Given the proliferation of ‘intelligent’ and ‘socially-aware’ digital assistants embodying everyday mobile technology – and the undeniable logic that utilising voice-activated controls and interfaces ...in cars reduces the visual and manual distraction of interacting with in-vehicle devices – it appears inevitable that next generation vehicles will be embodied by digital assistants and utilise spoken language as a method of interaction. From a design perspective, defining the language and interaction style that a digital driving assistant should adopt is contingent on the role that they play within the social fabric and context in which they are situated. We therefore conducted a qualitative, Wizard-of-Oz study to explore how drivers might interact linguistically with a natural language digital driving assistant. Twenty-five participants drove for 10 min in a medium-fidelity driving simulator while interacting with a state-of-the-art, high-functioning, conversational digital driving assistant. All exchanges were transcribed and analysed using recognised linguistic techniques, such as discourse and conversation analysis, normally reserved for interpersonal investigation. Language usage patterns demonstrate that interactions with the digital assistant were fundamentally social in nature, with participants affording the assistant equal social status and high-level cognitive processing capability. For example, participants were polite, actively controlled turn-taking during the conversation, and used back-channelling, fillers and hesitation, as they might in human communication. Furthermore, participants expected the digital assistant to understand and process complex requests mitigated with hedging words and expressions, and peppered with vague language and deictic references requiring shared contextual information and mutual understanding. Findings are presented in six themes which emerged during the analysis – formulating responses; turn-taking; back-channelling, fillers and hesitation; vague language; mitigating requests and politeness and praise. The results can be used to inform the design of future in-vehicle natural language systems, in particular to help manage the tension between designing for an engaging dialogue (important for technology acceptance) and designing for an effective dialogue (important to minimise distraction in a driving context).
•Observations show that drivers interacted socially with a digital driving assistant.•Six themes were identified that closely resembled human-human dialogue.•Language patterns show that the digital assistant was afforded equal social status.•Wizard-of-Oz is a valid approach to research natural language interfaces.
Augmented reality (AR) offers new ways to visualize information on-the-go. As noted in related work, AR graphics presented via optical see-through AR displays are particularly prone to color ...blending, whereby intended graphic colors may be perceptually altered by real-world backgrounds, ultimately degrading usability. This work adds to this body of knowledge by presenting a methodology for assessing AR interface color robustness , as quantitatively measured via shifts in the CIE color space, and qualitatively assessed in terms of users' perceived color name. We conducted a human factors study where twelve participants examined eight AR colors atop three real-world backgrounds as viewed through an in-vehicle AR head-up display (HUD); a type of optical see-through display used to project driving-related information atop the forward-looking road scene. Participants completed visual search tasks, matched the perceived AR HUD color against the WCS color palette, and verbally named the perceived color. We present analysis that suggests blue, green, and yellow AR colors are relatively robust, while red and brown are not, and discuss the impact of chromaticity shift and dispersion on outdoor AR interface design. While this work presents a case study in transportation, the methodology is applicable to a wide range of AR displays in many application domains and settings.
Tropical peatland across Southeast Asia is drained extensively for production of pulpwood, palm oil and other food crops. Associated increases in peat decomposition have led to widespread subsidence, ...deterioration of peat condition and CO2 emissions. However, quantification of subsidence and peat condition from these processes is challenging due to the scale and inaccessibility of dense tropical peat swamp forests. The development of satellite interferometric synthetic aperture radar (InSAR) has the potential to solve this problem. The Advanced Pixel System using Intermittent Baseline Subset (APSIS, formerly ISBAS) modelling technique provides improved coverage across almost all land surfaces irrespective of ground cover, enabling derivation of a time series of tropical peatland surface oscillations across whole catchments. This study aimed to establish the extent to which APSIS-InSAR can monitor seasonal patterns of tropical peat surface oscillations at North Selangor Peat Swamp Forest, Peninsular Malaysia. Results showed that C-band SAR could penetrate the forest canopy over tropical peat swamp forests intermittently and was applicable to a range of land covers. Therefore the APSIS technique has the potential for monitoring peat surface oscillations under tropical forest canopy using regularly acquired C-band Sentinel-1 InSAR data, enabling continuous monitoring of tropical peatland surface motion at a spatial resolution of 20 m.
