint. However, these stark differences were only marginally mirrored in lane change performance. Average safety margins tended to decrease and their variation tended to increase for the low camera position. Conclusion Even if the impact of the camera position on driving behavior seems to be small in sedans, driver expectations show clear-cut preferences. When designing CMS, this should be taken into account, as these preferences could promote the use of CMS and thus their positive impact on safety. Application Designers should place side-mounted cameras as high as possible to increase acceptance of CMS. Low camera positions are not recommended, as they might decrease safety margins and are not appreciated by drivers.

Background Mandatory rules for social distancing to curb the SARS-CoV-2 pandemic require individuals to maintain a critical interpersonal distance above 1.5 m. However, this contradicts our natural preference, which is closer to 1 m for non-intimate encounters, for example, when asking a stranger for directions. Objective This review addresses how humans typically regulate interpersonal distances, in order to highlight the challenges of enforcing atypically large interpersonal distances. Method To understand the challenges posed by social distancing requirements, we integrate relevant contributions from visual perception, social perception, and human factors. Results To date, research on preferred interpersonal distances suggests that social distancing could induce discomfort, heighten arousal, and decrease social signaling in the short term. While the protracted effects of social distancing are unclear, we propose hypotheses on the mid- to long-term consequences of violating preferred norms of interpersonal distances. Conclusion We suggest that enforcing a physical distance of 1.5–2 m presents a serious challenge to behavioral norms. Application We address how notifications, architectural design, and visualizations could be effectively applied to promote interpersonal distance requirements.

Visually induced motion sickness (VIMS) is a well-known side effect of virtual reality (VR) immersion, with symptoms including nausea, disorientation, and oculomotor discomfort. Previous studies have shown that pleasant music, odor, and taste can mitigate VIMS symptomatology, but the mechanism by which this occurs remains unclear. We predicted that positive emotions influence the VIMS-reducing effects. To investigate this, we conducted an experimental study with 68 subjects divided into two groups. The groups were exposed to either positive or neutral emotions before and during the VIMS-provoking stimulus. Otherwise, they performed exactly the same task of estimating the time-to-contact while confronted with a VIMS-provoking moving starfield stimulation. Emotions were induced by means of pre-tested videos and with International Affective Picture System (IAPS) images embedded in the starfield simulation. We monitored emotion induction before, during, and after the simulation, using the Self-Assessment Manikin (SAM) valence and arousal scales. VIMS was assessed before and after exposure using the Simulator Sickness Questionnaire (SSQ) and during simulation using the Fast Motion Sickness Scale (FMS) and FMS-D for dizziness symptoms. VIMS symptomatology did not differ between groups, but valence and arousal were correlated with perceived VIMS symptoms. For instance, reported positive valence prior to VR exposure was found to be related to milder VIMS symptoms and, conversely, experienced symptoms during simulation were negatively related to subjects' valence. This study sheds light on the complex and potentially bidirectional relationship of VIMS and emotions and provides starting points for further research on the use of positive emotions to prevent VIMS.

Objective: To lay the basis of studying autonomous driving comfort using driving simulators, we assessed the behavioral validity of two moving-base simulator configurations by contrasting them with a test-track setting. Background: With increasing level of automation, driving comfort becomes increasingly important. Simulators provide a safe environment to study perceived comfort in autonomous driving. To date, however, no studies were conducted in relation to comfort in autonomous driving to determine the extent to which results from simulator studies can be transferred to on-road driving conditions. Method: Participants ( N = 72) experienced six differently parameterized lane-change and deceleration maneuvers and subsequently rated the comfort of each scenario. One group of participants experienced the maneuvers on a test-track setting, whereas two other groups experienced them in one of two moving-base simulator configurations. Results: We could demonstrate relative and absolute validity for one of the two simulator configurations. Subsequent analyses revealed that the validity of the simulator highly depends on the parameterization of the motion system. Conclusion: Moving-base simulation can be a useful research tool to study driving comfort in autonomous vehicles. However, our results point at a preference for subunity scaling factors for both lateral and longitudinal motion cues, which might be explained by an underestimation of speed in virtual environments. Application: In line with previous studies, we recommend lateral- and longitudinal-motion scaling factors of approximately 50% to 60% in order to obtain valid results for both active and passive driving tasks.

Objective: The study explores associations of visually induced motion sickness (VIMS) with emergency braking reaction times (RTs) in driving simulator studies. It examines the effects over the progression of multiple simulated drives. Background: Driving simulator usage has many advantages for RT studies; however, if it induces VIMS, the observed driving behavior might deviate from real-world driving, potentially masking or skewing results. Possible effects of VIMS on RT have long been entertained, but the progression of VIMS across simulated drives has so far not been sufficiently considered. Method: Twenty-eight adults completed six drives on 2 days in a fixed-base driving simulator. At five points during each drive, pedestrians entered the road, necessitating emergency braking maneuvers. VIMS severity was assessed every minute using the 20-point Fast Motion Sickness Scale. The progression of VIMS was considered in mixed model analyses. Results: RT predictions were improved by considering VIMS development over time. Here, the relationship of VIMS and RT differed across days and drives. Increases in VIMS symptom severity predicted more prolonged RT after repeated drives on a given day and earlier within each drive. Conclusion: The assessment of VIMS in RT studies can be beneficial. In this context, VIMS measurements in close temporal proximity to the behaviors under study are promising and offer insights into VIMS and its consequences, which are not readily obtainable through questionnaires. Application: Driving simulator–based RT studies should consider cumulative effects of VIMS on performance. Measurement and analysis strategies that consider the time-varying nature of VIMS are recommended.

Der Bericht über Migration und Asyl bietet einen Gesamtüberblick über die wichtigsten politischen Diskussionen und Entwicklungen in den Bereichen Migration und Asyl in der Bundesrepublik Deutschland im Jahr 2006. Dabei werden auch die Implementation von EU-Gesetzgebung in nationales Recht beschrieben sowie Erfahrungen mit der Umsetzung von EU-Gesetzgebung dargestellt.

Der Bericht über Migration und Asyl bietet einen Gesamtüberblick über die wichtigsten politischen Diskussionen und Entwicklungen in den Bereichen Migration und Asyl in der Bundesrepublik Deutschland im Jahr 2006. Dabei werden auch die Implementation von EU-Gesetzgebung in nationales Recht beschrieben sowie Erfahrungen mit der Umsetzung von EU-Gesetzgebung dargestellt.

Der Bericht über Migration und Asyl bietet einen Gesamtüberblick über die wichtigsten politischen Diskussionen und Entwicklungen in den Bereichen Migration und Asyl in der Bundesrepublik Deutschland im Jahr 2005. Dabei werden auch die Implementation von EU-Gesetzgebung in nationales Recht beschrieben sowie Erfahrungen mit der Umsetzung von EU-Gesetzgebung dargestellt.

Der Bericht über Migration und Asyl bietet einen Gesamtüberblick über die wichtigsten politischen Diskussionen und Entwicklungen in den Bereichen Migration und Asyl in der Bundesrepublik Deutschland im Jahr 2005. Dabei werden auch die Implementation von EU-Gesetzgebung in nationales Recht beschrieben sowie Erfahrungen mit der Umsetzung von EU-Gesetzgebung dargestellt.

Der Bericht über Migration und Asyl bietet einen Gesamtüberblick über die wichtigsten politischen Diskussionen und Entwicklungen in den Bereichen Migration und Asyl in der Bundesrepublik Deutschland im Jahr 2005. Dabei werden auch die Implementation von EU-Gesetzgebung in nationales Recht beschrieben sowie Erfahrungen mit der Umsetzung von EU-Gesetzgebung dargestellt.

Der Bericht über Migration und Asyl bietet einen Gesamtüberblick über die wichtigsten politischen Diskussionen und Entwicklungen in den Bereichen Migration und Asyl in der Bundesrepublik Deutschland im Jahr 2007. Dabei werden auch die Implementation von EU-Gesetzgebung in nationales Recht beschrieben sowie Erfahrungen mit der Umsetzung von EU-Gesetzgebung dargestellt.