Analysis of thirty-one hours of video-data documenting 36 experienced drivers highlighted the prevalence of face-touching, with 819 contacts identified (mean frequency: 26.4 face touches/hour (FT/h); ...mean duration: 3.9-seconds). Fewer face-touches occurred in high primary workload conditions (where additional physical/cognitive demands were placed on drivers), compared to low workload (4.4 and 26.1 FT/h, respectively). In 42.5% of touches (or 11.2 FT/h), mucous membrane contact was made, with fingertips (33.1%) and thumbs (35.6%) most commonly employed. Individual behaviours differed (ranging from 5.1 to 90.7 FT/h), but there were no significant differences identified between genders, age-groups or hand used. Results are of relevance from an epidemiological/hygiene perspective within the context of the COVID-19 pandemic (and can therefore inform the design of practical solutions and encourage behavioural change to reduce the risk of self-inoculation while driving), but they also help to elucidate how habitual human behaviours are imbricated with the routine accomplishment of tasks.
Practitioner summary: The study highlights the propensity of face touching whilst driving through the analysis of on-road video datasets. Results have implications for the design of technological interventions (such as touchless interfaces and driver monitoring systems) and can inform awareness campaigns to reduce the risk of self-inoculation and infection transmission while driving.
•Conversing with voice assistant (VA) increased driver alertness in automated vehicles (AVs).•Verbal traffic cues can redirect visual attention to road environment in AVs.•VA could assist the drivers ...in takeover, building appropriate situation awareness.•VA increased the probability of making a timely (safe and aware) takeover by 39%.
Vehicle automation allows drivers to disengage from driving causing a potential decline in their alertness. One of the major challenges of highly automated vehicles is to ensure a timely (with respect to safety and situation awareness) takeover in such conditions. For this purpose, the current study investigated the role of an in-vehicle digital voice-assistant (VA) in conditionally automated vehicles, offering spoken discourse relating specifically to contextual factors, such as the traffic situation and road environment. The study involved twenty-four participants, each taking two drives (counterbalanced): with VA and without VA, in a driving simulator. Participants were required to takeover vehicle control following the issuance of a takeover request (TOR) near the end of each drive. A parametric duration model was adopted to find the key factors determining takeover time (TOT). Paired comparisons showed higher alertness and higher active workload (mean NASA-TLX rating) during automation when accompanied by the VA. Paired t-test comparison of gaze behavior prior to takeover showed significantly higher instances of checking traffic signal, roadside objects, and the roadway during the drive with VA, indicating higher situation awareness. The parametric model indicated that the VA increased the likelihood of making a timely takeover by 39%. There was also some evidence suggesting that male drivers are likely to resume control 1.21 times earlier than female drivers. The study findings highlight the benefits of adopting a digital voice assistant to keep the drivers alert and aware about the recent traffic environment in partially automated vehicles.
Focussed ultrasound can be used to create the sensation of touch in mid-air. Combined with gestures, this can provide haptic feedback to guide users, thereby overcoming the lack of agency associated ...with pure gestural interfaces, and reducing the need for vision – it is therefore particularly apropos of the driving domain. In a counter-balanced 2 × 2 driving simulator study, a traditional in-vehicle touchscreen was compared with a virtual mid-air gestural interface, both with and without ultrasound haptics. Forty-eight experienced drivers (28 male, 20 female) undertook representative in-vehicle tasks – discrete target selections and continuous slider-bar manipulations – whilst driving. Results show that haptifying gestures with ultrasound was particularly effective in reducing visual demand (number of long glances and mean off-road glance time), and increasing performance (shortest interaction times, highest number of correct responses and least ‘overshoots’) associated with continuous tasks. In contrast, for discrete, target-selections, the touchscreen enabled the highest accuracy and quickest responses, particularly when combined with haptic feedback to guide interactions, although this also increased visual demand. Subjectively, the gesture interfaces invited higher ratings of arousal compared to the more familiar touch-surface technology, and participants indicated the lowest levels of workload (highest performance, lowest frustration) associated with the gesture-haptics interface. In addition, gestures were preferred by participants for continuous tasks. The study shows practical utility and clear potential for the use of haptified gestures in the automotive domain.
•Reduced visual demand with gesture ultrasound-haptics interface while driving.•Lower workload with gestures and ultrasound compared to touchscreen.•Better task performance with ultrasound haptics and gestures for continuous tasks.•Improved vehicle control with addition of ultrasound haptics to gestures.
Objective
We controlled participants’ glance behavior while using head-down displays (HDDs) and head-up displays (HUDs) to isolate driving behavioral changes due to use of different display types ...across different driving environments.
Background
Recently, HUD technology has been incorporated into vehicles, allowing drivers to, in theory, gather display information without moving their eyes away from the road. Previous studies comparing the impact of HUDs with traditional displays on human performance show differences in both drivers’ visual attention and driving performance. Yet no studies have isolated glance from driving behaviors, which limits our ability to understand the cause of these differences and resulting impact on display design.
Method
We developed a novel method to control visual attention in a driving simulator. Twenty experienced drivers sustained visual attention to in-vehicle HDDs and HUDs while driving in both a simple straight and empty roadway environment and a more realistic driving environment that included traffic and turns.
Results
In the realistic environment, but not the simpler environment, we found evidence of differing driving behaviors between display conditions, even though participants’ glance behavior was similar.
Conclusion
Thus, the assumption that visual attention can be evaluated in the same way for different types of vehicle displays may be inaccurate. Differences between driving environments bring the validity of testing HUDs using simplistic driving environments into question.
Application
As we move toward the integration of HUD user interfaces into vehicles, it is important that we develop new, sensitive assessment methods to ensure HUD interfaces are indeed safe for driving.
Satellite Earth Observation (EO) is often used as a cost-effective method to report on the condition of remote and inaccessible peatland areas. Current EO techniques are primarily limited to ...reporting on the vegetation classes and properties of the immediate peat surface using optical data, which can be used to infer peatland condition. Another useful indicator of peatland condition is that of surface motion, which has the potential to report on mass accumulation and loss of peat. Interferometic SAR (InSAR) techniques can provide this using data from space. However, the most common InSAR techniques for information extraction, such as Persistent Scatterers’ Interferometry (PSI), have seen limited application over peat as they are primarily tuned to work in areas of high coherence (i.e., on hard, non-vegetated surfaces only). A new InSAR technique, called the Intermittent Small BAseline Subset (ISBAS) method, has been recently developed to provide measurements over vegetated areas from SAR data acquired by satellite sensors. This paper examines the feasibility of the ISBAS technique for monitoring long-term surface motion over peatland areas of the Flow Country, in the northeast of Scotland. In particular, the surface motions estimated are compared with ground data over a small forested area (namely the Bad a Cheo forest Reserve). Two sets of satellite SAR data are used: ERS C-band images, covering the period 1992–2000, and Sentinel-1 C-band images, covering the period 2015–2016. We show that the ISBAS measurements are able to identify surface motion over peatland areas, where subsidence is a consequence of known land cover/land use. In particular, the ISBAS products agree with the trend of surface motion, but there are uncertainties with their magnitude and direction (vertical). It is concluded that there is a potential for the ISBAS method to be able to report on trends in subsidence and uplift over peatland areas, and this paper suggests avenues for further investigation, but this requires a well-resourced validation campaign.
Touchscreen Human-Machine Interfaces (HMIs) are a well-established and popular choice to provide the primary control interface between driver and vehicle, yet inherently demand some visual attention. ...Employing a secondary device with the touchscreen may reduce the demand but there is some debate about which device is most suitable, with current manufacturers favouring different solutions and applying these internationally. We present an empirical driving simulator study, conducted in the UK and China, in which 48 participants undertook typical in-vehicle tasks utilising either a touchscreen, rotary-controller, steering-wheel-controls or touchpad. In both the UK and China, the touchscreen was the most preferred/least demanding to use, and the touchpad least preferred/most demanding, whereas the rotary-controller was generally favoured by UK drivers and steering-wheel-controls were more popular in China. Chinese drivers were more excited by the novelty of the technology, and spent more time attending to the devices while driving, leading to an increase in off-road glance time and a corresponding detriment to vehicle control. Even so, Chinese drivers rated devices as easier-to-use while driving, and felt that they interfered less with their driving performance, compared to their UK counterparts. Results suggest that the most effective solution (to maximise performance/acceptance, while minimising visual demand) is to maintain the touchscreen as the primary control interface (e.g. for top-level tasks), and supplement this with a secondary device that is only enabled for certain actions; moreover, different devices may be employed in different cultural markets. Further work is required to explore these recommendations in greater depth (e.g. during extended or real-world testing), and to validate the findings and approach in other cultural contexts.
•Providing multiple devices can increase performance and reduce visual cost.•UK drivers were less distracted by devices with fewer off-road glances.•Increased variability in speed and lane position were evident in China.•Different devices could be used to deliver cultural diversity.•Secondary devices should be enabled for specific actions only.
A full understanding of the atmospheric Pb cycle in Asia during the Holocene is key to palaeoclimate studies of past atmospheric circulation patterns, as well as to assess the impact of increasing ...industrial activities in this region. However, long-term records of atmospheric Pb isotopic trends in Asia are still sparse. Consequently, we study changes in the concentrations, fluxes and isotopic signature of deposited Pb contained in a 14C-dated peat core from the eastern Qinghai–Tibetan Plateau, dating back to 9.5kyr BP, and present the first peat record of the changing isotopic composition of atmospheric Pb in dust in Asia during this time. Lead concentrations and fluxes vary between 2.96–21.58μgg−1 and 0.06–3.52mgm−2y−1, respectively, with an average Pb baseline of 6.80±4.18μgg−1. These values agree with other Pb studies of lake and peat archives in China but are one order of magnitude larger than early and mid-Holocene values measured in Europe. Lead isotopic variability throughout the core is small, varying between 206Pb/207Pb=1.190–1.197, 206Pb/204Pb=18.648–18.786, 207Pb/204Pb=15.666–15.694 and 208Pb/204Pb=38.890–39.090. The application of Bayesian trans-dimensional changepoint modelling to the Pb dataset enabled the identification of eight significant changes in the isotopic composition of the deposited Pb. Such changes mark different phases of atmospheric Pb deposition, and hence variations in atmospheric circulation patterns and environmental conditions. Temporal variations in the potential natural and/or anthropogenic Pb sources are assessed based on the 206Pb, 207Pb, 208Pb and 204Pb isotopic composition and the 1/Pb ratio of the peat samples. Our results suggest that Pb deposition throughout the Holocene was governed by local deposition and long-range input from natural dust sources in northwestern (Taklamakan desert and Qaidam basin) and northern China (Badain Jaran and Tengger deserts). Input from the northern sources seems to have been particularly important between 3.1–2.7kyr BP and 1.7–0.9kyr BP, suggesting a possible strengthening of the East Asian winter monsoon, in agreement with previous reconstructions in Asia. Based on the Pb/Sc and isotopic composition profiles we do not note any evidence for anthropogenic Pb derived from the thriving mining or smelting activities in northern and eastern China in the last few millennia, suggesting that atmospheric deposition to this region of the eastern Tibetan Plateau was dominated by natural Pb fluxes. These can serve as a true Asian “background” value against which anthropogenic impacts can be quantified. Our results confirm that the combination of radiogenic isotopes (Pb) and trace elements in peat bogs enables observational reconstructions of changes in past regional atmospheric circulation. Such records will enable more refined interpretations of marine and terrestrial palaeorecords in Asia and the Pacific and consequently provide further constraints for changes in ocean and atmospheric circulation and for the testing of palaeoclimate models of circulation patterns.
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